Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency Test Procedures, and Other Technical Amendments

Published date15 March 2024
Record Number2024-05010
Citation89 FR 18808
CourtNational Highway Traffic Safety Administration
SectionRules and Regulations
Federal Register, Volume 89 Issue 52 (Friday, March 15, 2024)
[Federal Register Volume 89, Number 52 (Friday, March 15, 2024)]
                [Rules and Regulations]
                [Pages 18808-18831]
                From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
                [FR Doc No: 2024-05010]
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                DEPARTMENT OF TRANSPORTATION
                National Highway Traffic Safety Administration
                49 CFR Part 535
                [NHTSA-2020-0079]
                RIN 2127-AM28
                Improvements for Heavy-Duty Engine and Vehicle Fuel Efficiency
                Test Procedures, and Other Technical Amendments
                AGENCY: National Highway Traffic Safety Administration.
                ACTION: Final rule.
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                SUMMARY: The National Highway Traffic Safety Administration (NHTSA) is
                finalizing minor technical amendments to the test procedures for heavy-
                duty engines and vehicles to improve accuracy and reduce testing
                burden. These amendments affect the certification procedures for fuel
                efficiency standards and related requirements. These amendments
                increase compliance flexibility, harmonize with other requirements, add
                clarity, correct errors, and streamline the regulations. Given the
                nature of these changes, NHTSA does not expect either significant
                environmental impacts or significant economic impacts for any sector.
                DATES: This final rule is effective on May 14, 2024.
                ADDRESSES: NHTSA has established a docket for this action under Docket
                ID: NHTSA-2020-0079. For access to the dockets to read background
                documents or comments received, go to http://www.regulations.gov, and/
                or: Docket Management Facility, M-30, U.S. Department of
                Transportation, West Building, Ground Floor, Rm. W12-140, 1200 New
                Jersey Avenue SE, Washington, DC 20590. The DOT Docket Management
                Facility is open between 9 a.m. and 5 p.m. Eastern Standard Time (EST),
                Monday through Friday, except Federal holidays. Please call ahead if
                you plan to drop off or pick up a document to ensure someone is
                available to assist you. The Docket Management Facility can be reached
                at (202) 366-9826 or (202) 366-9317 to arrange a drop off/pick up.
                FOR FURTHER INFORMATION CONTACT: Seiar Zia, Deputy Division Chief, Fuel
                Economy Division, Office of Rulemaking, National Highway Traffic Safety
                Administration, 1200 New Jersey Avenue SE, Washington, DC 20590; email:
                [email protected].
                SUPPLEMENTARY INFORMATION:
                Table of Contents
                I. General Information
                 A. Does this action apply to me?
                 B. What action is the Agency taking?
                 C. What are the incremental costs and benefits of this action?
                II. Medium and Heavy-Duty Fuel Efficiency Program Technical
                Amendments
                 A. Overview of the Medium and Heavy-Duty Fuel Efficiency Program
                 B. Public Participation Opportunities and Summary of Comments
                 C. Overview of the Final Rule
                 D. Authority Citation for Part 535
                 E. 49 CFR 535.1 Scope
                 F. 49 CFR 535.3 Applicability
                 G. 49 CFR 535.4 Definitions
                 H. 49 CFR 535.5 Standards
                 I. 49 CFR 535.6 Measurement and Calculation Procedures
                 J. 49 CFR 535.7 Averaging, Banking, and Trading (ABT) Credit
                Program
                 K. 49 CFR 535.8 Reporting and Recordkeeping Requirements
                 L. 49 CFR 535.9 Enforcement Approach
                 M. 49 CFR 535.10 How do manufacturers comply with fuel
                consumption standards?
                III. Statutory Authority and Executive Order Reviews
                 A. Executive Order 12866: Regulatory Planning and Review and
                Executive Order 13563: Improving Regulation and Regulatory Review
                 B. Paperwork Reduction Act (PRA)
                 C. Regulatory Flexibility Act (RFA)
                 D. Unfunded Mandates Reform Act (UMRA)
                 E. Executive Order 13132: Federalism
                 F. Executive Order 13175: Consultation and Coordination With
                Indian Tribal Governments
                 G. Executive Order 13045: Protection of Children From
                Environmental Health Risks and Safety Risks
                 H. Executive Order 13211: Actions Concerning Regulations That
                Significantly Affect Energy Supply, Distribution or Use
                 I. National Technology Transfer and Advancement Act (NTTAA)
                 J. Executive Order 12898: Federal Actions To Address
                Environmental Justice in Minority Populations and Low-Income
                Populations
                I. General Information
                A. Does this action apply to me?
                 This action will affect companies that manufacture, sell, or import
                into the United States new heavy-duty engines and new Class 2b through
                8 trucks, including combination tractors, buses, vocational vehicles
                including municipal, commercial, recreational vehicles, and \3/4\-ton
                and 1-ton pickup trucks and vans. The heavy-duty category incorporates
                all motor vehicles with a gross vehicle weight rating of 8,501 lbs. or
                greater, and the engines that power them, except for medium-duty
                passenger vehicles covered by the corporate average fuel economy
                standards and greenhouse gas standards issued for light-duty vehicles.
                The regulations for the Medium- and Heavy-Duty Vehicle Fuel Efficiency
                Program are found at 49 CFR part 535.
                 Regulated categories and entities include the following:
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                 \1\ North American Industry Classification System (NAICS).
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                 Examples of
                 Category NAICS codes \1\ potentially
                 regulated entities
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                Industry..................... 333618, 336111, Motor vehicle
                 336112, 336120, manufacturers and
                 336211, 336212, engine
                 336611, 336911, manufacturers.
                 336999.
                [[Page 18809]]
                
                Industry..................... 811111, 811112, Commercial
                 811198, 423110. importers of
                 vehicles and
                 vehicle
                 components.
                Industry..................... 335312, 811198...... Alternative fuel
                 vehicle
                 converters.
                Industry..................... 326199, 332431...... Portable fuel
                 container
                 manufacturers.
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                 This list is not intended to be exhaustive, but rather provides a
                guide for readers regarding entities likely to be regulated by this
                action. If you have questions regarding the applicability of this
                action to a particular entity, consult the person listed in the FOR
                FURTHER INFORMATION CONTACT section.
                B. What action is the Agency taking?
                 This action finalizes amendments to the regulations that implement
                NHTSA's fuel efficiency standards for medium-duty and heavy-duty
                engines and vehicles. These amendments are technical in nature and
                include corrections and clarifications to a variety of existing
                regulatory provisions to improve consistency with related EPA standards
                and with NHTSA's original intent for those provisions. In other words,
                this final rule comprises a variety of small changes for multiple types
                of engines and vehicles.
                 These amendments parallel similar ones in a rulemaking conducted by
                the EPA under RIN 2060-AU62.\2\ These technical amendments are intended
                to maintain alignment between EPA's Medium and Heavy-Duty Vehicle
                Greenhouse Gas Emissions and NHTSA's Fuel Efficiency Standards. The
                technical amendments in this final rule are necessary to align with the
                technical amendments finalized by EPA under the parallel rulemaking
                referenced in this paragraph.
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                 \2\ NPRM published on May 12, 2020 (85 FR 28140); final rule
                published on June 29, 2021 (86 FR 34308), as corrected by notices
                published on September 23, 2021 (86 FR 52833) and October 26, 2022
                (87 FR 64864).
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                 Most of the amendments being finalized in this rule will modify
                existing test procedures for medium- and heavy-duty engines and
                vehicles. These test procedure changes will improve accuracy, and in
                some cases, reduce test burden.
                 Other amendments will update NHTSA's regulations to enhance the
                implementation of existing fuel efficiency standards. For example, some
                changes will reduce the likelihood that manufacturers will need to
                conduct unique certification testing for compliance with Canadian and
                CARB standards, in addition to NHTSA's standards. Some amendments will
                make it easier for manufacturers to more fully account for the fuel
                efficiency benefits of advanced fuel efficiency improving technology,
                which could provide them the opportunity to generate additional fuel
                consumption improvement values for compliance. These amendments are
                described in II.
                 Additionally, as a matter of housekeeping, NHTSA is removing
                portions of its regulations that were vacated by the United States
                Court of Appeals for the District of Columbia Circuit. In November
                2021, that Court ``vacate[d] all portions of the [2016 joint NHTSA and
                EPA] rule that apply to trailers.'' Truck Trailer Mfrs. Ass'n, Inc. v.
                EPA, 17 F.4th 1198, 1200 (D.C. Cir. 2021). The underlying statute
                authorizes NHTSA to examine the fuel efficiency of and prescribe fuel
                economy standards for ``commercial medium-duty [and/or] heavy-duty on-
                highway vehicles.'' 49 U.S.C. 32902(b)(1)(C); 49 U.S.C. 32902(k)(2).
                The Court reasoned that trailers do not qualify as ``vehicles'' when
                that term is used in the fuel economy context because trailers are
                motorless and use no fuel. Truck Trailer Mfrs. Ass'n, Inc., 17 F.4th at
                1200, 1204-08. Accordingly, the Court held that NHTSA does not have the
                authority to regulate the fuel economy of trailers. Id. at 1208.\3\ As
                a result, NHTSA is removing the vacated trailer provisions from its
                regulations.
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                 \3\ For similar reasons, the Court also held that the statute
                authorizing EPA to regulate the emissions of ``motor vehicles'' does
                not encompass trailers. Id. at 1200-03. The Court affirmed, however,
                that both agencies still ``can regulate tractors based on the
                trailers they pull.'' Id. at 1208. Moreover, NHTSA is still
                authorized to regulate trailers in other contexts, such as under 49
                U.S.C. chapter 301. See 49 U.S.C. 30102(a)(7) (defining ``motor
                vehicle'' to include ``a vehicle . . . drawn by mechanical power'');
                Truck Trailer Mfrs. Ass'n, Inc., 17 F.4th at 1207 (``A trailer is
                `drawn by mechanical power.' '').
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                 NHTSA, is however, keeping its definition of standard trailer as
                well as other specific types of trailers in 49 CFR 535.4 to assist
                manufacturers in determining tractor performance in the Greenhouse Gas
                Emissions Model (GEM). In October 2016, NHTSA and EPA issued its Phase
                2 Heavy-Duty (HD) National Program final rule that increased efficiency
                standards beginning in model year (MY) 2021.\4\ As part of the 2016
                rulemaking, NHTSA and EPA adopted provisions such that tractor
                performance in GEM is determined by assuming the tractor is pulling a
                ``standard'' trailer. The specific characteristics of a standard
                trailer are dependent upon the type of tractor. 40 CFR 1037.501(g)
                provides the specific criteria a standard trailer must meet for
                specific types of trailers. In addition to measurement criteria, some
                standard trailers must be of a specific type (e.g., tank trailer,
                flatbed trailer). Therefore, while NHTSA is removing the requirements
                for trailers, NHTSA is keeping its definition of standard trailer as
                well as other specific types of trailers in 49 CFR 535.4 to assist
                manufacturers in determining tractor performance in GEM.
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                 \4\ 81 FR 73478, October 25, 2016.
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                C. What are the incremental costs and benefits of this action?
                 This action is limited in scope and is not intended to include
                amendments that will have significant economic or environmental
                impacts. NHTSA has therefore not estimated the potential costs or
                benefits of this final rule.
                II. Medium and Heavy-Duty Fuel Efficiency Program Technical Amendments
                A. Overview of the Medium and Heavy-Duty Fuel Efficiency Program
                 In September 2011, NHTSA and EPA finalized Phase 1 of the
                Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and
                Heavy-Duty Engines and Vehicles.\5\ The Phase 1 program covered new
                commercial heavy-duty vehicles and work trucks manufactured in model
                years 2014 through 2020, with unique standards for combination
                tractors, heavy-duty pickup trucks and vans, and vocational vehicles,
                as well as separate standards for engines in tractors and vocational
                vehicles. NHTSA and EPA finalized Phase 2 of the standards in October
                2016.\6\ In addition to more stringent standards, the Phase 2 program
                also incorporated enhanced test procedures that (among other things)
                allow individual drivetrain and powertrain performance to be reflected
                in the vehicle certification process; and included an expanded and
                improved compliance simulation model.
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                 \5\ 76 FR 57106, September 15, 2011.
                 \6\ 81 FR 73478, October 25, 2016.
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                 Since the promulgation of the Phase 2 regulations, manufacturers
                have been revising their internal test procedures for compliance with
                the new
                [[Page 18810]]
                requirements that began for model year 2021. While doing so, they have
                made the agencies aware of several areas in which the test procedure
                regulations could be improved (in terms of overall accuracy,
                repeatability, and clarity) without changing the effective stringency
                of the standards.
                 In its May 12, 2020 NPRM, EPA proposed numerous changes to the test
                procedure regulations to address manufacturers' concerns in addition to
                other issues it had identified.\7\ EPA sought comment on those changes
                and issued a final rule on June 29, 2021 responding to the comments and
                adjusting the regulatory changes as appropriate.\8\ After carefully
                reviewing all technical amendments in the EPA proposal, public comments
                to EPA's proposal, and the technical amendments that EPA finalized,
                NHTSA published a NPRM proposing technical amendments to its
                regulations that parallel the technical amendments that EPA has
                finalized.\9\ After providing opportunity for public comment, NHTSA is
                now finalizing its proposed technical amendments. NHTSA's regulatory
                changes described below consist primarily of references and definitions
                contained in NHTSA regulations which were impacted by the technical
                amendments finalized by the EPA. This final rule also includes various
                minor editorial changes to NHTSA's regulations that simply correct
                typographical/formatting errors or revise NHTSA's regulatory text to
                improve clarity or to update references to EPA regulations that have
                changed as a result of the EPA technical amendments.
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                 \7\ 85 FR 28140.
                 \8\ 86 FR 34308, as corrected by documents published on
                September 23, 2021 (86 FR 52833) and October 26, 2022 (87 FR 64864).
                 \9\ 87 FR 56156, September 13, 2022.
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                B. Public Participation Opportunities and Summary of Comments
                 NHTSA published the NPRM on September 13, 2022, and provided a 60-
                day comment period. The agency left the docket open with the intention
                to consider late comments to the extent practicable. NHTSA's docket
                received two comments from individual members of the public
                10 11 and one comment from a stakeholder organization,\12\
                for an overall total of three comment submissions. The two comments
                from members of the public were outside the scope of the proposal.
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                 \10\ Docket ID: NHTSA-2020-0079-0002 commenter recommended stop
                engine testing and allowing unrestricted engines to be produced for
                all diesel vehicles.
                 \11\ Docket ID: NHTSA-2020-0079-0004 commenter recommended
                including ``off-road'' vehicles in these regulations and reduce the
                emissions of on-road vehicles.
                 \12\ Docket ID: NHTSA-2020-0079-003 Allison Transmission
                commented on the current version of the Greenhouse Gas Emissions
                Model and recommended five future changes to it.
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                 The stakeholder organization, Allison Transmission (Allison),
                commented on the current version of the Greenhouse Gas Emissions Model
                (GEM). Allison commented that ``while the current version of GEM offers
                adequate modeling of emissions in vehicles, Allison believes that some
                future changes to GEM could prove to be beneficial in improving the
                overall accuracy of the model.'' Allison then recommended five changes
                to GEM that it believes ``would promote further adoption of current
                vehicle technologies and strategies that improve fuel economy (FE) . .
                . as well as continue to enhance the accuracy of the modeled vs actual
                FE performance.''
                 NHTSA appreciates the comment from Allison. However, changes to the
                GEM are beyond the scope of this rulemaking. Although NHTSA relies on
                outputs from GEM to generate emissions and fuel consumption performance
                results and allows manufacturers to use GEM for compliance purposes,
                GEM was developed by EPA, who continues to maintain and update it.
                Accordingly, while NHTSA provides input to EPA regarding GEM and
                conducts its own analysis when deciding the appropriateness of using
                GEM in its fuel efficiency program, comments requesting changes to GEM
                are more appropriately addressed to EPA.
                 In conjunction with its final rule issued on June 29, 2021, EPA
                issued a notice of proposed rulemaking (NPRM) proposing further
                revisions to GEM.\13\ In the NPRM, EPA proposed to revise GEM after
                consideration of comments solicited and received on its technical
                amendments NPRM. EPA issued a final rule on July 28, 2022 (87 FR 45257)
                that included corrections, clarifications, additional flexibilities,
                and adjustment factors to improve the GEM compliance tool.\14\
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                 \13\ 86 FR 34189.
                 \14\ Additional information can be found on EPA's website.
                ``Greenhouse Gas Emissions Model (GEM) for Medium- and Heavy-Duty
                Vehicle Compliance.'' (n.d.). https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty. Accessed July 2, 2023.
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                 While none of the comments NHTSA received were within the scope of
                the proposal, the agency appreciates the information and opinions
                provided.
                C. Overview of the Final Rule
                 NHTSA is largely finalizing the requirements proposed in the NPRM.
                Although NHTSA is not making any changes based on the comments
                received, NHTSA is making minor changes to better align NHTSA with the
                changes EPA finalized regarding updates to the GEM as well as other
                minor technical amendments. The changes NHTSA is finalizing are
                described in more detail below.
                D. Authority Citation for Part 535
                 NHTSA is amending the citation for part 535 to remove reference to
                49 U.S.C. 30101 because the provision does not pertain to NHTSA's
                authority to establish a fuel efficiency program for medium- and heavy-
                duty vehicles and engines.
                E. 49 CFR 535.1 Scope
                 NHTSA is amending Sec. 535.1 by removing the reference to trailers
                from the scope section of MDHD Fuel Efficiency Program regulation,
                consistent with the 2021 D.C. Circuit decision discussed above.
                F. 49 CFR 535.3 Applicability
                1. Section 535.3(a) Enforcement Action Related to Compliance With NHTSA
                Standards
                 While NHTSA proposed amending Sec. 535.3(a) to clarify the
                applicability and compliance provisions of its MDHD Fuel Efficiency
                Program, NHTSA no longer believes the proposed changes are appropriate.
                Accordingly, NHTSA is not finalizing any changes to Sec. 535.3(a).
                2. Section 535.3(c) Applicable Vehicle and Engine Manufacturers
                 NHTSA is revising Sec. 535.3(c) by removing an outdated reference
                to 40 CFR part 86 and adding the specific subpart references for 40 CFR
                parts 1036 and 1037, such that the regulation will now reference 40 CFR
                part 1036, subpart C and 40 CFR part 1037, subpart C.
                3. Section 535.3(d)(5) Exclusion of Heavy-Duty Trailers
                 NHTSA is removing paragraph (d)(5) from Sec. 535.3, consistent
                with the 2021 D.C. Circuit decision discussed above, and reserving it
                for future use.
                4. Section 535.3(e)(1) Off-Road Vocational Vehicle Exemption
                 NHTSA is revising Sec. 535.3(e)(1) by removing details regarding
                exemptions and just referencing NHTSA's provision at Sec. 535.5(b)(9)
                that provides complete details about off-road exemptions. This change
                is intended to reduce confusion by providing details in only one
                location in NHTSA's regulations. Although NHTSA proposed adding
                additional details to paragraph (e)(1) to
                [[Page 18811]]
                better align with EPA's provision, NHTSA now believes those details
                would be more appropriately placed in Sec. 535.5(b)(9). As discussed
                below, NHTSA is finalizing a technical amendment to add language to
                Sec. 535.5(b)(9) that allows vocational vehicles with a date of
                manufacture before January 1, 2021, to automatically qualify for an
                exemption under Sec. 535.5(b)(9) if the tires installed on the vehicle
                have a maximum speed rating at or below 55 miles per hour. This new
                provision, found at 49 CFR 535.5(b)(9)(i), reflects the intention of
                the NPRM and achieves consistency with 40 CFR 1037.150(h).
                5. Section 535.3(e)(2)(ii)(A) and (B) Early Certification for Small
                Manufacturers
                 In the NPRM, NHTSA proposed adding paragraphs (A) and (B) to Sec.
                535.3(e)(2)(ii) to discuss two flexibilities to NHTSA's compliance
                provisions for small manufacturers. While, NHTSA is not finalizing the
                exact language proposed, NHTSA is finalizing the substance of the
                proposed change. Vehicle manufacturers that qualify as small businesses
                are exempt from the Phase 1 standards but must meet the Phase 2
                standards beginning January 1, 2022. However, some vehicle families
                have been certified voluntarily to Phase 1 standards by small
                manufacturers. To encourage more voluntary early certification to Phase
                1 standards, EPA finalized a new interim provision in 40 CFR
                1037.150(c)(4) for small manufacturers that certify their entire U.S.-
                directed production volume to the Phase 1 standards for calendar year
                2021 (see 86 FR 34337). These small manufacturers will be allowed to
                certify to the Phase 1 standards for model year 2022, instead of the
                otherwise applicable Phase 2 standards. The agencies believe that early
                compliance with the Phase 1 standards should more than offset any
                reduction in benefits that will otherwise be achieved from meeting
                Phase 2 standards starting January 1, 2022.\15\ NHTSA is finalizing
                this change at Sec. 535.3(e)(2)(ii)(B) and has shifted some existing
                language from Sec. 535.3(e)(2)(ii) into a new subparagraph (A).
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                 \15\ EPA stated that it believed that the magnitude of any
                impact on air quality would be small because of the low production
                volumes from these small business manufacturers.
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                 NHTSA also proposed allowing Phase 1 compliance credits that small
                manufacturers generate from model years 2018 through 2022 for
                vocational vehicles to be used through model year 2027. In the NPRM,
                NHTSA cited EPA's rationale for making its corresponding change. In its
                final rule, EPA stated that the agencies believe that the limit on
                credit life can be problematic for small manufacturers because their
                limited product lines provide them with less flexibility when averaging
                their fleets. EPA also stated that the agencies believe the longer
                credit life will provide small manufacturers with additional
                flexibility to ensure all their products are fully compliant by the
                time the Phase 2 standards are fully phased-in for model year 2027.
                NHTSA continues to believe that the rationale for these changes is
                valid. However, the scope of the change is smaller than NHTSA
                recognized when proposing the additional flexibility for small
                manufacturers. NHTSA's rationale in adopting EPA's reasoning was
                predicated on an incorrect understanding of the regulation. In
                proposing the technical amendment, NHTSA believed that all credit carry
                forwards for vocational vehicles between Phase 1 and Phase 2 were
                limited by the five-year credit life. This is incorrect. Under the
                existing regulations, fuel consumption credits a manufacturer generates
                for light and medium heavy-duty vocational vehicles in model years 2018
                through 2021 may be used through model year 2027, instead of being
                limited to a five-year credit life. These credits, generated under the
                Phase 1 program, can be used for compliance in the Phase 2 averaging,
                banking, and trading program. The existing regulations limit the use of
                fuel consumption credits generated for heavy heavy-duty vocational to a
                five-year credit life. Therefore, the proposed change would only extend
                the credit flexibility to heavy heavy-duty vocational vehicles produced
                by small manufacturers.
                 As EPA stated in its final rule, the agencies believe that the
                limit on credit life can be problematic for small manufacturers because
                their limited product lines provide them with less flexibility when
                averaging their fleets. The agencies believe the longer credit life
                will provide small manufacturers with additional flexibility to ensure
                all their products are fully compliant by the time the Phase 2
                standards are fully phased-in for model year 2027. Therefore, NHTSA
                will finalize an amendment, harmonizing with EPA's regulations, to
                allow fuel consumption credits generated for heavy heavy-duty
                vocational vehicles produced by small manufacturers in model years 2018
                through 2021 to be used through 2027, instead of being limited to a
                five-year credit life. This provision, however, is being more
                appropriately added to Sec. 535.7(a)(8), which includes provisions for
                credit transfers between Phase 1 and Phase 2.
                 Additionally, NHTSA is finalizing an amendment to address credit
                carry forwards for small manufacturers that certify 2022 vehicles to
                Phase 1 standards if the manufacturer voluntarily certified its entire
                U.S.-directed production volume to the Phase 1 standards for calendar
                year 2021. Specifically, NHTSA is adding a provision stating that fuel
                consumption credits that a small manufacturer generates for vocational
                vehicles in model year 2022 that are certified to Phase 1 standards as
                permitted under Sec. 535.3(e)(2)(ii)(B) may be used through model year
                2027. This provision is also being more appropriately added to Sec.
                535.7(a)(8), which includes provisions for credit transfers between
                Phase 1 and Phase 2. Although NHTSA's rationale for making this change
                varies slightly from EPA, the changes themselves maintain program
                alignment across both agencies.
                6. Section 535.3(e)(3) Transitional Allowance for Trailers
                 NHTSA is removing 535.3(e)(3) from its regulations, consistent with
                the 2021 D.C. Circuit decision discussed above, and reserving it for
                future use.
                Section 535.3(j) Potential Enforcement Actions for Incomplete,
                Incorrect or Fraudulent Information
                 In the NPRM, NHTSA proposed adding paragraph (j) to Sec. 535.3.
                The new paragraph was intended outline eligibility determinations and
                potential enforcement actions under the NHTSA fuel efficiency program
                if EPA denies, suspends or revokes, a manufacturer's certificate of
                conformity in accordance with 40 CFR 1036.255 or 1037.255, due to
                incomplete, incorrect or fraudulent information. However, NHTSA has
                decided not to finalize the provision because the agency no longer
                believes it is necessary. Manufacturers that submit fraudulent
                information may be subject to enforcement action under 18 U.S.C. 1001.
                Additionally, there is already an existing provision at Sec.
                535.8(a)(3) explaining that manufacturers providing incomplete
                information may be subject to civil penalties in accordance with 49
                U.S.C. 32912 and a provision at Sec. 535.9(a)(10) indicating actions
                NHTSA may take if EPA suspends or revokes a certificate of conformity.
                G. 49 CFR 535.4 Definitions
                 NHTSA is adding several new terms to its list of definitions and
                modifying the definitions of several existing terms
                [[Page 18812]]
                on the list to clarify the meaning of those terms. Almost all these
                definitions reference EPA regulatory definitions to ensure alignment of
                the NHTSA and EPA programs.
                1. Introductory Text
                 NHTSA is amending the introductory text by updating the statutory
                reference for the definitions of the terms manufacture and manufacturer
                to reference 49 U.S.C. 32901.
                2. Act
                 NHTSA is removing the term Act because it is no longer used in part
                535.
                3. Adjustable Parameter
                 NHTSA is adding the term adjustable parameter and defining it as
                having the same meaning given in 40 CFR 1065.1001. However, while the
                NPRM proposed only referencing 40 CFR 1037.801, NHTSA now believes it
                is more appropriate to provide the entire definition and reference 40
                CFR 1065.1001, which includes EPA's definition for adjustable
                parameter, and 40 CFR 1068.50, which provides general provisions that
                apply to adjustable parameters.
                4. Advanced Technology
                 NHTSA is amending the definition of advanced technology to remove
                an outdated reference and to streamline the definition to specify that
                it is specific vehicle technology for which manufacturers may earn
                special credits under Sec. 535.6 and Sec. 535.7 (e.g., hybrids with
                powertrain designs that include energy storage systems, vehicles with
                waste heat recovery, electric vehicles, and fuel cell vehicles).
                5. Alterers
                 NHTSA is amending the term alterers to be alterer as the definition
                refers to a single manufacturer.
                6. Alternative Fuel Conversion
                 Although NHTSA proposed adding the term alternative fuel conversion
                and defining it as having the meaning given for clean alternative fuel
                conversion in 40 CFR 85.502, the term already appears in the current
                regulation. Accordingly, NHTSA is not making any changes to the term.
                7. Averaging Set
                 NHTSA is removing the terms ``Long trailers'' and ``Short
                trailers'' from the definition of Averaging set, consistent with the
                2021 D.C. Circuit decision.
                8. Certificate of Conformity
                 In its 2021 final rule, EPA amended 40 CFR 1036.225(e) and
                1037.225(e) by adding a statement that clarifies the application date
                for amended applications for the certification of engine and vehicle
                families submitted to EPA under 40 CFR 1036 subpart C and 1037 subpart
                C, respectively.\16\ In response, NHTSA proposed updating its
                definition of Certificate of Conformity to include the same language
                finalized by EPA because the clarifications are also applicable to
                NHTSA's fuel efficiency program. After further consideration, NHTSA
                determined that no changes were needed to NHTSA's current definition to
                maintain program alignment across the agencies. Accordingly, NHTSA is
                not finalizing any change to the definition of Certificate of
                Conformity.
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                 \16\ 86 FR 34308, as corrected by documents published on
                September 23, 2021 (86 FR 52833) and October 26, 2022 (87 FR 64864).
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                9. Certified Emission Level
                 NHTSA is finalizing a technical amendment to remove the definition
                of certified emission level because the term is not used within part
                535 and to the extent that term is used in EPA's program for engine and
                vehicle families, the terms are defined in the respective regulations
                at 40 CFR 1036.801 and 1037.801.
                10. Class
                 NHTSA is removing the reference to trailers from its definition of
                class, consistent with the 2021 D.C. Circuit decision.
                11. Defeat Device
                 NHTSA is adding the term defeat device and defining it as having
                the same meaning given in 40 CFR 86.004-2. The addition will include a
                full definition of the term and note that the term is also defined in
                EPA's regulations at 40 CFR 86.004-2.
                12. Emission Data Engine
                 Although NHTSA proposed adding the term emission data engine and
                defining it as having the meaning given in 40 CFR 1036.801, NHTSA has
                reconsidered. Since the term is not used in part 535, NHTSA does not
                believe it is necessary or appropriate to define the term at Sec.
                535.4.
                13. Engine Configuration
                 NHTSA is adding the term engine configuration and defining it as
                having the same definition as given in 40 CFR 1036.801. However, while
                the NPRM proposed only referencing 40 CFR 1036.801, NHTSA now believes
                it is more appropriate to provide the entire definition and noting that
                the definition is also found in 40 CFR 1036.801.
                14. Engine Identification Number
                 NHTSA is adding the term engine identification number and defining
                it to have the same meaning as given in 40 CFR 1036.801 for
                identification number. This nonsubstantive change is to maintain
                alignment with EPA's program.
                15. Flexible-Fuel
                 NHTSA is adding the term flexible-fuel and defining it as having
                the same meaning given in 40 CFR 1036.801. However, while the NPRM
                proposed only referencing 40 CFR 1036.801, NHTSA now believes it is
                more appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1036.801.
                16. Fuel Type
                 NHTSA is adding the term fuel type and defining it as having the
                same meaning given in 40 CFR 1036.801. However, while the NPRM proposed
                only referencing 40 CFR 1036.801, NHTSA now believes it is more
                appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1036.801.
                17. Gear Ratio
                 NHTSA is adding the term gear ratio or transmission gear ratio, kg
                and defining it as having the same meaning given in 40 CFR 1037.801.
                However, while the NPRM proposed referencing 40 CFR 1036.801, the
                correct reference is Sec. 1037.801. Additionally, while NHTSA proposed
                only referencing EPA's definition, NHTSA now believes it is more
                appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1037.801.
                18. Good Engineering Judgment
                 NHTSA is amending 535.4 to place the term good engineering
                judgement in the correct alphabetical order.
                19. Greenhouse Gas
                 In the NPRM, NHTSA proposed adding the term greenhouse gas and
                defining it as having the meaning given in 40 CFR 1036.801. However,
                upon reconsideration NHTSA has determined that it is unnecessary to
                define it in part 535.
                20. Heavy-Duty Engine
                 NHTSA is adding the term heavy-duty engine and defining it as
                having the meaning given in 49 CFR 523.2. Although NPRM proposed
                referencing both 40 CFR 1036.801 and 49 CFR 523.2, NHTSA believes it is
                unnecessary to reference both. Additionally, NHTSA
                [[Page 18813]]
                will reference the specific section, Sec. 523.2, instead of the
                general part number.
                21. Hybrid or Hybrid Vehicle
                 NHTSA is amending the term hybrid vehicle to be hybrid or hybrid
                vehicle because part 535 uses hybrid as a standalone term to mean
                hybrid vehicle. The definition of hybrid or hybrid vehicle will remain
                the same as the definition of hybrid vehicle currently in Sec. 535.4.
                NHTSA has determined that is not appropriate to reference the
                definition of hybrid in 40 CFR 1036.801 because that term is defined in
                part as an ``engine or powertrain'' and NHTSA's use of the term hybrid
                as a standalone term in part 535 is to hybrid vehicles, not hybrid
                engines or powertrains. This definition aligns with the definition for
                hybrid vehicle in 40 CFR 1037.801.
                22. Hybrid Engine
                 To develop consistency with the revised hybrid powertrain test
                procedures it recently finalized in 40 CFR part 1036, subpart F, EPA
                has added the term hybrid engine along with its definition to 40 CFR
                1036.801. To maintain alignment across the agencies, NHTSA is removing
                the term hybrid engine or powertrain and adding the terms hybrid engine
                and hybrid powertrain and defining the terms as having the same
                meanings given in 40 CFR 1036.801. However, while the NPRM proposed
                only referencing 40 CFR 1036.801, NHTSA now believes it is more
                appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1036.801.
                23. Hybrid Powertrain
                 To develop consistency with the revised hybrid powertrain test
                procedures it recently finalized in 40 CFR part 1036, subpart F, EPA
                has added the term hybrid powertrain along with its definition to 40
                CFR 1036.801. To maintain alignment across the agencies, NHTSA is
                adding the term hybrid powertrain and defining it as having the same
                meaning given in 40 CFR 1036.801. However, while the NPRM proposed only
                referencing 40 CFR 1036.801, NHTSA now believes it is more appropriate
                to provide the entire definition and noting that the definition is also
                found in 40 CFR 1036.801.
                24. Manufacturer
                 In the NPRM, NHTSA proposed adding the term manufacturer and
                defining it as having the meaning given in 40 CFR 1037.801. However,
                NHTSA is not finalizing this change because the term manufacturer is
                defined in 49 U.S.C. 32901, as stated in the introductory paragraph to
                49 CFR 535.4.
                25. Model Year
                 NHTSA is revising its definition for model year as it pertains to
                vehicles and engines. NHTSA is also removing the reference to trailers
                from its definition of model year as it applies to vehicles, consistent
                with the 2021 D.C. Circuit decision. NHTSA has included the
                specifications for model year for vehicles and engines into a single
                definition as the same term is used for both vehicles and engines. The
                meanings for the vehicle categories and for engines are retained.
                Additionally, while the NPRM proposed adding details regarding ABT
                reports into the definition of model year, NHTSA has reconsidered. The
                details are already found in 49 CFR 535.8 and NHTSA has concluded that
                it is not appropriate or necessary to include them in the definition
                section.
                26. Motor Vehicle
                 NHTSA is adding the term motor vehicle and defining it as having
                the meaning given in 49 CFR 523.2. Although the NPRM proposed defining
                the term as having the meaning in 49 U.S.C. 32901, NHTSA has since
                realized that the term does not appear in section 32901.
                27. Multi-Purpose
                 NHTSA is adding the term multi-purpose and defining it as having
                the same meaning given in 40 CFR 1037.801. However, while the NPRM
                proposed only referencing 40 CFR 1037.801, NHTSA now believes it is
                more appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1037.801.
                28. Neutral-Idle
                 NHTSA is adding the term neutral-idle and defining it as having the
                same meaning given in 40 CFR 1037.801. However, while the NPRM proposed
                only referencing 40 CFR 1037.801, NHTSA now believes it is more
                appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1037.801.
                29. New Vehicles
                 In the NPRM, NHTSA proposed adding the term new vehicles and
                defining it as having the meaning given to new motor vehicle in 40 CFR
                1037.801. However, upon reconsideration, NHTSA has determined that is
                not necessary to define the term in part 535.
                30. Percent
                 NHTSA is adding the term percent and defining it as having the same
                meaning given in 40 CFR 1065.1001, which is the definition referenced
                in 40 CFR 1037.801. However, while the NPRM proposed only referencing
                40 CFR 1037.801, NHTSA believes it is more appropriate to provide the
                entire definition and noting that the definition is also found in 40
                CFR 1037.801 and 40 CFR 1065.1001.
                31. Phase 2
                 NHTSA is removing the reference to trailers from its definition of
                Phase 2, consistent with the 2021 D.C. Circuit decision.
                32. Placed Into Service
                 NHTSA is adding the term Placed into service and defining it as
                having the same meaning given in 40 CFR 1037.801. However, while the
                NPRM proposed only referencing 40 CFR 1037.801, NHTSA believes it is
                more appropriate to provide the entire definition and noting that the
                definition is also found in 40 CFR 1037.801.
                33. Primary Intended Service Class
                 NHTSA is amending the definition of primary intended service class
                to update an incorrect reference in the existing text. The change is
                nonsubstantive and only changes two references in paragraph (2)(iii).
                34. Rechargeable Energy Storage System (RESS)
                 NHTSA is amending the definition of rechargeable Energy Storage
                System (RESS) to correct a typographical error.
                35. Regulatory Subcategory
                 NHTSA is removing trailer subcategories from its definition of
                regulatory subcategory, consistent with the 2021 D.C. Circuit decision,
                and reserving the paragraph for future use.
                36. Relating To
                 NHTSA is adding the term relating to and defining it as having the
                same meaning given in 40 CFR 1037.801. However, while the NPRM proposed
                only referencing 40 CFR 1037.801, NHTSA believes it is more appropriate
                to provide the entire definition and noting that the definition is also
                found in 40 CFR 1037.801.
                37. Round
                 NHTSA is adding the term round and defining it as having the same
                meaning given in 40 CFR 1065.1001. However, while the NPRM proposed
                only referencing 40 CFR 1065.1001, NHTSA believes it is more
                appropriate to
                [[Page 18814]]
                provide the entire definition and noting that the definition is also
                found in 40 CFR 1065.1001.
                38. Standard Payload
                 NHTSA is removing paragraph (3), which includes defined standard
                payloads for trailers, from its definition of standard payload. This
                change is consistent with the 2021 D.C. Circuit decision.
                39. Standard Tractor
                 In the NPRM, NHTSA proposed amending the definition of standard
                tractor by defining it as having the meaning given in 40 CFR 1037.801
                not 40 CFR 1037.501, which is how it's currently defined. However, upon
                reconsideration, NHTSA determined that it was not necessary to define
                the term in part 535. Accordingly, NHTSA is removing the term standard
                tractor from the definitions section.
                40. Standard Trailer
                 NHTSA is amending the definition for standard trailer by defining
                it as having the same meaning given in 40 CFR 1037.801 not 40 CFR
                1037.501, which is how it's currently defined. However, while the NPRM
                proposed only referencing 40 CFR 1037.501, NHTSA now believes it is
                more appropriate to provide the entire definition and note that the
                definition is also found in 40 CFR 1037.801.
                41. Stop-Start
                 NHTSA is adding the term stop-start and defining it to have the
                same meaning as given for stop-start in 40 CFR 1037.801. However, while
                the proposed regulatory text in the NPRM only included a reference to
                40 CFR 1037.801, NHTSA now believes it is more appropriate to include
                the entire definition and note that the definition is also found in 40
                CFR 1037.801.
                42. Suspend
                 In the NPRM, NHTSA proposed adding the term Suspend and defining it
                as having the meaning given in 40 CFR 1037.801. However, NHTSA has now
                concluded that the proposed definition is neither necessary nor
                appropriate at it applies to NHTSA's use of the term suspend in part
                535. Accordingly, NHTSA is not adding the term to the definition
                section of part 535.
                43. Vehicle Identification Number
                 In the NPRM, NHTSA proposed adding the term identification number
                and defining it as having the meaning given in 40 CFR 1037.801.
                However, upon reconsideration, NHTSA realized that the term
                identification number is defined in both 40 CFR part 1037 and 40 CFR
                part 1036, with one term applying to vehicles and one applying to
                engines. To reduce confusion, NHTSA is finalizing amendments to add two
                new terms, vehicle identification number and engine identification
                number. Because NHTSA establishes requirements for vehicles to be
                assigned unique vehicle identification numbers, or VINs, NHTSA is
                defining vehicle identification number for purposes of part 535 as
                having the same meaning as VIN in 49 CFR 565.12.
                44. Vehicle Service Class
                 NHTSA is revising the definition of vehicle service class to align
                with the changes EPA to their definition given in 40 CFR 1037.140.
                Although the NPRM proposed only referencing EPA's definition in 40 CFR
                1037.140, NHTSA has concluded that it is important to maintain the
                entire definition as there are some important terminology differences
                between EPA's definition and NHTSA's that should be retained. However,
                even with these differences, the terms are aligned.
                 The recent EPA technical amendments clarify that the classification
                for tractors, where provisions are the same as vocational vehicles, are
                applicable to both hybrid and non-hybrid vehicles. The amendments also
                clarify that Class 8 hybrid and electric vehicles are considered heavy
                heavy-duty ``HHD'' vehicles while all other vehicles are classified by
                GVWR classes.
                 EPA explained in its final rule that prior to these revisions,
                manufacturers had expressed concern that the Phase 2 regulations were
                not specific enough regarding how to classify hybrid vocational
                vehicles, because vocational vehicles are generally classified by the
                class of the engines (as opposed to tractors, which are classified
                based on GVW), which was not applicable to electrically driven vehicles
                that have no engine.
                 To address these problems, EPA proposed changes to Sec.
                1037.140(g)(1) to clarify that the classification for tractors where
                provisions are the same as vocational vehicles applies for hybrid and
                non-hybrid vehicles, and paragraph (g)(4) to clarify that Class 8
                hybrid and electric vehicles are Heavy HHVs and all other vehicles are
                classified by GVWR classes. The changes we are finalizing maintain
                alignment with EPA's changes.
                45. Void
                 In the NPRM, NHTSA proposed adding the term void and defining it as
                having the meaning given in 40 CFR 1037.801. However, NHTSA has now
                concluded that the addition of the term is not necessary as the only
                use of the term in part 535 is in reference to an EPA action, and EPA
                provides its own definition for the term.
                H. 49 CFR 535.5 Standards
                1. Section 535.5(a) Introductory Text
                 NHTSA is amending Sec. 535.5(a) introductory text to clarify its
                regulatory standards relating to heavy-duty pickup trucks and vans.
                More specifically, the agency is adding language that ensures that
                manufacturers use the same options for purposes of grouping vehicles
                and/or engines for applying target standards and determining compliance
                for both EPA's and NHTSA's programs. NHTSA is also adding clarifying
                language explaining that engines installed in vehicles that are subject
                to the standards in paragraph (a) are not subject to the standards in
                paragraph (d) of this section and may not optionally comply with
                paragraph (d).
                2. Section 535.5(a)(1)
                 NHTSA is amending Sec. 535.5(a)(1) to update an outdated cross
                reference, such that the reference to 40 CFR 86.1819 now reads ``40 CFR
                86.1819-14''.
                3. Section 535.5(b) Introductory Text
                 NHTSA is amending the introductory text of Sec. 535.5(b) to
                clarify its regulatory standards relating to heavy-duty vocational
                vehicles. More specifically, the agency is adding language that ensures
                manufacturers use the same options for purposes of grouping vehicles
                and/or engines for applying standards and determining compliance for
                both EPA's and NHTSA's programs.
                4. Section 535.5(b)(1)(iii)(B)
                 NHTSA is removing paragraph (B) from Sec. 535.5(b)(1)(iii) and
                reserving it for future use. This change removes the requirement for
                heavy-duty vocational vehicles that meet the requirement in Sec.
                535.5(b)(1)(iii)(A) by being equipped with tire pressure monitoring
                systems to use low pressure warning and malfunction telltales in clear
                view of the driver as specified in S4.3 and S4.4 of 49 CFR 571.138. The
                revision, however, does not remove the requirements in Sec.
                535.5(b)(6)(vi)(C) for motorhomes that comply with Sec.
                535.5(b)(6)(vi)(B) by having a TPMS.
                5. Section 535.5(b)(4)
                 NHTSA is correcting the Vocational HHD Vehicle Regional compression
                ignition (CI) standards. The current published standard for this
                vehicle class
                [[Page 18815]]
                is incorrect and does not align with EPA GHG standards for this vehicle
                type. The incorrect values resulted from an incorrect calculation
                during the Phase 2 rulemaking which intended to maintain alignment of
                the NHTSA and EPA standards. The corrected value for this regulatory
                class is 20.1375 gallons per 1000 ton-miles not 20.2358 gallons per
                1000 ton-miles, which is the currently published standard.
                6. Section 535.5(b)(9)(i) Introductory Text
                 NHTSA is amending the introductory text of Sec. 535.5(b)(9)(i) to
                align with EPA's technical amendments by adding an exemption provision
                for vocational vehicles with a date of manufacture before January 1,
                2021. With this provision, vocational vehicles automatically qualify
                for an exemption under Sec. 535.5(b)(9), if the tires installed on the
                vehicle have a maximum speed rating at or below 55 miles per hour.
                7. Section 535.5(c) Introductory Text
                 NHTSA is amending the introductory text of Sec. 535.5(c) to
                clarify its regulatory standards relating to truck tractors. More
                specifically, the agency is adding language that ensures manufacturer
                options (in terms of grouping vehicles and/or engines for purposes of
                applying standards and determining compliance) for EPA and NHTSA
                vehicle standards are aligned across both agencies.
                8. Section 535.5(c)(5)
                 NHTSA is revising its Alternate Fuel Consumption Standards for
                Tractors above 120,000 pounds GCWR for model year 2021 and later. The
                revised standards are directly aligned with the revised GHG standards
                for this class of vehicles proposed and finalized by EPA as part of its
                technical amendment rulemaking.\17\ The revised standards provide
                additional clarity on this vehicle class along with fuel efficiency
                standards that increase in three increments, model years 2021 through
                2023, model years 2024 through 2026, and model years 2027 and later.
                ---------------------------------------------------------------------------
                 \17\ In December 2020, EPA proposed further revisions to the
                Phase 2 GEM Simulation Model in the December 2020 Notice of Proposed
                Rulemaking (NRPM) for technical amendments to the GHG Emissions
                Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty
                Vehicles and is soliciting comments on these revisions. S. The
                latest EPA's GEM model is released and can be found https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty which incorporates the
                revisions being considered.'' (last accessed: May 11, 2022)
                ---------------------------------------------------------------------------
                 As described in EPA's final rulemaking action, the agencies
                originally defined these alternate fuel consumption and greenhouse-gas
                standards during the Phase 2 rulemaking, to enable Environment and
                Climate Change Canada (ECCC) to fully harmonize with the U.S.'s HD
                Phase 2 standards.
                 In the interim, ECCC has since adopted final standards for these
                120,000- to 140,000-pound GCWR tractors, which differ from the optional
                standards finalized in Phase 2.\18\ Since the purpose of these
                standards was to facilitate certification of vehicles intended for
                Canada, EPA proposed optional standards in 40 CFR 1037.670 that would
                be the same as the final ECCC standards, and did not receive any
                adverse comments regarding that proposal. NHTSA is adopting these
                alternative standards, in gallons per 1,000 ton-miles, for 120,000- to
                140,000-pound GCWR tractors that are equivalent to the EPA and ECCC
                standards. This maintains harmonization across the programs for all
                three agencies.
                ---------------------------------------------------------------------------
                 \18\ Regulations Amending the Heavy-duty Vehicle and Engine
                Greenhouse Gas Emission Regulations and Other Regulations Made Under
                the Canadian Environmental Protection Act, 1999: SOR/2018-98, Canada
                Gazette, Part II, Volume 152, Number 11, May 16, 2018.
                ---------------------------------------------------------------------------
                9. Section 535.5(d) Introductory Text
                 NHTSA is clarifying the introductory text of 49 CFR 535.5(d) to
                expand its regulatory provision to optionally accommodate powertrain
                families and subfamilies added by EPA in 40 CFR 1036.108(a), and
                1036.230(d), and 1036.230(f). The EPA provisions allow manufacturers to
                apply CO2 standards to powertrain families and subfamilies.
                They also allow manufacturers to optionally certify powertrains using
                the engine testing provisions in 40 CFR part 1036 instead of part 1037.
                Manufacturers may choose to include electric powertrain and hybrid
                electric powertrain emissions in their engine families or subfamilies
                under 40 CFR part 1036 instead of (or in addition to) the otherwise
                applicable engine fuel maps. Doing so provides the same compliance
                options for manufacturers under the EPA and NHTSA programs. NHTSA is
                finalizing a similar amendment to Sec. 535.6(d).
                 NHTSA is also amending the introductory text of Sec. 535.5(d) to
                add language that ensures manufacturer options (in terms of grouping
                engines for purposes of applying standards and determining compliance)
                for EPA and NHTSA standards are aligned across both agencies.
                10. Section 535.5(d)(3)
                 NHTSA is correcting the Heavy-Duty Engine Fuel Consumption
                Standards for Phase 1 MHD and HHD compression ignition (CI) tractor
                engines. The current published standards for these engine classes are
                incorrect, and do not align with EPA GHG standards for these engine
                types. The incorrect values resulted from an incorrect calculation
                during the Phase 2 rulemaking which intended to maintain alignment of
                the NHTSA and EPA standards. The corrected values for these regulatory
                classes are 4.7839 gallons per 100 hp-hr for MHD CI tractor engines and
                4.5187 gallons per 100 hp-hr for HHD CI tractor engines.
                11. Section 535.5(d)(11)(i)(A) and (C)
                 NHTSA is correcting the Alternate transition option for Phase 2
                engine standards (i)(A) and (C). The current published standards for
                these engine standards are incorrect, and do not align with current EPA
                GHG standards for these engine types. The incorrect values resulted
                from an incorrect calculation during the Phase 2 rulemaking which
                intended to maintain alignment for the NHTSA and EPA standards. The
                corrected values for these regulatory classes are 5.3241 gallons per
                100 hp-hr for MHD vocational vehicle engines and 5.0098 gallons per 100
                hp-hr for HHD vocational engines.
                12. Section 535.5(e)
                 NHTSA is removing paragraph (e) from Sec. 535.3, which removes the
                Heavy-duty Trailer standards, consistent with the 2021 D.C. Circuit
                decision, discussed above.
                I. 49 CFR 535.6 Measurement and Calculation Procedures
                1. Section 535.6(b)(1)
                 NHTSA is amending Sec. 535.6(b)(1) by adding a reference to EPA's
                finalized regulation at 40 CFR 1037.150. This added reference will
                provide clear guidance that will be used to determine the proper
                vehicle and vehicle family to select when determining a manufacturer's
                regulatory subcategories for vocational vehicles and tractors. The
                addition also maintains program alignment across the agencies.
                2. Section 535.6(b)(4)(ii)
                 NHTSA is amending Sec. 535.6(b)(4)(ii) by adding references to
                EPA's finalized regulations at 40 CFR 1037.525, 1037.527, and 1037.528.
                These added references clarify how to determine a high-roof tractor's
                aerodynamic performance. EPA finalized this revision to more clearly
                relate the drag areas to
                [[Page 18816]]
                the defined effective yaw variable, as recommended by EMA as a comment
                to the EPA proposal.\19\ NHTSA is adopting this same measurement schema
                to keep programs aligned across the agencies. NHTSA is also amending
                Sec. 535.6(b)(4)(ii) to provide manufacturers with an alternate
                compliance approach for determining coefficient of aerodynamic drag
                values in GEM.
                ---------------------------------------------------------------------------
                 \19\ The variables
                CdAeffective-yaw-coastdown and
                CdAeffective-yaw-alt are now
                CdAcoastdown([psi]eff) and
                CdAalt([psi]eff), respectively.
                ---------------------------------------------------------------------------
                3. Section 535.6(b)(5)(i)
                 NHTSA is revising Sec. 535.6(b)(5)(i) to change the reference to
                an EPA regulation from 40 CFR 1036.510 to 1036.503. This revision
                aligns the NHTSA regulations to the revised and finalized EPA
                regulations, which also keeps the agencies' programs aligned.
                4. Section 535.6(b)(5)(v)(E)(3)
                 NHTSA is adding paragraph (3) to Sec. 535.6(b)(5)(v)(E), which
                allows manufacturers to characterize torque converters to determine
                their own torque converter capacity factor instead of using the default
                value provided in GEM. This change aligns with EPA provisions in 40 CFR
                1037.570 and maintains program alignment across both agencies.
                5. Section 535.6(b)(5)(v)(E)(4)
                 NHTSA is adding paragraph (4) to Sec. 535.6(b)(5)(v)(E), which
                allows vocational vehicles to input a value for neutral coasting in GEM
                as a compliance option for its fuel consumption program. This revision
                aligns the NHTSA regulations with the EPA regulations in 40 CFR
                1037.520 and keep both agencies aligned for program compliance.
                6. Section 535.6(d) Introductory Text
                 Like Sec. 535.5(d), NHTSA is amending the introductory text of
                Sec. 535.6(d) by adding clarifications to Sec. 535.6(d) to expand its
                regulatory provision to optionally accommodate powertrain families and
                subfamilies added by EPA in 40 CFR 1036.108(a), and 1036.230(d), and
                1036.230(f). The EPA provisions allow manufacturers to apply
                CO2 standards to powertrain families and subfamilies. They
                also allow manufacturers to optionally certify powertrains using the
                engine testing provisions in 40 CFR part 1036 instead of part 1037.
                Manufacturers may choose to include electric powertrain and hybrid
                electric powertrain emissions in their engine families or subfamilies
                under 40 CFR part 1036 instead of (or in addition to) the otherwise
                applicable engine fuel maps. Doing so provides the same compliance
                options for manufacturers under the EPA and NHTSA programs.
                7. Section 535.6(d)(1)
                 NHTSA is updating paragraph (d)(1) to reference to EPA regulation
                40 CFR 1036.501 for engines in heavy-duty truck tractors and vocational
                vehicles that make up each of the manufacturer's regulatory
                subcategories. This replaces the reference to 40 CFR part 86 and 40 CFR
                1036.235. This change maintains alignment across the NHTSA and EPA
                programs.
                8. Section 535.6(d)(2) Introductory Text
                 NHTSA is amending the introductory text of paragraph (d)(2) to
                align with the EPA regulation 40 CFR 1036.230(f) by expanding this
                regulatory provision to accommodate powertrains other than engines and
                to also include sub-families.
                9. Section 535.6(d)(3) Introductory Text
                 NHTSA is amending Sec. 535.6(d)(3) introductory text by replacing
                the existing provision with the prescribed emissions tests required for
                medium HD and heavy HD engines certified as a tractor and other long-
                haul engine family as well as those certified as a tractor and
                vocational engine family. In the same paragraph, NHTSA also prescribes
                the emissions test required for all other engines. These amendments are
                being made to align with EPA's technical amendments and to provide
                greater clarity to manufacturers about how compliance must be
                determined for the different types of engines.
                10. Section 535.6(d)(3)(ii)
                 NHTSA is expanding the provisions of Sec. 535.6(d)(3)(ii) to
                powertrains other than engines and subfamilies in addition to families.
                This change is being made to maintain alignment with EPA's technical
                amendments.
                11. Section 535.6(e)
                 NHTSA is removing paragraph (e) from Sec. 535.6, which removes
                heavy-duty trailers from its measurement and calculation procedures,
                consistent with the 2021 D.C. Circuit decision.
                J. 49 CFR 535.7 Averaging, Banking, and Trading (ABT) Credit Program
                1. Section 535.7(a) Introductory Text
                 NHTSA is removing the references to trailer manufacturers and
                trailers from the introductory text of Sec. 535.7(a), consistent with
                the 2021 D.C. Circuit decision.
                2. Section 535.7(a)(2)(v)
                 NHTSA is removing the reference to the application of banked or
                traded credits to trailers from Sec. 535.7(a)(2)(v), consistent with
                the 2021 D.C. Circuit decision.
                3. Section 535.7(a)(3)(v)
                 NHTSA is removing paragraph (v) from Sec. 535.7(a)(3), consistent
                with the 2021 D.C. Circuit decision, and reserving it for future use.
                4. Section 535.7(a)(4) Introductory Text
                 NHTSA is amending the introductory text of paragraph (a)(4) to
                remove reference to trailers, consistent with the 2021 D.C. Circuit
                decision.
                5. Section 535.7(a)(4)(v)
                 NHTSA is removing paragraph (v) from Sec. 535.7(a), consistent
                with the 2021 D.C. Circuit decision, and reserving it for future use.
                6. Section 535.7(a)(8)(i)
                 As discussed above, NHTSA is finalizing two amendments to provide
                greater flexibility to small manufacturers of vocational vehicles.
                First, NHTSA is finalizing an amendment such that fuel consumption
                credits a small manufacturer generates for heavy heavy-duty vocational
                vehicles in model years 2018 through 2021 may be used through 2027,
                instead of being limited to a five-year credit life (this flexibility
                is already provided for fuel consumption credits any manufacturer
                generates for light and medium heavy-duty vocational vehicles in model
                years 2018 through 2021). Second, as discussed above, NHTSA is
                finalizing an amendment to address credit carry forwards for small
                manufacturers that certify 2022 vehicles to Phase 1 standards if the
                manufacturer voluntarily certified its entire U.S.-directed production
                volume to the Phase 1 standards for calendar year 2021. Specifically,
                NHTSA is adding a provision stating that fuel consumption credits that
                a small manufacturer generates for vocational vehicles in model year
                2022 that are certified to Phase 1 standards as permitted under Sec.
                535.3(e)(2)(ii)(B) may be used through model year 2027.
                7. Section 535.7(a)(9)(iv)(B)
                 NHTSA is amending Sec. 535.7(a)(9)(iv)(B) by adding clarifying
                details regarding corporate relationship status as it relates to
                production limits for generating credits for drayage tractors under the
                custom chassis allowance. In the NPRM, NHTSA proposed language such
                that the limit would apply with respect to vehicles
                [[Page 18817]]
                produced by the parent manufacturer and its owned subordinate
                companies. However, to better align with existing regulations, NHTSA is
                finalizing language that specifies that the limit applies with respect
                to vehicles produced by manufactures within a control relationship as
                defined in Sec. 534.3.
                8. Section 535.7(a)(11)
                 NHTSA is adding paragraph (11) to Sec. 535.7(a), which is a
                provision that prevents manufacturers from generating fuel consumption
                credits more than once for compliance. NHTSA has updated the text that
                was proposed in the NPRM to provide greater clarity and to reduce
                ambiguity.
                9. Section 535.7(b)(1)
                 NHTSA is amending Sec. 535.7(b)(1) to correct the Total MY Fleet
                FCC equation for HDPUVs.
                10. Section 535.7(c)(1) Introductory Text
                 NHTSA is amending the introductory text Sec. 535.7(c)(1) to
                correct the Vehicle Family FCC equation for vocational vehicle and
                tractor families and subfamilies.
                11. Section 535.7(d)(1) Introductory Text
                 NHTSA is amending the introductory text of Sec. 535.7(d)(1) to
                correct the Engine Family FCC equation for heavy-duty engine families
                and subfamilies.
                12. Section 535.7(d)(7)
                 NHTSA is amending Sec. 535.7(d)(7) by removing the conditions for
                when engine credits generated for compression-ignition engines in model
                year 2020 and earlier can be used in model year 2021 and later and
                adding them to new lower-level paragraphs in this section.
                13. Section 535.7(d)(7)(i)
                 NHTSA is adding paragraph (i) to Sec. 535.7(d)(7), which states
                that engine credits generated for compression-ignition engines
                certified to the tractor engine standards in Sec. 535.5(d) in model
                year 2020 and earlier can be used in model year 2021 and later. This
                provision was in the existing regulation and is just being moved down
                to a lower-level paragraph.
                14. Section 535.7(d)(7)(ii)
                 NHTSA is also amending Sec. 535.7(d)(7) by removing the provision
                that manufacturers may otherwise use fuel consumption credits generated
                in one model year for certifying vehicles in a later model year without
                adjustment, even if the consumption standards are different. In its
                place, NHTSA is adding paragraph (ii) to Sec. 535.7(d)(7), stipulating
                that fuel consumption credits generated for compression-ignition
                engines certified to the vocational engine standards in Sec. 535.5(d)
                in MY 2020 and earlier can be used in MY 2021 and later in accordance
                with specific requirements. Specifically, the fuel consumption credits
                may only be used in later years relative to specified family
                certification levels (FCLs), consistent with EPA's regulations.
                15. Section 535.7(d)(7)(ii)(A)
                 NHTSA is adding paragraph (A) to Sec. 535.7(d)(7)(ii), which is
                the FCL manufacturers should use to calculate credits for compression-
                ignition medium HD engines certified to the vocational vehicle
                standards in Sec. 535.5(d) in MY 2020 and earlier and will be used in
                MY 2021 and later.
                16. Section 535.7(d)(7)(ii)(B)
                 NHTSA is adding paragraph (B) to Sec. 535.7(d)(7)(ii), which is
                the FCL manufacturers should use to calculate credits for compression-
                ignition heavy HD engines certified to the vocational vehicle standards
                in Sec. 535.5(d) in MY 2020 and earlier and will be used in MY 2021
                and later.
                17. Section 535.7(d)(7)(ii)(C)
                 NHTSA is adding paragraph (C) to Sec. 535.7(d)(7)(ii), which is
                the provision that provides instructions on how to use the FCLs in
                paragraphs (A) and (B) of this section to recalculate engine credits
                for compression-ignition engines certified to the vocational vehicle
                standards in Sec. 535.5(d) that have been generated in Phase 1 but
                used in Phase 2 of the program.
                18. Section 535.7(e)
                 NHTSA is removing paragraph (e) from Sec. 535.7, which removes the
                ABT provisions for trailers, consistent with the 2021 D.C. Circuit
                decision, discussed above, and reserving it for future use.
                19. Section 535.7(f)(1)(ii) Introductory Text
                 NHTSA is amending Sec. 535.7(f)(1)(ii) to clarify the final model
                year in which manufacturers may use the advanced technology credit
                multipliers to increase the credits they earn for advanced technology
                vehicles in Phase 2. In the Phase 2 final rule for the Heavy-Duty
                National Program, NHTSA and EPA jointly explained that we were adopting
                advanced technology credit multipliers for three types of advanced
                technologies. As described in the final rule, there will be a
                multiplier of 3.5 for advanced technology credits for plug-in hybrid
                vehicles, a multiplier of 4.5 for advanced technology credits for all-
                electric vehicles, and a multiplier of 5.5 for advanced technology
                credits for fuel cell vehicles. The agencies stated that their
                intention in adopting these multipliers was to create a meaningful
                incentive to manufacturers considering adopting these technologies in
                their vehicles. The agencies further noted that the adoption rates for
                these advanced technologies in heavy vehicles was essentially non-
                existent at the time the final rule was issued and seemed unlikely to
                grow significantly within the next decade without additional
                incentives. Because of their large size, the agencies decided to adopt
                them as an interim program that will continue through model year 2027.
                These changes, however, were not accurately reflected in the regulatory
                changes made by the Phase 2 final rule. NHTSA is now amending the
                introductory text of Sec. 535.7(f)(1)(ii) to clarify that for Phase 2,
                advanced technology credits may be increased by the applicable
                multiplier through model year 2027.
                20. Section 535.7(f)(1)(ii)(G)
                 NHTSA is adding paragraph (G) to Sec. 535.7(f)(1)(ii) to add a
                provision clarifying that advanced technology credits increased with a
                multiplier in Phase 2 cannot be used across averaging sets. In the
                Phase 2 final rule, the agencies explained that because of the adoption
                of the large multipliers, the agencies were discontinuing the allowance
                to use advanced technology credits across averaging sets. This change
                was not accurately reflected in the regulatory changes made by the
                Phase 2 final rule; therefore, NHTSA is adding the provision as Sec.
                535.7(f)(1)(ii)(G).
                21. Section 535.7(f)(2)(v)
                 NHTSA is removing paragraph (v) from Sec. 535.7(f)(2), which
                removes the provision that provides manufacturers with the ability to
                apply the off-cycle provisions of Sec. 535.7(f)(2) and 40 CFR 1037.610
                to trailers, consistent with the 2021 D.C. Circuit decision discussed
                above, and reserving it for future use.
                K. 49 CFR 535.8 Reporting and Recordkeeping Requirements
                1. Section 535.8(a)(6)
                 NHTSA is amending Sec. 535.8(a)(6) to correct the mailing address
                for NHTSA to 1200 New Jersey Avenue SE, NVS-200, Office W45-306,
                Washington, DC 20590.
                [[Page 18818]]
                2. Section 535.8(g)(11)(i)(C)
                 Like Sec. 535.6(d)(3)(ii), NHTSA is expanding the provisions of
                Sec. 535.8(g)(11)(i)(C) to broaden the language to provide clarity
                that the provision is referring to ``engine and powertrain families and
                subfamilies'' as opposed to just ``engine families.''
                3. Section 535.8(g)(12)
                 NHTSA is amending Sec. 535.8(g)(12) by removing all references to
                trailers and trailer manufacturers from its production reporting
                requirements, consistent with the 2021 D.C. Circuit decision, discussed
                above.
                4. Section 535.8(i)
                 NHTSA is amending Sec. 535.8(i) to include a statement reminding
                manufacturers that providing false, fictitious, or fraudulent
                information may subject them to penalties under 18 U.S.C. 1001.
                L. 49 CFR 535.9 Enforcement Approach
                1. Section 535.9(a)(1)(i)
                 NHTSA is amending Sec. 535.9(a)(1)(i) by adding additional
                language and clarifications that NHTSA may conduct audits or perform
                confirmatory testing on any configuration. Any such testing would be
                performed as specified in EPA's regulations and NHTSA will collaborate
                with EPA regarding any potential issues with testing results.
                2. Section 535.9(a)(1)(v)
                 NHTSA is adding paragraph (v) to Sec. 535.9(a)(1) to add a
                provision stating that NHTSA may require a manufacturer to perform
                selective enforcement audits with respect to any GEM inputs in its
                application for certification or in the end of the year ABT final
                reports. The provision further specifies that any such selective
                enforcement audit would be required to be conducted in a manner
                consistent with EPA's corresponding provisions for selective
                enforcement audits.
                M. Section 535.10 How do manufacturers comply with fuel consumption
                standards?
                1. Section 535.10(a)(3)
                 NHTSA is removing (a)(3) and reserving it for future use. Although
                the NPRM proposed clarifying that EPA's compliance requirements 40 CFR
                1037.601 and 40 CFR part 1068 apply similarly to NHTSA's fuel
                consumption program, except for the warranty provisions in 40 CFR
                1037.601(a)(5), NHTSA has now concluded that it is not appropriate for
                NHTSA to incorporate by reference EPA's general compliance provisions
                for regulations issued under 40 CFR parts 1037 and 1068. Accordingly,
                NHTSA is removing the provisions at (a)(3) and reserving it for future
                use.
                2. Section 535.10(a)(6)
                 NHTSA is amending Sec. 535.10(a)(6) by clarifying that vehicles
                required to meet the fuel consumption standards of this part must also
                comply with the same requirements as specified in 40 CFR 1037.115(a)
                and (d). However, while the NPRM proposed only referencing 40 CFR
                1037.115, NHTSA has now concluded that it would be more appropriate to
                place the entirety of the substantive requirements into part 535 and
                note that the requirements are consistent with 40 CFR 1037.115(a) and
                (d).
                3. Section 535.10(c)(2)
                 NHTSA is amending Sec. 535.10(c)(2) by removing the reference to
                box trailers, consistent with the 2021 D.C. Circuit decision, discussed
                above.
                4. Section 535.10(c)(3)
                 NHTSA is removing Sec. 535.10(c)(3), consistent with the 2021 D.C.
                Circuit decision discussed above, and reserving it for future use.
                III. Statutory Authority and Executive Order Reviews
                A. Executive Order 12866, Executive Order 14094, Executive Order 13563,
                and DOT Regulatory Policies and Procedures
                 We have considered the potential impact of this proposed rule under
                Executive Order 12866, Executive Order 14094, Executive Order 13563,
                and DOT Order 2100.6A. The Office of Management and Budget (OMB) has
                determined that this rule is not a significant regulatory action and,
                therefore, was not submitted to OMB for review.
                B. Paperwork Reduction Act (PRA)
                 This action does not impose any new information collection burden
                under the PRA. OMB has previously approved the information collection
                activities contained in the existing regulations and has assigned OMB
                control numbers 2060-0104, 2060-0287, 2060-0338, 2060-0545, 2060-0641.
                This rule clarifies and simplifies procedures without affecting
                information collection requirements.
                C. Regulatory Flexibility Act (RFA)
                 I certify that this action will not have a significant economic
                impact on a substantial number of small entities under the RFA. In
                making this determination, the impact of concern is any significant
                economic impact on small entities. This action is designed to reduce
                testing burdens, increase compliance flexibility, and make various
                corrections and adjustments to compliance provisions. We therefore
                anticipate no costs and no regulatory burden associated with this rule.
                We further do not believe the benefits of this rule would result in
                significant economic impact to regulated small entities. Accordingly,
                we have concluded that this action will have no significant economic
                impact on regulated small entities.
                D. Unfunded Mandates Reform Act (UMRA)
                 Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA),
                Public Law 104-4, requires Federal agencies to prepare a written
                assessment of the costs, benefits, and other effects of proposed or
                final rules that include a Federal mandate likely to result in the
                expenditure by State, local, or Tribal governments, in the aggregate,
                or by the private sector, of more than $100 million annually (adjusted
                for inflation with base year of 1995). Adjusting this amount by the
                implicit gross domestic product price deflator for the year 2010
                results in $136 million (110.993/81.606 = 1.36). This rule will not
                result in a cost of $136 million or more to either State, local, or
                Tribal governments, in the aggregate, or the private sector or uniquely
                affect small governments. Thus, this rule is not subject to the
                requirements of sections 202 of the UMRA.
                E. Executive Order 13132: Federalism
                 This action does not have federalism implications. It will not have
                substantial direct effects on the States, on the relationship between
                the Federal government and the States, or on the distribution of power
                and responsibilities among the various levels of government.
                F. Executive Order 13175: Consultation and Coordination With Indian
                Tribal Governments
                 This action does not have Tribal implications as specified in
                Executive Order 13175. This rule will be implemented at the Federal
                level and affects engine and vehicle manufacturers. Thus, Executive
                Order 13175 does not apply to this action.
                G. Executive Order 13045: Protection of Children From Environmental
                Health Risks and Safety Risks
                 This action is not subject to Executive Order 13045 because it is
                not
                [[Page 18819]]
                economically significant as defined in Executive Order 12866, and
                because there are no environmental health or safety risks created by
                this action that could present a disproportionate risk to children.
                H. Executive Order 13211: Actions Concerning Regulations That
                Significantly Affect Energy Supply, Distribution or Use
                 This action is not a ``significant energy action'' because it is
                not likely to have a significant adverse effect on the supply,
                distribution, or use of energy. We have concluded that this action is
                not likely to have any adverse energy effects because it is designed
                merely to reduce testing burdens, increase compliance flexibility, and
                make various corrections and adjustments to compliance provisions.
                I. National Technology Transfer and Advancement Act (NTTAA)
                 Under the National Technology Transfer and Advancement Act of 1995
                (NTTAA) (Pub. L. 104-113), all Federal agencies and departments shall
                use technical standards that are developed or adopted by voluntary
                consensus standards bodies, using such technical standards as a means
                to carry out policy objectives or activities determined by the agencies
                and departments. Voluntary consensus standards are technical standards
                (e.g., material specifications, test methods, sampling procedures, and
                business practices) that are developed or adopted by voluntary
                consensus standards bodies, such as the International Organization for
                Standardization (ISO) and the SAE International (SAE). The NTTAA
                directs agencies to provide Congress, through OMB, explanations when
                the agency decides not to use available and applicable voluntary
                consensus standards. NHTSA searched for but did not find voluntary
                consensus standards directly applicable to the amendments in this final
                rule.
                J. Executive Order 12898: Federal Actions To Address Environmental
                Justice in Minority Populations and Low-Income Populations
                 NHTSA believes this action does not have disproportionately high
                and adverse human health or environmental effects on minority
                populations, low-income populations or indigenous peoples, as specified
                in Executive Order 12898 (59 FR 7629, February 16, 1994). Due to the
                lack of environmental impact, these regulatory changes will not have a
                disproportionate adverse effect on minority populations, low-income
                populations, or indigenous peoples.
                List of Subjects in 49 CFR Part 535
                 Fuel economy, Reporting and recordkeeping requirements.
                Regulatory Text
                 For the reasons discussed in the preamble, NHTSA is amending 49 CFR
                part 535 as set forth below:
                PART 535--MEDIUM- AND HEAVY-DUTY VEHICLE FUEL EFFICIENCY PROGRAM
                0
                1. The authority citation for part 535 is revised to read as follows:
                 Authority: 49 U.S.C. 32902; delegation of authority at 49 CFR
                1.95.
                0
                2. Revise Sec. 535.1 to read as follows:
                Sec. 535.1 Scope.
                 This part establishes fuel consumption standards pursuant to 49
                U.S.C. 32902(k) for work trucks and commercial medium- and heavy-duty
                on-highway vehicles (hereafter referenced as heavy-duty vehicles), and
                engines manufactured for sale in the United States. This part
                establishes a credit program that manufacturers may use to comply with
                standards and requirements for manufacturers to provide reports to the
                National Highway Traffic Safety Administration regarding their efforts
                to reduce the fuel consumption of heavy-duty vehicles and engines.
                0
                3. Amend Sec. 535.3 by revising paragraph (c), removing and reserving
                paragraph (d)(5), and revising paragraph (e).
                 The revisions read as follows:
                Sec. 535.3 Applicability.
                * * * * *
                 (c) Vehicle and engine manufacturers that must comply with this
                part include manufacturers required to have approved certificates of
                conformity from EPA as specified in subparts C in 40 CFR parts 1036 and
                1037.
                * * * * *
                 (e) The following heavy-duty vehicles and engines are exempted from
                the requirements of this part:
                 (1) Off-road vehicles. Vocational vehicles intended for off-road
                use are exempt with or without request, subject to the provisions of
                Sec. 535.5(b)(9).
                 (2) Small business manufacturers. (i) For Phase 1, small business
                manufacturers are exempted from the vehicle and engine standards of
                Sec. 535.5 but must comply with the reporting requirements of Sec.
                535.8(g).
                 (ii) For Phase 2, fuel consumption standards apply on a delayed
                schedule for manufacturers meeting the small business criteria
                specified in 13 CFR 121.201 and in 40 CFR 86.1819-14(k)(5), 1036.150,
                and 1037.150.
                 (A) Qualifying manufacturers of truck tractors, vocational
                vehicles, heavy duty pickups and vans, and engines are not subject to
                the fuel consumption standards for vehicles built before January 1,
                2022, and engines (such as those engines built by small alternative
                fuel engine converters) with a date of manufacturer on or after
                November 14, 2011, and before January 1, 2022. Qualifying manufacturers
                may choose to voluntarily comply early.
                 (B) Small manufacturers that certify their entire U.S.-directed
                production volume to the Phase 1 standards for calendar year 2021 may
                certify to the Phase 1 standards for model year 2022 (instead of the
                otherwise applicable Phase 2 standards).
                 (iii) Small business manufacturers producing vehicles and engines
                that run on any fuel other than gasoline, E85, or diesel fuel meeting
                the criteria specified in 13 CFR 121.201 and in 40 CFR 86.1819-
                14(k)(5), 1036.150, and 1037.150 may delay complying with every new
                mandatory standard under this part by one model year.
                 (3) [Reserved]
                 (4) Engines for specialty vehicles. Engines certified to the
                alternative standards specified in 40 CFR 86.007-11 and 86.008-10 for
                use in specialty vehicles as described in 40 CFR 1037.605. Compliance
                with the vehicle provisions in 40 CFR 1037.605 satisfies compliance for
                NHTSA under this part.
                * * * * *
                0
                4. Revise Sec. 535.4 to read as follows:
                Sec. 535.4 Definitions.
                 The terms manufacture, manufacturer, commercial medium and heavy-
                duty on-highway vehicle, fuel, and work truck are used as defined in 49
                U.S.C. 32901. See 49 CFR 523.2 for general definitions related to
                NHTSA's fuel efficiency programs.
                 Adjustable parameter means any device, system, or element of design
                that someone can adjust (including those which are difficult to access)
                and that, if adjusted, may affect measured or modeled emissions (as
                applicable). In some cases, this may exclude a parameter that is
                difficult to access if it cannot be adjusted to affect emissions
                without significantly degrading engine performance, or if it will not
                be adjusted in a way that affects emissions during in-use operation.
                (See 40 CFR 1065.1001 and 40 CFR 1068.50).
                 Administrator means the Administrator of the National Highway
                [[Page 18820]]
                Traffic Safety Administration (NHTSA) or the Administrator's delegate.
                 Advanced technology means specific vehicle technology for which
                manufacturers may earn special credits under Sec. Sec. 535.6 and 535.7
                (e.g., hybrids with powertrain designs that include energy storage
                systems, vehicles with waste heat recovery, electric vehicles, and fuel
                cell vehicles).
                 Alterer means a manufacturer that modifies an altered vehicle as
                defined in 49 CFR 567.3
                 Alternative fuel conversion has the meaning given for clean
                alternative fuel conversion in 40 CFR 85.502
                 A to B testing has the meaning given in 40 CFR 1037.801.
                 Automated manual transmission has the meaning given in 40 CFR
                1037.801.
                 Automatic tire inflation system has the meaning given in 40 CFR
                1037.801.
                 Automatic transmission (AT) has the meaning given in 40 CFR
                1037.801.
                 Auxiliary power unit has the meaning given in 40 CFR 1037.801.
                 Averaging set means, a set of engines or vehicles in which fuel
                consumption credits may be exchanged. Credits generated by one engine
                or vehicle family may only be used by other respective engine or
                vehicle families in the same averaging set as specified in Sec. 535.7.
                Note that an averaging set may comprise more than one regulatory
                subcategory. The averaging sets for this HD program are defined as
                follows:
                 (1) Heavy-duty pickup trucks and vans.
                 (2) Light heavy-duty (LHD) vehicles.
                 (3) Medium heavy-duty (MHD) vehicles.
                 (4) Heavy heavy-duty (HHD) vehicles.
                 (5) Light heavy-duty engines subject to compression-ignition
                standards.
                 (6) Medium heavy-duty engines subject to compression-ignition
                standards.
                 (7) Heavy heavy-duty engines subject to compression-ignition
                standards.
                 (8) Engines subject to spark-ignition standards.
                 (9) Vehicle types certifying to optional custom chassis standards
                as specified in Sec. 535.5(b)(6) form separate averaging sets for each
                vehicle type as specified in Sec. 535.7(c).
                 Axle ratio or Drive axle ratio, ka has the meaning given in 40 CFR
                1037.801.
                 Basic vehicle frontal area has the meaning given in 40 CFR
                1037.801.
                 Cab-complete vehicle has the meaning given in 49 CFR 523.2.
                 Carryover has the meaning given in 40 CFR 1037.801.
                 Certificate holder means the manufacturer who holds the certificate
                of conformity for the vehicle or engine and that assigns the model year
                based on the date when its manufacturing operations are completed
                relative to its annual model year period.
                 Certificate of Conformity means an approval document granted by EPA
                to a manufacturer that submits an application for a vehicle or engine
                emissions family in 40 CFR 1036.205 and 1037.205. A certificate of
                conformity is valid from the indicated effective date until December 31
                of the model year for which it is issued. The certificate must be
                renewed annually for any vehicle a manufacturer continues to produce.
                 Certification has the meaning given in 40 CFR 1037.801.
                 Chassis-cab means the incomplete part of a vehicle that includes a
                frame, a completed occupant compartment and that requires only the
                addition of cargo-carrying, work-performing, or load- bearing
                components to perform its intended functions.
                 Chief Counsel means the NHTSA Chief Counsel, or his or her
                designee.
                 Class means relating to GVWR classes for vehicles, as follows:
                 (1) Class 2b vehicles are vehicles with a gross vehicle weight
                rating (GVWR) ranging from 8,501 to 10,000 pounds.
                 (2) Class 3 through Class 8 vehicles are vehicles with a gross
                vehicle weight rating (GVWR) of 10,001 pounds or more as defined in 49
                CFR 565.15.
                 Complete sister vehicle is a complete vehicle of the same
                configuration as a cab-complete vehicle.
                 Complete vehicle has the meaning given in 49 CFR part 523.
                 Compression-ignition (CI) means relating to a type of
                reciprocating, internal-combustion engine, such as a diesel engine,
                that is not a spark-ignition engine. Note, in accordance with 40 CFR
                1036.1, gas turbine engines and other engines not meeting the
                definition of compression-ignition are deemed to be compression-
                ignition engines for complying with fuel consumption standards.
                 Configuration means a subclassification within a test group for
                passenger cars, light trucks and medium-duty passenger vehicles and
                heavy-duty pickup trucks and vans which is based on basic engine,
                engine code, transmission type and gear ratios, and final drive ratio.
                 Container chassis trailer has the same meaning as container chassis
                in 40 CFR 1037.801.
                 Curb weight has the meaning given in 40 CFR 86.1803.
                 Custom chassis vehicle means a vocational vehicle that is a motor
                home, school bus, refuse hauler, concrete mixer, emergency vehicle,
                mixed-use vehicle or other buses that are not school buses or motor
                coaches. These vehicle types are defined in 49 CFR 523.3. A ``mixed-use
                vehicle'' is one that meets at least one of the criteria specified in
                40 CFR 1037.631(a)(1) or at least one of the criteria in 40 CFR
                1037.631(a)(2), but not both.
                 Date of manufacture means the date on which the certifying vehicle
                manufacturer completes its manufacturing operations, except as follows:
                 (1) Where the certificate holder is an engine manufacturer that
                does not manufacture the complete or incomplete vehicle, the date of
                manufacture of the vehicle is based on the date assembly of the vehicle
                is completed.
                 (2) EPA and NHTSA may approve an alternate date of manufacture
                based on the date on which the certifying (or primary) vehicle
                manufacturer completes assembly at the place of main assembly,
                consistent with the provisions of 40 CFR 1037.601 and 49 CFR 567.4.
                 (3) A vehicle manufacturer that completes assembly of a vehicle at
                two or more facilities may ask to use as the month and year of
                manufacture, for that vehicle, the month and year in which
                manufacturing is completed at the place of main assembly, consistent
                with provisions of 49 CFR 567.4, as the model year. Note that such
                staged assembly is subject to the provisions of 40 CFR 1068.260(c).
                NHTSA's allowance of this provision is effective when EPA approves the
                manufacturer's certificates of conformity for these vehicles.
                 Day cab has the meaning given in 40 CFR 1037.801.
                 Defeat device means, consistent with 40 CFR 86.004-2, an auxiliary
                emission control device (AECD) that reduces the effectiveness of the
                emission control system under conditions which may reasonably be
                expected to be encountered in normal vehicle operation and use, unless:
                 (1) Such conditions are substantially included in the applicable
                Federal emission test procedure for heavy-duty vehicles and heavy-duty
                engines described in subpart N of this part;
                 (2) The need for the AECD is justified in terms of protecting the
                vehicle against damage or accident;
                 (3) The AECD does not go beyond the requirements of engine
                starting; or
                 (4) The AECD applies only for engines that will be installed in
                emergency vehicles, and the need is justified in terms of preventing
                the engine from losing speed, torque, or power due abnormal conditions
                of the emission control system, or in terms of preventing such abnormal
                conditions from occurring, during operation related to
                [[Page 18821]]
                emergency response. Examples of such abnormal conditions may include
                excessive exhaust backpressure from an overloaded particulate trap, and
                running out of diesel exhaust fluid for engines that rely on urea-based
                selective catalytic reduction.
                 Drayage tractor has the meaning given in 40 CFR 1037.801.
                 Dual-clutch transmission (DCT) means a transmission has the meaning
                given in 40 CFR 1037.801.
                 Dual-fuel has the meaning given in 40 CFR 1037.801.
                 Electric vehicle has the meaning given in 40 CFR 1037.801.
                 Emergency vehicle means a vehicle that meets one of the criteria in
                40 CFR 1037.801.
                 Engine configuration means a unique combination of engine hardware
                and calibration (related to the emission standards) within an engine
                family, which would include hybrid components for engines certified as
                hybrid engines and hybrid powertrains. Engines within a single engine
                configuration differ only with respect to normal production variability
                or factors unrelated to compliance with emission standards. (See 40 CFR
                1036.801).
                 Engine family has the meaning given in 40 CFR 1036.230.
                Manufacturers designate families in accordance with EPA provisions and
                may not choose different families between the NHTSA and EPA programs.
                 Engine identification number means a unique specification (for
                example, a model number/serial number combination) that allows someone
                to distinguish a particular engine from other similar engines. (See the
                definition of identification number in 40 CFR 1036.801).
                 Excluded means a vehicle or engine manufacturer or component is not
                required to comply with any aspects with the NHTSA fuel consumption
                program.
                 Exempted means a vehicle or engine manufacturer or component is not
                required to comply with certain provisions of the NHTSA fuel
                consumption program.
                 Family certification level (FCL) has the meaning given in 40 CFR
                1036.801.
                 Family emission limit (FEL) has the meaning given in 40 CFR
                1037.801.
                 Final drive ratio has the meaning given in 40 CFR 1037.801.
                 Final-stage manufacturer has the meaning given in 49 CFR 567.3 and
                includes secondary vehicle manufacturers as defined in 40 CFR 1037.801.
                 Flatbed trailer has the meaning given in 40 CFR 1037.801.
                 Fleet in this part means all the heavy-duty vehicles or engines
                within each of the regulatory sub- categories that are manufactured by
                a manufacturer in a particular model year and that are subject to fuel
                consumption standards under Sec. 535.5.
                 Fleet average fuel consumption is the calculated average fuel
                consumption performance value for a manufacturer's fleet derived from
                the production weighted fuel consumption values of the unique vehicle
                configurations within 'ach vehicle model type that makes up that
                manufacturer's vehicle fleet in a given model year. In this part, the
                fleet average fuel consumption value is determined for each
                manufacturer's fleet of heavy-duty pickup trucks and vans.
                 Fleet average fuel consumption standard is the actual average fuel
                consumption standard for a manufacturer's fleet derived from the
                production weighted fuel consumption standards of each unique vehicle
                configuration, based on payload, tow capacity and drive configuration
                (2, 4 or all-wheel drive), of the model types that makes up that
                manufacturer's vehicle fleet in a given model year. In this part, the
                fleet average fuel consumption standard is determined for each
                manufacturer's fleet of heavy-duty pickup trucks and vans.
                 Flexible-fuel means relating to an engine designed for operation on
                any mixture of two or more different types of fuels. (See 40 CFR
                1036.801).
                 Fuel cell means an electrochemical cell that produces electricity
                via the non-combustion reaction of a consumable fuel, typically
                hydrogen.
                 Fuel cell electric vehicle means a motor vehicle propelled solely
                by an electric motor where energy for the motor is supplied by a fuel
                cell.
                 Fuel efficiency means the amount of work performed for each gallon
                of fuel consumed.
                 Fuel type means a general category of fuels such as diesel fuel,
                gasoline, or natural gas. There can be multiple grades within a single
                fuel type, such as premium gasoline, regular gasoline, or gasoline with
                10 percent ethanol. (See 40 CFR 1037.801).
                 Gaseous fuel has the meaning given in 40 CFR 1037.801.
                 Gear ratio or Transmission gear ratio, kg, means the dimensionless
                number representing the angular speed of the transmission's input shaft
                divided by the angular speed of the transmission's output shaft when
                the transmission is operating in a specific gear. (See 40 CFR
                1037.801).
                 Good engineering judgment has the meaning given in 40 CFR 1068.30.
                See 40 CFR 1068.5 for the administrative process used to evaluate good
                engineering judgement.
                 Greenhouse gas Emissions Model (GEM) has the meaning given in 40
                CFR 1037.801.
                 Gross axle weight rating (GAWR) has the meaning given in 49 CFR
                571.3.
                 Gross combination weight rating (GCWR) has the meaning given in 49
                CFR 571.3.
                 Gross vehicle weight rating (GVWR) has the meaning given in 49 CFR
                571.3.
                 Heavy-duty engine has the meaning given in 49 CFR part 523.2.
                 Heavy-duty off-road vehicle means a heavy-duty vocational vehicle
                or vocational tractor that is intended for off-road use.
                 Heavy-duty vehicle has the meaning given in 49 CFR part 523.
                 Heavy-haul tractor has the meaning given in 40 CFR 1037.801.
                 Heavy heavy-duty (HHD) vehicle has the meaning given in vehicle
                service class.
                 Hybrid or Hybrid vehicle means a vehicle that includes energy
                storage features (other than a conventional battery system or
                conventional flywheel) in addition to an internal combustion engine or
                other engine using consumable chemical fuel. Supplemental electrical
                batteries and hydraulic accumulators are examples of hybrid energy
                storage systems. Note that certain provisions in this part treat hybrid
                vehicles that include regenerative braking different than those that do
                not include regenerative braking.
                 Hybrid engine means a hybrid system with features for storing and
                recovering energy that are integral to the engine or are otherwise
                upstream of the vehicle's transmission other than a conventional
                battery system or conventional flywheel. Supplemental electrical
                batteries and hydraulic accumulators are examples of hybrid energy
                storage systems. Examples of hybrids that could be considered hybrid
                engines are P0, P1, and P2 hybrids where hybrid features are connected
                to the front end of the engine, at the crankshaft, or connected between
                the clutch and the transmission where the clutch upstream of the hybrid
                feature is in addition to the transmission clutch(s), respectively.
                Note other examples of systems that qualify as hybrid engines are
                systems that recover kinetic energy and use it to power an electric
                heater in the aftertreatment. (See 40 CFR 1036.801).
                 Hybrid powertrain means a powertrain that includes energy storage
                features other than a conventional battery system or conventional
                flywheel. Supplemental electrical batteries and hydraulic accumulators
                are examples of hybrid energy storage systems. Note
                [[Page 18822]]
                other examples of systems that qualify as hybrid powertrains are
                systems that recover kinetic energy and use it to power an electric
                heater in the aftertreatment. (See 40 CFR 1037.801).
                 Idle operation has the meaning given in 40 CFR 1037.801.
                 Incomplete vehicle has the meaning given in 49 CFR part 523. For
                the purpose of this regulation, a manufacturer may request EPA and
                NHTSA to allow the certification of a vehicle as an incomplete vehicle
                if it manufactures the engine and sells the unassembled chassis
                components, provided it does not produce and sell the body components
                necessary to complete the vehicle.
                 Innovative technology means technology certified under Sec. 535.7
                and by EPA under 40 CFR 86.1819-14(d)(13), 1036.610, and 1037.610 in
                the Phase 1 program.
                 Intermediate manufacturer has the meaning given in 49 CFR 567.3.
                 Light heavy-duty (LHD) vehicle has the meaning given in vehicle
                service class.
                 Liquefied petroleum gas (LPG) has the meaning given in 40 CFR
                1036.801.
                 Low rolling resistance tire means a tire on a vocational vehicle
                with a tire rolling resistance level (TRRL) of 7.7 kg/metric ton or
                lower, a steer tire on a tractor with a TRRL of 7.7 kg/metric ton or
                lower, or a drive tire on a tractor with a TRRL of 8.1 kg/metric ton or
                lower.
                 Manual transmission (MT) has the meaning given in 40 CFR 1037.801.
                 Medium heavy-duty (MHD) vehicle has the meaning given in vehicle
                service class.
                 Model type has the meaning given in 40 CFR 600.002.
                 Model year means one of the following for compliance with this
                part. Note that manufacturers may have other model year designations
                for the same vehicle for compliance with other requirements or for
                other purposes:
                 (1) For tractors and vocational vehicles with a date of manufacture
                on or after January 1, 2021, the vehicle's model year is the calendar
                year corresponding to the date of manufacture; however, the vehicle's
                model year may be designated to be the year before the calendar year
                corresponding to the date of manufacture if the engine's model year is
                also from an earlier year. Note that paragraph (2) of this definition
                limits the extent to which vehicle manufacturers may install engines
                built in earlier calendar years. Note that 40 CFR 1037.601(a)(2) limits
                the extent to which vehicle manufacturers may install engines built in
                earlier calendar years.
                 (2) For Phase 1 tractors and vocational vehicles with a date of
                manufacture before January 1, 2021, model year means the manufacturer's
                annual new model production period, except as restricted under this
                definition. It must include January 1 of the calendar year for which
                the model year is named, may not begin before January 2 of the previous
                calendar year, and it must end by December 31 of the named calendar
                year. The model year may be set to match the calendar year
                corresponding to the date of manufacture.
                 (i) The manufacturer who holds the certificate of conformity for
                the vehicle must assign the model year based on the date when its
                manufacturing operations are completed relative to its annual model
                year period. In unusual circumstances where completion of your assembly
                is delayed, we may allow you to assign a model year one year earlier,
                provided it does not affect which regulatory requirements will apply.
                 (ii) Unless a vehicle is being shipped to a secondary manufacturer
                that will hold the certificate of conformity, the model year must be
                assigned prior to introduction of the vehicle into U.S. commerce. The
                certifying manufacturer must re-designate the model year if it does not
                complete its manufacturing operations within the originally identified
                model year. A vehicle introduced into U.S. commerce without a model
                year is deemed to have a model year equal to the calendar year of its
                introduction into U.S. commerce unless the certifying manufacturer
                assigns a later date.
                 (3) For engines, model year means the manufacturer's annual new
                model production period, except as restricted under this definition. It
                must include January 1 of the calendar year for which the model year is
                named, may not begin before January 2 of the previous calendar year,
                and it must end by December 31 of the named calendar year.
                Manufacturers may not adjust model years to circumvent or delay
                compliance with emission standards or to avoid the obligation to
                certify annually.
                 Motor Vehicle has the meaning given in 49 CFR 523.2.
                 Multi-purpose means relating to the Multi-Purpose duty cycle as
                specified in 40 CFR 1037.510. (See 40 CFR 1037.801).
                 Natural gas has the meaning given in 40 CFR 1036.801. Vehicles that
                use a pilot-ignited natural gas engine (which uses a small diesel fuel
                ignition system), are still considered natural gas vehicles.
                 NHTSA Enforcement means the NHTSA Associate Administrator for
                Enforcement, or his or her designee.
                 Neutral coasting has the meaning given in 40 CFR 1037.801.
                 Neutral idle means a vehicle technology that automatically puts the
                transmission in neutral when the vehicle is stopped, as described in 40
                CFR 1037.660(a). (See 40 CFR 1037.801).
                 Off-cycle technology means technology certified under Sec. 535.7
                and by EPA under 40 CFR 86.1819-14(d)(13), 1036.610, and 1037.610 in
                the Phase 2 program.
                 Party means the person alleged to have committed a violation of
                Sec. 535.9, and includes manufacturers of vehicles and manufacturers
                of engines.
                 Payload means in this part the resultant of subtracting the curb
                weight from the gross vehicle weight rating.
                 Percent (%) means a representation of exactly 0.01. Numbers
                expressed as percentages in this part (such as a tolerance of 2%) have infinite precision, so 2% and 2.000000000% have the same
                meaning. This means that where we specify some percentage of a total
                value, the calculated value has the same number of significant digits
                as the total value. For example, 2% of a span value where the span
                value is 101.3302 is 2.026604. (See 40 CFR 1037.801 and 40 CFR
                1065.1001.
                 Petroleum has the meaning given in 40 CFR 1037.801.
                 Phase 1 means the joint NHTSA and EPA program established in 2011
                for fuel efficiency standards and greenhouse gas emissions standards
                regulating medium- and heavy-duty engines and vehicles. See Sec. 535.5
                for the specific model years that standards apply to vehicles and
                engines.
                 Phase 2 means the joint NHTSA and EPA program established in 2016
                for fuel efficiency standards and greenhouse gas emissions standards
                regulating medium- and heavy-duty vehicles and engines. See Sec. 535.5
                for the specific model years that standards apply to vehicles and
                engines.
                 Pickup truck has the meaning given in 49 CFR part 523.
                 Placed into service means put into initial use for its intended
                purpose, excluding incidental use by the manufacturer or a dealer. (See
                40 CFR 1037.801).
                 Plug-in hybrid electric vehicle (PHEV) means a hybrid electric
                vehicle that has the capability to charge the battery or batteries used
                for vehicle propulsion from an off-vehicle electric source, such that
                the off-vehicle source cannot be connected to the vehicle while the
                vehicle is in motion.
                [[Page 18823]]
                 Power take-off (PTO) means a secondary engine shaft or other system
                on a vehicle that provides substantial auxiliary power for purposes
                unrelated to vehicle propulsion or normal vehicle accessories such as
                air conditioning, power steering, and basic electrical accessories. A
                typical PTO uses a secondary shaft on the engine to transmit power to a
                hydraulic pump that powers auxiliary equipment such as a boom on a
                bucket truck.
                 Powertrain family has the meaning given in 40 CFR 1037.231.
                Manufacturers choosing to perform powertrain testing as specified in 40
                CFR 1037.550, divide product lines into powertrain families that are
                expected to have similar fuel consumptions and CO2 emission
                characteristics throughout the useful life.
                 Preliminary approval means approval granted by an authorized EPA
                representative prior to submission of an application for certification,
                consistent with the provisions of 40 CFR 1037.210. For requirements
                involving NHTSA, EPA will ensure decisions are jointly made and will
                convey the decision to the manufacturer.
                 Primary intended service class has the same meaning for engines as
                specified in 40 CFR 1036.140. Manufacturers must identify a single
                primary intended service class for each engine family that best
                describes vehicles for which it designs and markets the engine, as
                follows:
                 (1) Divide compression-ignition engines into primary intended
                service classes based on the following engine and vehicle
                characteristics:
                 (i) Light heavy-duty ``LHD'' engines usually are not designed for
                rebuild and do not have cylinder liners. Vehicle body types in this
                group might include any heavy-duty vehicle built from a light-duty
                truck chassis, van trucks, multi-stop vans, and some straight trucks
                with a single rear axle. Typical applications will include personal
                transportation, light-load commercial delivery, passenger service,
                agriculture, and construction. The GVWR of these vehicles is normally
                below 19,500 pounds.
                 (ii) Medium heavy-duty ``MHD'' engines may be designed for rebuild
                and may have cylinder liners. Vehicle body types in this group will
                typically include school buses, straight trucks with single rear axles,
                city tractors, and a variety of special purpose vehicles such as small
                dump trucks, and refuse trucks. Typical applications will include
                commercial short haul and intra-city delivery and pickup. Engines in
                this group are normally used in vehicles whose GVWR ranges from 19,500
                to 33,000 pounds.
                 (iii) Heavy heavy-duty ``HHD'' engines are designed for multiple
                rebuilds and have cylinder liners. Vehicles in this group are normally
                tractors, trucks, straight trucks with dual rear axles, and buses used
                in inter-city, long-haul applications. These vehicles normally exceed
                33,000 pounds GVWR.
                 (2) Divide spark-ignition engines into primary intended service
                classes as follows:
                 (i) Spark-ignition engines that are best characterized by paragraph
                (1)(i) or (ii) of this section are in a separate ``spark-ignition''
                primary intended service class.
                 (ii) Spark-ignition engines that are best characterized by
                paragraph (1)(iii) of this section share a primary intended service
                class with compression-ignition heavy heavy-duty engines. Gasoline-
                fueled engines are presumed not to be characterized by paragraph
                (1)(iii) of this section; for example, vehicle manufacturers may
                install some number of gasoline-fueled engines in Class 8 trucks
                without causing the engine manufacturer to consider those to be heavy
                heavy-duty engines.
                 (iii) References to ``spark-ignition standards'' in this part
                relate only to the spark-ignition engines identified in paragraph
                (2)(i) of this definition. References to ``compression-ignition
                standards'' in this part relate to compression-ignition engines, to
                spark-ignition engines optionally certified to standards that apply to
                compression-ignition engines, and to all engines identified under
                paragraph (2)(ii) of this definition as heavy heavy-duty engines.
                 Rechargeable Energy Storage System (RESS) means the component(s) of
                a hybrid engine or vehicle that store recovered energy for later use,
                such as the battery system in an electric hybrid vehicle.
                 Refuse hauler has the meaning given in 40 CFR 1037.801.
                 Regional has the meaning relating to the Regional duty cycle as
                specified in 40 CFR 1037.510.
                 Regulatory category means each of the four types of heavy-duty
                vehicles defined in 49 CFR 523.6 and the heavy-duty engines used in
                these heavy-duty vehicles.
                 Regulatory subcategory means the sub-groups in each regulatory
                category to which mandatory fuel consumption standards and requirements
                apply as specified in 40 CFR 1036.230 and 1037.230 and are defined as
                follows:
                 (1) Heavy-duty pick-up trucks and vans.
                 (2) Vocational vehicle subcategories have 18 separate vehicle
                service classes as shown in paragraphs (2)(i) and (ii) of this
                definition and include vocational tractors. Paragraph (2)(i) of this
                definition includes vehicles complying with Phase 1 standards. Phase 2
                vehicles are included in paragraph (2)(ii) of this definition which
                have separate subcategories to account for engine characteristics,
                GVWR, and the selection of duty cycle for vocational vehicles as
                specified in 40 CFR 1037.510; vehicles may additionally fall into one
                of the subcategories defined by the custom-chassis standards in Sec.
                535.5(b)(6) and 40 CFR 1037.105(h). Manufacturers using the alternate
                standards in Sec. 535.5(b)(6) and 40 CFR 1037.105(h) should treat each
                vehicle type as a separate vehicle subcategory.
                 (i) Phase 1 Vocational Vehicle Subcategories. (A) Vocational LHD
                vehicles.
                 (B) Vocational MHD vehicles.
                 (C) Vocational HHD vehicles.
                 (ii) Phase 2 vocational vehicle subcategories.
                ----------------------------------------------------------------------------------------------------------------
                 Engine type Vocational LHD vehicles Vocational MHD vehicles Vocational HHD vehicles
                ----------------------------------------------------------------------------------------------------------------
                CI................................... Urban.................. Urban.................. Urban.
                CI................................... Multi-Purpose.......... Multi-Purpose.......... Multi-Purpose.
                CI................................... Regional............... Regional............... Regional.
                SI................................... Urban.................. Urban.................. N/A.
                SI................................... Multi-Purpose.......... Multi-Purpose.......... N/A.
                SI................................... Regional............... Regional............... N/A.
                ----------------------------------------------------------------------------------------------------------------
                 (3) Tractor subcategories are shown in paragraph (3)(i) of this
                definition for Phase 1 and 2. Paragraph (3)(i) includes 10 separate
                subcategories for tractors complying with Phase 1 and 2 standards. The
                heavy-haul tractor subcategory only applies for Phase 2.
                [[Page 18824]]
                 (i) Phase 1 and 2 truck tractor subcategories.
                ------------------------------------------------------------------------
                 Class 8 sleeper
                 Class 7 Class 8 day cabs cabs
                ------------------------------------------------------------------------
                Low-roof tractors............... Low-roof day cab Low-roof sleeper
                 tractors. cab tractors.
                Mid-roof tractors............... Mid-roof day cab Mid-roof sleeper
                 tractors. cab tractors.
                High-roof tractors.............. High-roof day cab High-roof sleeper
                 Tractors. cab tractors.
                 ---------------------------------------
                N/A............................. Heavy-haul tractors (applies only to
                 Phase 2 program).
                ------------------------------------------------------------------------
                 (ii) [Reserved]
                 (4) [Reserved]
                 (5) Engine subcategories are shown for each primary intended
                service class in paragraph (5)(i) of this definition. Paragraph (5)(i)
                includes 6 separate subcategories for engines which are the same for
                Phase 1 and 2 standards.
                 (i) Engine subcategories.
                ------------------------------------------------------------------------
                 LHD engines MHD engines HHD engines
                ------------------------------------------------------------------------
                CI engines for vocational CI engines for CI engines for
                 vehicles. vocational vocational
                 vehicles. vehicles.
                N/A............................. CI engines for CI engines for
                 truck Tractors. truck tractors.
                -----------------------------------------------------
                All spark-ignition engines.......................... N/A.
                ------------------------------------------------------------------------
                 (ii) [Reserved]
                 Relating to as used in this section means relating to something in
                a specific, direct manner. This expression is used in this section only
                to define terms as adjectives and not to broaden the meaning of the
                terms. (See 40 CFR 1037.801).
                 Revoke has the same meaning given in 40 CFR 1068.30.
                 Roof height means the maximum height of a vehicle (rounded to the
                nearest inch), excluding narrow accessories such as exhaust pipes and
                antennas, but including any wide accessories such as roof fairings.
                Measure roof height of the vehicle configured to have its maximum
                height that will occur during actual use, with properly inflated tires
                and no driver, passengers, or cargo onboard. Determine the base roof
                height on fully inflated tires having a static loaded radius equal to
                the arithmetic mean of the largest and smallest static loaded radius of
                tires a manufacturer offers or a standard tire EPA approves. If a
                vehicle is equipped with an adjustable roof fairing, measure the roof
                height with the fairing in its lowest setting. Once the maximum height
                is determined, roof heights are divided into the following categories:
                 (1) Low-roof means a vehicle with a roof height of 120 inches or
                less.
                 (2) Mid-roof means a vehicle with a roof height between 121 and 147
                inches.
                 (3) High-roof means a vehicle with a roof height of 148 inches or
                more.
                 Round means to apply the rounding convention specified in 40 CFR
                1065.20(e), unless otherwise specified. (See 40 CFR 1065.1001).
                 Secondary vehicle manufacturer has the same meaning as final-stage
                manufacturer in 49 CFR part 567.
                 Service class group means a group of engine and vehicle averaging
                sets defined as follows:
                 (1) Spark-ignition engines, light heavy-duty compression-ignition
                engines, light heavy-duty vocational vehicles and heavy-duty pickup
                trucks and vans.
                 (2) Medium heavy-duty compression-ignition engines and medium
                heavy-duty vocational vehicles and tractors.
                 (3) Heavy heavy-duty compression-ignition engines and heavy heavy-
                duty vocational vehicles and tractors.
                 Sleeper cab means a type of truck cab that has a compartment behind
                the driver's seat intended to be used by the driver for sleeping. This
                includes both cabs accessible from the driver's compartment and those
                accessible from outside the vehicle.
                 Small business manufacturer means a manufacturer meeting the
                criteria specified in 13 CFR 121.201. For manufacturers owned by a
                parent company, the employee and revenue limits apply to the total
                number employees and total revenue of the parent company and all its
                subsidiaries.
                 Spark-ignition (SI) means relating to a gasoline-fueled engine or
                any other type of engine with a spark plug (or other sparking device)
                and with operating characteristics significantly similar to the
                theoretical Otto combustion cycle. Spark-ignition engines usually use a
                throttle to regulate intake air flow to control power during normal
                operation. Note that some spark-ignition engines are subject to
                requirements that apply for compression-ignition engines as described
                in 40 CFR 1036.140.
                 Standard payload means the payload assumed for each vehicle, in
                tons, for modeling and calculating emission credits, as follows:
                 (1) For vocational vehicles:
                 (i) 2.85 tons for light heavy-duty vehicles.
                 (ii) 5.6 tons for medium heavy-duty vehicles.
                 (iii) 7.5 tons for heavy heavy-duty vocational vehicles.
                 (2) For tractors:
                 (i) 12.5 tons for Class 7.
                 (ii) 19 tons for Class 8.
                 (iii) 43 tons for heavy-haul tractors.
                 Standard trailer means a trailer that meets the applicable criteria
                found in 40 CFR 1037.501(g). (See 40 CFR 1037.801).
                 Stop-start means a vehicle technology that automatically turns the
                engine off when the vehicle is stopped, as described in 40 CFR
                1037.660(a). (See the definition for stop-start in 40 CFR 1037.801)
                 Subconfiguration means a unique combination within a vehicle
                configuration of equivalent test weight, road-load horsepower, and any
                other operational characteristics or parameters that EPA determines may
                significantly affect CO2 emissions within a vehicle
                configuration as defined in 40 CFR 600.002.
                 Tank trailer has the meaning given in 40 CFR 1037.801.
                 Test group means the multiple vehicle lines and model types that
                share critical emissions and fuel consumption related features and that
                are certified as a group by a common certificate of conformity issued
                by EPA and is used collectively with other test groups within an
                averaging set or regulatory subcategory and is used by NHTSA for
                determining the fleet average fuel consumption.
                [[Page 18825]]
                 The agencies means the National Highway Traffic Safety
                Administration (NHTSA) and the Environmental Protection Agency (EPA) in
                this part.
                 Tire pressure monitoring system (TPMS) has the meaning given in
                section S3 of 49 CFR 571.138.
                 Tire rolling resistance level (TRRL) means a value with units of
                kg/metric ton that represents that rolling resistance of a tire
                configuration. TRRLs are used as inputs to the GEM model under 40 CFR
                1037.520. Note that a manufacturer may assign a value higher than a
                measured rolling resistance of a tire configuration.
                 Towing capacity in this part is equal to the resultant of
                subtracting the gross vehicle weight rating from the gross combined
                weight rating.
                 Trade means to exchange fuel consumption credits, either as a buyer
                or a seller.
                 U.S.-directed production volume means the number of vehicle units,
                subject to the requirements of this part, produced by a manufacturer
                for which the manufacturer has a reasonable assurance that sale was or
                will be made to ultimate purchasers in the United States.
                 Useful life has the meaning given in 40 CFR 1036.801 and 1037.801.
                 Vehicle configuration means a unique combination of vehicle
                hardware and calibration (related to measured or modeled emissions)
                within a vehicle family as specified in 40 CFR 1037.801. Vehicles with
                hardware or software differences, but that have no hardware or software
                differences related to measured or modeled emissions or fuel
                consumption can be included in the same vehicle configuration. Note
                that vehicles with hardware or software differences related to measured
                or modeled emissions or fuel consumption are considered to be different
                configurations even if they have the same GEM inputs and FEL. Vehicles
                within a vehicle configuration differ only with respect to normal
                production variability or factors unrelated to measured or modeled
                emissions and fuel consumption for EPA and NHTSA.
                 Vehicle family has the meaning given in 40 CFR 1037.230.
                Manufacturers designate families in accordance with EPA provisions and
                may not choose different families between the NHTSA and EPA programs.
                If a manufacturer is certifying vehicles within a vehicle family to
                more than one FEL, it must subdivide its greenhouse gas and fuel
                consumption vehicle families into subfamilies that include vehicles
                with identical FELs. Note that a manufacturer may add subfamilies at
                any time during the model year.
                 Vehicle identification number has the meaning given in 49 CFR
                565.12 for VIN.
                 Vehicle service class means classes of vehicles, generally based on
                a vehicle's weight class, that are used for purposes of determining
                applicable requirements. The vehicle service classes defined here for
                use in this part align with the vehicle service classes specified in 40
                CFR 1037.140(g). Fuel consumption standards and other provisions of
                this part apply to specific vehicle service classes for tractors and
                vocational vehicles as follows:
                 (1) Phase 1 and Phase 2 tractors are divided based on GVWR into
                Class 7 tractors and Class 8 tractors. Where provisions apply to both
                tractors and vocational vehicles, Class 7 tractors are considered
                medium heavy-duty ``MHD'' vehicles and Class 8 tractors are considered
                heavy heavy-duty ``HHD'' vehicles. This paragraph applies for both
                hybrid and non-hybrid vehicles.
                 (2) Phase 1 vocational vehicles are divided based on GVWR. Light
                heavy-duty ``LHD'' vehicles includes Class 2b through Class 5 vehicles;
                medium heavy-duty ``MHD'' vehicles includes Class 6 and Class 7
                vehicles; and heavy heavy-duty ``HHD'' vehicles includes Class 8
                vehicles.
                 (3) Phase 2 vocational vehicles with spark-ignition engines are
                divided based on GVWR. Light heavy-duty ``LHD'' vehicles includes Class
                2b through Class 5 vehicles, and medium heavy-duty ``MHD'' vehicles
                includes Class 6 through Class 8 vehicles.
                 (4) Phase 2 vocational vehicles with compression-ignition engines
                are divided as follows:
                 (i) Class 2b through Class 5 vehicles are considered light heavy-
                duty ``LHD'' vehicles.
                 (ii) Class 6 through 8 vehicles are considered heavy heavy-duty
                ``HHD'' vehicles if the installed engine's primary intended service
                class is heavy heavy-duty (see 40 CFR 1036.140), except that Class 8
                hybrid vehicles are considered heavy heavy-duty ``HHD'' vehicles
                regardless of the engine's primary intended service class. All other
                Class 6 through Class 8 vehicles are considered medium heavy-duty
                ``MHD'' vehicles.
                 (5) Heavy-duty vehicles with no installed propulsion engine, such
                as electric vehicles, are divided as follows:
                 (i) Class 2b through Class 5 vehicles are considered light heavy-
                duty ``LHD'' vehicles.
                 (ii) Class 6 and 7 vehicles are considered medium heavy-duty
                ``MHD'' vehicles.
                 (iii) Class 8 vehicles are considered heavy heavy-duty ``HHD''
                vehicles.
                 (6) In certain circumstances, manufacturers may certify vehicles to
                standards that apply for a different vehicle service class such as
                allowed in Sec. 535.5(b)(6) and (c)(7). If manufacturers optionally
                certify vehicles to different standards, those vehicles are subject to
                all the regulatory requirements as if the standards were mandatory.
                 Vehicle subfamily or subfamily means a subset of a vehicle family
                including vehicles subject to the same FEL(s).
                 Vocational tractor has the meaning given in 40 CFR 1037.801.
                 Zero emissions vehicle means an electric vehicle or a fuel cell
                vehicle.
                0
                5. Amend Sec. 535.5 by:
                0
                a. Revising paragraphs (a) introductory text, (a)(1), and (b)
                introductory text;
                0
                b. Removing and reserving paragraph (b)(1)(iii)(B);
                0
                c. Revising paragraphs (b)(4), (b)(9)(i) introductory text, (c)
                introductory text, (c)(5), (d) introductory text, (d)(3), and
                (d)(11)(i)(A) and (C); and
                0
                d. Removing paragraph (e).
                 The revisions read as follows:
                Sec. 535.5 Standards.
                 (a) Heavy-duty pickup trucks and vans. Each manufacturer's fleet of
                heavy-duty pickup trucks and vans shall comply with the fuel
                consumption standards in this paragraph (a) expressed in gallons per
                100 miles. Each vehicle must be manufactured to comply for its full
                useful life. For the Phase 1 program, if the manufacturer's fleet
                includes conventional vehicles (gasoline, diesel and alternative fueled
                vehicles) and advanced technology vehicles (hybrids with powertrain
                designs that include energy storage systems, vehicles with waste heat
                recovery, electric vehicles and fuel cell vehicles), it may divide its
                fleet into two separate fleets each with its own separate fleet average
                fuel consumption standard which the manufacturer must comply with the
                requirements of this paragraph (a). For Phase 2, manufacturers may
                calculate their fleet average fuel consumption standard for a
                conventional fleet and multiple advanced technology vehicle fleets.
                Advanced technology vehicle fleets should be separated into plug-in
                hybrid electric vehicles, electric vehicles, and fuel cell vehicles.
                The standards in this paragraph (a) correspond to EPA requirements
                specified in 40 CFR 86.1819-14. When applying the fuel consumption
                standards in this paragraph (a), manufacturers must use the same
                options they use to comply with EPA in 40 CFR part 86, subpart S in
                terms of grouping vehicles and/or engines for purposes of determining
                [[Page 18826]]
                applicable standards and determining compliance (i.e., the vehicles
                and/or engines and must be grouped in the same way for purposes of this
                paragraph (a) as they are grouped for compliance with EPA's
                requirements in 40 CFR part 86, subpart S). Engines that are installed
                in vehicles that are subject to the standards in this paragraph are not
                subject to the standards in paragraph (d) of this section and may not
                optionally comply with paragraph (d).
                 (1) Mandatory standards. For model years 2016 and later, each
                manufacturer must comply with the fleet average standard derived from
                the unique subconfiguration target standards (or groups of
                subconfigurations approved by EPA in accordance with 40 CFR 86.1819-14)
                of the model types that make up the manufacturer's fleet in a given
                model year. Each subconfiguration has a unique attribute-based target
                standard, defined by each group of vehicles having the same payload,
                towing capacity and whether the vehicles are equipped with a 2-wheel or
                4-wheel drive configuration. Phase 1 target standards apply for model
                years 2016 through 2020. Phase 2 target standards apply for model year
                2021 and afterwards.
                * * * * *
                 (b) Heavy-duty vocational vehicles. Each manufacturer building
                complete or incomplete heavy-duty vocational vehicles shall comply with
                the fuel consumption standards in this paragraph (b) expressed in
                gallons per 1,000 ton-miles. When applying the fuel consumption
                standards in this paragraph (b), manufacturers must use the same
                options they use to comply with EPA in 40 CFR 1037.105 in terms of
                grouping vehicles and/or engines for purposes of determining applicable
                standards and determining compliance (i.e., the vehicles and/or engines
                and must be grouped in the same way for purposes of this paragraph (b)
                as they are grouped for compliance with EPA's requirements in 40 CFR
                1037.105). Engines used in heavy-duty vocational vehicles shall comply
                with the standards in paragraph (d) of this section. Each vehicle must
                be manufactured to comply for its full useful life. Standards apply to
                the vehicle subfamilies based upon the vehicle service classes within
                each of the vocational vehicle regulatory subcategories in accordance
                with Sec. 535.4 and based upon the applicable modeling and testing
                specified in Sec. 535.6. Determine the duty cycles that apply to
                vocational vehicles according to 40 CFR 1037.140 and 1037.150(z).
                * * * * *
                 (4) Regulatory subcategory standards for model years 2021 and
                later. The mandatory fuel consumption standards for heavy-duty
                vocational vehicles are given in the following table:
                 Table 9 to Paragraph (b)(4)--Phase 2 Vocational Vehicle Fuel Consumption Standards
                 [Gallons per 1,000 ton-miles]
                ----------------------------------------------------------------------------------------------------------------
                
                ----------------------------------------------------------------------------------------------------------------
                 Model Years 2021 through 2023 Standards for CI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle LHD vocational MHD vocational Vocational HHD
                 vehicles vehicles vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 41.6503 29.0766 30.2554
                Multi-Purpose...................................... 36.6405 26.0314 25.6385
                Regional........................................... 30.5501 22.9862 20.1375
                ----------------------------------------------------------------------------------------------------------------
                 Model Years 2021 through 2023 Standards for SI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle LHD vocational MHD and HHD N/A
                 vehicles vocational vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 51.8735 36.9078 N/A
                Multi-Purpose...................................... 45.7972 32.9695 N/A
                Regional........................................... 37.6955 29.3687 N/A
                ----------------------------------------------------------------------------------------------------------------
                 Model Years 2024 through 2026 Standards for CI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle Vocational LHD Vocational MHD Vocational HHD
                 vehicles vehicles vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 37.8193 26.6208 27.7996
                Multi-Purpose...................................... 33.7917 24.1650 23.7721
                Regional........................................... 29.0766 21.7092 19.0570
                ----------------------------------------------------------------------------------------------------------------
                 Model Years 2024 through 2026 Standards for SI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle Vocational LHD Vocational MHD and N/A
                 vehicles HHD vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 48.6103 34.8824 N/A
                Multi-Purpose...................................... 43.3217 31.3942 N/A
                Regional........................................... 36.4577 28.2435 N/A
                ----------------------------------------------------------------------------------------------------------------
                 Model Years 2027 and later Standards for CI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle Vocational LHD Vocational MHD Vocational HHD
                 vehicles vehicles vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 36.0511 25.3438 26.4244
                Multi-Purpose...................................... 32.4165 23.0845 22.5933
                Regional........................................... 28.5855 21.4145 18.5658
                ----------------------------------------------------------------------------------------------------------------
                [[Page 18827]]
                
                 Model Years 2027 and later Standards for SI Vehicles
                ----------------------------------------------------------------------------------------------------------------
                Duty cycle Vocational LHD Vocational MHD and N/A
                 vehicles HHD vehicles
                ----------------------------------------------------------------------------------------------------------------
                Urban.............................................. 46.4724 33.4196 N/A
                Multi-Purpose...................................... 41.8589 30.1564 N/A
                Regional........................................... 35.8951 27.7934 N/A
                ----------------------------------------------------------------------------------------------------------------
                * * * * *
                 (9) * * *
                 (i) Qualifying criteria. Vocational vehicles with a date of
                manufacture before January 1, 2021 automatically qualify for an
                exemption under this paragraph (b)(9) if the tires installed on the
                vehicle have a maximum speed rating at or below 55 miles per hour.
                Vocational vehicles intended for off-road use are exempt without
                request, subject to the provisions of this section, if they are
                primarily designed to perform work off-road (such as in oil fields,
                mining, forests, or construction sites), and they meet at least one of
                the criteria of paragraph (b)(9)(i)(A) of this section and at least one
                of the criteria of paragraph (b)(9)(i)(B) of this section. See
                paragraph (b)(6) of this section for alternate standards that apply for
                vehicles meeting only one of these sets of criteria.
                * * * * *
                 (c) Truck tractors. Each manufacturer building truck tractors,
                except vocational tractors or vehicle constructed in accordance with 49
                CFR 571.7(e), with a GVWR above 26,000 pounds shall comply with the
                fuel consumption standards in this paragraph (c) expressed in gallons
                per 1,000 ton-miles. When applying the fuel consumption standards in
                this paragraph (c), manufacturers must use the same options they use to
                comply with EPA in 40 CFR 1037.106 in terms of grouping vehicles and/or
                engines for purposes of determining applicable standards and
                determining compliance (i.e., the vehicles and/or engines and must be
                grouped in the same way for purposes of this paragraph (c) as they are
                grouped for compliance with EPA's requirements in 40 CFR 1037.106).
                Engines used in heavy-duty truck tractors vehicles shall comply with
                the standards in paragraph (d) of this section. Each vehicle must be
                manufactured to comply for its full useful life. Standards apply to the
                vehicle subfamilies within each of the tractor vehicle regulatory
                subcategories in accordance with Sec. 535.4 and 40 CFR 1037.230 and
                based upon the applicable modeling and testing specified in Sec.
                535.6. Determine the vehicles in each regulatory subcategory in
                accordance with 40 CFR 1037.140.
                * * * * *
                 (5) Alternate standards for tractors at or above 120,000 pounds
                GCWR. Manufacturers may certify tractors at or above 120,000 pounds
                GCWR to the following fuel consumption standards in the following
                table:
                 Table 12 to Paragraph (c)(5)--Alternate Fuel Consumption Standards for Tractors Above 120,000 Pounds GCWR for
                 2021 MY and Later
                 [Gallons per 1,000 ton-miles]
                ----------------------------------------------------------------------------------------------------------------
                 Model years 2021 Model years 2024 Model years 2027
                 Regulatory subcategory through 2023 through 2026 and later
                ----------------------------------------------------------------------------------------------------------------
                Heavy Class 8 Low-Roof Day Cab...................... 5.25540 4.99018 4.80354
                Heavy Class 8 Low-Roof Sleeper Cab.................. 4.62672 4.37132 4.16503
                Heavy Class 8 Mid-Roof Day Cab...................... 5.46169 5.18664 4.99018
                Heavy Class 8 Mid-Roof Sleeper Cab.................. 4.87230 4.60707 4.39096
                Heavy Class 8 High-Roof Day Cab..................... 5.35363 5.04912 4.77407
                Heavy Class 8 High-Roof Sleeper Cab................. 4.62672 4.34185 4.02750
                ----------------------------------------------------------------------------------------------------------------
                * * * * *
                 (d) Heavy-duty engines. Each manufacturer of heavy-duty engines
                shall comply with the fuel consumption standards in this paragraph (d)
                of this section expressed in gallons per 100 horsepower-hour. When
                applying the fuel consumption standards in this paragraph (d),
                manufacturers must use the same options they use to comply with EPA in
                40 CFR 1036.108 in terms of grouping engines for purposes of
                determining applicable standards and determining compliance (i.e., the
                engines must be grouped in the same way for part 535.5(d) purposes as
                they are grouped for compliance with EPA's requirements in 40 CFR
                1036.108). Each engine must be manufactured to comply for its full
                useful life, expressed in service miles, operating hours, or calendar
                years, whatever comes first. The provisions of this part apply to all
                new 2014 model year and later heavy-duty engines fueled by conventional
                and alternative fuels and manufactured for use in heavy-duty tractors
                or vocational vehicles. Standards apply to the engine and powertrain
                families and sub-families based upon the primary intended service
                classes within each of the engine regulatory subcategories as described
                in Sec. 535.4 and based upon the applicable modeling and testing
                specified in Sec. 535.6.
                * * * * *
                 (3) Regulatory subcategory standards. The primary fuel consumption
                standards for heavy-duty engine families are given in the following
                table:
                [[Page 18828]]
                 Table 13 to Paragraph (d)(3)--Primary Heavy-Duty Engine Fuel Consumption Standards
                 [Gallons per 100 hp-hr]
                ----------------------------------------------------------------------------------------------------------------
                 Phase 1--Voluntary Standards
                -----------------------------------------------------------------------------------------------------------------
                 Regulatory subcategory CI LHD engines CI MHD engines and all HHD CI engines and all SI engines
                ------------------------------- and all other other engines other engines ---------------
                 engines ------------------------------------------------
                 Application ------------------ All
                 Vocational Vocational Tractor Vocational Tractor
                ----------------------------------------------------------------------------------------------------------------
                2015.......................... ................ ........... ......... ........... ......... 7.0552
                2013 through 2016............. 5.8939 5.8939 4.9312 5.5697 4.666 ..............
                ----------------------------------------------------------------------------------------------------------------
                
                 Phase 1--Mandatory Standards
                -----------------------------------------------------------------------------------------------------------------
                 Regulatory subcategory CI LHD engines CI MHD engines and all CI HHD engines and all SI engines
                ------------------------------- and all other other engines other engines ---------------
                 engines ------------------------------------------------
                 Application ------------------ All
                 Vocational Vocational Tractor Vocational Tractor
                ----------------------------------------------------------------------------------------------------------------
                2016.......................... ................ ........... ......... ........... ......... 7.0552
                2017 through 2020............. 5.6582 5.6582 4.7839 5.4519 4.5187 7.0552
                ----------------------------------------------------------------------------------------------------------------
                
                 Phase 2--Mandatory Standards
                -----------------------------------------------------------------------------------------------------------------
                 Regulatory subcategory CI LHD engines CI MHD engines and all CI HHD engines and all SI engines
                ------------------------------- and all other other engines other engines (except HHD
                 engines ------------------------------------------------ engines)
                 Application ------------------ ---------------
                 Vocational Vocational Tractor Vocational Tractor All
                ----------------------------------------------------------------------------------------------------------------
                2021 through 2023............. 5.5305 5.3536 4.6464 5.0393 4.3910 7.0552
                2024 through 2026............. 5.4519 5.2849 4.5285 4.9705 4.2829 7.0552
                2027 and Later................ 5.4224 5.2554 4.4892 4.9411 4.2436 7.0552
                ----------------------------------------------------------------------------------------------------------------
                * * * * *
                 (11) * * *
                 (i) * * *
                 (A) 5.3241 gallons per 100 hp-hr for MHD vocational vehicle
                engines.
                * * * * *
                 (C) 5.0098 gallons per 100 hp-hr for HHD vocational vehicle
                engines.
                * * * * *
                0
                6. Amend Sec. 535.6 by:
                0
                a. Revising paragraphs (b)(1), (b)(4)(ii), and (b)(5)(i);
                0
                b. Adding paragraphs (b)(5)(v)(E)(3) and (4)
                0
                c. Revising paragraphs (d) introductory text, (d)(1), (d)(2)
                introductory text, (d)(3) introductory text, and (d)(3)(ii)
                introductory text; and
                0
                d. Removing paragraph (e).
                 The revisions and additions read as follows:
                Sec. 535.6 Measurement and calculation procedures.
                * * * * *
                 (b) * * *
                 (1) Select vehicles and vehicle family configurations as specified
                in 40 CFR 1037.150 and 1037.230 for vehicles that make up each of the
                manufacturer's regulatory subcategories of vocational vehicles and
                tractors. For the Phase 2 program, select powertrain, axle and
                transmission families in accordance with 40 CFR 1037.231 and 1037.232.
                * * * * *
                 (4) * * *
                 (ii) Coefficient of aerodynamic drag (CdA) or drag area,
                as described in 40 CFR 1037.520(b), 1037.525, 1037.527, and 1037.528.
                Alternatively, manufacturers may use CdA values as specified
                in 40 CFR 1037.530, 1037.532, or 1037.534 if used for determining
                CO2 compliance for EPA. Manufacturers must use the same
                compliance approach for determining CdA values in GEM for
                the NHTSA and EPA programs.
                * * * * *
                 (5) * * *
                 (i) Engine characteristics. Enter information from the engine
                manufacturer to describe the installed engine and its operating
                parameters as described in 40 CFR 1036.503 and 1037.520(f).
                * * * * *
                 (v) * * *
                 (E) * * *
                 (3) Manufacturers may use values to characterize torque converters
                as inputs to GEM as specified in the procedure defined in 40 CFR
                1037.570.
                 (4) Vocational vehicle manufacturers may optionally use values for
                neutral coasting in GEM as specified in 40 CFR 1037.520
                * * * * *
                 (d) Heavy-duty engines. This section describes the method for
                determining equivalent fuel consumption family certification level
                (FCL) values for engine and powertrain families and subfamilies of
                heavy-duty truck tractors and vocational vehicles. The NHTSA heavy-duty
                engine fuel consumption FCLs are determined from the EPA FCLs tested in
                accordance with 40 CFR part 1036, subpart F. Each engine and powertrain
                family must use the same primary intended service class as designated
                for EPA in accordance with 40 CFR 1036.140.
                 (1) Manufacturers must select emission-data engines representing
                the tested configuration of each engine family specified in 40 CFR
                1036.501 for engines in heavy-duty truck tractors and vocational
                vehicles that make up each of the manufacturer's regulatory
                subcategories.
                 (2) Standards in Sec. 535.5(d) apply to the CO2 emissions rates
                for each emissions-data engine in an engine or powertrain family or
                sub-family subject to the procedures and equipment specified in 40 CFR
                part 1036, subpart F. Determine equivalent fuel consumptions rates
                using CO2 emissions rates in grams per hp-hr measured to at least one
                more decimal place than that of the applicable EPA standard in 40 CFR
                1036.108.
                * * * * *
                 (3) For medium HD and heavy HD engines certified as tractor and
                other long-haul engine families, use the CO2 emissions test results
                from the steady-state duty cycle, which is referred to as the
                Supplemental Emission Test (SET), as specified in 40 CFR 1036.510 for
                each model year; for medium HD and heavy HD engines certified as
                tractor and vocational engine families, use the CO2 test results from
                the transient duty
                [[Page 18829]]
                cycle, which is referred to as the Federal Test Procedure (FTP) duty
                cycle, as specified in 40 CFR 1036.512 for each model year; for all
                other engines (including those certifying to SI standards) use the CO2
                emissions test results from the appropriate duty cycle, as specified in
                40 CFR 1036.501 for each model year.
                * * * * *
                 (ii) The following engines are excluded from the engine and
                powertrain families and subfamilies used to determine fuel consumption
                FCL values and the benefit for these engines is determined as an
                advanced technology credit under the ABT provisions provided in Sec.
                535.7(e); these provisions apply only for the Phase 1 program:
                * * * * *
                0
                7. Amend Sec. 535.7 by:
                0
                a. Revising paragraphs (a) introductory text and (a)(2)(v);
                0
                b. Removing paragraph (a)(3)(v);
                0
                c. Revising paragraph (a)(4) introductory text;
                0
                d. Removing and reserving paragraph (a)(4)(v);
                0
                e. Revising paragraphs (a)(8)(i) and (a)(9)(iv)(B);
                0
                f. Adding paragraph (a)(11);
                0
                g. Revising paragraphs (b)(1), (c)(1) introductory text, (d)(1)
                introductory text, and (d)(7);
                0
                h. Removing and reserving paragraph (e);
                0
                i. Revising paragraph (f)(1)(ii) introductory text;
                0
                j. Adding paragraph (f)(1)(ii)(G); and
                0
                k. Removing and reserving paragraph (f)(2)(v).
                 The revisions and additions read as follows:
                Sec. 535.7 Averaging, banking, and trading (ABT) credit program.
                 (a) General provisions. After the end of each model year,
                manufacturers must comply with the fuel consumption standards in Sec.
                535.5 for averaging, banking and trading credits. Manufacturers comply
                with standards if the sum of averaged, banked and traded credits
                generate a ``zero'' credit balance or a credit surplus within an
                averaging set of vehicles or engines. Manufacturers fail to comply with
                standards if the sum of the credit flexibilities generate a credit
                deficit (or shortfall) in an averaging set. Credit shortfalls must be
                offset by banked or traded credits within three model years after the
                shortfall is incurred. These processes are hereafter referenced as the
                NHTSA ABT credit program. The following provisions apply to all fuel
                consumption credits.
                * * * * *
                 (2) * * *
                 (v) If a manufacturer certifies a vehicle family to an FEL that
                exceeds the otherwise applicable standard, it must obtain enough FCC to
                offset the vehicle family's deficit by the due date of its final report
                required in Sec. 535.8. The emission credits used to address the
                deficit may come from other vehicle families that generate FCCs in the
                same model year (or from the next three subsequent model years), from
                banked FCCs from previous model years, or from FCCs generated in the
                same or previous model years that it obtained through trading.
                * * * * *
                 (4) Trading. Trading is a transaction that transfers banked family
                regulatory subcategory or averaging set fuel consumption credits.
                Tractor, vocational vehicle and engine manufacturers may trade credits
                generated for vehicle or engine families or subfamilies while
                manufacturers of heavy-duty pickup trucks and vans certified as
                complete vehicles may trade credit credits generated for averaging
                sets. A manufacturer may use traded FCCs for averaging, banking, or
                further trading transactions.
                 (8) * * *
                 (i) Fuel consumption credits a manufacturer generates for light and
                medium heavy-duty vocational vehicles in model years 2018 through 2021
                may be used through model year 2027, instead of being limited to a
                five-year credit life as specified in this part. Fuel consumption
                credits that small manufacturers generate for heavy heavy-duty
                vocational vehicles in model years 2018 through may be used through
                model year 2027, instead of being limited to a five-year credit life as
                specified in this part. Fuel consumption credits that a small
                manufacturer generates for vocational vehicles in model year 2022 that
                are certified to Phase 1 standards as permitted under Sec.
                535.3(e)(2)(ii)(B) may be used through model year 2027.
                * * * * *
                 (9) * * *
                 (iv) * * *
                 (B) Manufacturers may produce up to 200 drayage tractors in a given
                model year to the standards described in Sec. 535.5(b)(6) for ``other
                buses''. Treat these drayage tractors as being in their own averaging
                set. This limit applies with respect to vehicles produced by
                manufacturers within a control relationship as defined Sec. 534.3.
                * * * * *
                 (11) Fuel consumption credits may not be generated more than once.
                This means that fuel consumption credits may only be generated once for
                a given engine or vehicle and fuel consumption credits may not be
                generated for both a given engine and the vehicle in which the engine
                is installed. For example, if a manufacturer generates fuel consumption
                credits for a given hybrid vehicle under this part, no one may generate
                fuel consumption credits for the associated hybrid engine. This
                provision, however, does not prevent manufacturers from generating fuel
                consumption credits for engines that are identical to the given engine
                in the example if those engines are installed in vehicles for which
                fuel consumption credits are not generated. This provision does not
                impact any adjustment factor or multiplier that is applied to the fuel
                consumption credits as specified or permitted by this part.
                 (b) * * *
                 (1) Calculate fuel consumption credits in a model year for one
                fleet of conventional heavy-duty pickup trucks and vans and if
                designated by the manufacturer another consisting of advance technology
                vehicles for the averaging set as defined in Sec. 535.4. Calculate
                credits for each fleet separately using the following equation:
                Total MY Fleet FCC (gallons) = (Std-Act) x (Volume) x (UL) x (10\2\)
                Where:
                Std = Fleet average fuel consumption standard (gal/100 mile).
                Act = Fleet average actual fuel consumption value (gal/100 mile).
                Volume = the total U.S.-directed production of vehicles in the
                regulatory subcategory.
                UL = the useful life for the regulatory subcategory. The useful life
                value for heavy- pickup trucks and vans manufactured for model years
                2013 through 2020 is equal to the 120,000 miles. The useful life for
                model years 2021 and later is equal to 150,000 miles.
                * * * * *
                 (c) * * *
                 (1) Calculate the fuel consumption credits in a model year for each
                participating family or subfamily consisting of conventional vehicles
                in each averaging set (as defined in Sec. 535.4) using the equation in
                this section. Each designated vehicle family or subfamily has a
                ``family emissions limit'' (FEL) that is compared to the associated
                regulatory subcategory standard. An FEL that falls below the regulatory
                subcategory standard creates ``positive credits,'' while fuel
                consumption level of a family group above the standard creates a
                ``negative credits.'' The value of credits generated for each family or
                subfamily in a model year is calculated as follows and must be rounded
                to nearest whole number:
                [[Page 18830]]
                Vehicle Family FCC (gallons) = (Std-FEL) x (Payload) x (Volume) x (UL)
                x (10\3\)
                Where:
                Std = the standard for the respective vehicle family regulatory
                subcategory (gal/1,000 ton-mile).
                FEL = family emissions limit for the vehicle family (gal/1,000 ton-
                mile).
                Payload = the prescribed payload in tons for each regulatory
                subcategory as shown in the following table:
                 Table 1 to Paragraph (c)(1) Introductory Text
                ------------------------------------------------------------------------
                 Payload
                 Regulatory subcategory (tons)
                ------------------------------------------------------------------------
                Vocational LHD Vehicles................................. 2.85
                Vocational MHD Vehicles................................. 5.60
                Vocational HHD Vehicles................................. 7.5
                MDH MHD Tractors........................................ 12.50
                HHD Tractors, other than heavy-haul Tractors............ 19.00
                Heavy-haul Tractors..................................... 43.00
                ------------------------------------------------------------------------
                Volume = the number of U.S.-directed production volume of vehicles
                in the corresponding vehicle family.
                UL = the useful life for the regulatory subcategory (miles) as shown
                in the following table:
                 Table 2 to Paragraph (c)(1) Introductory Text
                ------------------------------------------------------------------------
                 Regulatory subcategory UL (miles)
                ------------------------------------------------------------------------
                LHD Vehicles.................................... 110,000 (Phase
                 1);150,000 (Phase 2).
                Vocational MHD Vehicles and tractors at or below 185,000.
                 33,000 pounds GVWR.
                Vocational HHD Vehicles and tractors at or above 435,000.
                 33,000 pounds GVWR.
                ------------------------------------------------------------------------
                * * * * *
                 (d) * * *
                 (1) Calculate the fuel consumption credits in a model year for each
                participating family or subfamily consisting of engines in each
                averaging set (as defined in Sec. 535.4) using the equation in this
                section. Each designated engine family has a ``family certification
                level'' (FCL) which is compared to the associated regulatory
                subcategory standard. A FCL that falls below the regulatory subcategory
                standard creates ``positive credits,'' while fuel consumption level of
                a family group above the standard creates a ``credit shortfall.'' The
                value of credits generated in a model year for each engine family or
                subfamily is calculated as follows and must be rounded to nearest whole
                number:
                Engine Family FCC (gallons) = (Std-FCL) x (CF) x(Volume) x (UL) x
                (10\2\)
                Where:
                Std = the standard for the respective engine regulatory subcategory
                (gal/100 hp-hr).
                FCL = family certification level for the engine family (gal/100 hp-
                hr).
                CF= a transient cycle conversion factor in hp-hr/mile which is the
                integrated total cycle horsepower-hour divided by the equivalent
                mileage of the applicable test cycle. For engines subject to spark-
                ignition heavy-duty standards, the equivalent mileage is 6.3 miles.
                For engines subject to compression-ignition heavy-duty standards,
                the equivalent mileage is 6.5 miles.
                Volume = the number of engines in the corresponding engine family.
                UL = the useful life of the given engine family (miles) as shown in
                the following table:
                 Table 3 to Paragraph (d)(1) Introductory Text
                ------------------------------------------------------------------------
                 Regulatory Subcategory UL (miles)
                ------------------------------------------------------------------------
                SI and CI LHD Engines........................... 120,000 (Phase 1);
                 150,000 (Phase 2).
                CI MHD Engines.................................. 185,000.
                CI HHD Engines.................................. 435,000.
                ------------------------------------------------------------------------
                * * * * *
                 (7) Engine credits generated for compression-ignition engines in
                model year 2020 and earlier may be used in model year 2021 and later as
                follows:
                 (i) For credit-generating engines certified to the tractor engine
                standards in Sec. 535.5(d), you may use credits calculated relative to
                the tractor engine standards.
                 (ii) For credit-generating engines certified to the vocational
                engine standards in Sec. 535.5(d), you may use credits calculated
                relative to the following family certification levels (FCLs):
                 (A) Medium Heavy-Duty Engines = 5.4813 gallons/100 hp-hr
                 (B) Heavy Heavy-Duty Engines = 5.1572 gallons/100 hp-hr
                 (C) To transfer Phase 1 credits for use in the Phase 2 fuel
                consumption program, manufacturers must recalculate credit values for
                the Phase 1 model years by substituting the FCLs in paragraph (d)(1) of
                this section with the those in paragraphs (d)(7)(ii)(A) and (B) of this
                section.
                * * * * *
                 (f) * * *
                 (1) * * *
                 (ii) There are no separate credit allowances for advanced
                technology vehicles in the Phase 2 program. Instead, through model year
                2027, vehicle families containing plug-in battery electric hybrids,
                all-electric, and fuel cell vehicles certifying to Phase 2 vocational
                and tractor standards may multiply credits by a multiplier of:
                * * * * *
                 (G) Advanced technology credits increased with a multiplier in
                Phase 2,
                [[Page 18831]]
                in accordance with Sec. 535.7(f)(1)(ii), cannot be used across
                averaging sets.
                * * * * *
                0
                8. Amend Sec. 535.8 by revising paragraphs (a)(6), (g)(11)(i)(C),
                (g)(12), and (i) to read as follows:
                Sec. 535.8 Reporting and recordkeeping requirements.
                 (a) * * *
                 (6) Any information that must be sent directly to NHTSA. In
                instances in which EPA has not created an electronic pathway to receive
                the information, the information should be sent through an electronic
                portal identified by NHTSA or through the NHTSA CAFE database (i.e.,
                information on fuel consumption credit transactions). If hardcopy
                documents must be sent, the information should be sent to the Associate
                Administrator of Enforcement at 1200 New Jersey Avenue SE, NVS-200,
                Office W45-306, Washington, DC 20590.
                * * * * *
                 (g) * * *
                 (11) * * *
                 (i) * * *
                 (C) The averaging set corresponding to the engine and powertrain
                families and subfamilies that generated fuel consumption credits for
                the trade, including the number of fuel consumption credits from each
                averaging set.
                * * * * *
                 (12) Production reports. Within 90 days after the end of the model
                year and no later than March 31st, manufacturers participating and not-
                participating in the ABT program must send to EPA and NHTSA a report
                including the total U.S.-directed production volume of vehicles it
                produced in each vehicle and engine family during the model year (based
                on information available at the time of the report) as required by 40
                CFR 1036.250 and 1037.250. Each manufacturer shall report by vehicle or
                engine identification number and by configuration and identify the
                subfamily identifier. Report uncertified vehicles sold to secondary
                vehicle manufacturers. Small business manufacturers may omit reporting.
                Identify any differences between volumes included for EPA but excluded
                for NHTSA.
                * * * * *
                 (i) Information received from EPA. NHTSA will receive information
                from EPA as specified in 40 CFR 1036.755 and 1037.755. The knowing and
                willful submission of false, fictitious or fraudulent information under
                this part will subject a manufacturer to the civil and criminal
                penalties of 18 U.S.C. 1001.
                * * * * *
                0
                9. Amend Sec. 535.9 by revising paragraph (a)(1)(i) and adding
                paragraph (a)(1)(v) to read as follows:
                Sec. 535.9 Enforcement approach.
                 (a) * * *
                 (1) * * *
                 (i) NHTSA may conduct audits or confirmatory testing on any
                configuration prior to first sale throughout a given model year or
                after the model year in order to validate data received from
                manufacturers and will discuss any potential issues with EPA and the
                manufacturer. NHTSA may perform confirmatory testing. Any such testing
                would be performed as specified in EPA's regulations at 40 CFR part
                1037. Audits may periodically be performed to confirm manufacturers'
                credit balances, or other credit transactions or other information
                submitted to EPA and NHTSA.
                * * * * *
                 (v) NHTSA may require a manufacturer to perform selective
                enforcement audits with respect to any GEM inputs in its application
                for certification or in the end of the year ABT final reports. Any
                required selective enforcement audits would be required to be conducted
                in a manner consistent with EPA's corresponding provisions at 40 CFR
                1037.301, 1037.305, and 1037.320.
                * * * * *
                0
                10. Amend Sec. 535.10 by:
                0
                a. Removing and reserving paragraph (a)(3);
                0
                b. Revising paragraphs (a)(6) and (c)(2); and
                0
                c. Removing and reserving paragraph (c)(3).
                 The revisions read as follows:
                Sec. 535.10 How do manufacturers comply with fuel consumption
                standards?
                 (a) * * *
                 (6) Manufacturers apply the fuel consumption standards specified in
                Sec. 535.5 to vehicles, engines and components that represent
                production units and components for vehicle and engine families,
                subfamilies and configurations consistent with the EPA specifications
                in 40 CFR 86.1819, 1036.230, and 1037.230. Vehicles required to meet
                the fuel consumption standards of this part must also comply with the
                following additional requirements, consistent with CFR 1037.115(a) and
                (d):
                 (i) Adjustable parameters. Vehicles that have adjustable parameters
                must meet all the requirements of this part for any adjustment in the
                practically adjustable range. We may require that you set adjustable
                parameters to any specification within the practically adjustable range
                during any testing. See 40 CFR 1068.50 for general provisions related
                to adjustable parameters. You must ensure safe vehicle operation
                throughout the practically adjustable range of each adjustable
                parameter, including consideration of production tolerances. Note that
                adjustable roof fairings and trailer rear fairings are deemed not to be
                adjustable parameters.
                 (ii) Defeat devices. Consistent with 40 CFR 1068.101, the use of
                defeat devices is prohibited.
                * * * * *
                 (c) * * *
                 (2) For truck tractors, vocational vehicles, and engines the
                manufacturer's fuel consumption performance for each vehicle or engine
                family (or subfamily), as determined in Sec. 535.6, is lower than the
                applicable regulatory subcategory standards in Sec. 535.5.
                * * * * *
                 Issued in Washington, DC, under authority delegated in 49 CFR
                1.95 and 501.5.
                Sophie Shulman,
                Deputy Administrator.
                [FR Doc. 2024-05010 Filed 3-14-24; 8:45 am]
                BILLING CODE 4910-59-P
                

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