6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 1/268[Federal Register Volume 86, Number 122 (Tuesday, June 29, 2021)]  
[Rules and Regulations]  
[Pages 34308-34590]  
From the Federal Register Online via the Government Publishing Office [ www.gpo.gov ] 
[FR Doc No: 2021-05306]  
[[Page 34307]]  
Vol. 86 
Tuesday,  
No. 122 
June 29, 2021  
Part II 
Environmental Protection Agency  
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40 CFR Parts 9, 59, 60, et al.  
 Improvements for Heavy-Duty Engine and Vehicle Test Procedures, and  
Other Technical Amendments; Final Rule  
Federal Register / Vol. 86, No. 122 / Tuesday, June 29, 2021 / Rules  
and Regulations  
[[Page 34308]]  
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ENVIRONMENTAL PROTECTION AGENCY  
40 CFR Parts 9, 59, 60, 85, 86, 88, 89, 90, 91, 92, 94, 1027, 1033,  
1036, 1037, 1039, 1042, 1043, 1045, 1048, 1051, 1054, 1060, 1065,  
1066, 1068, and 1074  
[EPA-HQ-OAR-2019-0307; FRL-10018-52-OAR]  
RIN 2060-AU62  
Improvements for Heavy-Duty Engine and Vehicle Test Procedures,  
and Other Technical Amendments  
AGENCY: Environmental Protection Agency (EPA).  
ACTION: Final rule.  
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SUMMARY: The Environmental Protection Agency (EPA) is amending the test  
procedures for heavy-duty engines and vehicles to improve accuracy and  
reduce testing burden. EPA is also making other regulatory amendments  
concerning light-duty vehicles, heavy-duty vehicles, highway  
motorcycles, locomotives, marine engines, other nonroad engines and  
vehicles, and stationary engines. These amendments affect the  
certification procedures for exhaust emission standards and related  
requirements. EPA is finalizing similar amendments for evaporative  
emission standards for nonroad equipment and portable fuel containers.  
The amendments increase compliance flexibility, harmonize with other  
requirements, add clarity, correct errors, and streamline the  
regulations. Given the nature of the amendments, they will have neither  
significant environmental impacts nor significant economic impacts for  
any sector.  
DATES: This final rule is effective on July 29, 2021. The incorporation  
by reference of certain publications listed in this regulation is  
approved by the Director of the Federal Register as of July 29, 2021.  
ADDRESSES: The EPA has established a docket for this action under  
Docket ID No. EPA-HQ-OAR-2019-0307. All documents in the docket are  
listed on the www.regulations.gov  website. Although listed in the  
index, some information is not publicly available, e.g., confidential  
business information (CBI) or other information whose disclosure is  
restricted by statute. Certain other material, such as copyrighted  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 2/268material, is not placed on the internet and will be publicly available  
only in hard copy form. Publicly available docket materials are  
available either electronically in www.regulations.gov  or in hard copy  
at Air and Radiation Docket and Information Center, EPA Docket Center,  
EPA/DC, EPA WJC West Building, 1301 Constitution Ave. NW, Room 3334,  
Washington, DC. Note that the EPA Docket Center and Reading Room were  
closed to public visitors on March 31, 2020, to reduce the risk of  
transmitting COVID-19. The Docket Center staff will continue to provide  
remote customer service via email, phone, and webform. The telephone  
number for the Public Reading Room is (202) 566-1744, and the telephone  
number for the Air Docket is (202) 566-1742. For further information on  
EPA Docket Center services and the current status, go to https://www.epa.gov/dockets . 
FOR FURTHER INFORMATION CONTACT: Alan Stout, Office of Transportation  
and Air Quality, Assessment and Standards Division, Environmental  
Protection Agency, 2000 Traverwood Drive, Ann Arbor, MI 48105;  
telephone number: (734) 214-4805; email address: stout.alan@epa.gov .
SUPPLEMENTARY INFORMATION:  
Table of Contents  
I. General Information  
II. Heavy-Duty Highway Amendments  
    A. Test Procedures and Compliance Model Changes  
    B. Heavy-Duty Engine GHG Emission Standards and Flexibility  
    C. Heavy-Duty Vehicle GHG Emission Standards and Flexibility  
    D. Onboard Diagnostics (``OBD'')  
III. Other Amendments  
    A. Ethanol-Blend Test Fuels for Nonroad Spark-Ignition Engines  
and Vehicles, Highway Motorcycles, and Portable Fuel Containers  
    B. Removing Obsolete CFR Content  
    C. Certification Fees (40 CFR Part 1027)  
    D. Additional Amendments for Motor Vehicles and Motor Vehicle  
Engines (40 CFR Parts 85 and 86)  
    E. Additional Amendments for Locomotives (40 CFR Part 1033)  
    F. Additional Amendments for Land-Based Nonroad Diesel Engines  
(40 CFR Part 1039)  
    G. Additional Amendments for Marine Diesel Engines (40 CFR Parts  
1042 and 1043)  
    H. Portable Fuel Containers (40 CFR Part 59)  
    I. Evaporative Emission Standards for Nonroad Spark-Ignition  
Engines and Equipment (40 CFR Part 1060)  
    J. Additional Amendments for Nonroad Spark-Ignition Engines at  
or Below 19 kW (40 CFR Part 1054)  
    K. Amendments for General Compliance Provisions (40 CFR Part  
1068) 
    L. Other Requests for Comment  
IV. Statutory Authority and Executive Order Reviews  
I. General Information  
Does this action apply to me?  
    This action relates to companies that manufacture, sell, or import  
into the United States new heavy-duty engines or Class 2b through 8  
trucks, including combination tractors, vocational vehicles, and all  
types of buses.\1\ Vocational vehicles include municipal, commercial,  
and recreational vehicles. Additional amendments apply for different  
manufacturers of light-duty vehicles, light-duty trucks, highway  
motorcycles, stationary engines, and various types of nonroad engines,  
vehicles, and equipment.\2\ Regulated categories and entities include  
the following:  
---------------------------------------------------------------------------  
    \1\ ``Heavy-duty engine'' and ``heavy-duty vehicle,'' are  
defined in 40 CFR 1037.801.  
    \2\ ``Light-duty vehicle'' and ``light-duty truck'' are defined  
in 40 CFR 86.1803-01.  
------------------------------------------------------------------------  
                                                          Examples of  
                                                          potentially  
          NAICS codes a              NAICS titles          regulated  
                                                           entities  
------------------------------------------------------------------------  
333618, 336111, 336112, 336120,   Other Engine        Motor vehicle  
 336211, 336212, 336611, 336999.   Equipment           manufacturers and  
                                   Manufacturing,      engine  
                                   Automobile          manufacturers.  
                                   Manufacturing,  
                                   Light Truck and  
                                   Utility Vehicle  
                                   Manufacturing,  
                                   Heavy Duty Truck  
                                   Manufacturing,  
                                   Motor Vehicle  
                                   Body  
                                   Manufacturing,  
                                   Truck Trailer  
                                   Manufacturing,  
                                   Ship Building and  
                                   Repairing, All  
                                   Other  
                                   Transportation  
                                   Equipment  
                                   Manufacturing.  
811111, 811112, 811198, 423110..  General Automotive  Commercial  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 3/268                                   Repair,             importers of  
                                   Automotive          vehicles and  
                                   Exhaust System      vehicle  
                                   Repair, All Other   components.  
                                   Automotive Repair  
                                   and Maintenance,  
                                   Automobile and  
                                   Other Motor  
                                   Vehicle Merchant  
                                   Wholesalers.  
335312, 811198..................  Motor and           Alternative fuel  
                                   Generator           vehicle  
                                   Manufacturing,      converters.  
                                   All Other  
                                   Automotive Repair  
                                   and Maintenance.  
[[Page 34309]]  
  
326199, 332431..................  All Other Plastics  Portable fuel  
                                   Product             container  
                                   Manufacturing,      manufacturers.  
                                   Metal Can  
                                   Manufacturing.  
------------------------------------------------------------------------  
a North American Industry Classification System (NAICS).  
    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.  
What action is the Agency taking?  
    This action amends the regulations that implement our air pollutant  
emission standards for engines, vehicles and mobile equipment. The  
amendments include corrections, clarifications, and flexibilities for  
multiple types of vehicles, engines and equipment.  
    The majority of these amendments modify existing test procedures  
for heavy-duty highway engines and vehicles. These test procedure  
changes improve accuracy, and in some cases, reduce test burden. They  
mainly apply for measurement of greenhouse gas (GHG) pollutants  
(primarily CO2), though some apply for criteria pollutants (such as  
NOX), as well. See Section II.A.  
    Additional heavy-duty highway amendments update EPA regulations to  
enhance implementation of existing emission standards. For example,  
some changes reduce the likelihood that manufacturers would need to  
duplicate certification efforts to comply with EPA, Canadian, and  
Californian standards. Some amendments make it easier for manufacturers  
to more fully account for the emission benefits of advanced emission  
control technology, which could provide them the opportunity to  
generate additional emission credits. These heavy-duty highway  
amendments are described in Section II.B.  
    This rule includes other amendments that are generally  
administrative or technical in nature and include amendments for  
nonroad engines and vehicles, stationary engines, and portable fuel  
containers. These amendments are described in Section III. Perhaps the  
most visible administrative amendment is the elimination of hundreds of  
pages of obsolete regulations, which is described in Section III.B.  
    EPA published a proposed rule on May 12, 2020 (85 FR 28140). This  
final rule follows from that proposal, with several adjustments that  
reflect EPA's consideration of comments received. Most of the proposed  
revisions from that document are addressed in this final rule. EPA is  
also issuing a new notice of proposed rulemaking to supplement the  
earlier proposed rule, published in the Proposed Rules section of this  
issue of the Federal Register, titled ``Improvements for Heavy-Duty  
Engine and Vehicle Test Procedures,'' docket number EPA-HQ-OAR-2019-  
0307; FRL-10018-51-OAR. In the supplemental proposal, EPA proposes  
further amendments concerning only certain specific aspects of the  
Greenhouse gas Emissions Model (GEM) (see Section II of the preamble to  
the supplemental proposal).  
    The proposed rule included requests for comment on a wide range of  
issues, including some broad areas where we were interested only in  
gathering information for potential future rulemaking(s). This preamble  
does not include a discussion of those comment areas where we are not  
taking any action in this final rule. The ``Improvements for Heavy-Duty  
Engine and Vehicle Test Procedures, and other Technical Amendments  
Response to Comments'' document (``Response to Comments'') in the  
docket for this rulemaking includes a summary of the input received  
from commenters and EPA's responses.\3\  
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    \3\ EPA, ``Improvements for Heavy-Duty Engine and Vehicle Test  
Procedures, and other Technical Amendments Response to Comments,''  
December 2020, Docket EPA-HQ-OAR-2019-0307, Publication Number: EPA-  
420-R-20-026.  
---------------------------------------------------------------------------  
    In addition, we have prepared a docket memo with redline text to  
highlight all the changes to the regulations in the proposed rule.\4\  
This is especially helpful for reviewing provisions that we are  
removing from the Code of Federal Regulations. For obsolete provisions  
we are removing, see especially 40 CFR 1027.105, 1033.150, 1042.145,  
1045.145, 1048.145, 1051.145, 1054.145, and 1054.625. We prepared  
additional docket memos to show regulatory changes after the proposed  
rule.\5\  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 4/268---------------------------------------------------------------------------  
    \4\ ``Redline Document Showing Proposed Changes to Regulatory  
Text in the Heavy-Duty Greenhouse Gas Amendments'', EPA memorandum  
from Alan Stout to Docket EPA-HQ-OAR-2019-0307, March 2020.  
    \5\ ``Redline Version of EPA's Final Regulatory Amendments for  
Heavy-Duty Greenhouse Gas Standards and other Programs'', EPA  
memorandum from Alan Stout to Docket EPA-HQ-OAR-2019-0307, December  
9, 2020.  
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What are the incremental costs and benefits of this action?  
    This action is limited in scope and does not include amendments  
that have significant economic or environmental impacts. EPA has  
therefore not estimated the potential costs or benefits of this final  
rule (and we did not for the proposal).  
II. Heavy-Duty Highway Amendments  
A. Test Procedures and Compliance Model Changes  
    Since the promulgation of the Phase 2 regulations, manufacturers  
have been revising their internal test procedures to ensure they will  
be able to comply with the new requirements that begin in model year  
2021. In doing so, they have identified 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.  
    EPA is making numerous changes to the test procedure regulations to  
address manufacturers' concerns and other issues we have identified.  
These changes are described below. The list includes numerous editorial  
changes that simply correct typographical/formatting errors or revise  
the text to improve clarity. Although these amendments are being made  
primarily in the context of heavy-duty engines and vehicles, the  
amendments to part 1065 will also apply to nonroad engines, and the  
amendments to part 1066 will also apply to light-duty vehicles. Since  
these amendments are mostly editorial or adding flexibility, they will  
not adversely impact these other sectors.  
1. 40 CFR Part 1036 Test Procedures  
    EPA proposed several updates to the testing and measurement  
provisions of part 1036, subpart F, and appendices of part 1036 related  
to how to measure emissions from heavy-duty engines and requested  
comment on general improvements to the engine test procedures and  
compliance provisions (85 FR 28141). This section presents the changes  
we are adopting to engine test procedures after consideration of  
comments received. Additional details on some of these and other engine  
testing and measurement amendments or clarifications requested by  
[[Page 34310]]  
commenters and our responses are available in Chapter 2 of our Response  
to Comments. Amendments to other subparts of part 1036 (i.e.,  
amendments not directly related to test procedures) are discussed in  
Section II.B.  
    These updates are primarily for the purposes of adding flexibility  
and reducing variability in test results. Additional information that  
led to and supports these changes arose from a test program at  
Southwest Research Institute (SwRI) that was jointly funded by EPA and  
the Truck and Engine Manufacturers Association (EMA).\6\  
---------------------------------------------------------------------------  
    \6\ Sharp, Christopher A., et al., ``Measurement Variability  
Assessment of the GHG Phase 2 Fuel Mapping Procedure'', Final  
Report, Southwest Research Institute, December 2019.  
---------------------------------------------------------------------------  
    We are generally finalizing revisions as proposed; however, some  
revisions include further changes and clarifications after  
consideration of public comments to better ensure clarity, accuracy and  
consistency with the intent of the proposed rule.  
     Section 1036.501(g)--Providing a new paragraph (g) to  
specify duty cycles for testing model year (MY) 2016-2020 engines,  
including additional clarifications to the proposed amendment to refer  
to the steady-state duty cycle as the Supplemental Emission Test  
(``SET'') rather than the Ramped Modal Cycle (``RMC'') to avoid  
confusion as steady-state cycles are run as RMCs in many standard  
setting parts, and to change a reference for the Federal Test Procedure  
(``FTP'') duty cycle from appendix B of 40 CFR part 1036 to 40 CFR  
1036.510 because 40 CFR 1036.510 gives an overview of the duty cycle  
and provides the reference to appendix B of 40 CFR part 1036.  
     Section 1036.501(h)--Renumbering existing paragraph (g)  
concerning testing of MY 2021 and later engines as new paragraph (h),  
modifying paragraph (h)(1) to address restarting the engine during  
dynamometer testing for engines with stop-start technologies, and  
adding paragraph (h)(3) (shown as (h)(2) in the proposed rule) to  
cross-reference transient test cycle specifications, including  
additional clarifications in final paragraph (h)(2) to refer to the  
Supplemental Emission Test cycle to avoid confusion as steady-state  
cycles are run as RMCs in many standard setting parts and in paragraph  
(h)(2)(ii) that weighting factors for the Supplemental Emission Test  
are to be applied to CO2 to calculate the composite emission result.  
     Section 1036.503--Migrating Sec.  1036.510 to new Sec.   
1036.503, renumbering existing paragraph (d) as new paragraph (c),  
updating paragraphs (b) and (c)(1) through (3) and adding paragraphs  
(c)(4) and (5) and (d), including provisions to specify that the engine  
manufacturer must provide idle speed and torque to the vehicle  
manufacturer and to provide additional direction on handling data  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 5/268points for a low speed governor where the governor is active. We  
further modified proposed paragraph (b) to denote that there are four  
methods to generate fuel maps with the addition of the hybrid  
powertrain and hybrid engine testing procedures and to more clearly  
explain which method(s) apply to which application, paragraphs (b)(1)  
and (2) to add more specificity to which referenced paragraphs in Sec.   
1036.535 are applicable, paragraph (b)(3) to clarify that the option in  
Sec.  1037.520(d)(2) is only allowed for hybrid powertrain testing and  
not powertrain testing in general, and added paragraph (b)(4) to  
include a method to perform hybrid engine testing. We also further  
updated paragraph (c)(1) to clarify how to measure torque curve for  
engines that have a rechargeable energy storage system (RESS) and for  
those that don't.  
     Section 1036.505--Adding paragraph (b) to give direction  
on both engine and powertrain testing and modifying Table 1 to include  
vehicle speed and grade parameters to facilitate the hybrid powertrain  
testing option. We further modified the proposed language in this  
section by: Adding a new paragraph (b)(2)(v) to calculate curb mass for  
hybrid powertrain testing as this calculation is needed to determine  
the linear equivalent mass of rotational moment of inertias in  
clarified paragraph (b)(2)(vi), adding reference speed determination  
requirements for powertrain testing in paragraphs (c)(2)(i) and (ii) to  
address underspeed conditions in the hybrid powertrain SET testing,  
including a removal of default A, B, and C SET speeds and calculation  
of the A and B speeds based on C speed, modifying Table 1 further to  
include vehicle speed and grade parameters to facilitate the hybrid  
powertrain testing option so the road grade equation is now vehicle  
speed-dependent to address vehicle underspeed concerns corresponding to  
the determination and use of vehicle C speed, and replacing ramped  
modal cycle with supplemental emission test for the reason discussed in  
the first bullet of this subsection of the preamble.  
     Section 1036.510--Providing a new section regarding  
transient testing of engines and hybrids to facilitate hybrid  
certification for both GHG and criteria pollutants.  
     Section 1036.525(a)--Adding a clarification in the final  
rule that the hybrid engine testing procedure in this section applies  
only for model year 2014 to 2020 hybrid engines since the new hybrid  
powertrain and hybrid engine test procedure being adopted in this  
rulemaking will apply for model year 2021 and later engines.  
     Section 1036.525(d)(4)(i)--Editorial revisions to equation  
and the addition of example calculations.  
     Section 1036.527--Adding a section to provide a means to  
determine powertrain systems rated power and continuous rated power, to  
facilitate the hybrid and conventional powertrain testing options. This  
test procedure is applicable for powertrain testing defined in 40 CFR  
1037.550 for both the engine and vehicle standards. We further modified  
the proposed language, including modifying how the test is carried out  
by reducing the number of test intervals from 9 to 1, paragraph (e) to  
address the determination of Psys for speed and torque measurements at  
different locations, with new paragraphs (g) and (h) to provide an  
improved method for determining continuous rated power and vehicle C  
speed, and addressed typographical errors.  
     Section 1036.530(a), (b)(1)(i) and (ii), and (b)(2)(i) and  
(ii)--Updating carbon mass fraction determination to allow analysis by  
a single lab only to facilitate on-line analysis from pipeline supplied  
natural gas and adding the ASTM International method for determination  
of test fuel mass-specific energy content for natural gas. We have  
further modified the proposed language by clarifying in paragraph (a)  
that the infrequent regeneration adjustment factors (IRAF) are applied  
to CO2 emission results for all duty-cycles, not just cycle average  
engine fuel map results, and updating paragraph (b) to require test  
fuel mass-specific energy content and carbon mass fraction to be  
analyzed by at least three different labs and the median of all the  
results to be used in the calculation. We are also adding a  
recommendation that you screen your results to determine if additional  
observations are needed by performing an outlier test and provided  
critical values for this check. The critical values were determined as  
1.27 times the method reproducibility R. The R value used for fuel  
mass-specific energy content is 0.234 which is the published R value  
for ASTM D4809 and the R value used for carbon mass fraction is 1.23,  
which was based on analysis of the fuel survey data for ASTM D5291 that  
was used in the Fuel Mapping Variability Study at SwRI.  
     Section 1036.530 Table 1--Updating footnote format in  
table. 
[[Page 34311]]  
     Section 1036.535--Generally updating to improve the engine  
fuel mapping test procedures based on the jointly funded EPA-EMA test  
program. The overall result of these updates is to reduce the  
variability of the emission test results to reduce lab-to-lab  
variability. We further modified the proposed language by adding  
paragraph (h) to describe how EPA will determine the official fuel  
consumption rate during a confirmatory test, based on carbon balance  
results, updating paragraph (b)(7)(iv) to require validation of test  
intervals that were complete prior to a lab equipment or engine  
malfunction, updating the variable description for w Cmeas in  
paragraph (b)(8) to make clear that you may not account for the  
contribution to [alpha], [beta], [gamma], and [delta] of diesel exhaust  
fluid or other non-fuel fluids injected into the exhaust, and  
clarifying regulatory text and correcting paragraph references.  
     Section 1036.540--Generally updating to improve the cycle-  
average engine fuel mapping test procedure as a result of the jointly  
funded EPA-EMA test program at SwRI. The overall result of these  
updates is to reduce the variability of the emission test results to  
reduce lab-to-lab variability. We further modified the proposed  
language in a few ways by adding paragraph (b)(4) to address the  
ability of gaseous fueled engines with single point fuel injection to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 6/268pass alternate cycle statistics to validate the transient duty cycle in  
40 CFR part 1037, appendix I, by adding paragraph (e)(2) to describe  
how EPA will determine the official fuel consumption rate during a  
confirmatory test, based on carbon balance results, by deleting the  
requirement for EPA to use an average of indirect measurement of fuel  
flow with dilute sampling and direct sampling for fuel mapping as EPA  
will now perform the carbon balance verification in 40 CFR 1065.543,  
and by generally adding some clarifying text.  
     Section 1036.543--Adding a section to address carbon  
balance error verification. This is a result of the jointly funded EPA-  
EMA test program. The overall result of these updates is to reduce the  
variability of the emission test results to reduce lab-to-lab  
measurement variability.  
     Section 1036.801--Adding a definition for hybrid engine to  
correspond with the addition of the hybrid powertrain test procedures  
to part 1036. Modifying the definition from the proposed language to  
provide examples of hybrid engine architecture and hybrid energy  
storage systems.  
     Section 1036.801--Adding definitions for ``hybrid  
powertrain'' and ``mild hybrid'' in the final rule. These definitions  
are needed as a result of adding hybrid powertrain test procedures to  
part 1036, subpart F, including mild hybrid certification where engine  
testing can use a transmission model. The definitions make clear what  
hybrid architectures are covered by each of these terms.  
     Section 1036.801--Updating definition of ``steady-state''  
to clarify that fuel map and idle tests are steady-state tests.  
     Section 1036.805(b)--Updating quantity and quantity  
descriptions, including some changes to those proposed to ensure  
consistency throughout the part.  
     Section 1036.805(c) and (d)--Updating table introductory  
sentence and column headings in the table to be consistent with format  
in other parts.  
     Section 1036.805(e)--Updating acronyms and abbreviations,  
including some changes to those proposed to ensure that the table  
contained all that were used throughout the part.  
     Section 1036.805(f)--Adding gravitational constant,  
including an updated value for the gravitational constant based on  
consideration of comments received on the proposal.  
     Part 1036, appendix A--Adding a new appendix A to provide  
a historic summary of previous emission standards which EPA originally  
adopted under 40 CFR part 85 or 86, that apply to compression-ignition  
engines produced before model year 2007 and to spark-ignition engines  
produced before model year 2008.  
     Part 1036, appendix B(a)--Adding a new paragraph (a) of  
appendix B to specify transient duty cycles for the engine and  
powertrain testing described in Sec.  1036.510.  
     Part 1036, appendix B(b)--Adding a new paragraph (b) of  
appendix B to migrate over the spark-ignition FTP duty cycle from part  
86, which includes no changes to the FTP duty-cycle weighting factors  
or the duty-cycle speed values from the current heavy duty diesel  
engine (HDDE) FTP duty cycle that applies to criteria pollutant  
regulation in paragraph (f)(1) of 40 CFR part 86, appendix I, a change  
to the negative torque values, and migration of the HDDE FTP drive  
schedule to paragraph (b) of 40 CFR part 1036, appendix B, to add  
vehicle speed and road grade to the duty-cycle to facilitate powertrain  
testing for compliance with the HD Phase 2 GHG standards. The change to  
negative torque values is the removal of and footnoting of the negative  
normalized vehicle torque values over the HDDE FTP duty-cycle. The  
footnote denotes that these torque points are controlled using closed  
throttle motoring, which would then match how negative torque values  
have been controlled in the HDDE FTP. This change also reflects the way  
that engine manufacturers are already controlling to negative torque  
from spark-ignition engines and harmonizes the methodology with the  
HDDE FTP, with no effect on stringency. The spark-ignition engine  
denormalization equation in 40 CFR 86.1333(a)(1)(ii) includes division  
by 100 which equates it to the denormalization equation in 40 CFR  
1065.610(c)(1) (Equation 1065.610-3), with no effect on stringency. We  
have further modified the proposed language in this section by updating  
the road-grade coefficients to reflect additional refinement of the  
road-grade development process that is described in Section II.A.7 of  
the preamble.  
     Part 1036, appendix B(c)--Adding a new paragraph (c) of 40  
CFR part 1036, appendix B, to migrate over the compression-ignition FTP  
duty cycle from part 86, which includes no changes to the HDDE FTP  
weighting factors or the duty-cycle torque values from the duty cycle  
that currently apply to criteria pollutant regulations in paragraph  
(f)(2) of 40 CFR part 86, appendix I, a change to the speed values that  
does not influence the ultimate denormalized speed, and migration of  
the HDDE FTP drive schedule to add vehicle speed and road grade to the  
duty-cycle to facilitate powertrain testing for compliance with the  
Phase 2 GHG standards. The change to speed values takes the normalized  
vehicle speeds over the HDDE FTP duty-cycle and multiplies them by 100/  
112 to eliminate the need to divide by 112 in the diesel engine  
denormalization equation in 40 CFR 86.1333(a)(1)(i). This eliminates  
the need for use of a denormalization equation and allows commonization  
(between compression- and spark-ignition engines) of the use of the  
denormalization equation in 40 CFR 1065.610(c)(1) (Equation 1065.610-  
3), with no effect on stringency. We have further modified the proposed  
language in this section by updating the road grade coefficients to  
reflect additional refinement of the road grade development process  
that is described in Section II.A.7 of the preamble.  
2. 40 CFR Part 1037 Test Procedures  
    EPA proposed several updates to the testing and measurement  
provisions of 1037 subpart F related to how to measure emissions from  
heavy-duty vehicles and determine certain GEM inputs and requested  
comment on general improvements to the vehicle test procedures and  
compliance provisions (see 85 FR 28142). This section presents  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 7/268[[Page 34312]]  
the changes we are adopting to vehicle test procedures after  
consideration of comments received. Chapter 2 of our Response to  
Comments includes additional details on some of these amendments, as  
well as other testing and measurement amendments or clarifications  
requested by commenters and our responses. Amendments for other  
subparts of part 1037 (i.e., amendments not directly related to test  
procedures) are discussed in Section II.C.15. We are generally  
finalizing revisions as proposed; however, some revisions include  
further changes and clarifications after consideration of public  
comments to better ensure clarity, accuracy and consistency with the  
intent of the proposed rule.  
     Section 1037.501(i)--Adding paragraph (i) to note that the  
declared GEM inputs for fuel maps and aerodynamic drag area typically  
includes compliance margins to account for testing variability; for  
other measured GEM inputs, the declared values are typically the  
measured values without adjustment.  
     Section 1037.510(a)(2)--Updating the powertrain testing  
procedure used to generate GEM inputs to reduce the variability of the  
emission test results and to improve lab-to-lab measurement variability  
consistent with the results from the jointly funded EPA-EMA test  
program at SwRI.  
     Section 1037.510 Table 1--Updating footnote format in  
table. 
     Section 1037.510(d)--Clarifying the reference to  
specifically refer to paragraphs ``(b) and (c)'' of Sec.  1066.425.  
     Section 1037.510(e)--Clarifying to specifically state that  
the use of cruise control is optional.  
     Section 1037.515 Table 2--Correcting a table entry to  
include the proper mathematical symbols in response to a comment by the  
California Air Resources Board (CARB).  
     Section 1037.515 Table 3--Updating footnote format in  
table. 
     Section 1037.520--Updating a reference to reflect the  
updated version of the GEM model released in conjunction with this  
rulemaking.  
     Section 1037.520(b)(3)(i)--Adding a reference to Sec.   
1037.525 to clarify how to determine a high-roof tractor's aerodynamic  
test results in response to a comment request from EMA.  
     Section 1037.520 Table 4--Correcting a typographical error  
in a tractor aerodynamic test result C dA value for Bin III  
low-roof cabs.  
     Section 1037.520 Table 5--Correcting a typographical error  
in a tractor input C dA value for Bin II High-Roof Sleeper  
Cabs. 
     Section 1037.520(c)--Adding a clarification to Sec.   
1037.520(c)(6) and updating the GEM user guide to clarify that a time-  
and load-weighted average be applied to calculate the rolling  
resistance of tires installed on liftable axles, given that tires on  
liftable axles are only in contact with the ground when the axle is in  
a deployed state in response to a comment from EMA.  
     Section 1037.520 Table 6--Updating footnote format in  
table. 
     Section 1037.520 Table 7--Clarifying that the nonwheel-  
related weight reductions from alternative materials applied to  
tractors for non-suspension crossmembers is for a set of three.  
     Section 1037.520 Table 8--Adding two footnotes to address  
how weight reduction values apply and what values to use for medium  
heavy-duty vehicles (Medium HDV) with 6x4 or 6x2 axle configurations.  
Also see Section II.C.3.  
     Section 1037.520(f)--Updating a cross-reference.  
     Section 1037.520(g)--Adding and clarifying which vehicle  
characteristics need to be reported, including providing a better  
description in paragraph (g)(2)(iv) of the 6x4D drive axle  
configuration as well as qualifying conditions for use of this  
configuration. After considering comments received by Allison and Ford,  
we are further modifying this paragraph by noting in paragraph (g)(1),  
and similarly in Sec.  1037.231(b)(7), that available forward gear  
means the vehicle has the hardware and software to allow operation in  
those gears and providing in paragraph (g)(2)(i) that the 4x2 drive  
axle configuration is available to vehicles with two drive axles where  
one of them is disconnectable and designed to be connected only when  
used in off road or slippery road conditions and based on a qualifying  
condition.  
     Section 1037.520(h)--Adding provisions to determine  
appropriate vehicle idle speed based on vehicle service class and  
applicable engine standard, including in the final rule a clarification  
that the 750 rpm value applies to Light HDV and Medium HDV vocational  
vehicles and providing an idle speed value of 700 rpm for Medium HDV  
tractors, corresponding to the idle speed used to set the standards for  
those vehicles, in response to a comment from EMA. These final  
provisions incorporated in a new table format, with an updated footnote  
noting the appropriate adjustable idle speed to choose if an engine  
cannot operate at the idle speed specified in the table.  
     Section 1037.520(i)--Adding that a manufacturer can  
characterize a torque converter, in addition to an axle and  
transmission, which will improve the accuracy of GEM by replacing  
default GEM values with more representative values.  
     Section 1037.520(j)(2)--Removing a superfluous reference  
to tractors in paragraph (j)(2)(i); clarifying paragraph (j)(2)(iii) in  
response to a comment from EMA to indicate how to demonstrate the  
performance of high-efficiency air conditioning compressors.  
     Section 1037.520(j)(4) Table 9--Including additional  
combinations of idle reduction technologies and their corresponding GEM  
input values.  
     Section 1037.520(j)(5)--Correcting typographical error  
that transposed school and coach bus GEM inputs.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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comments and final revisions to this section.  
     Section 1037.528--Replacing the phrase ``primary  
procedures'' with ``reference method'' for tractors and ``alternate  
procedures'' with ``an alternate method'' for trailers to maintain  
consistency with terminology used throughout subpart F.  
     Section 1037.528(c)--Clarifying that the conditions listed  
in paragraph (c) apply to each run separately.  
     Section 1037.528(e)--Removing requirement that the  
anemometer be ``electro-mechanical'' to rely instead on the  
specifications outlined in the existing reference to SAE J1263.  
     Section 1037.528(g)(3)--Clarifying that the measured air  
direction correction is ``from all the high-speed segments.''  
     Section 1037.528(h)(3)(i)--Clarifying how to account for  
measurement noise near the 2 mile/hour boundary.  
     Section 1037.528(h)(6)--Adding a definition of  
DFTRR to the introduction of paragraph (h)(6) to clarify the  
required calculations; relocating the proposed direction to determine  
the difference in rolling resistance between 65 mph and 15 mph for each  
tire and to use good engineering judgment when measuring multiple  
results to paragraph (v) with the corresponding DF TRR  
equation.  
     Section 1037.528--Updating equation 11 and the  
corresponding example to include the appropriate variable to represent  
inflation pressure variable with a lowercase ``p''.  
     Section 1037.528--Updating equation 13 to include  
appropriate units for the ambient temperature variable.  
     Section 1037.528--Updating equation 14 to replace a ``+''  
with a ``-'' to correct a typographical error.  
     Section 1037.528(h)(12)--Updating a variable name to  
provide consistency with updates made to Sec.  1037.525.  
[[Page 34313]]  
     Section 1037.532--See Section II.A.6 for a description of  
comments and final revisions to this section.  
     Section 1037.534--Updating equation 6 and the  
corresponding example to include the appropriate variable to represent  
increments by italicizing the ``i''.  
     Section 1037.540--Updating equations 1, 2, and 3 to  
include the appropriate variable to represent increments by italicizing  
the ``i''.  
     Section 1037.540 Table 1--Updating footnote format in  
table; updating a parameter name.  
     Section 1037.540(e) and (f)--Removing incorrect cross-  
reference to Sec.  1036.540(d)(5); adding reference to definition of  
standard payload.  
     Section 1037.550--Updating the powertrain testing  
procedure to reduce the variability of the emission test results and  
improve lab-to-lab variability consistent with the results from the  
jointly funded EPA-EMA test program at SwRI. We further modified this  
section to include an introduction paragraph and reorganized paragraphs  
with new paragraph headings to improve navigation. Additional  
modifications to this section in the final rule include clarifying in  
paragraph (a)(3) options available to create the models for powertrain  
testing, adding clarifications in several paragraphs to address where  
the torque and speed are measured based on powertrain setup, adding a  
new paragraph (f)(2) to address testing of hybrid engines using the  
transmission model in GEM, modifying paragraph (b) to give additional  
clarification on how to set the engine idle speed, adding a new  
paragraph (f)(2) for testing with torque measurement at the engine's  
crankshaft and how to calculate the transmission output rotational  
speed, updating paragraph (j)(2) to describe how to transition between  
duty cycles if the preceding cycle ends at 0 mi/hr, adding a new  
paragraph (j)(5) to describe how to warm up the powertrain, adding a  
new paragraph (o)(2) to describe how EPA will determine the official  
fuel consumption rate during a confirmatory test, based on carbon  
balance results, and updating paragraphs (o)(3) through (5) to better  
define when a vehicle is not moving, moving the text from paragraph (p)  
into paragraph (o)(1), moving the text of paragraph (q) to the general  
provisions as a new paragraph (a)(5). The final rule includes  
additional revisions regulatory text to provide greater clarity and  
more carefully describe the procedures.  
     Section 1037.551(b)--Updating a reference.  
     Section 1037.555--Updating equations 1 and 3 to include  
the appropriate variable to represent increments by italicizing the  
``i''; updating a parameter name in Table 1 for consistency in this  
part. 
     Section 1037.560--Clarifying that it is optional to drain  
gear oil after the break in period is complete, providing the option of  
an alternative temperature range to provide international harmonization  
of testing, editing the P loss (i.e., power loss) variable  
description to improve the readability, and adding paragraph (h) to  
describe how to derive axle power loss maps for untested configurations  
in a family. We further modified this section in the final rule by  
clarifying in paragraph (a) that for tandem axles that can be  
disconnected, testing both single-drive and tandem axle configurations  
includes 4x4 axles where one of the axles is disconnectable; adding a  
new paragraph (h)(4) and modifying (h)(5) to address comments regarding  
results when multiple gear ratios are tested and one of the points is  
above the linear regression line, which could cause the regression  
values to understate power loss, to clarify that you must add the  
difference between the datapoint and the regression line to the  
intercept values of the regression line to mitigate this effect; and  
updating the use of the term ``axle'' to ``axle assembly'' throughout  
the section to provide consistency.  
     Section 1037.565--Providing an option to map additional  
test points to provide international harmonization of testing,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 9/268including edits to improve the readability of the P loss  
variable description, and adding paragraph (d)(4) and clarifying  
paragraphs (e)(6) and (7) regarding the gears the transmission is  
tested in. After considering comments from Allison, EMA, and Eaton  
Cummins Automated Transmission Technologies, we further modified this  
section by: Updating the torque transducer accuracy requirements in  
paragraph (c) to link it to the highest transmission input torque or  
respective output torque; adding additional detail in paragraph (d)(1)  
on the maximum transmission input shaft speed to test, specifically the  
maximum rated input shaft speed of the transmission or the maximum test  
speed of the highest speed engine paired with the transmission. and the  
minimum idle speed to test, specifically 600 r/min or the minimum idle  
speed of the engines paired with the transmission; modifying paragraph  
(d)(2) in response to comments regarding transmission torque setpoints  
to optionally allow, in higher gear ratios where output torque may  
exceed dynamometer torque limits, the use of good engineering judgment  
to measure loaded test points at input torque values lower than  
specified (in this case GEM may need to extrapolate values outside of  
the measured map, however extrapolation time may not exceed 10% for any  
given cycle and you must describe in the application for certification  
how you adjusted the torque setpoints); modifying paragraph (e)(9) to  
allow the use of the maximum loss value achieved from all the repeats  
of the test points to calculate transmission efficiency if you cannot  
meet the repeatability requirements; adding a new paragraph (e)(11)  
clarifying what needs to be calculated for each point in the test  
matrix; modifying paragraph (g) and moving part of existing paragraph  
(g) to a new paragraph (h) to avoid a potentially never-ending cycle of  
repeat testing if repeatability requirements are not achieved. If the  
repeatability requirement is not met after conducting three or more  
tests, the maximum loss value may be used to calculate transmission  
efficiency, or you can continue to test until you pass the  
repeatability requirement.  
     Section 1037.570--Adding new section to characterize  
torque converters to allow a manufacturer to determine their own torque  
converter capacity factor instead of using the default value provided  
in GEM. The option to use the default value remains. The final rule  
includes updated regulatory text to provide greater clarity and more  
carefully describe the procedures. Final revisions do not change the  
proposed procedure; instead, they include updates to revise the section  
heading, reorganize paragraphs, ensure consistent terminology, and  
clarify measurement points.  
3. 40 CFR Part 1065 Test Procedures  
    EPA proposed several updates to the testing and measurement  
provisions of 40 CFR part 1065 related to how to measure emissions from  
heavy-duty highway and nonroad engines and requested comment on general  
improvements to the engine test procedures and compliance provisions  
(see 85 FR 28142). This section presents the changes we are adopting  
primarily to reduce variability associated with engine test procedures  
after consideration of comments received. Chapter 2 of our Response to  
Comments includes additional details on some of these amendments, as  
well as other testing and measurement amendments or clarifications  
requested by commenters and our responses.  
[[Page 34314]]  
    The regulations in part 1065 rely heavily on acronyms and  
abbreviations (see 40 CFR 1065.1005 for a complete list). Acronyms used  
here are summarized in Table II-1:
  Table II-1--Summary of Acronyms Related to 40 CFR Part 1065 That Are  
                     Referenced in These Amendments  
------------------------------------------------------------------------  
  
------------------------------------------------------------------------  
ASTM.............................  American Society for Testing and  
                                    Materials  
CVS..............................  Constant-Volume Sampler  
DEF..............................  Diesel Exhaust Fluid  
ECM..............................  Electronic Control Module  
NIST.............................  National Institute for Standards and  
                                    Technology  
NMC FID..........................  Nonmethane Cutter with a Flame  
                                    Ionization Detector  
NMHC.............................  Nonmethane Hydrocarbon  
NMNEHC...........................  Nonmethane Nonethane Hydrocarbon  
RMC..............................  Ramped Modal Cycle  
THC FID..........................  Flame Ionization Detector for Total  
                                    Hydrocarbons  
------------------------------------------------------------------------  
    We are generally finalizing revisions as proposed; however, some  
revisions include further changes and clarifications after  
consideration of public comments to better ensure clarity, accuracy and  
consistency with the intent of the proposed rule.  
     Section 1065.1(g)--Updating the test procedure Uniform  
Resource Locator (URL).  
     Section 1065.2(c)--Correcting a typographical error by  
replacing ``engines'' with ``engine''.  
     Section 1065.130(e)--Revising to denote that a carbon  
balance procedure should be performed to verify exhaust system  
integrity in place of a chemical balance procedure.  
     Section 1065.140(c)(6)(i)--Correcting a typographical  
error by replacing ``dew point'' with ``dewpoint''.  
     Section 1065.140(e)(2)--Clarifying how to determine the  
minimum dilution ratio for discrete mode testing.  
     Section 1065.145(e)(3)(i)--Removing the requirement to  
heat a sample pump if it is located upstream of a NO X  
converter or chiller and replacing it with a requirement to design the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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concerns with the loss of NO 2 in the sampling system where  
methods other than heating the pump can be used to prevent  
condensation.  
     Section 1065.170--Updating to allow you to stop sampling  
during hybrid tests when the engine is off and allow exclusion of the  
sampling off portions of the test from the proportional sampling  
verification, and adding a provision for hybrid testing to allow  
supplemental dilution air to be added to the bag in the event that  
sampled volumes are too low for emission analysis.  
     Section 1065.205 introductory and Table 1--Revising and  
adding recommended performance specifications for fuel and DEF mass  
scales and flow meters to reduce fuel flow measurement error.  
     Section 1065.220(a) introductory and (a)(3)--Updating the  
application of fuel flow meters to more correctly reflect how and what  
they are used for in part 1065.  
     Section 1065.225(a) introductory and (a)(3)--Updating the  
application of intake flow meters to more correctly reflect how and  
what they are used for in part 1065.  
     Section 1065.247--Revising to add acronym for DEF  
throughout in place of ``diesel exhaust fluid'' and in paragraph (c)(2)  
account for any fluid that bypasses or returns from the dosing unit to  
the fluid storage tank.  
     Section 1065.260(e)--Adding the word ``some'' as a  
qualifier for gaseous fueled engines with respect to using the additive  
method for NMHC determination.  
     Section 1065.266(a) and (b)--Adding flexible fuel engines  
under the allowance to use Fourier transform infrared (FTIR) and  
updating the URL for EPA method 320.  
     Section 1065.275--Deleting the URL and replacing with a  
reference to Sec.  1065.266(b).  
     Section 1065.280(a)--Updating to reflect that there is no  
method in Sec.  1065.650 for determining oxygen balance and that you  
may develop a method using good engineering judgment.  
     Section 1065.303 Table 1--Updating the formatting and  
entries in the summary table to reflect revised requirements, including  
adding fuel mass scale and DEF mass scale to the linearity  
verifications in Sec.  1065.307, updating the verification in Sec.   
1065.341 to replace ``batch sampler'' with ``PFD'' as partial-flow  
dilution (PFD) is the preferred language, updating one footnote to  
include the PFD flow verification (propane check) as not being required  
for measurement systems that are verified by a carbon balance error  
verification as described in Sec.  1065.341(h) and adding two footnotes  
excluding linearity verification for DEF flow if the ECM is used and  
for intake air, dilution air, diluted exhaust, batch sampler, and raw  
exhaust flow rates flow if propane checks or carbon balance is  
performed. These are not new exemptions; they are simply relocated to  
the footnotes.  
     Section 1065.307(c)(13)--Adding a clarification that the  
calculation used for arithmetic mean determination in Sec.  1065.602  
uses a floating intercept.  
     Section 1065.307(d)(4)--Revising to include DEF mass flow  
rate and to correct or account for buoyancy effects and flow  
disturbances to improve the flow measurement.  
     Section 1065.307(d)(6)(i)--Revising to state that the span  
gas can only contain one single constituent in balance air (or  
N2 if using a gas analyzer) as the reference signal for  
linearity determination.  
     Section 1065.307(d)(7)--Revising to state that the span  
gas can only contain one single constituent in balance air (or  
N2 if using a gas analyzer) as the reference signal for  
linearity determination.  
     Section 1065.307(d)(9)--Expanding the paragraph to include  
fuel and DEF mass scales and requirements for performing the linearity  
verification on these scales.  
     Section 1065.307(e)(3)(i) and (ii)--Editing to clarify the  
intent of the requirements.  
     Section 1065.307(e)(3)(iii) through (xi)--Defining maximum  
flowrate for fuel and DEF mass scales and flow meters as well as  
maximum molar flowrate for intake air and exhaust flow meters and  
defining maximum for electrical power, current, and voltage  
measurement.  
     Section 1065.307(e)(5)--Providing additional information  
surrounding requirements for using a propane check or carbon balance  
verification in place of a flow meter linearity verification.  
     Section 1065.307(e)(7)(i)(F) and (G)--Adding transmission  
oil and axle gear oil to temperature measurements that require  
linearity verification.  
     Section 1065.307(f)--Adding new paragraph (f) to denote  
that table 1 follows.  
     Section 1065.307 Table 1--Adding DEF flow rate, fuel mass  
scale, and DEF mass scale to measurement systems and updating the  
footnote format.  
     Section 1065.307(g)--Adding a new paragraph (g) to denote  
that table 2 follows.  
     Section 1065.307 Table 2--Adding a new Table 2 to provided  
additional guidance on when optional verifications to the flow meter  
linearity verifications can be used.  
     Section 1065.309(d)(2)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
from EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.320(b)--Deleting existing paragraph (b) and  
marking it  
[[Page 34315]]  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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     Section 1065.341--Revising section heading, adding  
introductory text, revising paragraph (a) to clarify which  
subparagraphs apply to CVS and which apply to PFD, relocating some of  
existing paragraph (a) to paragraph (f) and reordering existing  
paragraphs (b) through (f) as paragraphs (a) through (e).  
     Section 1065.341(g)--Revising to replace ``batch sampler''  
with ``PFD'' throughout and editing to provide further clarification on  
the procedure.  
     Section 1065.341(h)--Adding a new paragraph to reference  
Table 2 of Sec.  1065.307 regarding when alternate verifications can be  
used. 
     Section 1065.342(d)(2)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
by EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.350(d)(2)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
by EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.355(d)(2)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
by EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.360(a)(4)--Adding a new option to determine  
methane and ethane THC FID response factors as a function of exhaust  
molar water content when measuring emissions from a gaseous fueled  
engine. This is to account for the effect water has on non-methane  
cutters. We received a comment regarding whether the new regulatory  
text for the allowance is optional. The intent is that if you decide to  
use the option to determine the methane and ethane THC FID response  
factors as a function of exhaust molar water content, you must generate  
and verify the humidity as described in Sec.  1065.365(d)(12).  
Paragraph (a)(4) has been modified to make this clear.  
     Section 1065.360(d)(12)--Adding a process to determine  
methane and ethane THC FID response factors as a function of exhaust  
molar water content when measuring emissions from a gaseous fueled  
engine. This is to account for the effect water has on non-methane  
cutters.  
     Section 1065.365(a)--Removing chemical symbol for methane  
in parenthetical.  
     Section 1065.365(d)--Adding a requirement to determine NMC  
FID methane penetration fraction and ethane response factor as a  
function of exhaust molar water content when measuring emissions from a  
gaseous fueled engine. This is to account for the effect water has on  
non-methane cutters.  
     Section 1065.365(d)(9)--Adding C 2H6 
before ``response factor'' and ``penetration fraction'' to clarify, as  
intended, that these are the ethane response factor and ethane  
penetration fraction.  
     Section 1065.365(d)(10), (11), and (12)--Adding a process  
to determine NMC FID methane penetration fraction and ethane response  
factors as a function of exhaust molar water content when measuring  
emissions from a gaseous fueled engine. This is to account for the  
effect water has on non-methane cutters.  
     Section 1065.365(f)(9) and (14)--Adding  
C2H6 before ``response factor'' and ``penetration  
fraction'' to clarify, as intended, that these are the ethane response  
factor and ethane penetration fraction. Adding CH 4 before  
``penetration fraction'' to clarify, as intended, that this is the  
methane penetration fraction.  
     Section 1065.370(e)(5)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
by EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.375(d)(2)--Updating to allow the use of water  
vapor injection for humidification of gases. After considering comments  
by EMA and Auto Innovators, we further modified this section to make  
language consistent where water vapor injection was added as an  
alternative.  
     Section 1065.410(c)--Replacing ``bad engine'' with  
``malfunctioning'' in relation to engine components after considering a  
comment by Auto Innovators.  
     Section 1065.410(d)--Updating to state that you may repair  
a test engine if the parts are unrelated to emissions without prior  
approval. If the part may affect emissions, prior approval is required.  
     Section 1065.510(a), (b)(5)(i), (c)(5), and (f)(4)(i)--  
Moving provision for engine stabilization during mapping from Sec.   
1065.510(a) to Sec.  1065.510(b)(5)(i), which lays out the mapping  
procedure, adding allowance in Sec.  1065.510(f)(4)(i) to specify curb  
idle transmission torque (CITT) as a function of idle speed in cases  
where an engine has an adjustable warm idle or enhanced idle. We  
further modified this section in the final rule by adding a provision  
in Sec.  1065.510(c)(5) for hybrid powertrain testing to map negative  
torque required to motor the engine with the RESS fully charged.  
     Section 1065.512(b)(1) and (2)--Updating procedures on how  
to operate the engine and validate the duty-cycle when an engine  
utilizes enhanced-idle speed. This also addresses denormalization of  
the reference torque when enhanced-idle speed is active.  
     Section 1065.514(e)--Clarifying that a floating intercept  
as described in Sec.  1065.602 is used to calculate the regression  
statistics to harmonize with changes made to Sec.  1065.602 and further  
modifying paragraph (e)(3) in the final rule to change ``standard  
estimates of errors'' to ``standard error of the estimate'' for  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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     Section 1065.514 Table 1--Updating a parameter name in the  
final rule for consistency with other parts.  
     Section 1065.530(a)(2)(iii)--Adding instructions on how to  
determine that the engine temperature has stabilized for air cooled  
engines.  
     Section 1065.530(g)(5)--Adding a new paragraph on carbon  
balance error verification if it is performed as part of the test  
sequence.  
     Section 1065.543--Adding a new section on carbon balance  
error verification procedure to further reduce measurement variability  
for the fuel mapping test procedure in part 1036. We have further  
modified this section in the final rule to make it optional to account  
for the flow of other non-fuel carbon-carrying fluids into the system  
as the overall contribution from any such fluids to the total carbon in  
the system is negligible.  
     Section 1065.545--Revising to clarify that a forcing the  
intercept through zero as described in Sec.  1065.602 is used to  
calculate the standard error of the estimate (SEE) to harmonize with  
changes to Sec.  1065.602.  
     Section 1065.602(b), (c), (d), (e), (f), (g), (h), (j),  
(k)--Updating to include the appropriate variable to represent  
increments by italicizing the ``i''.  
     Section 1065.602 Table 1--Updating footnote format in  
table. 
     Section 1065.602 Table 2--Correcting a typographical error  
where the N ref-1 value should be ``22'' but was mistakenly  
listed as ``20''.  
     Section 1065.602(h)--Defining the existing Equation  
1065.602-9 as a least squares regression slope calculation where the  
intercept floats, i.e., is not forced through zero, designating this  
[[Page 34316]]  
paragraph as (h)(1) and adding a new paragraph (h)(2) for Equation  
1065-602-10, a least squares regression slope calculation where the  
intercept is forced through zero.  
     Section 1065.602(i)--Editing to state that the intercept  
calculation Equation 1065.602-11 is for a floating intercept.  
     Section 1065.602(j)--Defining the existing Equation  
1065.602-12 (renumbered from 1065.602-11) as a SEE calculation where  
the intercept floats, i.e., is not forced through zero, designating  
this paragraph as (j)(1), adding a new paragraph (j)(2) for Equation  
1065.602-13, a SEE calculation where the intercept is forced through  
zero, and further modifying paragraph (j) in the final rule to change  
``Standard estimate of error'' to ``Standard error of the estimate''  
for consistency with other parts.  
     Section 1065.610(a)(1)(iv)--Updating to include the  
appropriate variable to represent increments by italicizing the ``i''.  
     Section 1065.610(a)(2)--Clarifying that the alternate  
maximum test speed determined is for all duty-cycles.  
     Section 1065.610(d)(3)--Adding provision to use good  
engineering judgment to develop an alternate procedure for adjusting  
CITT as a function of speed.  
     Section 1065.640(a), (b)(3), and (d)(1)--Deleting a comma  
in paragraph (a), specifying that the least square regression  
calculation in paragraph (b)(3) is with a floating intercept, providing  
a conversion to kg/mol for M mix in the example problem for  
paragraph (d)(1), and correcting an error in the example problem in  
applying Equation 1065.640-10 where M mix was used with the  
wrong units.  
     Section 1065.640(d)(3)--Providing additional guidance on  
how to calculate SEE for C d to correspond with the changes  
made to Sec.  1065.602.  
     Section 1065.642(b)--Correcting a cross-reference.  
     Section 1065.642(c)(1)--Defining C f. 
     Section 1065.643--Adding a new section on carbon balance  
error verification calculations to support the new Sec.  1065.543.  
     Section 1065.650(b)(3)--Adding DEF to clarify what is  
needed for chemical balance calculations.  
     Section 1065.650(c)(1)--Relocating transformation time  
requirement from Sec.  1065.650(c)(2)(i) to Sec.  1065.650(c)(1).  
     Section 1065.650(c)(3)--Updating the equation to include  
the appropriate variable to represent increments by italicizing the  
``i''. 
     Section 1065.650(d)--Correcting cross-references.  
     Section 1065.650(d)(7)--Updating to include the  
appropriate variable to represent increments by italicizing the ``i''.  
     Section 1065.650(f)(2)--Adding DEF to clarify what is  
needed for chemical balance calculations.  
     Section 1065.650(g)--Updating the equations to include the  
appropriate variable to represent increments by italicizing the ``i''  
and correcting variable name from e NOxcomposite  to  
eNOxcomp. 
     Section 1065.655--Adding ``DEF'' to the section heading.  
     Section 1065.655(a) and (c) introductory text--After  
considering comments by EMA, we modified this section to clarify that  
the inclusion of diesel exhaust fluid in the chemical balance is  
optional.  
     Section 1065.655(c)(3)--Updating the x Ccombdry   
variable description to include injected fluid.  
     Section 1065.655(d)--After considering comments by EMA, we  
modified this section to clarify that the inclusion of diesel exhaust  
fluid in the wC determination is optional.  
     Section 1065.655(e)(1)(i)--Clarifying the determination of  
carbon and hydrogen mass fraction of fuel, specifically to S and N  
content.  
     Section 1065.655(e)(3)--Clarifying that nonconstant fuel  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 13/268mixtures also applies to flexible fueled engines.  
     Section 1065.655(e)(4)--Updating to include the  
appropriate variable to represent increments by italicizing the ``i''.  
     Section 1065.655(e)(5)--Adding new paragraph (e)(5) to  
denote that table 1 follows.  
     Section 1065.655 Table 1--Updating cross-reference.  
     Section 1065.655(f)(3)--Restricting the use of Equation  
1065.655-25 if the standard setting part requires carbon balance  
verification and including the appropriate variable to represent  
increments by italicizing the ``j''; adding in the final rule a  
description of the variable for carbon mass fraction, as it was  
missing.  
     Section 1065.655(g)(1)--Updating cross-reference.  
     Section 1065.659(c)(2) and (3)--Adding DEF to clarify what  
is needed for chemical balance chemical balance calculations.  
     Section 1065.660(a)(5) and (6)--Adding new paragraphs to  
those proposed codifying existing practice to calculate THC based on  
measurements made with FTIR for gaseous fueled engines. EPA intended in  
previous updates to part 1065 to allow the determination of NMNEHC and  
NMHC using FTIR from gaseous fueled engines, but the HD Phase 2  
rulemaking inadvertently omitted instructional text in paragraph (a) on  
calculating THC using the two FTIR additive methods.  
     Section 1065.660(b)(2) and (3)--Correcting typographical  
errors, including adding missing commas.  
     Section 1065.660(b)(4)--Correcting a typographical error  
for the chemical formula of acetaldehyde in a variable.  
     Section 1065.660(c)(2)--Including NMC FID as allowable  
option in NMNEHC calculation and further modifying Sec.  1065.660(c) in  
the final rule adding additional information on performing the NMNEHC  
calculation and to correct typos in variables.  
     Section 1065.660(d)--Adding missing parentheses.  
     Section 1065.665(a)--Deleting the variable and description  
for C# as it is not used in any calculation in this section.  
     Section 1065.667(d)--Adding DEF to clarify what is needed  
for chemical balance description.  
     Section 1065.675(d)--Editing variable descriptions to  
refer to a humidity generator rather than a bubbler (accommodates both  
a bubbler and humidity generator).
     Section 1065.695(c)(8)(v)--Adding carbon balance  
verification.  
     Section 1065.701(b)--Updating name of California gasoline  
type. 
     Section 1065.701 Table 1--Updating footnote format in  
table. 
     Section 1065.703 Table 1--Updating to correct units for  
kinematic viscosity and updating footnote format in table.  
     Section 1065.705 Table 1--Updating to correct units for  
kinematic viscosity and updating footnote format in table.  
     Section 1065.710 Table 1--Editing format for consistency  
and updating footnote format in table.  
     Section 1065.710 Table 2--Editing format for consistency,  
adding allowance to use ASTM D1319 or D5769 for total aromatic content  
determination and ASTM D1319 or D6550 for olefin determination because  
the dye used in ASTM D1319 is becoming scarce and an alternate method  
is needed, and updating a footnote format in table.  
     Section 1065.715 Table 1--Updating footnote format in  
table. 
     Section 1065.720 Table 1--Updating footnote format in  
table and revising Table 1 after considering a comment by EMA to  
specify ASTM D6667 instead of ASTM D2784 as the reference procedure for  
measuring sulfur in liquefied petroleum gas. We requested comment on  
amending the  
[[Page 34317]]  
regulation to replace ASTM D2784, which has been withdrawn by ASTM  
without replacement, received comment from EMA and agree that ASTM  
D6667 is a suitable method. EPA is similarly changing other regulatory  
provisions to specify ASTM D6667 as the reference procedure for fuel  
manufacturers measuring sulfur in butane (see 40 CFR 1090.1350).  
     Section 1065.750 Table 1--Updating footnote format in  
table. 
     Section 1065.790(b)--Adding a NIST traceability  
requirement for calibration weights for dynamometer, fuel mass scale,  
and DEF mass scale.  
     Section 1065.905 Table 1--Updating footnote format in  
table. 
     Section 1065.910(a)(2)--Adding a revision in the final  
rule to change the requirement to use 300 series stainless steel tubing  
to connect the PEMS exhaust and/or intake air flow meters into a  
recommendation because there are other materials that are equally  
suitable for in-use testing other than stainless steel tubing.  
     Section 1065.915 Table 1--Updating footnote format in  
table. 
     Section 1065.1001--Adding a definition for enhanced-idle.  
     Section 1065.1001--Clarifying definition of test interval  
as duration of time over which the mass of emissions is determined.  
     Section 1065.1005(a)--Updating footnote format in table  
and parameter names for consistency with other parts.  
     Section 1065.1005(c), (d), and (e)--Updating to ensure  
column headings use terminology consistent with NIST SP-811.  
     Section 1065.1005(a) and (e)--Updating tables of symbols  
and subscripts to reflect revisions to part 1065.  
     Section 1065.1005(f)(2)--Adding molar mass of ethane and  
updating footnote format in table.
     Section 1065.1005(g)--Updating acronyms and abbreviations  
for ASTM, e.g., and i.e.  
     Section 1065.1010(b)(23) and (43)--Incorporating by  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 14/268reference ASTM D6667 into the regulations instead of ASTM D2784,  
consistent with replacing ASTM D2784 with ASTM D6667 as the reference  
procedure for measuring sulfur in liquefied petroleum gas in Sec.   
1065.720, as explained above in this section. EPA is similarly  
specifying ASTM D6667 as the reference procedure for fuel manufacturers  
measuring sulfur in butane.  
4. 40 CFR Part 1066 Test Procedures  
    EPA proposed several updates to the testing and measurement  
provisions of 40 CFR part 1066 related to how to measure emissions from  
light- and heavy-duty vehicles and requested comment on general  
improvements to the vehicle test procedures and compliance provisions  
(see 85 FR 28144). This section presents the changes we are adopting to  
vehicle test procedures after consideration of comments received.  
Chapter 2 of our Response to Comments includes additional details on  
some of these amendments, as well as other testing and measurement  
amendments or clarifications requested by commenters and our responses.  
    We are generally finalizing revisions as proposed; however, some  
revisions include further changes and clarifications after  
consideration of public comments to better ensure clarity, accuracy and  
consistency with the intent of the proposed rule.  
     Section 1066.1(g)--Updating the URL.  
     Section 1066.135(a)(1)--Revising to widen the range for  
verifications of a gas divider derived analyzer calibration curve to 10  
to 60% to ease lab burden with respect to the number of gas cylinders  
they must have on hand and revising to make the midspan check optional  
as the part 1066 requirement for yearly linearity verification of the  
gas divider has provided more certainty of the accuracy of the gas  
blending device.  
     Section 1066.210(d)(3)--Changing the value for  
acceleration of Earth's gravity from a calculation under 40 CFR  
1065.630 to a default value of 9.80665 m/s2 because the  
track coastdown doesn't take place in the same location that the  
dynamometer resides. Therefore, best practice is to use a default value  
for gravity.  
     Section 1066.255(c)--Clarifying that the torque transducer  
zero and span are mathematically done prior to the start of the  
procedure.  
     Section 1066.260(c)(4)--Correcting an error in the example  
problem result.  
     Section 1066.265(d)(1)--Correcting example equation to  
replace a subtraction sign that was a typographical error with a  
multiplication sign.  
     Section 1066.270(c)(4)--Correcting units for force in mean  
force variable description and correcting example problem solution.  
     Section 1066.270(d)(2)--Adding corrections in the final  
rule of typographical errors on maximum allowable error where error  
tolerances were indicated as `` '', but paragraph is clear  
that the allowable error is a maximum value as Equation 1066.270-2  
determines error as an absolute value. Therefore, the error values are  
positive and not a positive and negative range.  
     Section 1066.275--Extending the dynamometer readiness  
verification interval from within 1 day before testing to an optional 7  
days prior to testing if historic data from the test site supports an  
interval of more than 1 day. Adding corrections in the final rule of  
typographical errors in paragraphs (d)(1) and (2) on allowable error  
where error tolerances were indicated as `` '', but  
paragraph is clear that the allowable error is a maximum value as  
Equation 1066.270-2 determines error as an absolute value. Therefore,  
the error values are positive and not a positive and negative range.  
     Section 1066.405--Updating heading to include  
``maintenance''.  
     Section 1066.405(a) through (c)--Designating existing text  
as paragraph (a), adding new paragraphs (b) and (c) to address test  
vehicle inspection, maintenance and repair, consistent with Sec.   
1065.410, and, after considering a comment by Auto Innovators,  
replacing ``bad engine'' with ``malfunctioning'' in relation to engine  
components in paragraph (b).  
     Section 1066.420 Table 1--Updating footnote format in  
table and, after considering comments from Auto Innovators and VW,  
clarifying that SC03 humidity tolerance is an ``average'' value  
consistent with 40 CFR 86.161-00(b)(1) and inadvertently not carried  
over in part 1066. All SC03 capable test cells have been designed to  
meet the humidity requirement in Sec.  86.161-00 which is on an average  
basis. 
     Section 1066.605--Correcting a typographical error in  
paragraph (c)(4) where NMHC should read NMHCE and editing Equation  
1066.605-10 adding italics for format consistency.  
     Section 1066.610--Editing Equation 1066.610-4 adding  
italics for format consistency.  
     Section 1066.710(c)--Clarifying to reflect how heating,  
ventilating, and air conditioning (HVAC) control systems operate in  
vehicles and how they should be operated for the test. Further  
modifying paragraph (c)(1)(i)(A) in the final rule to state that for  
automatic temperature control systems that allow the operator to select  
a specific temperature, set the air temperature at 72 [deg]F or higher,  
which the vehicle then maintains by providing air at that selected  
constant temperature. Further modifying paragraph (c)(2) in the final  
rule to state that for full automatic temperature control systems that  
allow the operator to select a specific temperature, set the air  
temperature at 72 [deg]F, which the vehicle then maintains by varying  
temperature, direction and  
[[Page 34318]]  
speed of air flow. Clarifying terminology is consistent with EPA  
compliance guidance CD-2020-04.  
     Section 1066.801 Figure 1--Updating to reflect that the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 15/268initial vehicle soak, as outlined in the regulations, is a 6-hour  
minimum and not a range of 6 to 36 hours.  
     Section 1066.835(a)--Clarifying that the last drain and  
fill operation is after the most recent FTP or highway fuel economy  
test (HFET) measurement (with or without evaporative emission  
measurements).  
     Section 1066.835(f)(2)--Deleting the word  
``instantaneous'' to reflect that the SC03 temperature and humidity  
tolerances in paragraph (f)(1) are not all instantaneous in response to  
comments received from Auto Innovators and Volkswagen. This was an  
inadvertent error in part 1066.  
     Section 1066.930--Adding a period to the end of the  
sentence.  
     Section 1066.1005(a)--Updating a parameter name to be  
consistent with use in other parts.  
     Section 1066.1005(c) and (d)--Updating to ensure column  
headings use terminology consistent with NIST SP-811.  
     Section 1066.1005(f)--Updating footnote format in table.  
5. Greenhouse Gas Emissions Model (GEM)  
    EPA proposed several updates to the GEM model related to how to  
measure emissions from heavy-duty engines and requested comment on  
whether the differences in GEM would impact the effective stringency of  
the standards and, if so, whether either GEM or the regulations need to  
be revised to address the changes (see 85 FR 28145, May 12, 21020).  
This section presents the changes we are adopting to GEM after  
consideration of comments received. Additional details on these and  
other amendments or clarifications requested by commenters and our  
responses are available in Chapter 2 of our Response to Comments.  
    GEM is a computer application that estimates the greenhouse gas  
(GHG) emissions and fuel efficiency performance of specific aspects of  
heavy-duty (HD) vehicles. GEM is used to determine compliance with the  
Phase 2 standards from several vehicle-specific inputs, such as engine  
fuel maps, aerodynamic drag coefficients, and vehicle weight rating.  
GEM simulates engine operation over two cruise cycles, one transient  
cycle, and for vocational vehicles, idle operation. These results are  
weighted by GEM to provide a composite GEM score that is compared to  
the standard.  
    EPA proposed to update GEM, in a revised version 3.5 to replace the  
current version 3.0, and requested comment on whether the differences  
in GEM would impact the effective stringency of the standards and, if  
so, whether either GEM or the regulations need to be revised to address  
the changes. We received one comment on the proposal on this topic from  
the California Air Resources Board (CARB), stating the importance of  
GEM results being consistent with the current program standards to  
ensure stringency is maintained and recommending that EPA revise GEM to  
maintain this consistency.  
    After considering the comment and further evaluating the  
performance of GEM 3.5 with the input files used to set the Phase 2  
vehicle standards, EPA is finalizing GEM version 3.5.1 applicable for  
MY 2021 vehicles that includes the changes proposed in version 3.5 as  
well as changes that correct three errors in the GEM 3.5 code. The  
following changes were proposed in version 3.5 and are finalized in  
version 3.5.1 to allow additional compliance flexibilities and improve  
the vehicle simulation:  
     Corrected how idle emission rates are used in the model.  
     Increased the allowable weight reduction range to 25,000  
pounds. 
     For powertrain input, added an input for powertrain rated  
power to scale default engine power.  
     Recalibrated driver over speed allowance on cruise cycles  
from 3 mph to 2.5 mph.  
     Revised engine cycle generation outputs with corrected  
engine cycle generation torque output from model based on simulated  
inertia and rate limited speed target.  
     Added scaling of powertrain simulation default engine and  
transmission maps based on new rated power input.  
     Changed interpolation of fuel map used in post processing  
to be consistent with one used in simulation.  
     Corrected accessory load value on powertrain test when  
coasting or decelerating.  
     Added torque converter k-factor input option.  
     Cycle average cycles: added flag for points that are to be  
considered ``idle.''  
     Improved handling of large input tables.  
     Allow hybrid engine input.  
    The three additional changes in GEM 3.5.1 correct the following  
errors in GEM 3.5 code: (1) A typographical error, where GEM used a  
weighting factor of 0.25 instead of 0.23 for the Heavy Heavy-Duty (HHD)  
Multipurpose vehicle subcategory; (2) an idle map error when the cycle  
average fuel mapping procedure is used for all three drive cycles; and  
(3) a functional error that unnecessarily required transmission power  
loss data when using the option to enter a unique (instead of default)  
k-factor for the torque converter. The GEM version we are releasing  
with and incorporating by reference in this final rule is identified as  
``3.5.1.''  
    EPA is also issuing a supplemental proposal published in the  
Proposed Rules section of this issue of the Federal Register, titled  
``Improvements for Heavy-Duty Engine and Vehicle Test Procedures,''  
docket number EPA-HQ-OAR-2019-0307; FRL-10018-51-OAR. This supplemental  
proposal provides notice and opportunity for comment on a proposed  
further updated version of GEM for MY 2022 and later, proposes to allow  
use of the updated model for MY 2021 for demonstrating compliance with  
the Phase 2 standards, including obtaining a certificate of conformity  
and submitting end-of-year reports, and requests comment on whether  
this version of GEM should be required for MY2021 end-of-year reports.  
This proposed revised version in the supplemental proposal includes  
corrections, clarifications, additional flexibilities, and adjustment  
factors to the Greenhouse gas Emissions Model (GEM) compliance tool for  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 16/268heavy-duty vehicles after consideration of comments received on the  
proposed rule. The supplemental proposal proposes limiting the use of  
GEM 3.5.1 to MY 2021 vehicles only, except where this MY 2021 data can  
be used for carryover requests for certificates of conformity for MY  
2022 and future years for qualifying vehicles under Sec.  1036.235(d);  
however, manufacturers would still need to use GEM 3.8 for end-of-year  
reporting for MY 2022 and future years.  
    EPA is finalizing GEM 3.5.1 after considering comments, further  
evaluating the performance of GEM 3.5.1 with the input files used to  
set the Phase 2 vehicle standards, considering the corrections and  
improvements made in GEM 3.5.1, and identifying potential additional  
corrections and improvements for GEM. Evaluation of GEM 3.5.1 indicated  
that there was some difference in output 96results for both tractor and  
vocational vehicles when compared to GEM 3.0. To assess the magnitude  
of any differences between using GEM 3.0 and GEM 3.5.1, we repeated the  
process used in 2016 to calculate the numerical level of the vehicle  
standards, replacing GEM 3.0 with GEM 3.5.1. On average, the  
differences in the resulting standards  
[[Page 34319]]  
from using GEM 3.5.1 instead of GEM 3.0 are decreases of 0.09 percent  
and 0.54 percent for the tractor and vocational vehicle standards,  
respectively. The tractor standards resulting from GEM 3.5.1 ranged  
from 0.29 percent below to 0.15 percent above the GEM 3.0 standards.  
The vocational vehicle standards resulting from GEM 3.5.1 ranged from  
0.32 percent above to 1.45 percent below the GEM 3.0 standards. A  
summary of the process taken to calculate the vehicle standards using  
GEM and a comparison of the results generated by GEM 3.0 and GEM 3.5.1  
are provided in a docket memo.\7\  
---------------------------------------------------------------------------  
    \7\ Sanchez, James, Memorandum to Docket EPA-HQ-OAR-2019-0307.  
Process of Using GEM to Set Vehicle Standards. December 4, 2020.  
---------------------------------------------------------------------------  
    We are finalizing GEM 3.5.1 without adopting adjustment factors in  
the related test procedures.\8\ In the same memo noted previously, we  
compare the GEM 3.8 results to those from GEM 3.0. In the supplemental  
proposal, EPA proposes GEM 3.8 and corresponding adjustment factors to  
adjust the results to more closely match the results produced by the  
original GEM 3.0 version and we intend to issue a final rule before the  
start of model year 2022. If finalized as proposed, we would limit the  
potential impact on effective stringency due to a change in GEM  
versions to model year 2021 only, which should have a minimal impact on  
the effective stringency and environmental benefits of the overall  
Phase 2 program.  
---------------------------------------------------------------------------  
    \8\ Greenhouse gas Emissions Model (GEM) Phase 2, Version 3.5.1,  
December 2020. A working version of this software is also available  
for download at https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem-medium-and-heavy-duty . 
---------------------------------------------------------------------------  
6. Aerodynamic Test Procedures  
    EPA proposed several updates to the testing and modeling provisions  
of 1037 subpart F related to aerodynamic testing and requested comment  
on general improvements to the aerodynamic test procedures and  
compliance provisions (see 85 FR 28147). This section presents the  
changes we are adopting to aerodynamic test procedures after  
consideration of comments received. Additional details on these and  
other aerodynamic amendments or clarifications requested by commenters  
and our responses are available in Chapter 2 of our Response to  
Comments.  
a. Aerodynamic Measurements for Tractors  
    The aerodynamic drag of a vehicle is determined by the vehicle's  
coefficient of drag (C d), frontal area, air density and  
speed. The regulations in Sec.  1037.525 allow manufacturers to use a  
range of techniques, including wind tunnel testing, computational fluid  
dynamics, and constant speed tests. This broad approach is appropriate  
given that no single test procedure is superior in all aspects to other  
approaches. However, we also recognized the need for consistency and a  
level playing field in evaluating aerodynamic performance. To address  
the consistency and level playing field concerns, EPA adopted an  
approach that identified coastdown testing as the reference aerodynamic  
test method, and specified a procedure to align results from other  
aerodynamic test procedures with the reference method by applying a  
correction factor (F alt-aero ) to results from alternative  
methods (Sec.  1037.525(b)). We are adding a sentence to the  
introductory text of Sec.  1037.525 to clarify that coastdown testing  
is the ``reference method for aerodynamic measurements''.  
    In the proposed rule, we proposed to separate Sec.  1037.525(b)(1)  
into a paragraph (b)(1) defining F alt-aero  and a new  
paragraph (b)(2) allowing manufacturers to assume F alt-aero   
is constant for a given alternate method. We are finalizing two  
separate paragraphs and the subsequent renumbering of the remaining  
paragraphs as proposed except as explained here. Our proposed update to  
the definition of F alt-aero  in Equation 1037.525-1 and the  
related text in Sec.  1037.525(b)(1) inadvertently removed the  
definition of effective yaw, c eff, which is used throughout  
Sec.  1037.525 and incorrectly replaced the C dA variables  
measured at [psi] eff with wind-averaged C dA  
values, as noted in comment by EMA. We agree that Equation 1037.525-1  
should continue to be based on the definition from HD GHG Phase 2 final  
rule such that F alt-aero  is a function of the coefficient of  
drag areas at the effective yaw angle. We are finalizing paragraph  
(b)(1) with the same Equation 1037.525-1 as the current requirement but  
with the updated variable names throughout Sec.  1037.525 (and where  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 17/268referenced in Sec.  1037.525(h)(12)(v)) to more clearly relate the drag  
areas to the defined effective yaw variable, as recommended by EMA.\9\  
We are also adding a ``Where:'' statement to Equation 1037.525-1 to  
define the variables in that equation and are restoring the existing  
language we proposed to remove that defines the effective yaw angle to  
apply for Phase 1 and Phase 2 compliance.  
---------------------------------------------------------------------------  
    \9\ The variables  
CdAeffective-yaw-coastdown  and  
CdAeffective-yaw-alt  are now  
CdAcoastdown (ceff) and  
CdAalt(ceff), respectively.  
---------------------------------------------------------------------------  
    We proposed and received no adverse comments on two additional  
changes in Sec.  1037.525(b). In paragraph (b)(3), we proposed and are  
finalizing removal of the sentence ``Where you have test results from  
multiple vehicles expected to have the same F alt-aero , you  
may either average the F alt-aero  values or select any  
greater value.'' By removing this statement, we are allowing  
manufacturers the flexibility to propose a method for calculating their  
Falt-aero  from multiple test vehicles that suits their  
unique compliance margin targets. In paragraph (b)(5), we proposed to  
add a statement that manufacturers may test earlier model years than  
the 2021, 2024, and 2027 model years specified and are finalizing  
additional clarifying text and a new example. We are finalizing two  
additional typographical edits correcting references to our renumbered  
paragraphs in the paragraph (b)(5). The reference to ``paragraph  
(b)(2)'' was corrected to paragraph (b)(3) and the reference to ``this  
paragraph (b)(4)'' was corrected to paragraph (b)(5). Finally, we are  
adding the phrase ``drag area from your alternate method'' to describe  
the previously undefined term, C dAalt. 
    EPA proposed a change to Sec.  1037.525(b)(7), to clarify that the  
use of good engineering judgment with respect to the specified tractor-  
trailer gap dimension ``applies for all testing, including confirmatory  
and SEA testing''. Both EMA and Volvo requested further clarification  
through use of an example. We are finalizing three clarifying changes  
to Sec.  1037.525(b)(7). First, we are adding a reference to the  
tractor-trailer gap specifications in Sec.  1037.501(g)(1)(ii), as  
requested. Second, we provide an example of good engineering judgment  
that could be applied to correct a difference between the specified and  
tested tractor-trailer gaps. Lastly, we clarify that the allowance  
applies ``for certification, confirmatory testing, SEA, and all other  
testing to demonstrate compliance with standards.''  
    We also proposed a provision to our regulations at Sec.   
1037.525(b)(8) to encourage manufacturers to proactively coordinate  
with EPA to have compliance staff present when a manufacturer conducts  
its coastdown testing to establish F alt-aero  values. Section  
208 of the Clean Air Act provides EPA broad oversight authority for  
manufacturer testing. Being present for the testing would give EPA  
greater confidence that the test was conducted properly, and thus,  
would make it less likely that EPA would need to conduct aerodynamic  
confirmatory testing on the  
[[Page 34320]]  
vehicle. Consistent with the intent of the proposed revision and EPA's  
authority under section 208, we are finalizing in Sec.  1037.525(b)(8)  
a provision that refers to the existing preliminary approval provisions  
of Sec.  1037.210 with the note that EPA may witness the testing.  
Section 1037.210 provides an established protocol for manufacturers to  
coordinate with EPA for testing.  
    EMA's comment requested additional modifications to the yaw sweep  
correction provisions in Sec.  1037.525(c), suggesting that coastdown  
results do not need to be corrected to wind-averaged and that all of  
paragraph (c)(2) was ``unnecessary'' because another regulatory  
provision ``serves that function''. Their request appears to be a  
misunderstanding of the existing regulations. Wind-averaged drag area  
(CdAwa) is a required input for GEM in Phase 2.  
Paragraph (c)(1) specifies how to calculate C dAwa  
when using an alternate test method and paragraph (c)(2) specifies how  
to calculate it for coastdown testing. EPA may use coastdown for  
confirmatory testing and manufacturers may choose to use coastdown  
testing for all aerodynamic testing. Consequently, paragraph (c)(2) is  
needed to properly calculate the wind-averaged input required by GEM in  
these situations. To address any potential confusion on the necessity  
of both paragraphs under the current regulatory text, we are finalizing  
three updates to Sec.  1037.525(c) as follows:  
     Clarifying the use of the yaw correction provisions by  
revising paragraph (c) introductory text to add ``as specified in Sec.   
1037.520'' and to remove the phrase ``differences from coastdown  
testing'' that only applies to paragraph (c)(1).  
     Updating the text of paragraphs (c)(1) and (2) to more  
clearly communicate that they are two separate options that apply based  
on which testing method is chosen.
     Adopting the updated drag area variable names from Sec.   
1037.525(b).  
b. Aerodynamic Measurements for Vocational Vehicles  
    We did not specifically propose changes to or request comment on  
our procedures for measuring aerodynamic performance of vocational  
vehicles in Sec.  1037.527. EMA commented that the existing provisions  
of Sec.  1037.527 to determine a DC dA value for vocational  
vehicles refer to the trailer provisions in Sec.  1037.526; however,  
Sec.  1037.526 does not specify how to choose an appropriate baseline  
for vocational vehicles. EMA requested that manufacturers should be  
able to ``choose an appropriate baseline vehicle for the technology and  
applications''. We are not taking any final action on this issue at  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 18/268this time. However, we are providing a summary of the current  
provisions and their original intent in this preamble to assist  
manufacturers.  
    The current Sec.  1037.527(a) states that DC dA is  
determined for vocational vehicles as follows: ``Determine  
DCdA values by performing A to B testing as described for  
trailers in Sec.  1037.526, with any appropriate adjustments,  
consistent with good engineering judgment.'' The A to B testing  
provisions for trailers are specified in Sec.  1037.526(a), where  
paragraph (a)(1) describes the baseline trailer, paragraph (a)(2)  
describes the general intent of the A to B test, and paragraph (a)(3)  
describes how to calculate the DC dA from the test results.  
    We acknowledge that the reference to a ``standard trailer'' in  
Sec.  1037.526(a)(1) may cause confusion to vocational vehicle  
manufacturers, since it would be a challenge to identify a single  
``standard'' vehicle to represent the range of vocational applications.  
However, the baseline trailer description in that paragraph equates to  
a trailer without aerodynamic components, which is the key aspect of  
that baseline description the regulatory cross-reference in Sec.   
1037.527(a) applies to vocational vehicles. The trailer provision of  
Sec.  1037.526(a)(2) states that the general intent of the A to B test  
is to ``demonstrate the reduction in aerodynamic drag associated with  
the improved design'', which can be directly applied to vocational  
vehicles. The general process of calculating DC dA in Sec.   
1037.526(a)(3) could be applied to vocational vehicles as well, but its  
reference to test trailer and baseline trailer may cause confusion for  
reasons similar to those discussed for Sec.  1037.526(a)(1).  
    Similar to the trailer provision, a vocational vehicle's  
aerodynamic performance is based on a DC dA value relative to  
a baseline vehicle. Manufacturers wishing to perform aerodynamic  
testing on their vocational vehicles are encouraged to coordinate with  
their Designated Compliance Officer and use the existing provision in  
Sec.  1037.527, including its reference to the description of how to do  
so for the trailer-specific provision in Sec.  1037.526. As noted in  
Sec.  1037.527(a), we expect manufacturers to make ``appropriate  
adjustments'' when applying the cross-referenced provision to  
vocational vehicle testing consistent with good engineering judgment.  
When followed, this should result in a manufacturer choosing an  
appropriate baseline vehicle, similar to the clarification requested by  
the commenter. For example, a manufacturer may choose an aerodynamic  
test method, determine a baseline C dA value (in m\2\) using  
a vehicle that represents a production configuration without the  
aerodynamic improvement, then repeat the same aerodynamic method for a  
test vehicle that is a nearly equivalent configuration but includes the  
aerodynamic improvement of interest. In this case, the manufacturer  
would calculate DC dA by subtracting the measured drag area  
for the test vehicle from the drag area for the baseline vehicle.  
Calculating DC dA in this manner would generally be  
consistent with the intent that the test ``accurately demonstrate the  
reduction in aerodynamic drag associated with the improved design'' for  
the vocational vehicle since any improvement to aerodynamic performance  
would be attributable to the aerodynamic technology on the test  
vehicle.  
c. Computational Fluid Dynamics Procedures  
    We proposed one correction to our computational fluid dynamics  
(CFD) provisions of Sec.  1037.532 that replaced the incorrect ``or''  
in paragraph (a)(1) with ``and'' to include yaw angles of +4.5[deg] and  
-4.5[deg]. EMA requested three additional modifications related to our  
CFD provisions. In Sec.  1037.532(a)(3), they requested that we clarify  
our specified Reynolds number of 5.1 million is based on the 102-inch  
trailer width as the characteristic length. We agree with this  
suggestion and updated the language in Sec.  1037.532(a)(3) for clarity  
that the Reynolds number is based on a 102-inch trailer width  
consistent with our specifications for a ``standard trailer'' in Sec.   
1037.501(g)(1)(i). EMA also suggested the phrase ``the General On-Road  
Simulation'' in Sec.  1037.532(a)(4) be replaced with ``an open-road  
simulation'' to avoid confusion with SAE International's revisions of  
SAE J2966 to incorporate the impact of traffic. We agree that open-road  
simulation is representative of our initial intent and are updating the  
regulatory text of Sec.  1037.532(a)(4). See Chapter 2 of our Response  
to Comments for additional details.  
    EMA's third request was that we remove the requirement to set the  
``free stream turbulence intensity to 0.0 percent'' in Sec.   
1037.532(a)(5), and instead recommended we replace that requirement  
with a ``uniform inlet velocity profile.'' EPA is not taking any final  
action on revision to that paragraph at this time. Furthermore, EPA  
disagrees with the requested change to paragraph (a)(5). Turbulence  
intensity is a common parameter in CFD packages and, as described in  
Chapter 
[[Page 34321]]  
3.2.2.3 of the Final Regulatory Impact Analysis (Final RIA) for the HD  
Phase 2 Rule, we evaluated a range of turbulence intensities and  
intentionally specified a value of zero to ensure consistency, stating  
that ``Turbulence intensity must be 0.0 percent.'' \10\ Manufacturers  
who wish to use alternative parameters and criteria related to their  
CFD models, which includes seeking to substitute the specified  
turbulence intensity with a uniform inlet velocity profile, continue to  
have the option to seek to do so through requesting EPA approval under  
Sec.  1037.532(f).  
---------------------------------------------------------------------------  
    \10\ US EPA, US DOT/NHTSA. Greenhouse Gas Emissions and Fuel  
Efficiency Standards for Medium- and Heavy-Duty Engines and  
Vehicles--Phase 2: Regulatory Impact Analysis. EPA-420-R-16-900.  
August 2016. Page 3-41.  
---------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 19/268    CARB requested EPA add provisions that set a requirement for a  
maximum limit of computational elements to perform Computational Fluid  
Dynamics (CFD) simulation, define a specific transient averaging  
methodology, quantify the uncertainty in using CFD simulation, and  
assess CFD simulation credibility. We are not taking any final action  
on these requests, but may consider the changes suggested by the  
commenter in an appropriate future rulemaking with notice and comment.  
See our complete response in Chapter 2 of our Response to Comments.  
7. Hybrid Powertrain Test Procedures  
    As explained above in Sections II.A.1 and II.A.2, EPA proposed  
several updates to the hybrid powertrain test procedures that apply to  
engine and vehicle standards provisions in 40 CFR 1036.503, 1036.505,  
1036.510, and 1036.527, 40 CFR part 1036, appendix B, and 40 CFR  
1037.550 related to how to perform hybrid powertrain testing and  
requested comment on general improvements to the hybrid powertrain test  
procedure provisions (see 85 FR 28152). This section further explains,  
in addition to the specific descriptions in Sections II.A.1. and  
II.A.2. above, the changes we are adopting to hybrid powertrain test  
procedures after consideration of comments received. Additional details  
on these and other hybrid powertrain testing and measurement amendments  
or clarifications requested by commenters and our responses are  
available in Chapter 2 of our Response to Comments.  
a. Hybrid Test Procedures for Engine Standards  
    EPA worked with industry prior to proposal and also considered  
input provided during this rulemaking to develop a powertrain test  
procedure that includes the addition of a transmission model to GEM and  
options in GEM to test without the transmission present, using the  
model in its place to be used to certify a hybrid powertrain to the FTP  
and SET HD GHG Phase 2 greenhouse gas engine standards. The two primary  
goals of this development process were to make sure that the powertrain  
version of each test cycle was equivalent to the respective engine  
cycle in terms of positive power demand versus time and that the  
powertrain cycle had appropriate levels of negative power demand.  
    Our current regulations do not have a certification procedure for  
powertrain certification of heavy-duty hybrid vehicles to any engine  
standards. The powertrain certification test for certification to both  
the FTP and SET is carried out by following 40 CFR 1037.550 as  
described in 40 CFR 1036.505 and 1036.510 and is applicable for  
powertrain systems located in the P0, P1, P2, and P3 positions.  
    For this test procedure, EPA is finalizing addition of a vehicle  
speed and road grade profile to the existing FTP duty cycles for  
compression-ignition and spark-ignition engines in 40 CFR part 1036,  
appendix B, and to the SET duty cycle in 40 CFR 1036.505. EPA also is  
finalizing vehicle parameters to be used in place of those in 40 CFR  
1037.550; namely vehicle test mass, vehicle frontal area, vehicle drag  
area, coefficient of rolling resistance, drive axle ratio, tire radius,  
vehicle curb mass, and linear equivalent mass of rotational moment of  
inertias. Under the final test procedure, determination of system and  
continuous rated power along with the maximum vehicle speed (C speed)  
is also required using 40 CFR 1036.527. Under the final test procedure,  
the combination of the generic vehicle parameters, the engine duty-  
cycle vehicle speed profile, and road grade profile fully defines the  
system load and this is designed to match up the powertrain load with  
the compression-ignition engine vFTP, spark ignition engine vFTP, and  
vSET load for an equally powered engine.  
    The development of this test procedure was based on the process  
contained in Global Technical Regulation No. 4.11 12  
Generally speaking, the final test procedure is powertrain in the loop  
using a vehicle-based cycle (vehicle speed vs. time and grade vs.  
time). The final vehicle speed profiles were developed by following SAE  
2012-01-0878.\13\  
---------------------------------------------------------------------------  
    \11\ United Nations Economic Commission for Europe. Addendum 4:  
Global technical regulation No. 4. Test procedure for compression  
ignition (C.I.) engines and positive-ignition (P.I.) engines fueled  
with natural gas (NG) or liquefied petroleum gas (LPG) with regard  
to the emission of pollutants Amendment 3., March 12, 2015.  
    \12\ Six, C., Siberholz, G., Fredriksson, J., Geringer, B.,  
Hausberger, S. Development of an exhaust emission and CO2  
measurement test procedure for heavy-duty hybrids (HDH). October 27,  
2014. Available online at: https://wiki.unece.org/download/attachments/4064802/20141027_ACEA_Report.pdf?api=v2 . 
    \13\ Andreae, M., Salemme, G., Kumar, M., and Sun, Z.,  
``Emissions Certification Vehicle Cycles Based on Heavy Duty Engine  
Test Cycles,'' SAE Int. J. Commer. Veh. 5(1):299-309, 2012, https://doi.org/10.4271/2012-01-0878 . 
---------------------------------------------------------------------------  
    The engine operational profile for engines installed in vehicles  
depends on the entire vehicle setup, including the use of hybrid  
systems if applicable, thus the entire vehicle must be considered when  
certifying a powertrain. Given that heavy duty vehicles can vary quite  
a bit even though the powertrain configuration remains unchanged,  
testing of every conceivable configuration is not possible; therefore,  
a representative average vehicle, consisting of generic vehicle  
parameters, is used to provide a representative configuration for  
certification testing. Generic vehicle parameters were developed with  
the intent of maintaining the same system load for engines installed in  
conventional vehicles and hybrid systems with the same power rating to  
maintain comparability in terms of emissions.\14\  
---------------------------------------------------------------------------  
    \14\ Six, C., Siberholz, G., Fredriksson, J., Geringer, B.,  
Hausberger, S. Development of an exhaust emission and CO2  
measurement test procedure for heavy-duty hybrids (HDH). October 27,  
2014. Available online at: https://wiki.unece.org/download/attachments/4064802/20141027_ACEA_Report.pdf?api=v2 . 
---------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 20/268    EPA is finalizing vehicle parameters for hybrid powertrain testing  
in place of those in 40 CFR 1037.550 to be used in the vehicle model in  
40 CFR 1037.550(f). These final parameters can be found in 40 CFR  
1036.505 (via reference from 40 CFR 1036.510 for FTP testing) and  
included vehicle test mass, M, vehicle frontal area, A front,  
vehicle drag area, C dA, coefficient of rolling resistance,  
Crr, drive axle ratio, k a, tire radius, r,  
transmission efficiency if the hybrid powertrain is being tested  
without the transmission, axle efficiency, Eff axle, vehicle  
curb mass, M curb, and linear equivalent mass of rotational  
moment of inertias, M rotating . The requirements for the  
determination of these parameters were taken from the Global Technical  
Regulation (GTR) No. 4 referenced above.  
    Under the final test procedure, to align the system demands for  
conventional and hybrid engines, the generic vehicle parameters are  
defined as a function of the system's power  
[[Page 34322]]  
rating. 40 CFR 1036.527 provides the procedure for determining the peak  
rated power, P rated, and continuous rated power of the  
hybrid system, P contrated , that goes into the vehicle test  
mass determination. These revisions also provide a procedure for the  
determination of the maximum vehicle speed (C speed), vrefC. In  
general, the process for determining both P rated and  
Pcontrated  is very similar to the GTR No. 4 hybrid system  
rated power determination procedure with a few exceptions. In the final  
40 CFR 1036.527 procedure, the default axle efficiency is 0.955 because  
that is the default value in GEM. The determination of continuous rated  
power in the final EPA process versus the system rated power in the GTR  
No. 4 process is to address the lack of a steady state vehicle test  
cycle in GTR No. 4. The full throttle test to determine system rated  
power in GTR No. 4 lasts 50 to 150 seconds and GTR No. 4 determines  
rated power as peak power during these tests. While this process is  
appropriate for the FTP, the SET is 2400 seconds long and the extended  
operation at some high speed and load points can lead to some hybrid  
systems not being able to sustain peak power over the course of the  
test due to thermal limitations on the motor generator (generally due  
to material limitations) and limitations on the battery storage  
capacity and available usable energy. Under these scenarios, the hybrid  
system will typically derate the motor generator to thermally protect  
it, resulting in a sustained peak power that is lower than that  
determined using the GTR No. 4 process.  
    Under the final test procedure, the powertrain system rated power  
determination in 40 CFR 1036.527 includes the determination of both  
peak and continuous rated power. The peak rated power  
(Prated) is used in the transient FTP test procedure, while  
the continuous rated power (P contrated ) is used in the  
steady-state SET test procedure. The vehicle C speed, v refC,  
is also determined as a result of this process. This is the maximum  
vehicle speed at which Psys equals Pcontrated.  
    The final compression-ignition vFTP duty cycle vehicle speed  
profile was derived from the compression-ignition FTP vehicle duty-  
cycle developed in SAE 2012-01-0878. In this work, a vehicle FTP cycle  
and a vehicle SET cycle were created based on the transient diesel  
engine FTP and engine SET duty cycles. The vehicle cycles are the same  
duration and have similar power requirements and performance when  
compared to the engine cycles. The alignment of the engine and vehicle  
cycles maintain a consistency within vehicle and engine emissions  
evaluations. The compression-ignition FTP vehicle speed profile is not  
applicable to the spark-ignition FTP vehicle speed profile due to  
differences in the engine duty-cycle lengths, speed profiles, and  
torque profiles. Thus, a separate vehicle speed profile had to be  
developed for the spark-ignition FTP duty cycle. Using the methodology  
in SAE 2012-01-0878, a vehicle speed profile was developed for the  
spark-ignition FTP duty cycle and a comparison between the two cycles  
can be found in Table II-2. The vehicle speed profiles can be found in  
Figure II-1 and Figure II-2.  
    Table II-2--Comparison Between FTP Vehicle Duty-Cycle Metrics for  
      Vehicles with Compression-Ignition and Spark-Ignition Engines  
------------------------------------------------------------------------  
                                      Compression-       Spark-ignition  
          Cycle metric               ignition  FTP     FTP vehicle  duty  
                                  vehicle  duty cycle        cycle  
------------------------------------------------------------------------  
Maximum acceleration (m/s2).....                 1.55               1.47  
Maximum deceleration (m/s2).....                -2.26              -2.15  
Average speed (mph).............                 20.1               19.2  
Maximum speed (mph).............                 60.6               60.8  
Stop duration (%)...............                  3.3                4.7  
Distance (miles)................                  6.4                6.4  
------------------------------------------------------------------------  
BILLING CODE 6560-50-P  
[[Page 34323]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.003  
    The road gradient profile is designed to further align the  
powertrain system load for engines installed in conventional vehicles  
and hybrid systems to eliminate the deviations in cumulative work done  
between the engine and powertrain test. The grade profiles were  
developed to align the power versus time and cycle work of the vehicle  
profiles (compression-ignition vFTP, spark-ignition vFTP, and vSET) to  
the compression-ignition and spark-ignition FTPs, and SET. The general  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 21/268process was based on the development of the grade profile for the World  
Harmonized Vehicle Cycle (WHVC).\15\ A reference normalized power curve  
was generated using denormalized torque and speed curves from 50  
different compression-ignition engines with multiple engine ratings for  
the compression-ignition FTP, and SET. The denormalized curves were  
normalized individually for each engine based on the engine's rated  
power. The normalized power curves were then averaged to define the  
final reference normalized power curve. Ten different spark-ignition  
engine torque curves were used for the spark-ignition FTP. The duty-  
cycle velocity profile over time was then divided into multiple mini-  
cycles. Within each mini-cycle, a constant grade was defined in such a  
way that the energy calculated from the normalized power curve was  
matched for a given engine power rating. Power ratings between 100 and  
500 kW were used to develop the compression-ignition vFTP, spark-  
ignition vFTP, and vSET duty-cycles. The average slope was calculated  
from the road grade profiles generated for the power ratings between  
100 and 500 kW. The average fixed slope was calculated for every time  
step along the drive cycle, and a second order polynomial was chosen  
for the FTP duty-cycles to describe correlation between, and account  
for the differences in, the average fixed and individual slopes based  
on the rated power (Prated) of the powertrain. The equation and  
coefficient descriptions follow:  
---------------------------------------------------------------------------  
    \15\ Six, C., Siberholz, G., Fredriksson, J., Geringer, B.,  
Hausberger, S. Development of an exhaust emission and CO2  
measurement test procedure for heavy-duty hybrids (HDH). October 27,  
2014. Available online at: https://wiki.unece.org/download/attachments/4064802/20141027_ACEA_Report.pdf?api=v2 . 
[GRAPHIC] [TIFF OMITTED] TR29JN21.004  
    Where a is error compensation in %/kW\2\, b is error compensation  
in %/kW, and c is the average fixed slope pattern. Negative road grade  
is included in the profile to ensured that a representative amount of  
recuperation energy is provided by the test cycle for hybrid  
applications. This enables accurate cycle power/work alignment for all  
vehicles with the FTP duty cycles for both compression-ignition and  
spark-ignition engines. Example vehicle road  
[[Page 34324]]  
grade profiles for a 350 kW compression-ignition and 400 kW spark-  
ignition engine can be found in Figure II-3 and Figure II-4.  
BILLING CODE 6560-50-P  
[GRAPHIC] [TIFF OMITTED] TR29JN21.005  
[[Page 34325]]  
    During additional review of the development of the road grade  
profile for vSET included in the proposal, it became apparent that the  
powertrain might not be able to achieve the default vehicle C speed of  
75.0 mph. To provide a representative maximum vehicle speed and vehicle  
A and B speeds that are scaled to the C speed in the final test  
procedure, the determination of vehicle C speed was added as an  
additional revision to 40 CFR 1036.527. This maximum achievable vehicle  
speed is used as the vehicle C speed in Table 1 of Sec.  1036.505 and A  
and B speed are calculated as described in 40 CFR 1036.505. The final  
test procedure replaces the proposed maximum vehicle C speed and the  
default vehicle A and B speeds in the proposed additions to Table 1 of  
Sec.  1036.505 with these calculated speeds. Adding the allowance to  
scale the vSET test speeds based on the vehicle maximum achievable  
speed required an accounting of the effect of these lower speeds on the  
road grade determination. This resulted in an expansion of the proposed  
second order polynomial equation for the vFTP to include vehicle speed  
in the final test procedure. The expanded equation and coefficient  
descriptions follow:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.006  
    Where a is error compensation in %/kW3, b is error compensation in  
%/kW2[middot]mi/hr, c is error compensation in %/kW2, d is error  
compensation in %/(mi/hr)2, e is error compensation in %/kW[middot]mi/  
hr, f is error compensation in %/kW, g is error compensation in %/mi/  
hr, and h is the average fixed slope pattern. Negative road grade is  
included in the profile to ensure that a representative amount of  
recuperation energy is provided by the test cycle for hybrid  
applications. This enables accurate cycle power/work alignment for all  
vehicles with the engine SET duty-cycle.  
    The final test procedure also includes updates to the road grade  
coefficients for the compression-ignition and spark-ignition vFTP duty  
cycles from those proposed. EPA further reviewed the GTR No. 4 process  
and noted that the work in mini cycles number 4 and 6 was set to zero.  
This was a policy decision made during the GTR No. 4 process but is not  
appropriate for the generation of EPA's duty-cycles, which should  
include the actual work for these two mini cycles. While this  
improvement results in only a marginal difference from that proposed,  
it provides a more aligned comparison of work between the engine and  
vehicle duty-cycles. The result of this was included in the final test  
procedure in updated coefficients for the compression-ignition vFTP,  
spark-ignition vFTP, and vSET duty cycles (vSET improvements are in  
addition to the road grade coefficient updates already discussed).  
Figure II-5 and Figure II-6 show a comparison of the effect on work  
matching from changing the mini cycle work in mini cycles number 4 and  
6 from zero to the actual work for a 300 kW engine. Note, this final  
test procedure is limited to hybrid powertrains to avoid having two  
different testing pathways for non-hybrid engines for the same  
standards.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 22/268[[Page 34326]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.007  
BILLING CODE 6560-50-C  
b. Hybrid Test Procedures for Vehicle Standards  
i. Hybrid Fuel Maps  
    We are finalizing an option, after consideration of comments  
received, to generate fuel maps for engine hybrids using the powertrain  
test procedure in 40 CFR 1037.550. This was done by updating the hybrid  
engine test procedures finalized in 40 CFR 1036.503, 1036.505,  
1036.527, and 1037.550 and include the addition of a transmission model  
to GEM and options in GEM to test without the transmission present,  
using the model in its place.  
ii. Mild Hybrid Certification  
    Under the Phase 2 regulations, manufacturers must conduct  
powertrain testing if they wish to take credit for hybrid systems,  
including mild hybrid systems. However, manufacturers have expressed  
concerns about the cost of powertrain testing and that the existing  
procedure may not measure improvements from certain mild hybrid  
systems. EPA requested comment on alternative means of evaluating mild  
hybrids noting that manufacturers have asked EPA to consider the  
following options:  
[[Page 34327]]  
     Allow manufacturers to test a powertrain and apply  
analytically derived scaling factors to others (e.g., scale by fraction  
of battery capacity or motor capacity) under 40 CFR 1037.235(h).  
     Allow manufacturers to use international test procedures  
for battery capacity, motor power, and motor efficiency.  
     Provide smaller credit (potentially with a volume limit  
and/or only for limited time) in exchange for less testing (e.g.,  
reduced benefit when using the simplified model spreadsheet that is  
available under docket no. EPA-HQ-OAR-2014-0827-2109).  
    Commenters generally responded with support for EPA addressing mild  
hybrid certification but did not provide any concrete means to address  
concerns surrounding the cost of powertrain testing. In addition,  
commenters stated that the existing procedures in the proposal may not  
measure improvements from certain mild hybrid systems. This section  
presents the changes we are adopting to hybrid test procedures after  
consideration of comments received. Additional details on these and  
other hybrid test procedure amendments or clarifications requested by  
commenters and our responses are available in Chapter 2 of our Response  
to Comments.  
    After further consideration, including the lack of additional input  
on these mild-hybrid certification options, we have concluded that the  
engine hybrid test procedure proposed in this rule, is the best pathway  
for these hybrids. This will allow a manufacturer to test a mild hybrid  
engine without having to certify the hybrid with a transmission under  
the powertrain testing option. Finalizing these changes allows the test  
results to better reflect the performance of mild hybrid's that are not  
integrated into the transmission, without requiring that the  
transmission be part of the certified configuration. Finalizing this  
procedure also allows the test results to be used for additional  
appropriate vehicles, since the test results will not be limited to the  
transmission that was included during the test, as is required for non-  
hybrid powertrains utilizing 40 CFR 1037.550. This mild hybrid engine  
test procedure was finalize via additions to the hybrid powertrain test  
procedure revisions in 40 CFR 1036.503, 1036.505, 1036.510, 1036.527,  
and 1037.550 and includes the addition of a transmission model to GEM  
and options in GEM to test without the transmission present, using the  
model in its place.  
B. Heavy-Duty Engine GHG Emission Standards and Flexibility  
1. Revisions to Credit Provisions for Vocational Engine Emissions  
Standards  
    EPA proposed several updates to the credit provisions related to  
credit provisions for vocational engines and requested comment on these  
credit provisions (see 85 FR 28145). This section presents the changes  
we are adopting to vocational engine credit provisions after  
consideration of comment received. Additional details on comment on  
these credit provisions and our response are available in Chapter 2.4  
of our Response to Comments.  
    In developing the baseline emission rates for vocational engines in  
the final Phase 2 rulemaking, we considered MY 2016 FTP certification  
data for diesel engines, which showed an unexpected step-change  
improvement in engine fuel consumption and CO 2 emissions  
compared to data considered in the proposed rule. The proposed baseline  
emission rates came from the Phase 1 standards, which in turn were  
derived from our estimates of emission rates for 2010 engines. The  
underlying reasons for this shift in the 2016 Phase 2 final rule were  
mostly related to manufacturers optimizing their selective catalytic  
reduction (SCR) thermal management strategy over the FTP in ways that  
we (mistakenly) thought they already had in MY 2010 (i.e., the Phase 1  
baseline).  
    As background, the FTP includes a cold-start, a hot-start and  
significant time spent at engine idle. During these portions of the  
FTP, the NO X SCR system can cool down and lose  
NOX reducing efficiency. To maintain SCR temperature,  
manufacturers initially used a simplistic strategy of burning extra  
fuel to heat the exhaust system. However, during the development of  
Phase 1, EPA believed manufacturers were using more sophisticated and  
efficient strategies to maintain SCR temperature. EPA's  
misunderstanding of the baseline technology for Phase 1 provided engine  
manufacturers the opportunity to generate windfall credits against the  
FTP standards.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 23/268    For the Phase 2 final rule, EPA revised the baseline emission rate  
for vocational engines to reflect the actual certified emission levels.  
The Phase 2 vocational engine final CO 2 baseline emissions  
are shown in the table below. More detailed analyses on these Phase 2  
baseline values of tractor and vocational vehicles can be found in  
Chapter 2.7.4 of the Phase 2 Final RIA.\16\  
---------------------------------------------------------------------------  
    \16\ U.S. EPA, U.S. DOT/NHTSA. Greenhouse Gas Emissions and Fuel  
Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles  
-Phase 2: Regulatory Impact Analysis, August 2016, EPA-420-R-16-900.  
See p. 2-76.  
 Table II-3--Phase 2 Vocational Engine CO2 and Fuel Consumption Baseline  
                                Emissions  
------------------------------------------------------------------------  
                    Units                        HHD      MHD      LHD  
------------------------------------------------------------------------  
g/bhp-hr.....................................      525      558      576  
gal/100 bhp-hr...............................   5.1572   5.4813   5.6582  
------------------------------------------------------------------------  
    EPA did not allow the carryover of Phase 1 vocational engine  
credits into the Phase 2 program, consistent with these adjustments to  
the baselines. Since this issue does not apply for RMC emissions, the  
restriction was applied only for engines certified exclusively to the  
FTP standards (rather than both FTP and RMC standards). We believed  
that allowing engine credits generated against the Phase 1 diesel FTP  
standards to be carried over into the Phase 2 program would have  
inappropriately diluted the Phase 2 engine program. However, this was  
in the context of unadjusted credits.  
    After further consideration, we now believe that it would not  
dilute the program if the credits were appropriately adjusted to more  
accurately reflect improvement over the true baseline levels.  
    Allowing the portion of the credits that represent actual emission  
improvements to be carried forward is consistent with our rationale  
from Phase 2. Thus, we are allowing in Sec.  1036.701(j), for the  
purpose of carrying Phase 1 credits into the Phase 2 program, and not  
compliance with Phase 1 standards, that manufacturers may recalculate  
the credits in their initial Phase 1 averaging, banking, and trading  
(ABT) vocational engine averaging set relative to the Phase 2 baseline  
engine values. The recalculated vocational engine credits for an ABT  
averaging set will be allowed into the Phase 2 engine program to the  
same extent as tractor engine credits. Cummins submitted a late comment  
(see Docket ID EPA-HQ-OAR-2019-0307-0066) requesting clarification of  
whether manufacturers would have the option of applying these  
vocational carryover provisions to one ABT averaging set but not  
another (i.e., that EPA would not require the recalculation of all  
averaging sets.) This final rule affirms that recalculation of  
vocational credits is to be applied to all engines within an individual  
ABT averaging set and that  
[[Page 34328]]  
other averaging sets, such as tractors, are not affected by these  
vocational carryover provisions. EMA commented that manufacturers  
should be able to opt in to recalculating credits on an engine family  
by engine family basis, as applying this adjustment to all engine  
families could affect existing Phase 1 compliance for engines above the  
Phase 2 baseline value. However, EPA is only allowing this  
recalculation for the purpose of determining the amount of credit that  
can be carried into the Phase 2 program, and adjusting the credits for  
all the engine families a manufacturer chose to include in their  
initial ABT averaging set for Phase 1 program properly accounts for the  
net credits that can be carried forward. In the ABT program, all engine  
families within an averaging set are used in the calculation of  
credits, and manufacturers cannot pick and choose which engine families  
are used in that calculation.  
    As noted in the Phase 2 final rule, allowing additional flexibility  
for compliance with engine standards does not cause any increase in  
emissions because the manufacturers must still comply with the vehicle  
standards (See 81 FR 73499, October 25, 2016). However, this  
flexibility could allow some manufacturers to find a less expensive  
compliance path.  
2. Special Flexibility for Vocational Engines and Credits  
    EPA requested comment on several updates to the special flexibility  
provisions for vocational engines (see 85 FR 28145). This section  
presents the regulatory changes we are adopting after consideration of  
comments received. Additional details on comments received on these  
provisions and our responses are available in Chapter 2.4 of our  
Response to Comments.  
    In the existing regulations at 40 CFR 1036.150(p), EPA provided  
special flexibility for engine manufacturers that certify all their  
model year 2020 engines within an averaging set to the model year 2021  
FTP and SET standards and requirements. Where 40 CFR 1036.150(p)  
applies, paragraph (p)(1) specifies that GHG emission credits that  
manufacturers generate with model year 2018 through 2024 engines may be  
used through model year 2030, instead of being limited to a five-year  
credit life as specified in 40 CFR 1036.740(d). Note that under the  
Phase 2 final rule this provision in effect only applies to  
manufacturers of tractor engines, as under 40 CFR 1036.701(j) EPA did  
not allow the carryover of Phase 1 vocational engine credits into the  
Phase 2 program (81 FR 73499, October 25, 2016). Where 40 CFR  
1036.150(p) applies, paragraph (p)(2) specifies that manufacturers are  
also allowed to certify model year 2024 through 2026 tractor engines to  
alternative standards that are slightly higher than the otherwise  
applicable standards. Note that in the table of alternative standards  
in the Phase 2 final rule EPA included values for medium and heavy  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 24/268heavy-duty vocational engines, but these values are identical to the  
Phase 2 standards and not slightly higher due to our concerns about  
windfall credits if carryover of Phase 1 credits were allowed.  
    The applicability of 40 CFR 1036.150(p) is based on the choices  
manufacturers made when certifying their MY 2020 engines. Instead of  
certifying engines to the final year of the Phase 1 engine standards,  
manufacturers electing the alternative instead certified to the MY 2021  
Phase 2 engine standards. Because these engine manufacturers reduced  
emissions of engines that would otherwise have been subject to the more  
lenient MY 2020 Phase 1 engine standards, there can be a net benefit to  
the environment. These engines do not generate credits relative to the  
Phase 1 standards but instead generate credits relative to the pulled  
ahead MY 2021 Phase 2 engine standards. Because the vehicle standards  
themselves are unaffected, the alternative MY 2024-2026 engine  
standards will not dilute or diminish the overall GHG reductions or  
fuel savings of the program. Vehicle manufacturers using engines  
subject to the alternative MY 2024-2026 standards would need to adopt  
additional vehicle technology (i.e., technology beyond that projected  
to be needed to meet the engine standards) to meet the applicable  
vehicle GHG standards. The result is that the vehicles would still  
achieve the same GHG emissions in use.  
    The proposed rule included an amendment to address the concern  
regarding Phase 1 windfall credits and requested comment on the  
possibility of a similar set of alternative standards for vocational  
engines. CARB and Volvo commented that they support these changes and  
flexibilities. Cummins commented opposing both the alternative MY 2024  
through 2026 vocational engine standards and extending the life of  
credits generated from early compliance with Phase 2 vocational  
standards. The American Council for an Energy-Efficient Economy  
commented opposing extending the life of vocational engine credits  
generated in Phase 1, stating that doing so does not result in emission  
reductions but would increase emissions and reduce the rule's overall  
stringency. Cummins also commented that manufacturers had already  
developed and certified MY 2020 products without consideration of these  
changes, and even if post hoc recertification was possible, allowing  
them now would potentially be an advantage or disadvantage to  
individual manufacturers.  
    As discussed in section II.B.1, we are finalizing provisions on  
calculating credits relative to a baseline that addresses these  
windfall credit concerns, which also results in the extended credit  
life flexibility under 40 CFR 1036.150(p)(1) now being available to  
vocational vehicles that qualify under 40 CFR 1036.150(p). We are also  
finalizing a set of alternative standards for vocational engines, as  
shown in Table II-4.  
        Table II-4--Alternative Standards for Vocational Engines  
------------------------------------------------------------------------  
                                                 Medium     Heavy  heavy-  
                                               heavy-duty       duty  
                 Model years                   vocational    vocational  
                                                (g/hp-hr)     (g/hp-hr)  
------------------------------------------------------------------------  
2024-2026...................................          542           510  
------------------------------------------------------------------------  
    The Phase 2 standards are implemented in three MY steps: 2021,  
2024, and 2027. The largest step change in stringency occurs in MY  
2024, where approximately two-thirds of the total numeric reduction in  
the MY 2021 through MY 2027 standards is achieved, with the remaining  
one-third occurring in MY 2027. For the alternative tractor engine  
standards, EPA reversed the magnitude of the MY 2024 and MY 2027 step  
changes, where the MY 2024 alternative standard represents one-third of  
the total numeric reduction and is slightly higher than the Phase 2  
standard. The standards at the beginning (MY 2021) and ending (MY 2027)  
steps of the Phase 2 program remain the same in either case, and only  
the level of decrease in standard for MY 2024 changes with the  
alternative standards. EPA determined the alternative standards for  
vocational engines by adjusting the magnitude of the MY 2024 standard  
in the same manner as used to determine the alternative tractor engine  
standards in the Phase 2. The Phase 2 vocational engine standards  
decrease by 10 g/hp-hr between MY 2021 and MY 2027, with a 7 g/hp-hr  
step change in the MY 2024 standard (approximately two-thirds of the  
total numeric reduction) and a 3 g/hp-hr step change in MY 2027. For  
the alternative vocational engine standards in MY 2024-2026, we are  
adopting a 3 g/hp-hr reduction from the MY 2021 standard (from 545 to  
542 g/hp-hr for  
[[Page 34329]]  
medium heavy-duty (MHD) and 513 to 510 g/hp-hr for heavy heavy-duty)  
instead of 7 g/hp-hr. EPA believes that allowing these slightly higher  
(approximately 0.7 to 0.8% compared to the Phase 2 final rule) engine  
standards for vocational vehicles is justified, as the overall vehicle  
standards will still be met. Engine development and vehicle technology  
choices are pathways to meeting overall vehicle standards, as is the  
use of credits generated by early compliance. EPA's alternative engine  
standards provisions for vocational vehicles for MYs 2024-2026 allows  
manufacturers flexibility to choose the mix of engine and vehicle  
technologies that will comply with the standards. As noted in the Phase  
2 final rule and this rule's proposal, EPA views this type of  
alternative as being positive from the environmental and energy  
conservation perspectives, as vehicle-level emission standards remain  
the same, but manufacturers are provided with significant flexibility  
on engine emission standards and credit life provisions that may reduce  
their compliance costs.  
    Regarding the adverse comments received, including whether or not  
manufacturers had the opportunity to consider these changes prior to MY  
2020, these changes correspond to the corrected approach to Phase 1  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 25/268credit calculations explained in Section II.B.1 above. At the time of  
the Phase 2 final rule, we believed that allowing Phase 1 vocational  
engine credits, without adjustment, to be carried over to the Phase 2  
program would result in ``windfall'' credits, or dilution of the  
benefits of the Phase 2 program, and we adopted restrictions to limit  
their use. However, after the Phase 2 final rule we recognized that an  
alternative to restricting Phase 1 vocational engine credits because of  
windfall concerns would be to adjust credits earned in Phase 1  
downward, relative to a baseline of the lower Phase 2 emissions  
standards, and in doing so, we would be extending to vocational engine  
manufactures the same flexibilities that were provided to tractor  
engine manufacturers. In this final rule we are allowing the vocational  
engine credits generated in Phase 1 to be adjusted downward and used in  
Phase 2 program through MY 2030, just as they were for tractors. In  
setting lower baseline emission values for Phase 1 vocational engine  
credits and providing the corresponding program flexibilities, EPA does  
not intend to advantage or disadvantage any manufacturer. Rather, we  
are removing restrictions that were applied only to vocational engines  
but no longer should be applied now that we are finalizing provisions  
that provide a proper accounting of the emission improvements realized  
by manufacturers who chose to certify their MY 2020 engines to the MY  
2021 Phase 2 standards, so vocational and tractor engines are treated  
the same. In addition, the revised MY 2024-2026 alternative standards  
for vocational engines, while slightly higher than those in the Phase 2  
final rule by 0.7 to 0.8%, do not reduce the overall stringency of the  
Phase 2 program, but instead reflect the alternative standards we would  
have adopted in the Phase 2 final rule alongside the similar tractor  
provisions, and for the same reasons we finalized those tractor  
provisions, had we considered adjusting baseline emission rates used  
for calculating Phase 1 credits. Manufacturers that qualify to use the  
alternative MYs 2024-2026 engine standards accelerated their compliance  
with the more stringent MY 2021 Phase 2 standards by one model year. As  
we explained in the Phase 2 final rule, because the vehicle standards  
themselves are unaffected, these alternative engine standards will not  
dilute or diminish the overall GHG reductions or fuel savings of the  
program. Vehicle manufacturers using engines subject to the alternative  
MYs 2024-2026 standards will need to adopt additional vehicle  
technology (i.e., technology beyond that projected to be needed to meet  
the engine standard) to meet the applicable vehicle GHG standards. The  
result is that the vehicles using engines that comply with the  
alternative standards will still achieve the same overall GHG emissions  
in use. EPA believes that these alternative standards are appropriate,  
and allowing alternative engine standards for vocational vehicles that  
qualify is justified, for these reasons, and that vocational engine  
manufacturers who met the Phase 2 engine standards one year in advance  
of the MY 2021 implementation date should have the same flexibility as  
tractors to earn and use those credits through MY 2030.  
3. Confirmatory Testing of Engines and Measurement Variability  
    EPA proposed updates to the procedure for confirmatory testing of  
the fuel mapping test procedure related to providing an interim 2%  
allowance during confirmatory testing of the fuel mapping test  
procedure finalized in the Phase 2 final rule and requested comment on  
``. . . whether it appropriately balances the impacts of testing  
variability for fuel maps'' (see 85 FR 28146, May 12, 2020). This  
section presents the changes we are adopting to the confirmatory  
testing portion of the fuel mapping test procedure after consideration  
of comments received. Additional details on these comments and our  
responses are available in Chapter 2 of our Response to Comments.  
    During the Phase 2 rulemaking, manufacturers raised concern about  
measurement variability impacting the stringency of the engine GHG  
standards and fuel map requirements. As noted in the Phase 2 final  
rule, the final standards were developed to account for this. (81 FR  
73571, October 25, 2016). Manufacturers raised particular concern about  
variability of fuel map measurements because neither they nor EPA had  
sufficient experience measuring fuel maps (in a regulatory context) to  
fully understand the potential impacts of measurement variability. We  
estimated the fuel map uncertainty to be equivalent to the uncertainty  
associated with measuring CO 2 emissions and fuel consumption  
over the FTP and SET cycles, which we estimated to be about one  
percent. However, the Phase 2 final rule noted that we were  
incorporating test procedure improvements that would further reduce  
test result uncertainty. We also noted that ``[i]f we determine in the  
future . . . that the +1.0 percent we factored into our stringency  
analysis was inappropriately low or high, we will promulgate technical  
amendments to the regulations to address any inappropriate impact this  
+1.0 percent had on the stringency of the engine and vehicle  
standards.'' (81 FR 73571, October 25, 2016)  
    In conjunction with this intention, EPA has worked with engine  
manufacturers to better understand the variability of measuring fuel  
maps using the test procedures and cycles specified by EPA in the Phase  
2 final rule. Through that work, we identified several sources of  
variability that can be reduced by making small changes to the test  
procedures. EPA is adopting these changes, as explained in Sections  
II.A.1 through II.A.3 of this final rule.  
    SwRI performed emission measurements in multiple test cells and  
identified distributions of error for other test inputs such as  
measured fuel properties and calibration gas concentrations. SwRI then  
used a Monte Carlo simulation to estimate a distribution of errors in  
measured fuel maps.\17\ After reviewing the results, EPA had several  
significant observations which we discussed in the proposal for  
[[Page 34330]]  
this final rule and which EPA confirms in this final action:  
---------------------------------------------------------------------------  
    \17\ Sharp, Christopher A., et al., ``Measurement Variability  
Assessment of the GHG Phase 2 Fuel Mapping Procedure'', Southwest  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 26/268Research Institute, Final Report, December 2019.  
---------------------------------------------------------------------------  
    1. The variability of measuring CO 2 and fuel consumption  
during fuel mapping is greater than the one percent assumed in the  
Phase 2 final rule. Variability from vehicles without idle test cycles  
is <1.8% (1.68 to 1.8%), while variability from vehicles with idle test  
cycles is <2.8% (2.0 to 2.79%).  
    2. The variability of measuring CO 2 and fuel consumption  
during the fuel mapping procedure is roughly the same as that of the  
FTP and SET cycles, 3.34% for the FTP and 1.99% for the SET.  
    3. Measuring CO 2 and fuel consumption at idle is  
particularly challenging.  
    4. The data obtained during the test program at SwRI did not  
include all the test procedure changes being adopted in 40 CFR parts  
1036 and 1037 that will further reduce fuel mapping test variability  
and therefore the variability is likely to be lower than reported by  
the SwRI.  
    Manufacturers have indicated they are concerned about the  
possibility of EPA changing an official fuel map result as a  
consequence of EPA confirmatory testing where the measured maps were  
within an expected range of variability. In the context of the SwRI  
test program, EPA observed similarity between the range of variability  
of measuring fuel maps and the range of variability of measuring  
CO2 and fuel consumption over the FTP and SET cycles  
(measurements for which EPA has already determined in both Phase 1 and  
Phase 2 that no such allowances are needed). These results indicate  
that there is no additional source of increased variability associated  
with the fuel mapping test procedure and suggest that manufacturers  
should be able to comply without any special provisions. Additionally,  
the data we have available indicates that the manufacturers may  
potentially over time be able to take advantage of the 2% allowance,  
resulting in a reduction in stringency of the standards. We anticipate  
that this would not happen over the next few model years, as  
manufacturers will need time to implement the revised test procedures  
adopted in this rule that will reduce the variability of the fuel map  
test procedure to levels at or below the variability of the FTP and SET  
test procedures.  
    After considering the comments received, we are adopting the  
limited transitional approach aimed at addressing the manufacturers'  
variability concerns. As manufacturers implement this rule's revised  
test procedures to reduce variability, we will analyze and compare a  
manufacturer's declared and measured fuel maps to those that result  
from our confirmatory testing, with the goal of ensuring the long-term  
integrity of the Phase 2 program. We are codifying the interim  
provision for model years 2021 and later in 40 CFR 1036.150, under  
which EPA will not replace a manufacturer's fuel maps during  
confirmatory testing if the difference between the EPA-measured fuel  
maps and the manufacturer's declared maps is less than or equal to 2.0  
percent. We may revisit the interim 2% allowance in a future  
rulemaking.  
    EPA also intends to further review data and developments in this  
area. We intend to review this provision as we learn more about the  
impact of measurement variability on measured and declared fuel maps  
submitted during the certification process for future model years  
(including the full impact of the test procedure improvements that are  
intended to reduce measurement variability), which may inform whether  
we determine additional action is warranted in the future with respect  
to fuel mapping variability. We also intend to enter into a round robin  
study of criteria and GHG pollutant engine testing variability with  
interested engine manufacturers, with the involvement of the Truck and  
Engine Manufacturer's Emission Measurement and Testing Committee. This  
data will add to the existing knowledge regarding the variability of  
the FTP, SET and fuel mapping test procedures and may help inform if  
future action is needed to further improve the test procedures.  
    We are also finalizing an algorithm for comparing fuel maps.  
Because fuel maps are multi-point surfaces instead of single values, it  
would be a common occurrence that some of EPA's points would be higher  
than the manufacturer's while others would be lower. This algorithm was  
inadvertently proposed as an interim provision in 40 CFR 1036.150(q)  
along with the 2.0 percent variability allowance. The algorithm and  
fuel map comparison process during a confirmatory test is needed for  
confirmatory testing regardless of an allowance. Therefore, in this  
final rule the algorithm and all supporting text are located at 40 CFR  
1036.235(c)(5). The limited interim 2.0 percent variability allowance  
is located at 40 CFR 1036.150(q).  
    EPA's measured fuel maps will be used with GEM according to 40 CFR  
1036.540 to generate emission duty cycles which simulate several  
different vehicle configurations, generating emission results for each  
of the vehicles for each of the duty cycles. Each individual duty cycle  
result will be weighted using the appropriate vehicle category  
weighting factors in Table 1 of 40 CFR 1037.510 to determine a  
composite CO 2 emission value for that vehicle configuration.  
Note that the equation is being finalized to use values before rounding  
as this is consistent with the provisions in 40 CFR 1065.20 to not  
round intermediate values. When the process is repeated for the  
manufacturer's fuel maps, the average percent difference between fuel  
maps will be calculated as:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.008  
Where: 
i = an indexing variable that represents one individual weighted  
duty cycle result for a vehicle configuration.  
N = total number of vehicle configurations.  
eCO2compEPA i = unrounded composite mass of CO 2  
emissions in g/ton-mile for the EPA confirmatory test.  
eCO2compManu  = unrounded composite mass of CO 2  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 27/268emissions in g/ton-mile for the manufacturer declared map.  
4. Other Minor Heavy-Duty Engine Amendments  
    EPA proposed three additional updates to the testing and  
measurement provisions of 40 CFR part 1036, related to measuring  
emissions from heavy-duty  
[[Page 34331]]  
engines and requested comment on general improvements to the engine  
test procedures and compliance provisions (see 85 FR 28147). This  
section presents these three additional changes we are adopting to  
engine test procedures. Additional details on these and other engine  
testing and measurement amendments or clarifications requested by  
commenters and our responses are available in Chapter 2 of the Response  
to Comments.  
     Correcting the assigned N2O deterioration factor in Sec.   
1036.150(g). In the Phase 2 proposed rule, EPA proposed to lower the  
N2O standard from 0.10 g/hp-hr to 0.05 g/hp-hr for model  
year 2021 and later diesel engines. In that context, we also proposed  
to lower the assigned deterioration factor (DF) from 0.020 g/hp-hr to  
0.010 g/hp-hr for model year 2021 and later diesel engines. EPA  
explained in the preamble to the Phase 2 final rule that we were not  
finalizing the change to the standard (81 FR 73530, October 25, 2016),  
but inadvertently finalized the proposed DF change in the regulations.  
We proposed in this rulemaking to correct this error, consistent with  
EPA's clear statement in the Phase 2 final rule that we were not  
finalizing the change to the standard. However, given that finalizing  
the assigned DF of 0.01 g/hp-hr for N 2O in the regulations  
was an oversight on EPA's part in the Phase 2 final rule and that the  
Phase 2 final rule was inadvertently internally inconsistent, and after  
consideration of EMA's comment that manufacturers will not have time to  
correct or account for a change in the assigned DF in time for their MY  
2021 certifications, we are deferring changing the assigned DF to 0.02  
g/hp-hr until MY 2022 within the revisions finalized in this  
rulemaking.  
     Clarifying a reference to non-gasoline engine families in  
Sec.  1036.705(b)(5). The second sentence of Sec.  1036.705(b)(5) is  
intended to refer to non-gasoline engine families. However, the  
existing text is not clear. As written, it can be read to mean that  
gasoline engine families may not generate emission credits. EPA is  
adding ``non-gasoline'' to clarify the intended meaning.  
     Engine families. We are revising Sec.  1036.230 to allow  
engine families to be divided into subfamilies with respect to  
CO2. This allowance simplifies the certification process  
without changing the overall requirements.  
     Adding a summary of previously applicable emission  
standards as appendix A of part 1036. The new appendix is being  
provided for reference purposes only regarding previously applicable  
emission standards and will cover regulatory text being deleted from 40  
CFR part 86.  
    Except as noted above, we received no adverse comments on these  
proposed amendments and are adopting them without modification.  
C. Heavy-Duty Vehicle GHG Emission Standards and Flexibility  
1. Aerodynamic Compliance Provisions  
    In addition to the aerodynamic test procedure amendments described  
in Section II.A.6, we proposed several updates to Sec.  1037.150(s) as  
it relates to EPA's confirmatory testing of aerodynamic parameters and  
Sec.  1037.305 as it relates to our selective enforcement audit (SEA)  
procedures. We also requested comment on general improvements to the  
aerodynamic compliance provisions (see 85 FR 28147). This section  
presents the changes we are adopting to our confirmatory testing and  
SEA procedures after consideration of comments received. Additional  
details on these and other aerodynamic amendments or clarifications  
requested by commenters and our responses are available in Chapter 2 of  
our Response to Comments.  
a. Confirmatory Testing for F alt-aero  
    As described in 40 CFR 1037.235(c), EPA may perform confirmatory  
testing on a manufacturer's vehicles, including a vehicle tested to  
establish the F alt-aero  value. The regulations also include  
an interim provision in Sec.  1037.150(s) that outlines how EPA may and  
when EPA will not replace a manufacturer's F alt-aero  value  
based on confirmatory test results. This interim provision connects  
EPA's confirmatory testing to the audit procedures of Sec.  1037.305.  
In keeping with the principle that good engineering judgment \18\ would  
generally call for more data rather than selecting a single value, and  
after consideration of comment, EPA is finalizing our proposed  
provision to require EPA to perform a minimum of 100 valid runs before  
replacing a manufacturer's F alt-aero  value in confirmatory  
testing with some additional clarifications in Sec.  1037.150(s).  
---------------------------------------------------------------------------  
    \18\ Good engineering judgment is defined in 40 CFR 1068.30 as  
judgments made consistent with generally accepted scientific and  
engineering principles and all available relevant information. See  
40 CFR 1068.5 for requirements regarding applying good engineering  
judgment.  
---------------------------------------------------------------------------  
    CARB commented in support of increasing the number of runs from SEA  
to 100 to limit false failures, but requested in comment to know the  
origin of the proposed minimum 100 valid runs for confirmatory testing.  
Our intent with the finalized requirement for 100 valid confirmatory  
runs is to maintain consistency with the existing regulatory language  
adopted in the Phase 2 final rulemaking for SEA testing. The existing  
Sec.  1037.305(a)(7)(iii) states: ``The vehicle passes if you perform  
100 coastdown runs and C dAwa-upper  is greater  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 28/268than and C dAwa-lower  is lower than the upper  
limit of the bin to which you certified the vehicle.'' Similarly, as  
noted below in Section II.C.1.b, we are also finalizing our  
corresponding proposed language in the audit procedures of Sec.   
1037.305(a)(5) clarifying that manufacturers must perform a minimum of  
24 runs to pass and a minimum of 100 runs to fail.  
    EMA requested additional modifications to Sec.  1037.150(s)  
regarding EPA's approach to calculating a new F alt-aero   
value in confirmatory testing. EMA suggested that the regulation more  
explicitly connect to the SEA procedures for pass/fail criteria and the  
coastdown procedures for calculating F alt-aero . They also  
suggested we directly outline how EPA will replace a manufacturer's  
Falt-aero . EMA suggested that EPA calculate two  
Falt-aero  values and apply the average of those values to  
replace a manufacturer's value. We agree with EMA's suggestions to  
clarify the connections to the SEA procedures of Sec.  1037.305 and the  
coastdown test procedures of Sec.  1037.528 and we updated Sec.   
1037.150(s) accordingly. While we generally agree that additional data  
is preferable, we are not committing to calculating multiple  
Falt-aero  values, as requested by EMA, due to consideration  
of potential resource constraints; however, we have revised the  
regulatory language to allow for it. We also are not finalizing an  
approach to calculate the final F alt-aero  when there are  
multiple values. Our revised Sec.  1037.150(s) states that EPA will  
``will generate a replacement value of F alt-aero  based on at  
least one C dA value and corresponding effective yaw angle''.  
    Additionally, as noted in the proposal regarding Sec.  1037.150(s),  
we recognize that test conditions for coastdown testing are an  
important consideration. For our confirmatory testing, EPA intends to  
minimize the differences between our test conditions and those of the  
manufacturer and we proposed a note in Sec.  1037.150(s) stating our  
intent to test at similar times of the year. EMA requested additional  
regulatory language regarding our intent to test at the same location  
as well as time of year. We are expanding our proposed note in Sec.   
1037.150(s) to include our intent to test at both the same time of year  
and the same location, subject to  
[[Page 34332]]  
certain considerations. More specifically, we emphasize that the note  
in Sec.  1037.150(s) is not a commitment by the agency due to the  
limited number of coastdown test facilities, the challenges of  
scheduling time for testing, and our prerogative to choose an  
alternative facility if we have concerns about the original test  
location. Our revised language in Sec.  1037.150(s) states that we  
intend to test ``at similar times of the year where possible and at the  
same location where possible and when appropriate.''  
b. Selective Enforcement Audits for Tractors  
    We proposed and received no adverse comments to three typographical  
edits to our aerodynamic testing audit procedures for tractors in Sec.   
1037.305. We are finalizing those three edits as proposed and  
additional editorial edits as follows:  
     Section 1037.305--Replaced reference to 40 CFR 1068.420  
with the range ``40 CFR 1068.415 through 1068.425'' as proposed.  
     Section 1037.305(a)--Rephrased ``whether or not a tractor  
fails to meet'' to the more concise ``whether a tractor meets''.  
     Section 1037.305(a)(2)--Corrected ``coastdown effective''  
to ``coastdown effective yaw angle'' as proposed.  
     Section 1037.305(a)(7)--Added a missing ``m2'' following  
the bin value of 5.95 in the example as proposed. Editorial revisions  
to remove passive voice.  
    In comment, EMA suggested additional revisions to Sec.  1037.305(a)  
allowing manufacturers to apply good engineering judgment in their  
selective enforcement audit (SEA) testing if a production vehicle could  
not be configured to meet the trailer height specified in Sec.   
1037.501(g)(1)(i). We accept that a future production vehicle may be  
designed such that it cannot be configured to match a trailer that  
meets our current definition of standard trailer. We are finalizing a  
broader revision to address all such scenarios where a production  
vehicle cannot be configured to match a trailer that meets our current  
definition of standard trailer, including but not limited to height,  
that will address EMA's specific concern with meeting the standard  
trailer's height requirements. We are adding language to clarify that a  
manufacturer may seek EPA approval to use an alternate or modified  
vehicle configuration, consistent with good engineering judgment, if  
EPA chooses to audit a production vehicle configuration that cannot  
meet any of the standard trailer requirements specified in Sec.   
1037.501(g)(1).  
    As noted in Section II.C.1.a, we proposed and are finalizing a  
provision in Sec.  1037.150(s) to require EPA to perform a minimum of  
100 valid runs before replacing a manufacturer's F alt-aero   
value in confirmatory testing. Similarly, we are finalizing our  
corresponding proposed language in the audit procedures of Sec.   
1037.305(a)(5) clarifying that manufacturers must perform a minimum of  
24 runs to pass and a minimum of 100 runs to fail. Finally, we received  
no adverse comments and are finalizing the proposed regulatory language  
in Sec.  1037.305(a)(7)(v) allowing manufacturers to continue testing  
and to generate additional data that EPA may consider in our pass/fail  
determinations.  
2. Idle Reduction Technologies  
    EPA proposed several provisions related to idle reduction  
technologies. This section presents the changes we are adopting after  
consideration of the comments received. See Chapter 2 of our Response  
to Comments for further details, including additional idle reduction  
amendments or clarifications requested by commenters and our responses.  
a. Extended-Idle Reduction for Tractors  
    The Phase 1 version of GEM gives credit for extended idle emission  
reduction technologies that include a tamper-proof automatic engine  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 29/268shutoff system (AESS), with few override provisions. Phase 2 GEM gives  
credit for a wider variety of idle reduction strategies, recognizing  
technologies that are available on the market today, such as auxiliary  
power units (APUs), diesel fired heaters, and battery powered units.  
For example, a tamper-proof AESS with a diesel APU would be credited  
with a 4 percent reduction in emissions, while an adjustable AESS with  
a diesel fired heater would be credited with a 2 percent reduction in  
emissions (81 FR 73601, October 25, 2016).  
    Our proposal to revise Sec.  1037.520(j)(4) to include GEM input  
values for combinations of these technologies received support from  
CARB, EMA, and Volvo and we are finalizing our proposed combinations of  
idle reduction technologies as shown in Table II-5. Adding these values  
to GEM reduces the compliance burden for manufacturers who would  
otherwise need to apply for off-cycle credits for these technology  
combinations. The values of these technology benefits were determined  
using the same methodology used in the Phase 2 final rule.  
              Table II-5--GEM Input Values for AES Systems  
------------------------------------------------------------------------  
                                                     GEM input values  
                                                ------------------------  
                   Technology                                   Tamper-  
                                                  Adjustable   resistant  
------------------------------------------------------------------------  
Standard AES system............................            1           4  
With diesel APU................................            3           4  
With battery APU...............................            5           6  
With automatic stop-start......................            3           3  
With fuel-operated heater (FOH)................            2           3  
With diesel APU and FOH........................            4           5  
With battery APU and FOH.......................            5           6  
With stop-start and FOH........................            4           5  
------------------------------------------------------------------------  
b. Idle Reduction Overrides  
    In 40 CFR 1037.660, we identify three idle reduction technologies  
(i.e., automatic engine shutdown, neutral idle, and stop-start) and  
specify how these systems must operate to qualify for GEM credit.  
Included among those provisions are allowances for overriding these  
systems where it may damage the engine or create a safety issue for the  
vehicle occupants or service personnel. This section highlights the  
some of the idle reduction override provisions we are adopting, either  
as proposed or further revisions after consideration of comments  
received.  
i. Automatic Engine Shutdown (AES) Overrides  
    While we did not specifically propose or request comment on AES  
overrides, New Flyer (a bus manufacturer) commented that the override  
condition for AES systems during servicing in Sec.  1037.660(b)(1)(ii)  
(cross-referenced under the existing regulations for vocational  
vehicles in Sec.  1037.660(b)(2)(i)) could pose a safety risk to  
maintenance personnel. They stated that maintenance personnel may not  
have a diagnostic scan tool required to deactivate the system and some  
maintenance may require longer than the current 60-minute limit before  
reactivation. New Flyer suggested an ``open engine compartment'' would  
be a more appropriate override condition.  
    After consideration of New Flyer's safety concern for vocational  
vehicles, we are revising Sec.  1037.660(b)(2) to allow a vocational  
vehicle's AES system to delay shutdown if necessary while servicing the  
vehicle without the scan tool requirement and time limit. Our final  
revision removes the cross-reference in Sec.  1037.660(b)(2)(i) to that  
particular provision in Sec.  1037.660(b)(1) and replaces it with a new  
provision in Sec.  1037.660(b)(2)(ii). Our new provision allows a delay  
in shutdown for vocational vehicles if the engine compartment is open  
and replaces the  
[[Page 34333]]  
regulatory text regarding unsafe cab temperatures in the current Sec.   
1037.660(b)(2)(ii), which is redundant with the existing cross-  
reference to paragraph (b)(1) in paragraph (b)(2)(i). For vocational  
vehicles, we believe an open engine compartment sufficiently indicates  
that a vocational vehicle is being serviced and automatic engine  
shutdown would provide limited environmental benefit. We are not taking  
final action to revise the tractor-specific provision of Sec.   
1037.660(b)(1)(ii) to allow an open engine compartment as a condition  
for AES override, since the environmental benefits of AES on tractors  
occurs when these vehicles are parked for extended durations where an  
open engine compartment may not be a sufficient deterrent for the  
operator to circumvent the AES.\19\  
---------------------------------------------------------------------------  
    \19\ Tractor manufacturers have the option to request and we may  
approve additional override criteria as needed to protect the engine  
and vehicle from damage and to ensure safe vehicle operation, as  
stated in Sec.  1037.660(b).  
---------------------------------------------------------------------------  
    We are finalizing editorial revisions to Sec.  1037.660(b) so the  
paragraphs consistently begin with ``When''. Additionally, we reordered  
the paragraphs of Sec.  1037.660(b)(1) to move the servicing provision  
previously located at paragraph (b)(1)(ii) to paragraph (b)(1)(vi) such  
that the vocational vehicle AES provisions can continue to reference  
the range of relevant (b)(1) paragraphs in paragraph (b)(2)(i).  
ii. Neutral Idle Overrides  
    EPA proposed and is finalizing a provision in Sec.   
1037.660(b)(3)(ii) that would allow the neutral idle system to delay  
shifting the transmission into neutral if the transmission is in  
reverse gear (85 FR 28271, May 12, 2020). New Flyer requested an  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 30/268additional override when the vehicles is on a road grade of 6.0 percent  
or more to prevent the safety concern of vehicle rollback. EPA agrees  
with this safety concern and is finalizing a provision in Sec.   
1037.660(b)(3)(iii) to allow a delay in neutral idle when the vehicle  
is on a grade greater than or equal to 6.0 percent. EMA requested  
additional overrides for ``safety; thermal protection of the emissions  
aftertreatment; and maintenance of aftertreatment temperature within a  
range for adequate emissions control''. EPA is not adopting EMA's  
suggested override conditions as we do not think that they would likely  
be appropriate without more specific criteria. Manufacturers continue  
to have the option to justify the need for additional overrides for  
their individual systems and seek EPA approval through Sec.   
1037.660(b).  
iii. Stop-Start Overrides  
    We requested comment on a specific list of override conditions for  
stop-start systems (85 FR 28151, May 12, 2020). CARB expressed concern  
that additional overrides may compromise emissions and requested a  
requirement that manufacturers bring their proposed overrides to EPA  
for approval. We are not requiring a ``case-by-case'' approval process  
for these overrides, as suggested by CARB, but we note that, in the  
certification application provisions of Sec.  1037.205(b)(5),  
manufacturers are required to include a description of their idle  
reduction technology, including the override conditions of Sec.   
1037.660. We believe this continues to be an appropriate level of  
oversight for these idle technologies and their associated override  
conditions.  
    EMA and New Flyer supported the inclusion of all override  
conditions listed in the proposed rule for comment, but their comments  
did not expand on the need for any of the individual conditions to be  
adopted. Each commenter requested additional override conditions and  
included the rationale for those requests. Our final revisions to Sec.   
1037.660(b)(4) cross-reference the provisions for vocational vehicle  
AES (paragraph (b)(2)) and neutral idle (paragraphs (b)(3)(ii) and  
(iii)) such that the new open engine compartment, reverse gear, and  
road grade provisions for those systems also apply for stop-start  
systems. EPA considered the original list and the commenters'  
additional suggested override conditions and we are adopting the  
following additional override criteria specific to stop-start systems  
to ensure safety and/or effective system operation as noted in Sec.   
1037.660(b)(4):  
     When the steering angle is at or near the limit of travel  
to avoid steering wheel kickback during engine start.  
     When a wheel speed sensor failure may prevent the anti-  
lock braking system from detecting vehicle speed.  
     When an automatic transmission is in ``park'' or in  
``neutral'' with the parking brake engaged because the feature is  
intended to be used during driving operation.  
     When a component failure protection mode is active, such  
as starter motor overheating, which may prevent the engine from  
restarting.  
     When a fault is active on a system component needed to  
start the engine, which may prevent the engine from restarting.  
     When the flow of diesel exhaust fluid is limited due to  
freezing, because an engine-off condition may further delay thawing and  
SCR operation.  
    It was not clear that the remaining override conditions suggested  
by commenters or presented for comment in the proposed rule pose a  
widespread concern for safety, vehicle operation, or serviceability, or  
could not be easily overridden by the driver, and we are not adopting  
those overrides in our final revisions. However, manufacturers continue  
to have the option to seek EPA approval for these or additional  
criteria they believe are needed to protect the engine and vehicle from  
damage and to ensure safe vehicle operation (see Sec.  1037.660(b)).  
3. Weight Reduction  
    EPA proposed minor revisions to the weight reduction provisions  
(see 85 FR 28150). This section presents the changes we are adopting  
after consideration of comments received. See Chapter 2 of our Response  
to Comments for additional details on some of these amendments,  
including other amendments or clarifications requested by commenters  
and our responses.  
    The regulations in 40 CFR 1037.520 include tables to calculate  
weight reduction values for using certain lightweight components. The  
sum of the weight reductions is used as an input to GEM. As noted in  
Section II.A.2, EPA proposed two changes to Table 8 of that section  
allowing manufacturers to use the heavy heavy-duty (HHD) values for  
medium heavy-duty (MHD) vehicles with three axles (i.e., 6x4 and 6x2  
configurations) and adding a footnote to the table to clarify that the  
weight reduction values apply per vehicle (instead of per component)  
unless otherwise noted. We received no adverse comments to the proposed  
updates to Table 8 and we are finalizing the two changes.  
    We received comment from EMA requesting ``a process for adding in  
other weight-savings technologies''. As described in Sec.   
1037.520(e)(5), this process is available in the existing off-cycle  
provisions of Sec.  1037.610 and no further action is needed or being  
finalized in this rule. EMA also requested clarification on the origin  
of certain weight reduction values for tires and recommended use of a  
``base'' value for comparison. We note that all the values in Table 6  
through Table 8 of Sec.  1037.520 were developed through notice and  
comment in the HD Greenhouse Gas Emissions Phase 1 and Phase 2  
rulemakings based on information as described in the Regulatory Impact  
Analysis for the rules. We did not propose changes to the weight  
reduction tables and are not taking any final action at this time to  
[[Page 34334]]  
update values to refer to a base weight, but manufacturers continue to  
have the ability to apply through our off-cycle process.  
4. Self-Contained Air Conditioning Units  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 31/268    We proposed a revision to Sec.  1037.115(e) to clarify that it is  
``intended to address air conditioning systems for which the primary  
purpose is to cool the driver compartment (85 FR 28151). This would  
generally include all complete pickups and vans, but not self-contained  
air conditioning or refrigeration units on vocational vehicles.'' CARB  
and New Flyer requested additional clarification on the phrase ``self-  
contained''. After consideration of submitted comments, we are  
finalizing a modified version of the proposed changes to Sec.   
1037.115(e)(1) that incorporates some of the feedback from commenters.  
We are maintaining the proposed statement that this provision is  
intended for A/C systems that cool the driver compartment. We're  
clarifying that it generally applies to ``cab-complete'' pickups and  
vans (see definition at Sec.  86.1803-01) which is more appropriate for  
heavy-duty than ``complete pickups and vans'' as proposed. We are  
expanding the existing statement that the paragraph does not apply for  
self-contained A/C or refrigeration units by adding the phrases ``used  
to cool passengers'' and ``used to cool cargo''. Finally, we further  
clarify that a self-contained system for purposes of this provision is  
an ``enclosed unit with its own evaporator and condenser even if it  
draws power from the engine.''  
5. Manufacturer Testing of Production Vehicles  
    The regulations require tractor manufacturers to annually chassis  
test five production vehicles over the GEM cycles to verify that  
relative reductions simulated in GEM are being achieved in actual  
production. See 40 CFR 1037.665. We do not expect absolute correlation  
between GEM results and chassis testing. GEM makes many simplifying  
assumptions that do not compromise its usefulness for certification but  
do cause it to produce emission rates different from what would be  
measured during a chassis dynamometer test. Given the limits of  
correlation possible between GEM and chassis testing, we would not  
expect such testing to accurately reflect whether a vehicle was  
compliant with the GEM standards. Therefore, Sec.  1037.665 does not  
apply compliance liability to such testing.  
    The regulation also allows manufacturers to request approval of  
alternative testing ``that will provide equivalent or better  
information.'' Manufacturers have asked us to clarify this allowance  
and we proposed to revise Sec.  1037.665 to provide an example that the  
EPA may allow manufacturers to provide CO 2 data from in-use  
operation, and CO 2 data from manufacturer-run on-road  
testing, as long as the data allows for reasonable year-to-year  
comparisons and includes testing from non-prototype vehicles (85 FR  
28148). We didn't receive any comments on the proposed changes to Sec.   
1037.665, and we are finalizing changes to the regulation as proposed.  
To qualify, the vehicles would need to be actual production vehicles  
rather than custom-built prototype vehicles. Such vehicles could be  
covered by testing or manufacturer owned exemptions but would need to  
be produced on an assembly line or other normal production practices.  
Manufacturers would also need to ensure test methods are sufficiently  
similar from year to year to allow for a meaningful analysis of trends.  
6. Vehicle Model Year Definition  
    For Phase 2 tractors and vocational vehicles, the vehicle's  
regulatory model year is usually the calendar year corresponding to the  
vehicle's date of manufacture. However, the Phase 2 regulations allow  
the vehicle's model year to be designated as the year before the  
calendar year corresponding to the vehicle's date of manufacture if the  
engine's model year is from an earlier year. We are amending as  
proposed the definition of model year in Sec.  1037.801 to allow  
vehicle manufacturers to extend the period during which a vehicle's  
certification is valid to account for this flexibility. This  
clarification more explicitly explains how vehicle manufacturers  
utilize this existing flexibility.
    After promulgation of the Phase 2 final rule, it became apparent  
that the Phase 2 vehicle model year definition does not allow starting  
vehicle production before the start of the named year if the engine  
model year also begins in the earlier year. For example, if a  
manufacturer would start its 2024 engine model year in December 2023,  
the definition would not allow vehicles produced in 2023 to be model  
year 2024.  
    To address this issue, EPA is allowing the option for the vehicle's  
model year to be designated as the year after the calendar year  
corresponding to the vehicle's date of manufacture. This has the effect  
of allowing manufacturers to meet standards earlier with aligned engine  
and vehicle model years. Model years would still be constrained to  
reflect annual (rather than multi-year) production periods and include  
January 1 of the named year.  
    We did not receive comments on these proposed change to the  
definition of model year for vehicles. We are accordingly adopting the  
revised definition for model year in 40 CFR 1037.801 for tractors and  
vocational vehicles with a date of manufacture on or after January 1,  
2021, as proposed, except that the final rule includes additional text  
to make explicit the requirement for the model year to be based on the  
manufacturer's annual production period for new models. This is  
consistent with the definition of model year for vehicles subject to  
Phase 1 standards in the same section.  
7. Compliance Margins for GEM Inputs  
    The regulations at 40 CFR 1037.620(d) allow component manufacturers  
to conduct testing for vehicle manufacturers, but they do not specify  
restrictions for the format of the data. Vehicle manufacturers have  
raised concerns about component manufacturers including compliance  
margins in GEM inputs--in other words, inputting a value that is  
significantly worse than the tested result. They state that many  
component suppliers are providing GEM inputs with compliance margins,  
rather than raw test results. However, when stacked together, the  
compliance margins would result in inappropriately high GEM results  
that would not represent the vehicles being produced.  
    We proposed to note in 40 CFR 1037.501(i) that declared GEM inputs  
for fuel maps and aerodynamic drag area will typically include  
compliance margins to account for testing variability and that, for  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 32/268other measured GEM inputs, the declared values will typically be the  
measured values, and received comment requesting additional  
clarification and providing additional suggested revisions as described  
in Chapter 2 of the Response to Comments document. One commenter  
suggested that EPA finalize default allowance values at this time,  
however we lack adequate data to make a thorough determination on what  
these values should be. In addressing manufacturers' concern, it is  
important to distinguish between engine fuel maps (which are certified  
separately) and other GEM inputs that are not certified. As is  
discussed in Section II.B.3, certified engine fuel maps are expected to  
include compliance margins to account for manufacturing and test  
variability. However, EPA did not expect each of the other GEM input to  
have a 
[[Page 34335]]  
significant compliance margin of its own. (Note that the aerodynamic  
bin structure serves to provide an inherent compliance margin for most  
vehicles.) Rather, we expected the certifying original equipment  
manufacturer (OEM) to include compliance margins in their Family  
Emission Limits (FELs) relative to the GEM outputs.  
    For vehicle GHG standards, the primary role for FEL compliance  
margins is to protect against SEA failures. Without a compliance margin  
under the Phase 2 regulations, normal production variability would  
cause some vehicles to fail, which would require the testing of  
additional vehicles. Even if the family ultimately passed the SEA, it  
would probably require the manufacturer to test a large number of  
vehicles. However, because SEAs and confirmatory tests for particular  
components would not target GEM inputs for other components, a modest  
vehicle FEL compliance margin determined by the vehicle manufacturer,  
that accounts for the component input with the highest uncertainty used  
to determine the vehicle FEL, would be sufficient to cover the full  
range of uncertainty for all components.  
    While we are not adopting explicit changes with respect to  
compliance margins that were requested in comments, we are finalizing  
the revision in Sec.  1037.501(i) as with clarifying edits that, for  
other measured GEM inputs, the declared values are typically the  
measured values without adjustment, and finalizing a related provision  
after consideration of comments on this proposed revision and on  
conducting a confirmatory test and SEA for an axle or transmission  
apart from a specific vehicle. Specifically, the additional change  
clarifies this intent for confirmatory testing in 40 CFR 1037.235(c)(2)  
by stating that the results will only affect your vehicle FEL if the  
results of our confirmatory testing result in a GEM vehicle emission  
value that is higher than the vehicle FEL declared by the manufacturer.  
    These revisions further obviate a need for component-specific  
compliance margins and should thus further clarify that component-  
specific suppliers should be providing GEM inputs with raw test  
results, rather than values that include an associated compliance  
margin. While we do not believe that suppliers should normally include  
compliance margins when providing test data to OEMs for GEM inputs, we  
do believe they should provide to OEMs some characterization of the  
statistical confidence they have in their data. This allows the OEM to  
apply an appropriate overall compliance margin for their vehicle FEL.  
During a confirmatory test, EPA would compare the GEM results using our  
measured inputs with the declared FEL for the vehicles, which means  
that the compliance margin for measurement variability should be built  
into the FEL of the vehicle. Again, EPA notes that the certified engine  
fuel maps are expected to include small compliance margins to account  
for manufacturing and test variability.  
    Finally, none of this is intended to discourage suppliers and OEMs  
from entering into commercial agreements related to the accuracy of  
test results or SEA performance.  
8. SEAs for Axles and Transmissions  
    Under 40 CFR 1037.320, a selective enforcement audit (SEA) for  
axles or transmissions would consist of performing measurements with a  
production axle or transmission to determine mean power loss values as  
declared for GEM simulations, and running GEM over one or more  
applicable duty cycles based on those measured values. The axle or  
transmission is considered passing for a given configuration if the new  
modeled emission result for every applicable duty cycle is at or below  
the modeled emission result corresponding to the declared GEM inputs.  
As described below, EPA is revising the provision regarding where an  
axle or transmission does not pass.  
    We believe special provisions are needed for axles and  
transmissions given their importance as compliance technologies and a  
market structure in which a single axle or transmission could be used  
by multiple certifying OEMs. Under the existing SEA regulations, if an  
axle or transmission family from an independent supplier fails a SEA,  
vehicle production could be disrupted for multiple OEMs and have  
serious economic impacts on them. We are finalizing a revision that  
will minimize the disruption to vehicle production.  
    Under the revised provision, if the initial axle or transmission  
passes, then the family would pass, and no further testing would be  
required. This is the same as under the existing regulations. However,  
if the initial axle or transmission does not pass, two additional  
production axles or transmissions, as applicable, would need to be  
tested. We are finalizing this revision as proposed, except we are  
finalizing additional changes to Sec.  1037.320(c) after consideration  
of comments received to the proposal in a couple respects. We further  
clarified that these additional production axels or transmissions to be  
tested could be different axle and transmission configurations within  
the family to cover the range of product included in the family. We  
also are finalizing an additional clarification in 40 CFR 1037.320(c)  
that further address how the results from the SEA will be used to  
determine if the manufacturer declared map should be replaced, by  
stating that if you fail the audit test for any of the axles or  
transmissions tested, the audit result becomes the declared map, also  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 33/268requiring revision of any analytically derived maps if applicable, and  
that these would become official test results for the family. In other  
words, this approach would correct the data used by the OEM for their  
end-of-year report.  
    After consideration of comments, we are also finalizing changes to  
40 CFR 1037.320(b) to clarify that the test transmission's gear ratios  
and not the default ratios in 40 CFR 1036.540 should be used in GEM.  
After consideration of comment regarding the lack of an engine defined  
for use as a GEM input when a component-level SEA is being performed,  
we have specified the use of the default engine map in 40 CFR part  
1036, appendix C, and a default torque curve that we have added as  
Table 1 to 40 CFR 1037.520. The axle and transmission GEM inputs can  
now be determined based on the default map and torque curve. See  
Chapter 2 of the Response to Comments for further details on comments  
received and our responses.  
9. Electric and Hybrid Vehicles in Vocational Applications  
    Prior to the proposal, manufacturers expressed concern that the  
Phase 2 regulations are not specific enough regarding how to classify  
hybrid vocational vehicles (see Sec.  1037.140). This is not an issue  
for tractors, which are classified based on gross vehicle weight rating  
(GVWR). However, vocational vehicles are generally classified by the  
class of the engines. Obviously, this approach does not work for  
electric vehicle without engines. This approach could also misrepresent  
a hybrid vehicle that is able to use an undersized engine. To address  
these problems, we 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 HDVs and all other vehicles are classified by GVWR classes.  
CARB and Tesla supported the regulation changes proposed in Sec.   
1037.140(g). We did not receive any  
[[Page 34336]]  
adverse comments on these proposed revisions and we are finalizing the  
proposed revisions with the addition of ``electric'' to paragraph  
(g)(1) for consistency with the rest of the section and an expanded  
clarification in paragraph (g)(4)(iii) that Class 8 hybrid and electric  
vehicles are considered Heavy HDV, regardless of the engine's primary  
intended service class.  
    CARB suggested tying certification provisions such as warranty and  
useful life to the vehicle GVWR to avoid allowing a downsized hybrid  
powertrain installed in a heavier vehicle weight class to have shorter  
useful life and emission warranty obligations. We note that useful life  
(Sec.  1037.105(e)) and warranty (Sec.  1037.120(b)) for vocational  
vehicles are defined by vehicle service class (i.e., Light HDV, Medium  
HDV, and Heavy HDV) and our final revision to Sec.  1037.140(g)(4)  
ensures all Class 8 hybrid and electric vehicles are classified in our  
heaviest weight class with the longest useful life and warranty  
periods. Consequently, any powertrain in a Class 8 vehicle, including a  
downsized hybrid, would be a Heavy HDV and subject to all corresponding  
certification provisions for Heavy HDVs.  
    We also requested comment on alternative approaches, such as  
specifying the useful life in hours rather than miles for these  
vocational vehicles or allowing electric vehicles to step down one  
weight class, with justification from the manufacturer. With respect to  
the potential alternative approaches we requested comment on, Ford  
supported specifying useful life in hours rather than miles for  
vocational vehicles. However, CARB raised questions on how the useful  
life in miles correlates to engine hours. Tesla encouraged EPA to  
continue to use a single, miles-based criteria for useful life. In  
addition, Ford expressed support for allowing electric vehicles to step  
down one weight class. We are not taking final action on any of the  
potential alternative approaches at this time. Regarding adopting  
useful life criteria based on engine hours, we currently lack the data  
required to link engine hours to miles for the range of vocational  
vehicles. Regarding potentially allowing electric vehicles to step down  
one weight class, we currently have concerns that this may allow for  
inappropriate useful life and warranty requirements.  
    Section 1037.140(g)(5) references Sec.  1037.106(f) in specifying  
that, in certain circumstances, you may certify vehicles to standards  
that apply for a different vehicle service class. We received comments  
from EMA and Volvo and agree with the commenters' suggestion to clarify  
how our revision to Sec.  1037.140(g)(1) regarding hybrid and electric  
tractors interacts with the cross-referenced Sec.  1037.106(f).  
Consistent with our explanation at proposal that the current  
requirements in Sec.  1037.140(g) applied to all tractors, we are also  
finalizing a corresponding clarification in Sec.  1037.106(f)(2)  
regarding Class 7 hybrid and electric tractor's ability to certify to  
the Class 8 standards, by adding a sentence that ``[t]his applies  
equally for hybrid and electric vehicles.'' See Chapter 2 of the  
Response to Comments for further details on comments received and our  
responses.  
10. Vocational Vehicle Segmentation  
    The Phase 2 regulatory structure applies the primary vocational  
standards by subcategory. Manufacturers are generally allowed to  
certify vocational vehicles in the particular duty-cycle subcategory  
they believe to be most appropriate, consistent with good engineering  
judgment.\20\ This process for selecting the correct subcategory is  
often called ``segmentation.'' Under this structure, EPA expects  
manufacturers to choose a subcategory for each vehicle configuration  
that best represents the type of operation that vehicle will actually  
experience in use. This is important because several technologies  
provide very different emission reductions depending on the actual in-  
use drive cycle. For example, stop-start would provide the biggest  
emission reductions for urban vehicles and much less reduction for  
vehicles that operate primary on long intercity drives.  
---------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 34/268    \20\ See 40 CFR 1068.5 for specifications on applying good  
engineering judgment.  
---------------------------------------------------------------------------  
    Vocational vehicles are classified based upon the gross vehicle  
weight rating (GVWR) as defined in Sec.  1037.140(g). Once classified,  
manufacturers identify the intended regulatory subcategory duty cycles  
(i.e., Urban, Multi-purpose, or Regional) for each vocational vehicle  
configuration as indicated in Sec.  1037.140(h). There are constraints  
for vocational duty cycle and regulatory subcategory, specified in  
Sec.  1037.150(z).  
    Prior to the proposal, manufacturers raised concerns about the  
impact of this structure on their ability to plan for and monitor  
compliance. They suggested that more objective and quantitative ``good  
engineering judgment'' criteria would be helpful. In response to these  
concerns, EPA proposed an interim ``safe harbor'' provision in Sec.   
1037.150(bb) for vocational vehicle segmentation. Under the proposal,  
manufacturers meeting the safe harbor criteria would be presumed to  
have applied good engineering judgment, and we explained that we  
thought the criteria were consistent with the intent of the Phase 2  
program and would not allow manufacturers to reduce the effective  
stringency the standards.  
    The first principle of the proposed safe harbor was that any  
vehicle could be classified as Multi-purpose. The Multi-purpose duty  
cycle weighting factors include significant weightings for highway  
operation, lower speed transient operation, and idle. Thus, it would  
not generally overvalue an individual technology. The second principle  
of the proposed safe harbor was that vehicles not classified as Multi-  
purpose should not be exclusively Regional or Urban. We proposed a  
quantitative measure that evaluates the ratio of Regional vehicles to  
Urban vehicles within an averaging set. Specifically, we proposed that  
the ratio of Regional vehicles to Urban vehicles must be between 1:5  
and 5:1. EPA requested comment on the proposed approach overall and the  
range of acceptable ratios.  
    CARB supported the proposed provision of allowing any vocational  
vehicle to be classified as Multi-purpose. However, both EMA and CARB  
questioned the ratios for vocational vehicle categories in the proposed  
provisions of Sec.  1037.150(bb). EMA commented that the proposed  
ratios were ``arbitrary'' and may not be represent a manufacturer's  
model mix during any specific year. Instead, EMA suggested that more  
appropriate ``good engineering judgment'' would be to base the vehicle  
category on ``the duty cycle weighting under which it performs most  
efficiently in GEM.'' CARB commented that the ratio could inadvertently  
drive manufacturers to certify the vehicles with an inappropriate duty  
cycle and recommended all vehicles be certified as Multi-purpose unless  
the manufacturer could provide ``good justification'' for a Regional or  
Urban categorization.  
    We are finalizing a revision in Sec.  1037.140(h) and throughout  
Sec.  1037.150(z) to replace ``duty cycle'' with the term ``regulatory  
subcategory'' that more appropriately reflects the intent of  
classifying a vehicle and its connection to a standard. Additionally,  
after considering the comments, EPA is finalizing one principle of the  
safe harbor provision proposed as Sec.  1037.150(bb); specifically, the  
paragraph that allows manufacturers to select the Multi-purpose  
subcategory for any vocational vehicle, unless otherwise  
[[Page 34337]]  
specified in Sec.  1037.150(z).\21\ As noted previously, selecting this  
subcategory and associated duty cycle would require technologies that  
reduce emissions across all operation (i.e., high speed, lower speed  
transient, and idle) and we believe it is an appropriate default duty  
cycle if a manufacturer is unsure of the final vehicle application when  
applying the good engineering judgment provision of Sec.  1037.140(h).  
We agree with the concerns expressed by CARB and EMA and are not  
finalizing the ratios of Regional to Urban vehicles in paragraph Sec.   
1037.150(bb)(2) of the proposed safe harbor provision. Instead, as  
discussed further below, we continue to rely on the constraints listed  
in Sec.  1037.150(z) to guide manufacturers in identifying an  
appropriate duty cycle, with the addition of a Multi-purpose safe  
harbor. 
---------------------------------------------------------------------------  
    \21\ This portion of the proposed safe harbor provision was  
proposed as Sec.  1037.150(bb)(1).
---------------------------------------------------------------------------  
    Section 1037.150(z) outlines the constraints manufacturers apply  
when determining the appropriate vocational subcategory for their  
vehicles as described in Sec.  1037.140. Instead of adding a new  
paragraph (bb) as proposed, we are reordering Sec.  1037.150(z) and  
incorporating a new paragraph to allow the Multi-purpose  
classification. The modified Sec.  1037.150(z)(1) through (3) now  
include the current provisions that identify the vehicle configurations  
(designed for higher-speed cruise operation) for which manufacturers  
must select the Regional subcategory, specifically if certified based  
solely on testing with the high-speed Supplemental Emission Test, if  
certified as a coach bus or motor home, or if equipped with a manual  
transmission after MY 2024. Except where one of those existing three  
criteria for the Regional subcategory apply, a new paragraph (z)(4)  
allows manufacturers to select the Multi-purpose subcategory for any  
vocational vehicle. The remaining renumbered paragraphs (z)(5) through  
(7) describe the current regulation's existing allowances for and  
limitations on selecting the Urban subcategory that are based on the  
most appropriate transmission configurations for lower speed, stop-and-  
go driving.  
    We continue to believe market forces will induce manufacturers to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 35/268design their vocational vehicles such that their GHG emission  
performance (and fuel efficiency) is optimized for their customers'  
specific applications and, in most cases, it will be clear which  
subcategory and associated duty cycle is appropriate for a given  
vocational vehicle configuration. Consequently, the vehicles and their  
associated technology packages will also be relatively optimized for  
one of the vocational duty cycles available for compliance using GEM,  
as shown in Table 1 of Sec.  1037.510. Where it is unclear, we would  
evaluate whether a manufacturer has applied the good engineering  
judgment required under Sec.  1037.140(h) taking into consideration  
whether the subcategory selected is best suited for the vehicle as  
indicated by the totality of its powertrain options, vehicle features,  
and duty cycle performance under which it demonstrates the most  
favorable emissions result relative to the emission standard. We note  
that in our review of a manufacturer's good engineering judgment  
request, we reserve the right to require the use of a more appropriate  
duty cycle and subcategory. We will continue to monitor use of the good  
engineering judgment provision of Sec.  1037.140(h) and the constraints  
listed in Sec.  1037.150(z) and may re-evaluate our approach in the  
future if we determine it is necessary.  
    Thus, the final regulations include consideration of both EMA and  
CARB's suggestions. As noted previously, we would consider the duty  
cycle weighting under which the vehicle performs most efficiently in  
GEM in considering whether good engineering judgment was used, and have  
provided manufacturers of vehicles not subject to the constraints  
listed in Sec.  1037.150(z) with a clear pathway to certify those  
vehicles as Multi-purpose if they are otherwise unable to justify  
Regional or Urban duty cycle when exercising good engineering judgment.  
    In the proposed rule, we also requested comment on the need for the  
subcategory on the label. EMA commented that it is unnecessary and a  
complication and burden for manufacturers to identify whether the  
vehicle is in the Urban, Multi-Purpose or Regional subcategory on the  
label and requested that we ``remove the requirements in Sec.   
1037.135(c)(3) and (4)''. CARB commented and encouraged EPA to require  
the subcategory be on the label because it would help consumers choose  
the appropriate certified vehicles for their intended vehicle operation  
cycles. After consideration of EMA's and CARB's comments, we are  
removing the requirement to explicitly state the regulatory subcategory  
on the emission label as specified in Sec.  1037.135(c)(4). In the  
Phase 2 final rulemaking, we concluded that it was unnecessary for the  
emission label to contain a comprehensive list of all emission  
components and that it is important to balance the manufacturers'  
``need to limit label content with the [the agencies'] interest in  
providing the most useful information for inspectors'' (81 FR 73636,  
October 25, 2016). Since stating the regulatory subcategory on the  
label provides limited additional information inspectors could use to  
quickly determine if the vehicle is in its certified condition and the  
subcategory can be identified from the vehicle family name required by  
paragraph (c)(3), we believe it is appropriate to remove it as a  
requirement on the emission label. We are not revising the current  
requirement to print the standardized designation for the vehicle  
family name as required by Sec.  1037.135(c)(3), which ensures  
consistency between the label and other compliance provisions that  
require the vehicle family name. As such, the regulatory subfamily can  
continue to be identified from the family name, which should help  
address CARB's concern if a consumer chooses to use the emissions label  
when deciding to purchase a vehicle.  
11. Early Certification for Small Manufacturers  
    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.\22\ However, some vehicle families have been  
certified voluntarily to Phase 1 standards by small manufacturers. In  
an effort to encourage more voluntary early certification to Phase 1  
standards, we proposed a new interim provision in Sec.  1037.150(y)(4)  
for small manufacturers that certify their entire U.S.-directed  
production volume to the Phase 1 standards for calendar year 2021 (85  
FR 28150). Small manufacturers may delay complying with the Phase 2  
standards by one year, and instead comply with the Phase 1 standards  
for that year, if they voluntarily comply with the Phase 1 standards  
for one full prior year. Specifically, small manufacturers may certify  
their model year 2022 vehicles to the Phase 1 greenhouse gas standards  
of Sec. Sec.  1037.105 and 1037.106 if they certify all the vehicles  
from their annual U.S.-directed production volume to the Phase 1  
standards starting on or before January 1, 2021. If the small  
manufacturers do so, the provision allows these manufacturers to  
certify to the Phase 1 standards for model year 2022 (instead of the  
otherwise applicable Phase 2 standards). Early compliance with the  
Phase 1 standards should more than offset any reduction in benefits  
that would otherwise be  
[[Page 34338]]  
achieved from meeting Phase 2 standards starting January 1, 2022.\23\  
---------------------------------------------------------------------------  
    \22\ See 40 CFR 1037.150(c).  
    \23\ The magnitude of any impact on air quality would be small  
because of the low production volumes from these small business  
manufacturers.  
---------------------------------------------------------------------------  
    The provision we proposed also allows the Phase 1 vehicle credits  
that small manufacturers generate from model year 2018 through 2022  
vocational vehicles to be used through model year 2027. Under the  
existing regulations, all manufacturers that generate credits under the  
Phase 1 program are allowed to use such Phase 1 vehicle credits in the  
Phase 2 vehicle averaging, banking, and trading program, but the  
credits are subject to the five-year credit life. As noted in the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 36/268proposed rule, we believe the limit on credit life can be problematic  
for small manufacturers with limited product lines which allow them  
less flexibility in averaging, and the longer credit life will provide  
them 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. We note that these Phase 1 emission credits are based  
on the degree to which the Family Emission Limit is below the Phase 1  
standard.  
    We received no adverse comment to either proposal for small  
manufacturers in Sec.  1037.150(y)(4). Our final revisions include  
minor edits to the proposed credit-related provision in Sec.   
1037.150(y)(4) to create a standalone sentence and moving the proposed  
provision that describes the certification flexibility for these small  
manufacturers to a new Sec.  1037.150(c)(4) where the applicable  
standards and implementation dates for qualifying small businesses are  
introduced.  
12. Delegated Assembly  
    In 40 CFR 1037.621, EPA specifies provisions to allow manufacturers  
to ship incomplete vehicles and delegate the final assembly to another  
entity. Manufacturers previously expressed the concern that these  
``delegated assembly'' requirements are too burdensome in some cases,  
particularly in cases such as auxiliary power units and natural gas  
fuel tanks. EPA requested comment on this issue and proposed a single  
clarifying edit in Sec.  1037.621(g). CARB encouraged EPA to maintain  
the existing delegated assembly provisions. We received no comments  
adverse these existing provisions or providing suggestions for updated  
text. The final rule adopts only the single clarifying edit in Sec.   
1037.621(g), as proposed.  
13. Canadian Vehicle Standards  
    During the Phase 2 rulemaking, Environment and Climate Change  
Canada (ECCC) emphasized that the highway weight limitations in Canada  
are much greater than those in the U.S. Where the U.S. Federal highways  
have limits of 80,000 pounds gross combined weight, Canadian provinces  
have weight limits up to 140,000 pounds. This difference could  
potentially limit emission reductions that could be achieved if ECCC  
were to fully harmonize with the U.S.'s HD Phase 2 standards because a  
significant portion of the tractors sold in Canada have GCWR (Gross  
Combined Weight Rating) greater than EPA's 120,000-pound weight  
criterion for ``heavy-haul'' tractors.  
    EPA addressed this in Phase 2 by adopting provisions that allow the  
manufacturers the option for vehicles above 120,000 pounds GCWR to meet  
the more stringent standards that reflect the ECCC views on appropriate  
technology improvements, along with the powertrain requirements that go  
along with higher GCWR (see 81 FR 73582, October 25, 2016). Vehicles in  
the 120,000 to 140,000 pound GCWR range would normally be treated as  
simple ``heavy haul'' tractors in GEM, which eliminates the GEM input  
for aerodynamics. However, vehicles certified to the optional standards  
would be classified as ``heavy Class 8'' tractors in GEM, which then  
requires an aerodynamic input. Nevertheless, they both use the heavier  
payload for heavy haul.  
    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.\24\ Since the purpose of these standards was to facilitate  
certification of vehicles intended for Canada, we proposed optional  
standards in Sec.  1037.670 that would be the same as the final ECCC  
standards. We did not receive any comments adverse the proposed  
optional standards and we are finalizing the optional standards as  
proposed in Sec.  1037.670. Note that these standards are not directly  
comparable to either the normal Class 8 standards or the heavy haul  
standards of Sec.  1037.106 because GEM uses different inputs for them.  
Manufacturers who choose to opt into meeting the Canadian standards  
would achieve greater emission reductions compared to EPA's program.  
---------------------------------------------------------------------------  
    \24\ Government of Canada. 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. Available online: http://gazette.gc.ca/rp-pr/p2/2018/2018-05-30/html/sor-dors98-eng.html . 
---------------------------------------------------------------------------  
    ECCC has also adopted new standards for tractors in the 97,000 to  
120,000 pound GCWR category. In general, EPA would classify a tractor  
in the 97,000 to 120,000 lb GCWR range in one of its Class 8 tractor  
subcategories. EPA's Class 8 tractor standards, which cover up to  
120,000 lb GCWR, have standards that are more stringent than ECCC's  
standards for their 97,000 to 120,000 lb GCWR subcategory. We did not  
propose special provisions for these tractors, but requested comment on  
the need for special provisions for these vehicles. Both EMA and Volvo  
commented that special provisions are necessary to facilitate  
certification of 97,000 to 120,000-pound GCWR tractors for export to  
Canada. EMA suggested a similar approach for these 97,000 to 120,000-  
pound GCWR tractors as the one provided for the optional certification  
for tractors at or above 120,000 pounds GCWR, proposed in Sec.   
1037.670. Similarly, Volvo requested that EPA provide subcategories and  
standards for these tractors that align with the ECCC regulations. We  
have concerns with the suggestion of providing an option for tractor  
standards that are less stringent than our current standards. EPA did  
not propose and is not taking any final action on special provisions  
for such vehicles at this time.  
14. Transmission Calibrations  
    Manufacturers with advanced transmission calibrations may use the  
powertrain test option in Sec.  1037.550 to demonstrate the performance  
of their transmissions. We adopted this option to provide an incentive  
for the development of advanced transmissions with sophisticated  
calibrations.  
    Transmission manufacturers have developed some new efficient  
calibrations, but must also maintain less efficient calibrations to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 37/268address special types of operation. Due to concerns about resale value,  
most customers want to retain the ability to select the correct  
calibration for their operation. For transmissions with such selectable  
calibrations, Sec.  1037.235(a) requires that they test using the  
worst-case calibration, which can undermine the incentive to continue  
improving the calibrations. We received comment requesting that we  
allow averaging of the worst-case and best-case performance, however  
this request would be a significant departure from how engine families  
are certified and what 40 CFR part 1037 currently requires for  
transmissions. We also received comment on weighting the  
[[Page 34339]]  
calibration performance based on the actual use of these calibrations  
in the field. We believe that this option will give the most  
representative use of these calibrations and their impact on  
CO2 emissions. After consideration of these comments, we are  
finalizing a change to allow manufacturers to measure both the best-  
and worst-case calibrations and weight them by prior model year based  
on survey data, prior model year sales volume, or other appropriate  
means. This weighting will be accomplished by testing both calibrations  
and weighting the results in Table 2 of Sec.  1037.550 as described in  
amendments made in Sec.  1037.235(a). See Chapter 2 of the Response to  
Comments for further details on comments received and our responses.  
15. Other Minor Heavy-Duty Vehicle Amendments  
    We received no adverse comments to the following proposed  
amendments. EPA is finalizing the following amendments to part 1037 as  
proposed:  
     Section 1037.103(c)--Adding phrase ``throughout the useful  
life''. 
     Section 1037.105 Table 5--Updating footnote format in  
table. 
     Section 1037.106 Table 1--Updating footnote format in  
table. 
     Section 1037.120(b)--Correcting the text with respect to  
tires and Heavy Heavy-Duty vehicles.  
     Section 1037.150(c)--Adding a sentence pointing to  
additional interim provisions for small manufacturers.  
     Section 1037.150(aa)--Clarifying the production limit for  
drayage tractors under the custom chassis allowance.  
     Section 1037.201(h)--Correcting phrase ``except that Sec.   
1037.245 describes . . .'' to refer to Sec.  1037.243.  
     Section 1037.205(e)--Correcting parenthetical ``(see 40  
CFR 1036.510)'' to refer to 40 CFR 1036.503.  
     Section 1037.225(e)--Reorganizing paragraph with the  
introduction noting starting data, paragraph (e)(1) with existing text,  
and a new paragraph (e)(2) regarding the requirement that the amended  
application be ``correct and complete''.  
     Section 1037.230(a)(2)--Adding two clarifying paragraphs  
for optional tractor subcategories.  
     Section 1037.243(c)--Rephrasing for consistency with other  
paragraphs in the section.  
     Section 1037.255--Replacing the possessive ``your'' with  
articles a/an/the throughout this section and added clarifying  
statements related to the information submitted in an application for a  
certificate of conformity.  
     Section 1037.301(b)--Removing phrase ``matches or exceeds  
the efficiency improvement''.  
     Section 1037.635(c)(1)--Editorial, adding a missing  
``the''.  
     Section 1037.701(h)--Editorial, fixing reference.  
     Section 1037.705(c)(2)--Adding a clarification for  
exported vehicles.  
     Section 1037.801--Correcting punctuation in Compression-  
ignition and Low rolling resistance tires definitions; adding the word  
``motor'' to definition of Electric vehicle; adding definition of  
electronic control module; clarifying Heavy-duty vehicle definition  
with respect to incomplete vehicles; adding definition of High-strength  
steel; clarifying Light-duty truck definition; adding Tonne definition.  
     Section 1037.805(c) and (d)--Editorial; updating to be  
consistent with format in other parts.  
    EPA is also finalizing the following additional amendments, that  
include revisions we are finalizing as proposed but with additional  
clarifications, editorial improvements, or to fix typographical errors,  
after consideration of comments, as noted. Chapter 2 of our Response to  
Comments includes additional details on some of these amendments, as  
well as other amendments or clarifications requested by commenters and  
our responses.  
     Section 1037.150(c)--Reorganizing the section into  
subparagraphs; removing ``qualifying'' throughout; moving reference to  
NAICS codes into definition of ``small manufacturer'' in Sec.   
1037.801; and combining the statements regarding the MY 2022  
implementation date for tractor and vocational vehicles and the  
additional delays in later years for alternatively-fueled tractors and  
vocational vehicles into the new paragraph (c)(2) to provide further  
clarification in response to CARB's seeming misinterpretation of the  
regulations in a submitted comment related to our proposed Sec.   
1037.150(y)(4) provision. Also moving the certification-focused portion  
of the early certification provision proposed as part of Sec.   
1037.150(y)(4) to a new paragraph (c)(4) as discussed in Section  
II.C.11.  
     Section 1037.231(b)(7)--Adding an additional revision to  
provide clarification on forward gear availability, noting that  
available forward gear means the vehicle has the hardware and software  
to allow operation in those gears, consistent with our final revision  
to Sec.  1037.520(g) as noted in Section II.A.2.  
     Section 1037.235(h)--Providing an example of an ``untested  
configuration'' in response to EMA's request for clarification.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 38/268     Section 1037.601(a)(2)--Removing limit of ``up to 50'' and  
added a more general statement that we will limit the number of  
engines.  
     Section 1037.615--Clarifying that fuel cells powered by  
hydrogen should have a Family Emission Limit of 0 g/ton-mile for  
calculating CO 2 credits. Vehicles fueled by hydrogen are  
inherently carbon-free, which supports treating these vehicles the same  
as electric vehicles. This clarification is responsive to a comment  
from EMA.  
     Section 1037.660(a)(2)--Revising to specify the  
permissible delay before engaging neutral idle when the vehicle is  
stopped; updating from proposed value of two seconds to the final value  
of five seconds after consideration of a request from Ford that  
suggested ``two seconds is too short to account for normal stops and  
restarts in real on-road driving''. This request was posed in an email  
to EPA following the proposed rule.\25\  
---------------------------------------------------------------------------  
    \25\ Memorandum to Docket EPA-HQ-OAR-2019-0307, Email from Ken  
McAlinden (Ford) Requesting Regulatory Change for Neutral Idle  
Credit, Christopher Laroo, September 23, 2020.  
---------------------------------------------------------------------------  
     Section 1037.740(b)--Updated naming convention to match  
vehicle service classes Our revised delay of five seconds for neutral  
idle accommodates Ford's request and is consistent with the permissible  
Sec.  1037.740(b)--Updating the naming convention to match vehicle  
service classes.  
     Section 1037.801--Updating the proposed definitions for  
``hybrid engine or powertrain'' and ``hybrid vehicle'' to be consistent  
with the proposed and further developed hybrid powertrain test  
procedure revisions to part 1036, subpart F, and the definitions of  
``hybrid powertrain'' and ``mild hybrid'' added to 40 CFR part 1036.  
These revisions add examples of systems that qualify as hybrid engines  
or powertrains, specifically systems that recover kinetic energy and  
use it to power an electric heater in the aftertreatment. Updating  
model year definition as discussed in Section II.C.6 and small  
manufacturer definition as discussed in II.C.11.  
     Section 1037.805(b)--Updating quantity and quantity  
descriptions including additional revisions to those proposed to ensure  
that these descriptions were consistent throughout the part.  
     Section 1037.805(f)--Adding an additional revision to  
those proposed to update gravitational constant after consideration of  
comments received on the proposal.
     Appendix III to part 1037--Updating the definition of the  
emission control identifier ``DWSW'' to clarify  
[[Page 34340]]  
high-strength steel wheel and maintain consistency with the related  
requirements in Table 6 of Sec.  1037.520, after consideration of  
comment by CARB.  
D. Onboard Diagnostics (``OBD'')  
    EPA proposed several updates to the onboard diagnostic (OBD)  
provisions of 40 CFR part 86, subpart A, related to onboard diagnostic  
requirements for heavy-duty engines and requested comment on general  
improvements and efforts to harmonize EPA and CARB OBD requirements  
(see 85 FR 28152). This section presents the changes we are adopting to  
OBD requirements after consideration of comments received. Additional  
details on these and other OBD amendments or clarifications requested  
by commenters and our responses are available in Chapter 2 of our  
Response to Comments document.  
    EPA's OBD regulations for heavy-duty engines are contained in 40  
CFR 86.010-18, and were promulgated February 24, 2009 (74 FR 8310).  
Although these regulations were originally harmonized with CARB's OBD  
program, CARB has since updated and made changes to their regulations  
which EPA has not adopted. Most recently, in October 2019, CARB  
approved revisions to the onboard diagnostics requirements that include  
implementation of real emissions assessment logging (REAL) for heavy-  
duty engines and other vehicles.  
    The proposed rule requested comment on differences between existing  
EPA and CARB OBD regulations and included specific proposed revisions  
intended to reduce these differences. EPA proposed six specific  
revisions to update existing OBD regulations and harmonize with CARB  
requirements. We received comments supportive of these proposals, as  
well as comments indicating that EPA should reconsider certain  
proposals to ensure the regulations are clear and have the desired  
effect. After further evaluation and consideration of comments, EPA is  
finalizing four of these six proposed revisions:  
    (1) Adopting as proposed the CARB 5% threshold for misfire in Sec.   
86.010-18(g)(2). This would allow manufacturers to not detect misfires  
under certain conditions, such as during aftertreatment regeneration  
and some low temperature operation.  
    (2) Adopting as proposed CARB's misfire flexibilities in  
1971.1(e)(2.3.3) which include identifying when it is reasonable for a  
manufacturer to seek approval for systems that cannot detect all  
misfire under all required speed and load conditions and where they  
seek approval to disable misfire detections.  
    (3) Adopting with a clarification the proposed revision to our in-  
use compliance standards in Sec.  86.010-18(p) to reflect the CARB  
approach for minimum ratios for representative samples where a system  
would be considered noncompliant if the representative test sample (or  
performance group) indicates that the in-use ratio is below 0.088. A  
clarification was added to specify that the in-use ratio is based on  
the ``average'' value for the test sample group.  
    (4) Adopting as proposed the allowance to use CARB OBD reporting  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 39/268templates for EPA OBD requirements.  
    EPA received comments on the 5% threshold for misfire indicating  
concern that the provision as proposed does not reflect CARB's most  
recent requirements. EPA's proposal in Sec.  86.010-18(g)(2)(iii)(C)  
was to require misfire detection on those engines equipped with sensors  
that can detect misfire occurrences. Existing CARB requirements state  
that all diesel engines are required to continuously monitor for  
misfire, not just those engines equipped to detect for misfire. EPA is  
finalizing the misfire provision as proposed but may further review  
this provision and may consider harmonizing with existing CARB  
requirements that require misfire detection for all diesel engines as a  
part of a future rulemaking. For example, the Cleaner Trucks Initiative  
(``CTI'') rulemaking intends to consider updating existing EPA OBD  
regulations and harmonizing further with CARB OBD requirements as noted  
in the advance notice of proposed rulemaking (ANPR) (85 FR 3306,  
January 21, 2020). EPA received comment on the proposal to revise our  
in-use compliance standards that recommended adding a clarification to  
the proposed language to indicate that the in-use ratio is based on the  
average in-use ratio of the engines in the test sample group. The  
comment pointed out that the regulations as proposed were not clear as  
to how the in-use ratio would be determined. Existing EPA regulations  
in Sec.  86.010-18(j)(3)(i) and (ii) specify that manufacturers must  
collect and report in-use monitoring performance data representative of  
production vehicles, separate production vehicles into monitoring  
performance groups and submit data that represents each of these  
groups. The purpose of this requirement is to analyze in-use data from  
more than one vehicle to ensure that the OBD system is functioning  
properly. The frequency that some OBD monitors run can vary depending  
on the duty cycle of a particular vehicle, therefore, using the average  
in-use ratio from to evaluate performance is most appropriate. Adding  
this clarification also increases the alignment of EPA and CARB OBD  
requirements. After consideration of these factors we have added the  
word ``average'' to Sec.  86.010-18(p)(4)(ii) to provide this clarity.  
Comments were also received on the in-use requirements stating that an  
additional provision should be included to Sec.  86.010-18(p)(4)(ii) to  
ensure that compliance with the in-use ratio requirement is not  
influenced by engines with very high ratios which could lower the  
average value. We are not finalizing this change at this time but  
intend to review whether or not revisions to this provision should be  
considered as a part of the CTI rulemaking effort. EPA received no  
adverse comments on the proposal to allow the use of CARB's OBD  
reporting template. Using the CARB template will help streamline  
certification processes and reduce the time manufacturers may spend  
entering duplicative information on different forms. EPA is finalizing  
this provision as proposed to help harmonize requirements and  
streamline the certification process.  
    EPA is not taking final action at this time on two proposed  
revisions: (1) To allow CARB certified configurations to not count as  
separate engines families for the purposes of determining OEM test  
requirements, and (2) to allow a simplified carryover OBD certification  
path intended for special engine families. We received comments  
indicating concern that these proposals were not clear. For example,  
CARB noted that the proposed regulatory requirements for both carryover  
certification and for determining required OBD demonstration testing  
requirements relied on the term ``special engine family'' which is not  
defined in EPA regulations. EPA intends to review these two issues and  
other comments received on existing OBD requirements as part of a more  
comprehensive effort to consider updating our existing OBD regulations  
in the intended CTI rulemaking.  
II. Other Amendments  
A. Ethanol-Blend Test Fuels for Nonroad Spark-Ignition Engines and  
Vehicles, Highway Motorcycles, and Portable Fuel Containers  
    EPA adopted exhaust and evaporative emission standards for  
gasoline-fueled nonroad engines, vehicles, and equipment before there  
was a Federal gasoline test fuel with 10 percent  
[[Page 34341]]  
ethanol (E10). Most of those programs therefore relied on testing with  
neat gasoline (E0) or with a splash-blended mix of neat gasoline and  
ethanol to make E10. In the meantime, EPA adopted a Federal gasoline  
test fuel with 10 percent ethanol for testing motor vehicles (79 FR  
23414, April 28, 2014).  
    California ARB adopted its own specification for an E10 test fuel  
for testing motor vehicles, referred to as ``LEV III E10.'' California  
ARB revised its nonroad emission control programs to require  
manufacturers to start using LEV III E10 test fuel for certification  
starting in model year 2020, without allowing for carryover of previous  
data from testing with neat gasoline. California ARB's move to require  
use of LEV III E10 test fuel for certification has led manufacturers to  
express a concern about the test burden associated with separate  
testing to demonstrate compliance with EPA and California ARB emission  
standards.  
    The concern for aligning test requirements related to test fuel  
applies for marine spark-ignition engines (40 CFR part 1045), nonroad  
spark-ignition engines above 19 kW (40 CFR part 1048), and recreational  
vehicles (40 CFR part 1051).\26\ We expect a similar situation to apply  
for highway motorcycles in the 2022-2025 time frame based on California  
ARB's plans for further rulemaking activity.  
---------------------------------------------------------------------------  
    \26\ EPA adopted amendments to address these concerns for  
nonroad spark-ignition engines at or below 19 kW in an earlier  
rulemaking (80 FR 9114, February 19, 2015).  
---------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 40/268    We have issued guidance for marine spark-ignition engines (40 CFR  
part 1045) \27\ and for recreational vehicles (40 CFR part 1051) \28\  
describing how we may approve certification based on emission  
measurements with an E10 test fuel. We are revising 40 CFR parts 1045,  
1048, and 1051, consistent with the recently issued guidance documents,  
to allow for certification based on emission measurements with EPA's  
E10 test fuel without requiring EPA approval, and without adjusting  
emission standards to account for fuel effects. For marine spark-  
ignition engines (40 CFR part 1045), this merely replaces the existing  
provision allowing for the alternative of using a splash-blended E10  
test fuel. For recreational vehicles (40 CFR part 1051) and Large  
spark-ignition (Large SI) engines (40 CFR part 1048), naming EPA's E10  
specification as the alternative test fuel is a new provision. We are  
not prepared in this rulemaking to justify adopting new emission  
standards or to otherwise change the stringency of the existing  
standards. It is therefore necessary for EPA to be able to do  
confirmatory testing with either the original E0 test fuel, or the  
manufacturer's selected alternative fuel.  
---------------------------------------------------------------------------  
    \27\ ``Marine Spark Ignition Engine Certification Testing with  
California ARB E10 Test Fuel,'' EPA guidance document CD-18-15,  
December 24, 2018.  
    \28\ ``Off-Highway Recreational Vehicle Certification Testing  
with California ARB E10 Test Fuel,'' EPA guidance document CD-19-03,  
April 22, 2019.  
---------------------------------------------------------------------------  
    We are also allowing the same approach for certification based on  
emission measurements with EPA's E10 test fuel for highway motorcycles  
(including EPA confirmatory testing with either E0 or E10).  
    We expect this approach of allowing E10 as an alternative test fuel  
to adequately address concerns for the identified sectors. Many of  
these engines have closed-loop fuel controls that reduce the effect of  
fuel variables on exhaust emissions. Many also have relatively large  
compliance margins relative to the standards that apply. These factors  
help manufacturers confidently test with E10 as an alternative fuel,  
knowing that they continue to be liable for meeting emission standards  
on the specified E0 test fuel.  
    In the proposed rule we described a process for approving the use  
of California ARB's LEV III E10 test fuel instead of EPA's E10 test  
fuel as the alternative test fuel. That process is detailed in the  
existing regulations at 40 CFR 1065.701(b). The National Marine  
Manufacturers Association, the Motorcycle Industry Council, and Polaris  
requested that we revise the regulation to include California ARB's LEV  
III E10 as an alternative test fuel. The two sets of fuel  
specifications are nearly identical, with the notable difference being  
that California ARB's LEV III E10 test fuel has a lower volatility,  
which corresponds to the fuel regulations that apply in California. For  
testing hot-stabilized engines, volatility has a very small effect on  
exhaust emissions.  
    We are not revising the regulation to specify California ARB's LEV  
III E10 test fuel as an alternative test fuel. We expect the approval  
process described in 40 CFR 1065.701(b) to allow for review that will  
typically result in approval to use the California test fuel. However,  
we remain concerned that there may be some limited circumstances in  
which testing with the California fuel may not be appropriate for EPA  
certification. For example, engine manufacturers might name a Family  
Emission Limit to earn emission credits with a very narrow compliance  
margin. In that case, we would want to be able to explore with the  
manufacturer whether its testing adequately supports the proposed  
application for certification. As another example, some nonroad sectors  
include standards and testing requirements for controlling off-cycle  
emissions. It may be appropriate for the manufacturer to perform some  
of this off-cycle testing for certification using EPA's E0 or E10 test  
fuel in addition to testing over specified duty cycles with California  
ARB's LEV III E10 test fuel. To illustrate this point, we observed from  
a recent experience exploring potential noncompliance that an engine  
that has electronic feedback control can have a sensitivity to fuel  
parameters that is much greater than we would expect based on a simple  
assessment of combustion chemistry. We also note that the experience of  
implementing these changes in test fuel requirements will inform our  
ongoing approach for approving requests. Data supporting the  
equivalence of EPA and California test fuels would lead us to reduce  
our concerns for approving requests. In contrast, if we learn that fuel  
effects are greater than expected, we would review requests more  
carefully. This more careful review could be limited to a single  
manufacturer or a single type of engine (or engine technology), or it  
may apply more broadly.  
    We specify evaporative emission standards and test procedures for  
portable fuel containers and nonroad spark-ignition equipment in 40 CFR  
part 59, subpart F, and 40 CFR part 1060, respectively. The gasoline  
test fuel is splash-blended E10. California ARB specifies their LEV III  
gasoline test fuel for the analogous procedures in California, but they  
allow manufacturers to submit data instead using EPA's specified test  
fuel. Accordingly, we believe manufacturers do not face the same burden  
of needing to perform duplicate measurements for the two agencies. We  
are therefore not changing the EPA test fuel for portable fuel  
containers.  
    Commenters largely affirmed the proposed approach for increased  
flexibility for using E10 test fuels.\29\ We understand this approach--  
allowing testing with E10 testing as an alternative procedure--to be an  
interim measure. We expect to continue the move toward adopting E10  
test fuel specifications, without referencing an E0 test fuel  
specification, as we consider updating emission standards for each  
sector over time. When we establish new standards, we would expect to  
evaluate the stringency of those standards based on  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 41/268[[Page 34342]]  
testing with E10 test fuel, which will allow for adopting a singular  
test fuel.  
---------------------------------------------------------------------------  
    \29\ See the Response to Comments for detailed input from  
commenters.  
---------------------------------------------------------------------------  
B. Removing Obsolete CFR Content  
    EPA first adopted emission standards for light-duty motor vehicles  
and heavy-duty highway engines in the 1970s. Emission standards for the  
first categories of nonroad engines started to apply in the 1990s. Each  
of these programs include emission standards that apply by model year.  
For most of these programs over time, engines and vehicles were subject  
to increasingly stringent standards and improved certification and  
testing requirements. All these standards and regulatory provisions are  
codified in the Code of Federal Regulations. As time passes, the  
regulations for past model years become obsolete, but it remains in  
print until there is a rulemaking change to remove it from print. We  
are removing large portions of this regulatory content that no longer  
applies. The following sections describe these changes for different  
sectors.  
    Note that Section III.D describes several amendments to emission  
control programs for motor vehicles in 40 CFR parts 85 and 86. These  
amendments include several provisions that also remove obsolete  
regulatory content.  
1. Clean Fuel Fleet Standards (40 CFR Part 88)  
    The Clean Air Act Amendments of 1990 included numerical standards  
for the Clean Fuel Fleet program that were intended to encourage  
innovation and reduce emissions for fleets of motor vehicles in certain  
nonattainment areas as compared to conventionally fueled vehicles  
available at the time. As originally adopted, those Clean Fuel Fleet  
standards were substantially more stringent than the standards that  
applied to vehicles and engines generally.  
    Now that we have begun implementing Tier 3 standards in 40 CFR part  
86, subpart S, the Clean Fuel Fleet standards are either less stringent  
than or equivalent to the standards that apply to vehicles and engines  
generally. Because the statute continues to require Clean Fuel Fleet  
standards for state clean-fuel vehicle programs, we cannot simply  
remove the Clean Fuel Fleet program from the regulations. Rather, we  
are implementing the Clean Fuel Fleet standards in 40 CFR part 88 with  
a compliance option where vehicles and engines certified to current  
standards under 40 CFR parts 86 and 1036 would be deemed to comply with  
the Clean Fuel Fleet standards as Ultra Low-Emission Vehicles. Further,  
the Clean Fuel Fleet program as adopted included labeling requirements  
for engine and vehicle manufacturers to identify compliant engines and  
vehicles, and a restriction against including such engines or vehicles  
when calculating emission credits. Both provisions would also no longer  
be applicable because of the earlier mentioned increased stringency of  
standards for engines and vehicles, and under the compliance option we  
are establishing. Therefore, we are also removing these regulations.  
This will give clear instructions to vehicle and engine manufacturers  
as well as states that continue to have Clean Fuel Fleet provisions in  
their State Implementation Plans or become subject to these  
requirements in the future under the Clean Air Act (CAA) sections  
182(c)(4)(A) and 246(a).  
    For states with areas that become subject to the clean-fuel vehicle  
program requirements in the future based on a new designation as an  
ozone nonattainment area, the required state implementation plan  
submission for the program or for a substitute measure is due within 42  
months after the effective date of an area's nonattainment designation.  
The clean-fuel vehicle program requirements apply for ozone  
nonattainment areas with an initial designation as Serious, Severe, or  
Extreme. For marginal and moderate ozone nonattainment areas that are  
reclassified as Serious, Severe, or Extreme, the required state  
implementation plan submission for the program or for a substitute  
measure is due on the date specified in the EPA rulemaking finalizing  
the area's reclassification.  
    The Clean Fuel Fleet program also depends on vehicle  
classifications that include Zero Emission Vehicles and Inherently Low-  
Emission Vehicles. We are therefore preserving these defined terms in  
40 CFR part 88. Under the new provisions, we will consider as Zero  
Emission Vehicles all electric vehicles and any vehicle that does not  
emit NOX, PM, HC, CO, or formaldehyde (including evaporative  
emissions). We are simplifying the definition of Inherently Low-  
Emission Vehicles to mean any certified vehicle that is designed to not  
vent fuel vapors to the atmosphere.  
2. Legacy Nonroad Standards (40 CFR Parts 89 Through 94)  
    The 1990 amendments to the Clean Air Act authorized EPA to set  
emission standards for nonroad engines. This led to a series of  
rulemakings to adopt emission control programs for different nonroad  
sectors. From 1994 through 1999, EPA adopted these emission control  
programs in 40 CFR parts 89, 90, 91, 92, and 94 (all part of subchapter  
C). 
    Starting in 2002, EPA adopted emission standards for additional  
nonroad emission control programs in a new subchapter, which allowed  
for improved organization and harmonization across sectors. We codified  
these new standards and related provisions in 40 CFR parts 1048, 1051,  
1065, and 1068 (all part of subchapter U). Since then, we have migrated  
the ``legacy'' emission control programs from subchapter C to  
subchapter U. In each case, the migration corresponded to new emission  
standards and substantially updated compliance and testing provisions.  
This applies for the following sectors:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 42/268------------------------------------------------------------------------  
             Sector                Legacy regulation  Current regulation  
------------------------------------------------------------------------  
Land-based nonroad diesel         40 CFR part 89....  40 CFR part 1039.  
 engines.  
Nonroad spark-ignition engines    40 CFR part 90....  40 CFR part 1054.  
 at or below 19 kW.  
Marine spark-ignition engines...  40 CFR part 91....  40 CFR part 1045.  
Locomotives and locomotive        40 CFR part 92....  40 CFR part 1033.  
 engines.  
Marine diesel engines...........  40 CFR part 94....  40 CFR part 1042.  
------------------------------------------------------------------------  
    As a result of this migration, engine manufacturers have not  
certified engines under the legacy parts for the last 5-10 years.  
Removing these legacy parts reduces the cost to the Agency and prevents  
confusion for readers who think that the old provisions still apply.  
    While EPA's engine certification programs don't rely on these  
obsolete provisions, the new programs refer to the legacy parts for  
some specific provisions. For example, the new standard-setting part  
for each type of engine/equipment allows manufacturers to continue to  
certify carryover engine families based on test data from procedures  
specified in the legacy parts.  
[[Page 34343]]  
We are not discontinuing further use of carryover data from engines  
originally certified under the legacy parts. On the other hand, this  
provision will gradually sunset itself as manufacturers update engine  
designs and perform new testing for their engine families to meet  
current standards.  
    Another example of relying on the legacy parts in the new  
regulations is emission credits generated under the legacy parts. In  
most cases, current programs either disallow using those credits for  
certification, or they allow it without keeping separate accounts for  
credits generated under the legacy parts. We are making no changes  
where credits from legacy parts are either unavailable or  
indistinguishable from currently generated credits. One exception is  
for land-based nonroad diesel engines certified under 40 CFR parts 89  
and 1039. Current provisions in Sec.  1039.740 allow for limited use of  
Tier 2 and Tier 3 credits from part 89 for certifying Tier 4 engines.  
We are revising Sec.  1039.740, as proposed, to continue to allow  
manufacturers to use credits generated from Tier 2 and Tier 3 engines  
by simply changing the relevant references 40 CFR part 89 to 40 CFR  
part 1039, appendix I.  
    We are also aware that other Federal and state regulations and  
compliance programs include numerous references to 40 CFR parts 89  
through 94. To address this, we are replacing the full text of  
regulations in the legacy parts with a paragraph describing the  
historical scope and purpose for each part. The remaining paragraph  
also directs readers to the new regulations that apply in subchapter U  
and clarifies how the regulatory requirements transition to the new  
content. As an example, the statute and regulations prohibit tampering  
with certified engines throughout an engine's lifetime, even if the  
original text describing that prohibition no longer resides in its  
original location in the Code of Federal Regulations.  
    We are also including the emission standards from the legacy parts  
as reference material in an appendix in the appropriate CFR parts. This  
allows for readily citing the historical standards in our own emission  
control programs, and in any other Federal or state regulations or  
compliance materials that depend on citing emission standards that are  
no longer current for purposes of gaining EPA certification as part of  
our nonroad emission control program.  
    In addition to removing references to the legacy parts, we are  
taking the opportunity to remove additional obsolete content from the  
newer regulations. Most of these changes were adopted to address  
temporary concerns as part of transitioning to new standards or other  
new requirements. We adopted these changes in isolated regulatory  
sections as ``interim provisions.'' Most of these interim provisions  
have been obsolete for several years.  
    References to the legacy parts are especially common for stationary  
engines EPA regulates under 40 CFR part 60, subparts IIII and JJJJ. The  
emission standards for stationary engines in many cases rely on current  
or past nonroad emission standards in 40 CFR parts 89, 90, and 94.  
Including all the iterations of these emission standards as reference  
material allows us to preserve the existing set of standards and  
requirements for stationary engines. This rule includes numerous  
amendments to 40 CFR part 60 to change regulatory cites from the legacy  
parts to the new regulatory parts in subchapter U, or to copy  
referenced text directly into 40 CFR part 60.  
    Most of the changes for stationary engines in 40 CFR part 60 are  
intended to update references without changing standards or other  
provisions. We are making three more substantive changes. First, we are  
allowing all manufacturers of emergency stationary compression-ignition  
internal combustion engines and stationary emergency spark-ignition  
engines to certify using assigned deterioration factors. Since these  
emergency engines generally serve in standby status in anticipation of  
emergency situations, they often have lifetime operation that is much  
less extensive than non-emergency engines. Assigned deterioration  
factors would allow manufacturers to demonstrate the durability of  
emission controls without performing testing that might otherwise  
exceed the operating life of the engines being certified. We are  
prepared to publish assigned deterioration factors based on currently  
available information. We may need to revise those values in the future  
as additional information becomes available, so we are not including  
specific values for assigned deterioration factors in this rulemaking.  
We are adopting these provisions as proposed, except that we are  
referencing the relevant nonroad regulations that apply and we are  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 43/268clarifying that assigned deterioration factors for stationary engines  
are not limited to small-volume manufacturers.  
    Second, stationary spark-ignition engines are currently subject to  
emission standards and certification procedures adopted under 40 CFR  
part 90 for Phase 1 engines. Revising the requirements for these  
engines to instead rely on the certification procedures in 40 CFR part  
1054 requires that we identify the Phase 1 standards as not including  
the following provisions that apply for Phase 3 engines (as noted in  
the amended regulatory text for appendix I of part 1054):  
     The useful life and corresponding deterioration factors.  
     Evaporative emission standards.  
     Altitude adjustments.  
     Warranty assurance provisions in Sec.  1054.120(f).  
     Emission-related installation instructions.  
     Bonding.  
    Third, in response to a comment from the EMA, we are revising the  
instruction regarding VOC measurement methods to allow manufacturers to  
use any method that is specified for highway or nonroad engines in 40  
CFR part 1065, subpart C. The current regulation at 40 CFR 60.4241(i)  
identifies specific measurement procedures. When we revised 40 CFR part  
1065 to include fourier transform infrared analyzers as an additional  
measurement method, it would have been appropriate to modify 40 CFR  
60.4241(i) to identify this additional measurement method. We are  
addressing that in this rule by broadly referencing test methods in 40  
CFR part 1065, subpart C, which includes fourier transform infrared  
analyzers.  
    In addition, following the proposed rule, we realized that 40 CFR  
part 89 includes content that is, in fact, not obsolete. Specifically,  
there is an interpretation of the Clean Air Act regarding the  
preemption of state regulations related to nonroad engines in 40 CFR  
part 89, subpart A, appendix A (62 FR 67736, December 30, 1997). This  
interpretation describes EPA's belief that states may regulate the use  
and operation of nonroad engines within certain parameters. This final  
rule preserves appendix A by copying it into 40 CFR part 1074, where we  
more broadly describe a range of issues related to preemption of state  
regulation of nonroad engines.  
C. Certification Fees (40 CFR Part 1027)  
    EPA is making several minor changes in 40 CFR part 1027 to update  
the procedures and align the instructions with current practices. None  
of these changes involve change or reconsideration of fee policies. We  
are finalizing the following changes:  
     Correcting the name of the compliance program.  
     Replacing the schedule of fees from 2005 with the fees  
that apply for applications submitted in 2020.  
     Revising the timeline for announcing adjusted fees for the  
upcoming year from a January 31  
[[Page 34344]]  
deadline to a March 31 deadline. This will allow for a more orderly  
process of calculating the new fees using the information from the  
previous year.  
     Correcting the equation for non-evaporative certificates  
to no longer apply the inflation adjustment to operating costs. This  
corrects a publishing error that mistakenly introduced parentheses in  
the equation.  
     Correcting the internet address for the consumer price  
index used for inflation adjustments.  
     Removing the sample calculation for determining fees for  
2006. 
     Revising submission and payment instructions to refer only  
to electronic forms and transactions through www.Pay.gov . 
     Clarifying that deficient filings must be resolved before  
the end of the model year, and that the time limit for requesting  
refunds applies equally to deficient filings.  
    We received no comments on the proposed amendments to 40 CFR part  
1027 and are adopting these amendments without modification.  
D. Additional Amendments for Motor Vehicles and Motor Vehicle Engines  
(40 CFR Parts 85 and 86)  
    Motor vehicles and motor vehicle engines are subject to emission  
standards and certification requirements under 40 CFR part 86. This  
applies for light-duty vehicles, light-duty trucks, heavy-duty vehicles  
and engines, and highway motorcycles. There are additional compliance  
provisions in 40 CFR part 85. We are adopting the following amendments  
to these provisions:  
     Part 85: We are amending the provisions for  
importation, exemptions, and model year to clarify that they no longer  
apply for heavy-duty engines. Those engines are already subject to  
analogous provisions under 40 CFR part 1068. While the two sets of  
provisions are largely the same, we want to avoid the ambiguity of  
having overlapping requirements. One aspect of this migration involves  
discontinuing the provisions that apply for Independent Commercial  
Importers for heavy-duty engines. No one has used these provisions for  
several years, and we have no reason to believe anyone will start to  
use these provisions. We are revising the regulatory text for the final  
rule, based on a comment, to clarify that the importation provisions  
continue to apply for highway motorcycles, and that references to  
engines in 40 CFR part 85, subpart P, continue to apply for replacement  
engines intended for installation in motor vehicles subject to the same  
importation provisions.  
     Part 85: We are making several minor corrections  
to (1) refer to provisions in 40 CFR part 1068 related to confidential  
business information and hearing procedures, and (2) clarify  
organization names and addresses for submitting information.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 44/268     Part 85, subpart O: This subpart set emission  
standards for 1993 and older model year urban buses undergoing engine  
rebuilding. We have confirmed with the American Public Transportation  
Association that there are very few such urban buses still operating,  
and that none of them will have engine rebuilds. We are therefore  
removing this content from the CFR.  
     Section 85.1902(b)(2): We are clarifying that  
defect-reporting requirements under paragraph (b)(2) apply for defects  
related to noncompliance with greenhouse gas emission standards, not  
criteria emission standards. This corrects an earlier amendment that  
inadvertently described the provisions as applying to noncompliance  
with any kind of emission standard. Defects related to criteria  
emission standards are covered by Sec.  85.1902(b)(1).  
     Sections 86.113-04, 86.213, and 86.513: Adding  
optional reference procedures for measuring aromatic and olefin content  
of E0 gasoline test fuel. These changes align with the reference  
procedures for EPA's Tier 3 E10 gasoline test fuel at 40 CFR  
1065.710(b). These changes are needed because material limitations  
prevent laboratories from using the procedures in ASTM D1319. This  
change also applies for the E0 gasoline test fuel specified in 40 CFR  
1065.710(c),  
     Section 86.129-00: Revising the description of  
test weight basis to be loaded vehicle weight for all light-duty  
vehicles and light-duty trucks. This is a correction to align the  
regulation with current practice.  
     Section 86.130-96: We are correcting the  
reference to a testing flowchart that was moved to 40 CFR 1066.801.  
     Sections 86.401-97 and 86.413-78: We are  
removing obsolete sections to prevent confusion.  
     Sections 86.419-2006 and 86.427-78: We are  
revising the table with service accumulation parameters to clarify how  
to perform testing separately for Class I-A and Class I-B, rather than  
treating them as a single class.  
     Sections 86.435-78 and 86.436-78: We are  
correcting references to the regulation to clarify that a motorcycle is  
compliant if measured test results are at or below the standards.  
     Section 86.531-78: We are adding instruction to  
seal exhaust system leaks as needed before testing highway motorcycles.  
The amendment also applies for testing off-highway motorcycles and all-  
terrain vehicles under 40 CFR part 1051. This same instruction also  
applies for light-duty vehicle testing under 40 CFR 1066.110(b)(1)(vi).  
We made minor wording changes after the proposed rule to clarify that  
manufacturers need to close all known leaks as part of the effort to  
prevent exhaust leaks from affecting the compliance demonstration.  
     Part 86, subpart P: The idle test procedures for  
spark-ignition engine and vehicles are no longer needed for  
certification or other compliance demonstrations. We are therefore  
removing this content from the CFR.  
     Part 86, subpart Q: Engine technology has  
advanced to include internal feedback controls and compensation to  
allow for operation at a wide range of altitudes. The certification  
requirements related to altitude adjustments are therefore mostly or  
completely obsolete. We are finalizing a simplified version of the  
altitude provisions for highway motorcycles at 40 CFR 86.408-78(c) and  
(d) in case there are some very small motorcycles that require  
adjustment for altitude.  
     Section 86.1803-01: We are revising the  
definition for heavy-duty vehicle, with a conforming revision to the  
definition for light-duty truck, to clarify that the sole regulatory  
criterion for whether a complete vehicle is a heavy-duty vehicle for  
purposes of the regulation is whether its gross vehicle weight rating  
is above 8,500 pounds. The current approach remains unchanged for  
incomplete vehicles; that is, heavy-duty vehicles also include  
incomplete vehicles even if their gross vehicle weight rating is at or  
below 8,500 pounds, if their curb weight is above 6,000 pounds or if  
their basic vehicle frontal area is greater than 45 square feet. The  
revisions are intended to (1) prevent light-duty trucks from becoming  
heavy-duty vehicles in a configuration involving a hybrid powertrain  
due to the extra weight related to energy storage and (2) avoid an  
incentive for manufacturers to add vehicle weight or frontal area  
simply to avoid the standards that apply for light-duty vehicles. In  
these cases, under the current definition, the curb weight or frontal  
area would artificially increase to the point that the vehicle would  
qualify as a heavy-duty vehicle, even though it otherwise has the  
characteristics of a light-duty truck. This same change is not  
necessary for incomplete vehicles because certifying manufacturers have  
the option to select  
[[Page 34345]]  
the appropriate vehicle classification for those vehicles. Note that  
the change applies only for future certification; any certified heavy-  
duty vehicle that would no longer fit the description will not be  
affected by the amended definition.  
     Section 86.1811-17: The Federal Register  
mistakenly published a reference to the Tier 3 p.m. standard. Since we  
intended for the standard to apply at all times, we are amending the  
regulation to properly refer to that as the Tier 3 p.m. standard.  
     Section 86.1813-01: We are clarifying that  
electric vehicles and fuel cell vehicles are not subject to evaporative  
and refueling emission standards. The preamble to the final rule  
adopting the light-duty Tier 3 standards stated that these emission  
standards apply only for volatile fuels, but we did not include a clear  
statement excluding electric vehicles and fuel cell vehicles in the  
regulations (79 FR 23514, April 28, 2014).  
     Section 86.1818-12: We are clarifying that  
manufacturers calculate the in-use CO2 standard using the appropriate  
test result for carbon-related exhaust emissions after adjustment with  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 45/268the deterioration factor to account for durability effects. In many  
cases, the deterioration factor is 0 (additive) or 1 (multiplicative),  
in which case the deterioration factor does not change the calculated  
in-use CO2 standard.  
     Section 86.1838-01: We are restoring text that  
was inadvertently removed in an earlier amendment. The restored text  
specifies which mileage provisions from Sec.  86.1845 do not apply for  
small-volume manufacturers doing in-use verification testing.  
     Section 86.1868: We are adopting detailed  
provisions describing how reduced air conditioning test requirements  
apply for electric vehicles and plug-in hybrid electric vehicles. These  
provisions are consistent with current practice described in EPA  
guidance. We specify that plug-in hybrid electric vehicles qualify for  
relief from AC17 testing, like electric vehicles, if they have an  
adjusted all electric range of 60 miles or more and they do not need  
engine power for cabin cooling during vehicle operation represented by  
the AC17 procedure; in response to a comment on the proposed rule, we  
have revised the amended regulatory text to clarify that the specified  
driving range applies for combined city/highway driving. Specifying a  
60-mile range is intended to include vehicles for which an owner can  
typically expect to avoid using the engine for daily commuting,  
including commutes on a hot summer day. Finally, we are clarifying that  
manufacturers do not need to make a demonstration to qualify for air  
conditioning efficiency credits for pure electric vehicles or for plug-  
in hybrid electric vehicles, provided that those vehicles qualify for  
waived AC17 testing as described above. This is due to the complexity  
of quantifying credit quantities in grams CO2 per mile for driving  
without engine power. We also specify that AC17 testing with plug-in  
hybrid electric vehicles, if required, always be done in charge-  
sustaining mode to avoid the confounding effect of intermittent engine  
operation during the test.  
E. Additional Amendments for Locomotives (40 CFR Part 1033)  
    EPA is updating 40 CFR part 1033 to remove references to specific  
content in 40 CFR part 92, as described in Section III.B.2. In  
addition, we are adopting the following minor corrections and changes:  
     Section 1033.150: Remove the interim provisions  
that no longer apply. This leaves paragraphs (e) and (k) as the only  
remaining paragraphs in this section.  
     Section 1033.255: Clarify that doing anything to  
make information false or incomplete after submitting an application  
for certification is the same as submitting false or incomplete  
information. For example, if there is a change to any corporate  
information or engine parameters described in the manufacturer's  
previously submitted application for certification, the manufacturer  
must amend the application to include the new information. Amendments  
include additional minor changes to align regulatory text across  
programs.  
     Section 1033.601: Correct references to specific  
provisions in 40 CFR part 1068.  
     Section 1033.701: Correct a paragraph reference.  
     Section 1033.740: Remove the reference to part  
92 because the emission credit provisions of part 92 are being removed  
from the CFR. We are replacing the reference to emission credits from  
part 92 with the equivalent statement saying that manufacturers may  
continue to use emission credits from locomotives certified in 2008 and  
earlier model years. EPA's recordkeeping will not identify credits as  
being from either part 92 or 1033. Any credits generated under part 92  
will continue to be available for certifying locomotives under part  
1033. 
     Section 1033.901: Name the date, January 1,  
2000, that marked the start of the original locomotive emission  
standards, rather than describing the date with reference to  
publication of the original final rule and its effective date (18978 FR  
63, April 16, 1998).  
     Section 1033.925: Removing text in paragraph (e)  
that is already in paragraph (b) of the same section.  
F. Additional Amendments for Land-Based Nonroad Diesel Engines (40 CFR  
Part 1039)  
    EPA's emission standards and certification requirements for land-  
based nonroad compression-ignition (CI) engines are identified in 40  
CFR part 1039. We refer to these as Nonroad CI engines. Several changes  
to 40 CFR part 1039 that apply broadly are described above.  
Specifically, Section III.B.2 describes how we are removing regulatory  
content related to the Tier 1, Tier 2, and Tier 3 standards originally  
adopted in 40 CFR part 89. We are accordingly amending 40 CFR part 1039  
to remove references to 40 CFR part 89 that no longer apply.  
    This section describes additional amendments for EPA's Nonroad CI  
program:  
     Section 1039.20: Remove the option to use a  
branded name instead of the engine manufacturer's corporate name for  
uncertified stationary engines. Since these engines are not certified,  
there is no way for EPA to document any relationship between the engine  
manufacturer and the branded company. We also are not aware of anyone  
using this provision.  
     Section 1039.20: Revise the label statement for  
stationary engines covered by Sec.  1039.20 to avoid references to  
specific parts of the CFR. This is intended to prevent confusion. We  
can approve continued use of labels with the older previous statement  
under the provisions of Sec.  1039.135(f). This may be needed, for  
example, if manufacturers have remaining labels in their inventory.  
     Section 1039.101: Add a table entry to clarify  
how standards apply for engines with maximum engine power above 560 kW.  
The current rendering in the Code of Federal Regulations can be  
misleading.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 46/268     Section 1039.102: Correct the heading of Table 6  
to include engines at or below 560 kW. The table was published in a way  
that inadvertently excluded 560 kW engines.  
     Section 1039.135: Discontinue the equipment  
labeling requirement to state that engines must be refueled with ultra  
low-sulfur diesel fuel (ULSD). Since in-use diesel fuel for these  
engines must universally meet ULSD requirements, there is no longer a  
benefit to including this label information.  
     Section 1039.205: Add text to clarify how engine  
manufacturers  
[[Page 34346]]  
should identify information in the application for certification  
related to engine diagnostic systems that are required under Sec.   
1039.110.  
     Section 1039.255: Clarify that doing anything to  
make information false or incomplete after submitting an application  
for certification is the same as submitting false or incomplete  
information. For example, if there is a change to any corporate  
information or engine parameters described in the manufacturer's  
previously submitted application for certification, the manufacturer  
must amend the application to include the new information. Amendments  
include additional minor changes to align regulatory text across  
programs.  
     Section 1039.740: Remove the reference to  
emission credits from part 89. There is no need for this since the  
records related to credit accounting do not identify credits as being  
from part 89 or 1039.  
     Section 1039.801: Revise the definition of ``low-hour'' to  
state that engines with NO X aftertreatment should qualify as  
``low-hour'' up to 300 hours, with other engines qualifying as ``low-  
hour'' up to only 125 hours. This is intended to ensure that engines  
tested to establish the low-hour emission result for an engine family  
are properly represented as new engines that have not started to  
experience deterioration of emission controls. In line with the  
comments from EMA, we understand the longer stabilization period to be  
appropriate for engines with NO X aftertreatment. In  
contrast, engines without NO X aftertreatment reach a point  
of stabilized emission levels much sooner, which supports the shorter  
duration for low-hour testing before starting service accumulation.  
This does not preclude continued testing beyond 125 hours for engines  
without NO X aftertreatment, but it would prevent  
manufacturers from planning test programs that extend well beyond 125  
hours. This is similar to provisions that already apply for marine  
diesel engines under 40 CFR part 1042; however, we are also adjusting  
the definition of ``low-hour'' for marine diesel engines to reference  
NOX aftertreatment instead of a power cutoff.  
     Section 1039.801: Revise the definition of ``small-volume  
engine manufacturer'' to remove the requirement to have certified  
engines in the United States before 2003. This limitation was related  
to the transition to meeting the Tier 4 standards. Now that those  
phase-in provisions have expired, the remaining provisions relate to  
reporting CH 4 and N2O emissions and using  
assigned deterioration factors. We believe these provisions can  
reasonably be applied to start-up small businesses meeting the Tier 4  
standards.  
G. Additional Amendments for Marine Diesel Engines (40 CFR Parts 1042  
and 1043)  
    EPA's emission standards and certification requirements for marine  
diesel engines under the Clean Air Act are set out in 40 CFR part 1042.  
Emission standards and related fuel requirements that apply  
internationally are set out in 40 CFR part 1043.  
    Several changes to 40 CFR part 1042 that apply more broadly are  
described above. Specifically, Section III.B.2 describes how we are  
removing regulatory content related to the Tier 1 and Tier 2 standards  
originally adopted in 40 CFR part 94. We are accordingly amending 40  
CFR part 1042 to remove references to 40 CFR part 94 that no longer  
apply. 
    This section describes additional amendments for our marine diesel  
engine program.  
1. Marine Replacement Engine Exemption  
    We are adopting several adjustments to the replacement engine  
exemption in Sec.  1042.615.  
a. EPA's Advance Determination for Tier 4 Marine Replacement Engines  
    The proposed rule described that we were intending to clarify the  
regulatory determination that applies for cases involving new  
replacement engines that are normally subject to Tier 4 standards (see  
Sec.  1042.615(a)(1)). In the 2008 final rule to adopt the Tier 4  
standards, we finalized a determination ``that Tier 4 engines equipped  
with aftertreatment technology to control either NO X or PM  
are not required for use as replacement engines for engines from  
previous tiers in accordance with this regulatory replacement engine  
provision.'' The preamble to that final rule made it clear that the  
determination was limited to ``Tier 4 marine diesel replacement engines  
that comply with the Tier 4 standards through the use of catalytic  
aftertreatment systems.'' (73 FR 37157) However, that limitation was  
not copied into the regulatory text. The development involving Tier 4  
engines that rely on exhaust gas recirculation (EGR) instead of  
aftertreatment led us to revisit the discrepancy from the 2008 rule.  
The 2008 rule also stated that ``[s]hould an engine manufacturer  
develop a Tier 4 compliant engine solution that does not require the  
use of such technology, then this automatic determination will not  
apply.''  
    EMA and the California Air Resources Board (CARB) both commented on  
the proposed change to the replacement engine exemption in Sec.   6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 47/2681042.615(a)(1). EMA's comment suggested that we should leave the  
regulatory text in Sec.  1042.615(a)(1) unchanged from what we adopted  
in 2008. CARB suggested that we entirely abandon the advance  
determination that Tier 4 engines are not suitable as replacements for  
earlier engines, regardless of aftertreatment, which would require a  
case-by-case engineering analysis in all cases to demonstrate that an  
exemption is appropriate.  
    As we explained in the 2008 rulemaking, an engine manufacturer is  
generally prohibited from selling a marine engine that does not meet  
the standards that are in effect when that engine is produced. However,  
we recognized that there may be situations in which a vessel owner may  
require an engine certified to an earlier tier of standards, including  
(1) when a vessel has been designed to use a particular engine such  
that it cannot physically accommodate a different engine due to size or  
weight constraints (e.g., a new engine model will not fit into the  
existing engine compartment); or (2) when the engine is matched to key  
vessel components such as the propeller, or when a vessel has a pair of  
engines that must be matched for the vessel to function properly. Our  
2008 rule allows the engine manufacturer to make the relevant  
determinations, but we adopted a provision that requires the engine  
manufacturer to consider all previous tiers and use any of their own  
engine models from the most recent tier that meets the vessel's  
physical and performance requirements. If an engine manufacturer  
produces an engine that meets a previous tier of standards representing  
better control of emissions than that of the engine being replaced, the  
manufacturer would need to supply the engine meeting the tier of  
standards with the lowest emission levels.  
    At that time, we made an advance determination that Tier 4 engines  
would not be required as replacement engines for previous tier engines.  
As we explained in Section IV.C.2 of the final rule preamble, we  
expected that installing such a Tier 4 engine in a vessel that was  
originally designed and built with a previous tier engine could require  
extensive vessel modifications (e.g., addition of a urea tank and  
associated plumbing; extra room for a SCR or PM filter; additional  
control equipment) that may affect important vessel characteristics  
such as vessel stability. We stated that we were not implying Tier 4  
engines would never be  
[[Page 34347]]  
appropriate as replacements for engines from previous tiers; rather,  
the determination was intended to simplify the search across engines  
and was based on the presumption that Tier 4 engines would not fit in  
most cases. We also stated that the advance determination was made  
solely for Tier 4 marine diesel replacement engines that comply with  
the Tier 4 standards through the use of catalytic aftertreatment  
systems. We stated: ``Should an engine manufacturer develop a Tier 4  
compliant engine solution that does not require the use of such  
technology, then this automatic determination will not apply. Instead  
our existing provision will apply and it would be necessary to show  
that a non-catalytic Tier 4 engine would not meet the required physical  
or performance needs of the vessel.''  
    We were also not intending to prevent states or local entities from  
including Tier 4 engines in incentive programs that encourage vessel  
owners to replace existing previous tier engines with new Tier 4  
engines or to retrofit control technologies on existing engines, since  
those incentive programs often are designed to offset some of the costs  
of installing or using advanced emission control technology solutions.  
However, on a national basis, we continue to believe our original  
approach described in the 2008 final rule is appropriate. The  
characteristics of the national fleet are likely different from the  
fleet of vessels affected in California; taking away the Tier 4  
determination should not be made lightly or without a thorough  
understanding of the impact on existing boats. It would therefore be  
appropriate for us to include the advance determination that Tier 4  
engines with aftertreatment are not suitable as replacement for earlier  
engines. In particular, we stand by our 2008 assessment that it is  
appropriate to automatically consider SCR-equipped engines to not have  
``the appropriate physical or performance characteristics to repower''  
pre-Tier 4 vessels, which in turn qualifies the repower for an exempt  
replacement engine.  
    EMA objected to the proposed clarification to apply the advance  
determination only for engines that meet Tier 4 standards with  
aftertreatment. The EMA comment suggests that the same presumption and  
regulatory burden should apply for EGR-equipped engines because  
compliant engines with EGR instead of aftertreatment also necessarily  
involve significant costs and vessel redesigns. EGR-equipped engines  
use exhaust gas recirculation (EGR) instead of SCR to control  
NOX emissions. Engines with EGR include additional hardware  
to manage airflow in and through the engine, and to manage wastewater.  
    Revising the regulation to make clear that the advance  
determination was not intended to include EGR-equipped engines from the  
advance determination is in fact a very minor change in policy. Engine  
manufacturers may still qualify for the replacement engine exemption  
based on a showing that an EGR-equipped engine does not have ``the  
appropriate physical or performance characteristics to repower the  
vessel.'' However, there are two reasons to believe that EGR-equipped  
engines may be suitable for repower. First, all EGR-equipped Tier 4  
engines are locomotive-sized Category 2 engines. Vessels with Category  
2 engines generally have engine compartments that have room for  
additional hardware and other componentry. Second, the additional  
hardware for EGR-equipped engines would generally involve a greater  
design effort than upgrading to a Tier 3 engine, but this kind of  
change would often fit within the scope of vessel repower projects.  
Vessel owners would also need to follow new protocols for maintaining  
the engines and dealing with wastewater and other technical issues.  
None of these challenges create any inherent conflict with installing  
the Tier 4 engines to replace earlier engines.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 48/268    These factors together support a policy in which an EGR-equipped  
engine can be considered unsuitable for repower based on its physical  
or performance characteristics, but this conclusion should not be  
presumed. We would accomplish that policy objective by revising Sec.   
1042.615(a)(1) as proposed.  
b. Other Amendments Related to Marine Replacement Engines  
    We are modifying the requirement that engine manufacturers notify  
EPA after shipping exempt replacement engines. As originally adopted,  
Sec.  1042.615(a) requires an engine manufacturer to send EPA  
notification 30 days after shipping an exempt engine to demonstrate  
that the selected engine was the cleanest available for the given  
installation. We indicated that ``[t]hese records will be used by EPA  
to evaluate whether engine manufacturers are properly making the  
feasibility determination and applying the replacement engine  
provisions.'' We also indicated that we expected engine manufacturers  
to examine ``not just engine dimensions and weight but other pertinent  
vessel characteristics such as drive shafts, reduction gears, cooling  
systems, exhaust and ventilation systems, and propeller shafts;  
electrical systems; . . . and such other ancillary systems and vessel  
equipment that would affect the choice of an engine.'' While engine  
manufacturers have submitted these reports, the information provided  
has not supported our original objective. Specifically, the reports  
vary widely in information provided but in many instances are too case-  
specific. Therefore, we are requiring manufacturers to submit a single  
annual report that is due at the same time as the general requirement  
for reporting on replacement engines under 40 CFR 1068.240. The annual  
report would include the information described in our 2008 rule for all  
the affected engines and vessels. This change would provide a  
predictable schedule for EPA to review the submitted information. This  
would also allow EPA to standardize the format and substance of the  
reported information. Manufacturers would benefit from submitting a  
consistent set of information in an annual submission for all their  
replacement engine information.  
    We are revising the regulatory instructions for submitting  
replacement engine reports under Sec.  1042.615. The replacement engine  
exemption applies only for engines that are shipped to boat owners or  
are otherwise designated for a specific vessel. Engine manufacturers  
may produce and ship exempt replacement engines (with per-cylinder  
displacement up to 7 liters) without making the specified  
demonstrations, as allowed under 40 CFR 1068.240(c), but manufacturers  
may produce only a limited number of those ``untracked'' engines in a  
given year. Those untracked replacement engines are covered by the  
reporting requirements that apply under Sec.  1068.240 since the  
tracked exemption under Sec. Sec.  1042.615 and 1068.240(b) does not  
allow for shipping engines to distributors without identifying a  
specific installation and making the necessary demonstrations for that  
installation. We are taking a streamlined approach for reporting  
related to Tier 3 engines since the demonstration for those engines  
consists of affirming EPA's regulatory determination that no suitable  
Tier 4 engines (without aftertreatment) are available for replacement.  
We do not expect engines with per-cylinder engine displacement below 7  
liters to be able to meet Tier 4 standards without aftertreatment  
devices. As a result, Tier 3 replacement engines are limited only in  
that they may not be used to replace engines that were certified to  
Tier 4 standards.  
    Finally, we are clarifying that the determination related to Tier 4  
replacement engines applies differently for engines that become new  
based on vessel modifications. Under the  
[[Page 34348]]  
definition of ``new vessel'' in Sec.  1042.901, modification of an  
existing vessel may cause the vessel to become ``new'' if the vessel  
modifications cause the vessel's assessed value to at least double. In  
this case, all engines installed on the vessel are subject to standards  
for the model year based on the date of vessel modifications. Since the  
effective dates of the Tier 4 standards, we have learned that there may  
be circumstances in which vessel modifications may be substantial  
enough to qualify a vessel as ``new,'' but the installation of new Tier  
4 engines may not be practical or feasible without cost-prohibitive  
additional vessel modifications. For example, a commercial vessel owner  
may want to substantially upgrade an older vessel, including engine  
replacement with a much lower-emitting engine. If the upgrade doubles  
the assessed value of the vessel, this would trigger a need for all  
installed or replacement engines above 600 kW to be certified to Tier 4  
standards. We have learned that such a project may become cost-  
prohibitive based on the additional vessel modifications needed to  
accommodate the Tier 4 engine, which could cause the vessel to continue  
operating in the higher-emitting configuration. To address this  
scenario, we are allowing the replacement engine exemption for certain  
vessels that become new because of modifications, subject to a set of  
conditions. Specifically, the exemption would apply only with EPA's  
advance approval based on a demonstration that the installation of a  
Tier 4 engine would require significant vessel redesign that is  
infeasible or impractical. EPA's assessment may account for the extent  
of the modifications already planned for the project. EPA may approve  
installation of Tier 3 engines instead of Tier 4 engines for qualifying  
vessels. Recreational engines and commercial engines below 600 kW are  
not subject to Tier 4 standards. As a result, if a vessel becomes new  
through modification, it should be reasonable to expect such new  
engines to be certified to Tier 3 standards rather than being eligible  
for the replacement engine exemption.  
2. Provisions Related to On-Off Controls for Marine Engines  
    EPA adopted the current set of emissions standards for Category 3  
marine diesel engines in 2010 (75 FR 22932; April 30, 2010). The Tier 3  
standards include provisions allowing engine manufacturers to design  
their engines with control systems that allow an engine to meet the  
Tier 3 standards while operating in U.S. waters, including the North  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 49/268American Emission Control Area and the U.S. Caribbean Sea Emission  
Control Area (ECAs), and the less stringent Tier 2 standards while  
operating outside of U.S. waters. We refer to this design strategy as  
``on-off control.'' These provisions reflect the geographic nature of  
the NOX engine standards contained in Regulation 13, MARPOL  
Annex VI.  
    Engine manufacturers have raised questions about the meaning of the  
regulatory provision at Sec.  1042.101 that requires Category 3 engines  
to ``comply fully with the Tier 2 standards when the Tier 3 emission  
controls are disabled.'' This was intended to incorporate the ``on-off  
controls'' allowed under MARPOL Annex VI for the IMO Tier III  
NOX limits. The HC and CO standards for Category 3 engines  
apply equally for EPA's Tier 2 and Tier 3 standards adopted under the  
Clean Air Act, so there should be no question that those standards  
apply even if NO X controls are disabled. While 40 CFR  
1042.104 includes a PM requirement, it is a reporting requirement only.  
The only other ``standard'' for Category 3 engines in 40 CFR part 1042  
is the requirement related to mode caps in Sec.  1042.104(c). The mode  
caps serve as separate emission standards for each test point in the  
duty cycle used for certifying the engines. The 2010 final rule  
describes how the mode caps are necessary for proper implementation of  
the Tier 3 standards for SCR-equipped engines (75 FR 22932). Since  
Category 3 engines with SCR systems would generally comply with the  
Tier 2 NO X standard in the ``disabled'' configuration  
without SCR, we believe there would be no benefit to applying the mode  
caps as a part of the Tier 2 configuration for these Tier 3 engines  
with on-off controls. We are therefore clarifying that the mode caps  
are associated only with the Tier 3 NO X standards. This  
approach is consistent with the on-off control provisions adopted under  
MARPOL Annex VI.  
    The regulation also allows for on-off controls for NO X  
for auxiliary engines used on vessels powered by Category 3 engines.  
More broadly, Sec.  1402.650(d) allows those auxiliary engines to be  
certified to MARPOL Annex VI standards instead of being certified to  
EPA's emission standards under 40 CFR part 1042. The regulation as  
originally written describes how these engines must comply with EPA's  
Tier 3 and Tier 4 standards in the same way that Category 3 engines  
must comply with EPA's Tier 2 and Tier 3 standards. However, since  
auxiliary engines installed on Category 3 vessels are certified to  
MARPOL Annex VI standards instead of EPA's emission standards, the  
regulation should describe how these auxiliary engines must meet the  
IMO Tier II and IMO Tier III NO X standards to comply with  
the on-off control provisions under Sec.  1042.115(g). These  
requirements related to the Engine International Air Pollution  
Prevention (EIAPP) certificates for engines with on-off controls are  
addressed under MARPOL Annex VI and 40 CFR part 1043.  
3. Miscellaneous Marine Diesel Amendments  
    EPA is making several additional changes across 40 CFR part 1042 to  
correct errors, to add clarification, and to make adjustments based on  
lessons learned from implementing these regulatory provisions.  
Specifically, the final rule includes the following amendments:  
     Section 1042.101: Revise the instruction for  
specifying a longer useful life. The regulation as originally adopted  
states that engine design, advertising, and marketing may equally serve  
as the basis for establishing a longer useful life. We would not expect  
manufacturers to specify a longer useful life based only on advertising  
and marketing claims. The amendment emphasizes that design life is the  
basis for specifying a longer useful life, with the further explanation  
that the recommended overhaul interval can be understood, together with  
advertising and marketing materials and other relevant factors, to  
properly represent an engine's design life.  
     Section 1042.101: The Federal Register  
mistakenly published references to Tier 3 p.m. standards and Tier 4  
p.m. standards. Since we intended for those standards to apply at all  
times, we are amending the regulation to properly refer to those as  
Tier 3 p.m. standards and Tier 4 p.m. standards.  
     Section 1042.115: Revise the provision related  
to on-off controls to clarify that we have designated NO X  
Emission Control Areas (ECAs) for U.S. waters. We no longer need to  
reference a possible future ECA. We will rely on the U.S. ECA  
boundaries to establish the area in which engines with on-off controls  
for aftertreatment-based standards need to be fully operational.  
     Section 1042.125: Add maintenance requirements  
for fuel-water separator cartridges or elements as an additional  
example of maintenance that is not emission-related. This aligns with  
the maintenance specifications for land-based nonroad diesel engines in  
40 CFR part 1039.  
     Section 1042.135: Revise the labeling  
instruction for engines installed  
[[Page 34349]]  
in domestic-only vessels to clarify that it applies only for engines  
above 130 kW, and that it applies equally for commercial and  
recreational vessels. These changes both align the EPA regulations to  
more closely align with the international standards under MARPOL Annex  
VI. 
     Section 1042.145: Remove obsolete paragraphs. We  
proposed to revise Sec.  1042.145(j) to adjust the provision related to  
using certified land-based engines in marine vessels; however, we are  
reconsidering those changes and may again pursue such further  
amendments to those provisions.  
     Section 1042.255: Clarify that doing anything to  
make information false or incomplete after submitting an application  
for certification is the same as submitting false or incomplete  
information. For example, if there is a change to any corporate  
information or engine parameters described in the manufacturer's  
previously submitted application for certification, the manufacturer  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 50/268must amend the application to include the new information. Amendments  
include additional minor changes to align regulatory text across  
programs.  
     Section 1042.302: For emission testing during  
sea trials for Category 3 engines with on-off controls, allow  
manufacturers the flexibility to omit testing in Tier 2 mode if they do  
not need aftertreatment to meet the Tier 2 standards. We are most  
interested in compliance with the Tier 3 standards, since those  
controls are active anytime vessels are operating within ECA  
boundaries. System design and calibration with aftertreatment involves  
greater uncertainty than engines that comply using only in-cylinder  
controls. As a result, we believe the compliance demonstration for Tier  
2 mode adds value only if it involves aftertreatment.  
     Section 1042.650: Revise the introductory text  
to clarify that paragraphs (a) through (c) continue to apply only for  
Category 1 and Category 2 engines, and that the provisions related to  
auxiliary engines on Category 3 vessels in paragraph (d) apply equally  
for Category 3 auxiliary engines. By adding paragraph (d) with  
limitation described in the section's introductory text, we  
inadvertently excluded Category 3 auxiliary engines.  
     Section 1042.655: Clarify that measuring engine-  
out emissions for engines that use exhaust aftertreatment must account  
for the backpressure and other effects associated with the  
aftertreatment devices. While improving the alignment between measured  
results and modeled results, this change also has the effect of  
removing the expectation that engine-out (pre-catalyst) emissions must  
meet Tier 2 standards; this is intended to address the case in which an  
engine may meet the Tier 2 standards with a different SCR dosing  
strategy rather than by completely disabling the SCR system.  
     Section 1042.701: Remove the reference to  
emission credits from part 94. This reference is not needed since the  
records related to credit accounting do not identify credits as being  
from part 94 or 1042.  
     Section 1042.801: Remove the requirement to  
register fuels used to certify remanufacturing systems. EPA does not  
register fuels such as natural gas or liquefied petroleum gas, so it is  
not appropriate to impose such a registration requirement. The  
requirement continues to apply for remanufacturing systems that are  
based on diesel fuel additives.  
     Section 1042.901: Revise the definition of  
``low-hour'' to state that engines with NO X aftertreatment  
should qualify as ``low-hour'' up to 300 hours, with other engines  
qualifying as ``low-hour'' up to only 125 hours. This change shortens  
the low-hour testing period for recreational engines above 560 kW, and  
for commercial engines with maximum engine power between 560 and 600  
kW. This change is intended to ensure that low-hour engine testing are  
properly represented as new engines that have not started to experience  
deterioration of emission controls. Engines with NO X  
aftertreatment need extra time to achieve stabilized emission rates. In  
contrast, engines without NO X aftertreatment reach a point  
of stabilized emission levels much sooner, which supports the shorter  
duration for low-hour testing before starting service accumulation.  
This does not preclude continued testing beyond 125 hours for engines  
without NO X aftertreatment, but it would prevent  
manufacturers from planning test programs that extend well beyond 125  
hours. We requested comment on this approach in the proposed rule, and  
EMA submitted comments supporting this adjustment.  
     Section 1043.41: Clarify that engine  
manufacturers may continue to produce new engines under an established  
EIAPP certificate after a change in emission standards for purposes  
other than installation in a new vessel. For example, manufacturers may  
need to produce engines certified to IMO Tier II NO X  
standards after 2016 for installation as replacement engines in vessels  
built before 2016.  
     Sections 1042.910 and 1043.100: Incorporate by  
reference the 2017 edition of MARPOL Annex VI and the NO X  
Technical Code, dated 2017, which contains all amendments through 2016.  
H. Portable Fuel Containers (40 CFR Part 59)  
    EPA's emission standards and certification requirements for  
portable fuel containers are described in 40 CFR part 59. Section III.A  
describes an amendment related to test fuel specifications. In  
addition, we are adopting the following amendments:  
     Section 59.626: Correct the reference to  
additional testing to recognize that the manufacturer may need to test  
multiple containers.  
     Section 59.628: Align recordkeeping  
specifications with the provisions that apply for nonroad engines and  
equipment. This removes the ambiguity from applying specifications  
differently for different types of testing information. As noted in  
Section III.J, now that test records are stored electronically, there  
is no reason to differentiate testing information into routine and non-  
routine records.  
     Section 59.650: Revise the blending instruction  
to specify a lower level of precision; specifying a range of 10.0  
 1.0 percent, which is consistent with the approach we take  
in 40 CFR 1060.515 and 1060.520.  
     Section 59.653: Correct the pressure  
specification for durability testing. The amendment adjusts the kPa  
value to match the psi value in the regulation. This aligns with the  
pressure testing specified for nonroad fuel tanks.  
     Section 59.653: Clarify that the fuel fill level  
needs to stay at 40 percent full throughout slosh testing. The  
container should be closed for the duration of the test, so this  
clarification is mainly intended to ensure that the fuel tank does not  
leak during the test.  
     Section 59.660: Revise the test exemption to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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testing exemption.  
     Section 59.664: Correct the web address for U.S.  
Department of Treasury Circular 570.  
     Section 59.680: Clarify how the definition of  
``portable fuel container'' applies for different colors. The  
regulatory text states that red, yellow, and blue utility jugs qualify  
as portable fuel containers regardless of any contrary labeling or  
marketing. This is intended to prevent circumvention of emission  
standards with containers that would be commonly recognized as portable  
fuel containers. Containers that are not red, yellow, or blue qualify  
as fuel containers if they meet the criteria described in the  
definition. The amendment to clarify this point does not represent a  
change in policy. For  
[[Page 34350]]  
example, anyone who sold uncertified purple portable fuel containers  
that were subject to standards may be in violation of the prohibitions  
in 40 CFR 59.602.  
    We received no adverse comments on the proposed amendments to 40  
CFR part 59 and are adopting these amendments without modification.  
I. Evaporative Emission Standards for Nonroad Spark-Ignition Engines  
and Equipment (40 CFR Part 1060)  
    EPA adopted evaporative emission standards and test procedures in  
40 CFR part 1060. Section III.A describes amendments related to test  
fuel specifications. EPA is also adopting numerous changes across 40  
CFR part 1060 to correct errors, to add clarification, and to make  
adjustments based on lessons learned from implementing these regulatory  
provisions. This includes the following changes:  
     Sections 1060.1 and 1060.801: Clarify how  
standards apply for portable nonroad fuel tanks.  
     Sections 1060.30 and 1060.825: Consolidate  
information-collection provisions into a single section.  
     Section 1060.104: Clarify that any approval from  
California ARB is sufficient for demonstrating compliance with running  
loss standards, rather than limiting this to approved Executive orders.  
     Section 1060.105: Clarify the requirement for  
tanks to be sealed to recognize the exception allowed under the  
regulation.  
     Sections 1060.105 and 1060.240: Allow  
manufacturers more generally to exercise the alternative of using  
procedures adopted by California ARB. This is necessary to allow  
testing with the E10 test fuel adopted by California ARB after the 2004  
version of its regulation that is currently referenced in the Code of  
Federal Regulations.  
     Section 1060.120: Update the terminology to  
refer to ``the date the equipment is sold to the ultimate purchaser''  
instead of the ``point of first retail sale.'' We also don't want to  
prohibit manufacturers from including components in the warranty if  
they fail without increasing evaporative emissions. These changes align  
with similar amendments in our other programs.  
     Section 1060.130: Clarify how manufacturers must  
identify limitations on the types of equipment covered by the  
application for certification, especially for fuel caps. We allow  
equipment manufacturers to certify their equipment using widely varying  
approaches for fuel caps. The equipment manufacturer's certification  
and testing method needs to be reflected in their instructions for  
anyone completing assembly of equipment from that equipment  
manufacturer.  
     Section 1060.135: Clarify how the equipment  
labeling provisions apply for engine manufacturers, and clarify that  
manufacturers need to apply labels at the time of manufacture. In many  
cases, the labeling is integral to the production process, such as for  
molded fuel tanks.  
     Section 1060.135: Allow for permanently  
identifying the date of manufacture somewhere other than the emission  
control information label using any method (not only stamping or  
engraving) and require that the manufacturer describe in the  
application for certification where the equipment identifies the date  
of manufacture.  
     Section 1060.135: We proposed to revise  
paragraph (b)(5) to simplify the equipment labeling options; however,  
we decided to defer action on this change in this rulemaking. This  
leaves the regulatory text unchanged, which allows all the existing  
labeling options available for manufacturers. We may consider amending  
these labeling provisions in a future rulemaking.  
     Section 1060.137: Clarify when and how to label  
fuel caps. This depends only on whether the fuel cap is certified, not  
on whether the fuel cap is mounted directly on the fuel tank. It is  
also important to include the part number on the fuel cap if the  
equipment is designed with a pressurized fuel tank.  
     Section 1060.205: Clarify that the application  
for certification needs to identify the EPA-issued emission family name  
if the certified configuration relies on one or more certified  
components.  
     Section 1060.205: Replace the requirement to  
submit data from invalid tests with a requirement to simply notify EPA  
in the application for certification if a test was invalidated.  
     Section 1060.225: Clarify how manufacturers may  
amend the application for certification during and after the model  
year, consistent with the current policy regarding field fixes.  
     Section 1060.235: Clarify that we can direct  
manufacturers to send test products to EPA for confirmatory testing, or  
to a different lab that we specify.  
     Section 1060.235: Add an explicit allowance for  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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running changes that are currently allowed over the course of a model  
year. The original text may have been understood to require that such  
running changes be made separate from certifying the engine family for  
the new model year.  
     Section 1060.250: Remove references to routine  
and standard tests and remove the shorter recordkeeping requirement for  
routine data (or data from routine tests). We are adopting an amendment  
to require that all test records must be kept for eight years. With  
electronic recording of test data, there should be no advantage to  
keeping the shorter recordkeeping requirement for a subset of test  
data. EPA also notes that the eight-year period restarts with  
certification for a new model year if the manufacturer uses carryover  
data. 
     Section 1060.255: Clarify that doing anything to  
make information false or incomplete after submitting an application  
for certification is the same as submitting false or incomplete  
information. For example, if there is a change to any corporate  
information or parameters described in the manufacturer's previously  
submitted application for certification, the manufacturer must amend  
the application to include the new information. Amendments include  
additional minor changes to align regulatory text across programs.  
     Section 1060.505: Revise the provision  
describing alternative test procedures to align with parallel text in  
40 CFR 1065.10(c). It is important to note that approved alternative  
procedures increase flexibility for certifying manufacturers without  
limiting available methods for EPA testing.  
     Section 1060.520: For slosh testing and for the  
preconditioning fuel soak, specify that the fuel fill level should not  
decrease during testing, other than what would occur from permeation  
and from any appropriate testing steps to perform durability tests  
during the preconditioning fuel soak. We also specify that leaking fuel  
tanks are never suitable for testing, even if there is a potential to  
repair the leak.  
     Section 1060.601: Remove the reference to fuel  
caps since there is no need for a separate description about how the  
regulatory prohibitions apply for fuel caps. As noted in Sec.   
1061.1(c), fuel cap manufacturers that choose to certify their fuel  
caps under 40 CFR part 1060 become subject to all the requirements  
associated with certification.  
     Section 1060.610: Adopt provisions clarifying  
how manufacturers can ship products that are not yet certified if that  
is needed for completing assembly at multiple locations, including  
shipment between companies and shipment between two facilities from a  
single company. These provisions are  
[[Page 34351]]  
analogous to the provisions that apply for engines in 40 CFR 1068.260.  
     Section 1060.640: Migrate engine branding to 40  
CFR 1068.45.  
     Section 1060.801: Update the contact information  
for the Designated Compliance Officer.  
     Section 1060.801: Revise the definition of  
``model year'' to clarify that the calendar year relates to the time  
that engines are produced under a certificate of conformity.  
     Section 1060.801: Revise the definition of  
``placed into service'' to prevent circumvention that may result from a  
manufacturer or dealer using a piece of equipment in a way that could  
otherwise cause it to no longer be new and subject to the prohibitions  
of 40 CFR 1068.101.  
     Section 1060.81: Correct the web address for the  
American Boat and Yacht Council.  
     Section 1060.815: Migrate provisions related to  
confidential business information to 40 CFR part 1068.  
J. Additional Amendments for Nonroad Spark-Ignition Engines at or Below  
19 kW (40 CFR Part 1054)  
    EPA's emission standards and certification requirements for nonroad  
spark-ignition engines at or below 19 kW are described in 40 CFR part  
1054. EPA is adopting numerous changes across 40 CFR part 1054 to  
correct errors, to add clarification, and to make adjustments based on  
lessons learned from implementing these regulatory provisions. This  
includes the following changes:  
     Section 1054.1: Clarify that the provision  
allowing for voluntary certification under 40 CFR part 1054 for larger  
engines applies only for engines up to 30 kW and up to 1,000 cubic  
centimeters.  
     Section 1054.2: Add a clarifying note to say  
that a person or other entity other than a conventional  
``manufacturer'' may need to certify engines that become new after  
being placed into service (such as engines converted from highway or  
stationary use). This is intended to address an assumption that only  
conventional manufacturers can certify engines.  
     Sections 1054.30, 1054.730, and 1054.825:  
Consolidate information-collection provisions into a single section.  
     Section 1054.120: Clarify that extended-warranty  
requirements apply for the emission-related warranty only to the extent  
that warranties are actually provided to the consumer, rather than to  
any published warranties that are offered. The principles are that the  
emission-related warranty should not be less effective for emission-  
related items than for items that are not emission-related, and that  
the emission-related warranty for a given component should not be less  
effective than the basic mechanical warranty for that same component.  
     Section 1054.125: Allow for special maintenance  
procedures that address low-use engines. For example, operators in  
certain circumstances may perform engine maintenance after a smaller  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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     Section 1054.130: Remove references to  
``nonroad'' equipment to accommodate regulations for stationary engines  
in 40 CFR part 60, subpart JJJJ, that rely on these same provisions.  
     Section 1054.135: Allow for including optional  
label content only if this does not cause the manufacturer to omit  
other information based on limited availability of space on the label.  
     Section 1054.145: Remove obsolete content. Most  
of the provisions in this section were needed only for the transition  
to the Phase 3 standards. We are also clarifying that the provision  
that allows for testing with California Phase 2 test fuel applies only  
through model year 2019. California ARB requires testing with its Phase  
3 test fuel starting in model year 2020.  
     Section 1054.205: Replace the requirement to  
submit data from invalid tests with a requirement to simply notify EPA  
in the application for certification if a test was invalidated.  
     Section 1054.205: Specify that the application  
for certification needs to include estimated initial and final dates  
for producing engines for the model year, and an estimated date for the  
initial introduction into U.S. commerce. This information helps with  
managing information in the application and overseeing testing and  
other compliance requirements. This amendment aligns with current  
practice.  
     Section 1054.225: Simplify the instruction on changing the  
Family Emission Limit during the model year to specify that the  
manufacturer must identify the date of the change based only on the  
month and year. This change aligns with current practice for amending  
applications for certification.  
     Section 1054.225: Clarify how manufacturers may amend the  
application for certification during and after the model year,  
consistent with the current policy regarding field fixes.  
     Section 1054.235: Clarify that air-fuel ratio and other  
adjustable parameters are part of the selection of a worst-case test  
configuration for emission-data engines. If an engine has rich and lean  
settings, the manufacturer should determine which is the worst-case  
setting for emission measurements to determine deterioration factors.  
In particular, it is not appropriate to combine results from different  
settings to calculate any kind of average or composite value. Service  
accumulation between emission measurements may include any  
representative combination of those settings.  
     Section 1054.235: Add an explicit allowance for carryover  
engine families to include the same kind of within-family running  
changes that are currently allowed over the course of a model year. The  
original text may have been understood to require that such running  
changes be made separate from certifying the engine family for the new  
model year.  
     Section 1054.235: Clarify how EPA will calibrate engines  
within normal production tolerances for things that are not adjustable  
parameters.  
     Sections 1054.235, 1054.240, 1054.245, 1054.601, and  
1054.801: Describe how to demonstrate compliance with dual-fuel and  
flexible-fuel engines. This generally involves testing with each  
separate fuel, or with a worst-case fuel blend.  
     Section 1054.240: Clarify that each measurement from  
emission-data vehicles must meet emission standards.  
     Section 1054.245: Clarify the basis for EPA approval for  
using deterioration factors from other engines. EPA approval depends on  
the manufacturer demonstrating that emission measurements reasonably  
represent in-use deterioration for the engine family being certified.  
This copies in regulatory text that already applies under other EPA  
programs.  
     Section 1054.245: Copy in the values and formulas used for  
assigned deterioration factors for handheld and nonhandheld engines.  
This includes a minor correction to the equation from 40 CFR 90.104(g)  
and a new description about combining deterioration factors for HC and  
NOX, but otherwise maintains the current policy and practice  
for these deterioration factors.  
     Section 1054.250: Remove references to routine and  
standard tests and remove the shorter recordkeeping requirement for  
routine data (or data from routine tests). We are adopting a  
requirement to keep all test records for eight years. With electronic  
recording of test data, there should be no advantage to keeping the  
shorter recordkeeping requirement for a subset of test data. EPA also  
notes that the eight-year period restarts with certification for a new  
model year if the manufacturer uses carryover data.  
[[Page 34352]]  
     Section 1054.255: Clarify that doing anything to make  
information false or incomplete after submitting an application for  
certification is the same as submitting false or incomplete  
information. For example, if there is a change to any corporate  
information or engine parameters described in the manufacturer's  
previously submitted application for certification, the manufacturer  
must amend the application to include the new information.  
     Section 1054.255: Clarify that voiding certificates for a  
failure to comply with recordkeeping or reporting requirements will be  
limited to the certificates that relate to the particular recordkeeping  
or reporting failure.  
     Section 1054.301: Clarify the process for requesting a  
small-volume exemption from production-line testing. This is better  
handled as preliminary approval under Sec.  1054.210 rather than  
including it as part of the application for certification.  
     Section 1054.310: Provide an example to illustrate how  
manufacturers may need to divide the annual production period into four  
quarters if it is longer (or shorter) than 52 weeks.  
     Section 1054.315: Clarify that results from repeat tests  
can be averaged together, provided that the engine is not modified  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
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switch to a different engine configuration or to improve emission  
control for a given engine configuration.  
     Sections 1054.315 and 1054.320: Clarify how to manage test  
results for engines that fail an emission standard. Manufacturers must  
use the production line testing (PLT) test result from a failing engine  
regardless of the disposition of the failing engine. Manufacturers  
report test results after modifying a failing engine to show that it  
can be covered by the certificate of conformity, but manufacturers may  
factor these test results into PLT calculations only if the  
manufacturer changes production processes for all further engines to  
match the adjustments made to the failing engine. In that case, the  
test results from the modified engine count as a new test engine for  
the PLT calculations, rather than replacing the results from the engine  
before modifications. These regulatory changes codify the practice we  
have already established by guidance.\30\  
---------------------------------------------------------------------------  
    \30\ ``Production Line Testing (PLT) Report Clarification'', EPA  
guidance document CD-15-21, August 31, 2015.  
---------------------------------------------------------------------------  
     Section 1054.505: Clarify the instructions for controlling  
torque at non-idle test modes, and for demonstrating compliance with  
cycle-validation criteria. The revised language more carefully  
describes the current practice for testing engines.  
     Section 1054.620: Clarify that provisions apply for any  
kind of competition, not just racing.  
     Sections 1054.625 and 1054.626: Remove obsolete text.  
     Section 1054.640: Migrate engine branding provisions to  
Sec.  1068.45.  
     Section 1054.690: Correct the web address for U.S.  
Department of Treasury Circular 570 and clarify how an automatic  
suspension of a certificate of conformity applies for certain numbers  
of engines, and how U.S. Customs incorporates the bonding requirements  
into its entry procedures.  
     Section 1054.701: Change terminology for counting engines  
from ``intended for sale in the United States'' to ``U.S.-direction  
production volume.'' This conforms to the usual approach for  
calculating emission credits for nonroad engines.  
     Section 1054.710: Clarify that it is not permissible to  
show a proper balance of credits for a given model by using emission  
credits from a future model year.  
     Section 1054.730: Clarify terminology for ABT reports.  
     Section 1054.740: Remove obsolete content.  
     Section 1054.801: Update the contact information for the  
Designated Compliance Officer.  
     Section 1054.801: Remove the note from the definition of  
``handheld'' describing which standards apply for various types of  
equipment. The note does not cover all the provisions that apply, which  
has led to more confusion than clarity.  
     Section 1054.801: Revise the definition of ``model year''  
to clarify that the calendar year relates to the time that engines are  
produced under a certificate of conformity.  
     Section 1054.801: Revise the definition of ``new nonroad  
engine'' to clarify that imported engines become new based on the  
original date of manufacture, rather than the original model year. This  
clarification is necessary because 40 CFR 1068.360 requires  
redesignation of an imported engine's model year in certain  
circumstances.  
     Section 1054.801: Revise the definition of ``placed into  
service'' to prevent circumvention that may result from a manufacturer  
or dealer using a piece of equipment in a way that could otherwise  
cause it to no longer be new and subject to the prohibitions of 40 CFR  
1068.101.  
     Section 1054.801: Revise the definition of ``small-volume  
equipment manufacturer'' to state that the volume limits apply for all  
calendar years, not just 2007 through 2009. We no longer use this  
definition for limiting the scope of transition or phase-in provisions.  
The provisions for reduced production-line testing, assigned  
deterioration factors, and reduced bonding burdens should apply without  
regard to the specific years identified in the original regulation  
adopting the Phase 3 standards.  
     Section 1054.815: Migrate provisions related to  
confidential business information to 40 CFR Part 1068.  
K. Amendments for General Compliance Provisions (40 CFR Part 1068)  
    We are amending the replacement engine exemption in Sec.  1068.240  
to adjust the criteria by which manufacturers qualify exempted engines  
under the tracked option in Sec.  1068.240(b). Engine manufacturers may  
produce any number of exempt replacement engines if they meet all the  
specified requirements and conditions. To account for the timing of  
making the necessary demonstrations, the regulation specifies that  
engines must be designated as either tracked or untracked by September  
30 following each production year, which coincides with the reporting  
requirement to document the number of exempt replacement engines each  
manufacturer produces. The regulation as adopted specifies that  
manufacturers must meet ``all the requirements and conditions that  
apply under paragraph (b). . . .''
    We proposed to amend the regulation to clarify that the requirement  
for the engine manufacturer to retrieve the replaced engine (or confirm  
that it had been destroyed) was not subject to the reporting deadline  
of September 30 following the production year. The Truck and EMA  
commented to suggest that it would be better to apply a later deadline  
rather than removing the deadline entirely. The specific suggestion was  
to require converting a replacement engine from tracked to untracked if  
the replaced engine was not recovered within five years. We agree that  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 55/268the suggested approach would be beneficial for ensuring that replaced  
engines are accounted for and believe that the reported information  
would fit within the scope of current compliance responsibilities for  
both manufacturers and EPA. We are therefore including this adjustment  
in the final rule.  
    We also requested comment on several possible adjustments to the  
replacement engine exemption to  
[[Page 34353]]  
address manufacturers' concerns about complying with the limit of  
producing only 0.5 percent of their production volume for specified  
sizes and types of engines under the untracked option. This is most  
challenging for large engines with very low production volumes.  
California ARB commented to recommend keeping the 0.5 percent limit  
because it should be rare to need more exempt replacement engines, and  
the regulation already allows for a greater number of exempt  
replacement engines where manufacturers are able to meet the tracking  
requirements.  
    EMA commented with a suggestion that the manufacturers should be  
allowed to produce up to five exempt replacement engines under the  
untracked option, in addition to the 0.5 percent. This was intended to  
account for the fact that 0.5 percent of a couple hundred engines does  
not allow for any substantial flexibility to supply distributors with  
these exempt replacement engines. We recognize the limit of the  
percentage-based approach and agree that allowing five engines per year  
to meet demand for these engines is appropriate. We are leaving the 0.5  
percent limit in place in this rulemaking, but we are including an  
adjustment to address the engine manufacturers' concerns about low-  
volume production. Rather than adding an allowance for these five  
engines for all companies and all sectors/categories, we are amending  
the regulation to allow for the greater of five engines or 0.5 percent  
of production. This focuses the amendment on the companies and product  
line where the percentage-based approach provides no substantial  
ability to participate in the untracked option for replacement engines.  
Allowing five engines makes a difference for engine models with annual  
production volumes below 900 for a given type and displacement  
category.  
    EMA had additional comments related to the limits and oversight  
provisions for the untracked option of the replacement engine  
exemption. As noted in the Response to Comments, we are deferring  
action on those broader comments until a future rulemaking.  
L. Other Requests for Comment  
    The proposed rule described several areas where we were interested  
in comments to gather information, perspectives, and feedback on  
possible future rulemaking amendments. These comments are included in  
Chapter 4 of the Response to Comments. The other chapters of the  
Response to Comments also include several issues with similar input  
regarding potential future rulemaking amendments.  
IV. Statutory Authority and Executive Order Reviews  
    Additional information about these statutes and Executive orders  
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders . 
A. Executive Order 12866: Regulatory Planning and Review and Executive  
Order 13563: Improving Regulation and Regulatory Review  
    This action is not a significant regulatory action and was  
therefore not submitted to the Office of Management and Budget (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  
adverse economic impact on small entities. An agency may certify that a  
rule will not have a significant economic impact on a substantial  
number of small entities if the rule relieves regulatory burden, has no  
net burden or otherwise has a positive economic effect on the small  
entities subject to the rule. This action is designed to reduce testing  
burdens, increase compliance flexibility, and make various corrections  
and adjustments to compliance provisions; as a result, we anticipate no  
costs associated with this rule. We have therefore concluded that this  
action will have no net regulatory burden for directly regulated small  
entities.  
D. Unfunded Mandates Reform Act (UMRA)  
    This action does not contain any unfunded mandate as described in  
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect  
small governments. This action imposes no enforceable duty on any  
state, local or tribal governments. Requirements for the private sector  
do not exceed $100 million in any one year.  
E. Executive Order 13132: Federalism  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 56/268    This action does not have federalism implications. It will not have  
substantial direct effects on the states, on the relationship between  
the National 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 economically significant as defined in Executive Order 12866, and  
because the EPA does not believe the environmental health or safety  
risks addressed by this action 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 subject to Executive Order 13211, because it is  
not a significant regulatory action under Executive Order 12866.  
I. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR  
Part 51 
    Section 12(d) of the National Technology Transfer and Advancement  
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note)  
directs EPA to use voluntary consensus standards in its regulatory  
activities unless to do so would be inconsistent with applicable law or  
otherwise impractical. Voluntary consensus standards are technical  
standards (e.g., materials specifications, test methods, sampling  
procedures, and business practices) that are developed or adopted by  
voluntary consensus standards bodies. NTTAA directs agencies to provide  
Congress, through OMB, explanations when the Agency decides not to use  
available and applicable voluntary consensus standards. This action  
involves technical standards.  
    Except for the standards discussed below, the standards included in  
the regulatory text as incorporated by reference (in parts 60, 86,  
1036, 1037, 1060, and 1065) were all previously approved for IBR and no  
change is included in this action.
[[Page 34354]]  
    In accordance with the requirements of 1 CFR 51.5, we are  
incorporating by reference the use of test methods and standards from  
ASTM International. This includes the following standards and test  
methods:  
------------------------------------------------------------------------  
     Standard or test method          Regulation           Summary  
------------------------------------------------------------------------  
ASTM D3588-98 (Reapproved          40 CFR 1036.530  Test method  
 2017)e1, Standard Practice for     and 1036.810.    describes how to  
 Calculating Heat Value,                             determine the lower  
 Compressibility Factor, and                         heating value and  
 Relative Density of Gaseous                         other parameters  
 Fuels.                                              for gaseous fuels.  
ASTM D5769-20, Standard Test       40 CFR 86.1,     Test method  
 Method for Determination of        86.113-04,       describes how to  
 Benzene, Toluene, and Total        86.213, and      measure aromatic  
 Aromatics in Finished Gasolines    86.513.          content of  
 by Gas Chromatography/Mass                          gasoline. This  
 Spectrometry.                                       would be an  
                                                     alternative to the  
                                                     currently specified  
                                                     method in ASTM  
                                                     D1319, as described  
                                                     in Section II.A.3  
                                                     for 40 CFR  
                                                     1065.710.  
ASTM D6550-20, Standard Test       40 CFR 86.1,     Test method  
 Method for Determination of        86.113-04,       describes how to  
 Olefin Content of Gasolines by     86.213, and      measure olefin  
 Supercritical-Fluid                86.513.          content of  
 Chromatography.                                     gasoline. This  
                                                     would be an  
                                                     alternative to the  
                                                     currently specified  
                                                     method in ASTM  
                                                     D1319, as described  
                                                     in Section II.A.3  
                                                     for 40 CFR  
                                                     1065.710.  
ASTM D6667-14 (Reapproved 2019),   40 CFR 1065.720  Test method  
 Standard Test Method for           and 1065.1010.   describes how to  
 Determination of Total Volatile                     measure sulfur in  
 Sulfur in Gaseous Hydrocarbons                      liquefied petroleum  
 and Liquefied Petroleum Gases by                    gas.  
 Ultraviolet Fluorescence.  
------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 57/268    The referenced standards and test methods may be obtained through  
the ASTM International website ( www.astm.org ) or by calling ASTM at  
(610) 832-9585.  
    As described in Section II.A.5, EPA is publishing a new version of  
the Greenhouse Gas emissions Model (GEM), which manufacturers will use  
for certifying heavy-duty highway vehicles to the Phase 2 GHG emission  
standards in 40 CFR part 1037. The model calculates GHG emission rates  
for heavy-duty highway vehicles based on input values defined by the  
manufacturer. GEM Version 3.5.1 applies for all Phase 2 vehicles. GEM  
also includes a Hardware-in-Loop submodel to simulate vehicle engines,  
transmissions, and other powertrain components. These models are  
referenced in Sec. Sec.  1037.520, 1037.550, and 1037.801. The models  
are available as noted in the amended regulations at 40 CFR 1037.810.  
    We are removing numerous referenced documents as part of the effort  
to remove obsolete provisions in 40 CFR parts 85 through 94 and  
elsewhere.  
J. Executive Order 12898: Federal Actions To Address Environmental  
Justice in Minority Populations and Low-Income Populations  
    The EPA 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  
small environmental impact, this regulatory action will not have a  
disproportionate adverse effect on minority populations, low-income  
populations, or indigenous peoples.  
K. Congressional Review Act (CRA)  
    This action is subject to the CRA, and EPA will submit a rule  
report to each House of the Congress and to the Comptroller General of  
the United States. This action is not a ``major rule'' as defined by 5  
U.S.C. 804(2).  
L. Judicial Review  
    Under CAA section 307(b)(1), judicial review of this final rule is  
available only by filing a petition for review in the U.S. Court of  
Appeals for the District of Columbia Circuit by August 30, 2021. Under  
CAA section 307(d)(7)(B), only an objection to this final rule that was  
raised with reasonable specificity during the period for public comment  
can be raised during judicial review. Section 307(d)(7)(B) of the Clean  
Air Act also provides a mechanism for EPA to convene a proceeding for  
reconsideration, ``[i]f the person raising an objection can demonstrate  
to EPA that it was impracticable to raise such objection within [the  
period for public comment] or if the grounds for such objection arose  
after the period for public comment (but within the time specified for  
judicial review) and if such objection is of central relevance to the  
outcome of the rule.'' Any person seeking to make such a demonstration  
should submit a Petition for Reconsideration to the Office of the  
Administrator, Environmental Protection Agency, Room 3000, William  
Jefferson Clinton Building, 1200 Pennsylvania Ave. NW, Washington, DC  
20460, with an electronic copy to the person listed in FOR FURTHER  
INFORMATION CONTACT, and the Associate General Counsel for the Air and  
Radiation Law Office, Office of General Counsel (Mail Code 2344A),  
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington,  
DC 20004. Note that under CAA section 307(b)(2), the requirements  
established by this final rule may not be challenged separately in any  
civil or criminal proceedings brought by EPA to enforce these  
requirements.  
List of Subjects  
40 CFR Part 9  
    Reporting and recordkeeping requirements.  
40 CFR Part 59  
    Air pollution control, Confidential business information, Labeling,  
Ozone, Reporting and recordkeeping requirements, Volatile organic  
compounds.  
40 CFR Part 60  
    Administrative practice and procedure, Air pollution control,  
Aluminum, Beverages, Carbon monoxide, Chemicals, Coal, Electric power  
plants, Fluoride, Gasoline, Glass and glass products, Grains,  
Greenhouse gases, Household appliances, Incorporation by reference,  
Industrial facilities, Insulation, Intergovernmental relations, Iron,  
Labeling, Lead, Lime, Metals, Motor vehicles, Natural gas, Nitrogen  
dioxide, Petroleum, Phosphate, Plastics materials and synthetics,  
Polymers, Reporting and recordkeeping requirements, Rubber and rubber  
products, Sewage disposal, Steel, Sulfur oxides, Vinyl, Volatile  
organic compounds, Waste treatment and disposal, Zinc.  
40 CFR Part 85  
    Confidential business information, Greenhouse gases, Imports,  
Labeling, Motor vehicle pollution, Reporting and recordkeeping  
requirements, Research, Warranties.  
40 CFR Part 86  
    Administrative practice and procedure, Confidential business  
information, Incorporation by reference, Labeling, Motor vehicle  
pollution,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 58/268[[Page 34355]]  
Reporting and recordkeeping requirements.  
40 CFR Part 88  
    Labeling, Motor vehicle pollution, Reporting and recordkeeping  
requirements.  
40 CFR Part 89  
    Administrative practice and procedure, Confidential business  
information, Imports, Labeling, Motor vehicle pollution, Reporting and  
recordkeeping requirements, Research, Vessels, Warranties.  
40 CFR Part 90  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Reporting and  
recordkeeping requirements, Research, Warranties.  
40 CFR Part 91  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 92  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Railroads,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 94  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Penalties, Reporting and  
recordkeeping requirements, Vessels, Warranties.  
40 CFR Part 1027  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Reporting and recordkeeping  
requirements.  
40 CFR Part 1033  
    Administrative practice and procedure, Confidential business  
information, Environmental protection, Labeling, Penalties, Railroads,  
Reporting and recordkeeping requirements.  
40 CFR Part 1036  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Environmental protection, Greenhouse  
gases, Incorporation by reference, Labeling, Motor vehicle pollution,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1037  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Environmental protection,  
Incorporation by reference, Labeling, Motor vehicle pollution,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1039  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1042  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Environmental protection, Imports,  
Incorporation by reference, Labeling, Penalties, Reporting and  
recordkeeping requirements, Vessels, Warranties.  
40 CFR Part 1043  
    Administrative practice and procedure, Air pollution control,  
Imports, Incorporation by reference, Reporting and recordkeeping  
requirements, Vessels.  
40 CFR Part 1045  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1048  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Research, Warranties.  
40 CFR Part 1051  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 59/268    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1054  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Labeling, Penalties,  
Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1060  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Incorporation by reference,  
Labeling, Penalties, Reporting and recordkeeping requirements,  
Warranties.  
40 CFR Part 1065  
    Administrative practice and procedure, Air pollution control,  
Incorporation by reference, Reporting and recordkeeping requirements,  
Research.  
40 CFR Part 1066  
    Air pollution control, Incorporation by reference, Reporting and  
recordkeeping requirements.  
40 CFR Part 1068  
    Administrative practice and procedure, Air pollution control,  
Confidential business information, Imports, Motor vehicle pollution,  
Penalties, Reporting and recordkeeping requirements, Warranties.  
40 CFR Part 1074  
    Administrative practice and procedure, Air pollution control.  
Jane Nishida,  
Acting Administrator.  
    For the reasons set out in the preamble, we are amending title 40,  
chapter I of the Code of Federal Regulations as set forth below.  
PART 9--OMB APPROVALS UNDER THE PAPERWORK REDUCTION ACT  
0 
1. The authority citation for part 9 continues to read as follows:  
    Authority:  7 U.S.C. 135 et seq., 136-136y; 15 U.S.C. 2001,  
2003, 2005, 2006, 2601-2671; 21 U.S.C. 331j, 346a, 31 U.S.C. 9701;  
33 U.S.C. 1251 et seq., 1311, 1313d, 1314, 1318, 1321, 1326, 1330,  
1342, 1344, 1345(d) and (e), 1361; E.O. 11735, 38 FR 21243, 3 CFR,  
1971-1975 Comp. p. 973; 42 U.S.C. 241, 242b, 243, 246, 300f, 300g,  
300g-1, 300g-2, 300g-3, 300g-4, 300g-5, 300g-6, 300j-1, 300j-2,  
300j-3, 300j-4, 300j-9, 1857 et seq., 6901-6992k, 7401-7671q, 7542,  
9601-9657, 11023, 11048.  
0 
2. Amend Sec.  9.1 by:  
0 
a. Removing entries for 85.1403 through 85.1415, 85.1514, 85.1712,  
85.1808, 85.2208, and 85.2401-85.2409;  
0 
b. Revising the entries under the heading ``Control of Emissions From  
New and In-Use Highway Vehicles and Engine'';  
0 
c. Removing the heading ``Clean-Fuel Vehicles'' and the items under  
that heading;  
0 
d. Removing the heading ``Control of Emissions From New and In-Use  
[[Page 34356]]  
Nonroad Compression-Ignition Engines'' and the items under that  
heading;  
0 
e. Removing the heading ``Control of Emissions From New and In-use  
Nonroad Engines'' and the items under that heading;  
0 
f. Removing the heading ``Control of Emissions From New and In-Use  
Marine Compression-Ignition Engines'' and the items under that heading;  
0 
g. Revising the entries under the heading ``Fuel Economy of Motor  
Vehicles'';  
0 
h. Removing the entry for ``1033.825'' and adding the entry  
``1033.925'' in its place; and  
0 
i. Removing the entry for ``1042.825'' and adding the entry  
``1042.925'' in its place.  
    The revisions and additions read as follows:  
Sec.  9.1  OMB approvals under the Paperwork Reduction Act.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 60/268* * * * *  
------------------------------------------------------------------------  
                                                             OMB control  
                      40 CFR citation                            No.  
------------------------------------------------------------------------  
  
                                * * * * *  
------------------------------------------------------------------------  
 Control of Air Pollution From Motor Vehicles and Motor Vehicle Engines  
------------------------------------------------------------------------  
85.503.....................................................    2060-0104  
85.505.....................................................    2060-0104  
85.1504....................................................    2060-0095  
85.1505....................................................    2060-0095  
85.1507....................................................    2060-0095  
85.1508....................................................    2060-0095  
85.1509....................................................    2060-0095  
85.1511....................................................    2060-0095  
85.1512....................................................    2060-0095  
85.1705....................................................    2060-0104  
85.1706....................................................    2060-0104  
85.1708....................................................    2060-0104  
85.1710....................................................    2060-0104  
85.1802....................................................    2060-0104  
85.1803....................................................    2060-0104  
85.1806....................................................    2060-0104  
85.1903....................................................    2060-0104  
85.1904....................................................    2060-0104  
85.1905....................................................    2060-0104  
85.1906....................................................    2060-0104  
85.1908....................................................    2060-0104  
85.1909....................................................    2060-0104  
85.2110....................................................    2060-0104  
85.2114....................................................    2060-0060  
85.2115....................................................    2060-0060  
85.2116....................................................    2060-0060  
85.2117....................................................    2060-0060  
85.2118....................................................    2060-0060  
85.2119....................................................    2060-0060  
85.2120....................................................    2060-0060  
------------------------------------------------------------------------  
  Control of Emissions From New and In-Use Highway Vehicles and Engines  
------------------------------------------------------------------------  
86.000-7...................................................    2060-0104  
86.000-24..................................................    2060-0104  
86.001-21..................................................    2060-0104  
86.001-23..................................................    2060-0104  
86.001-24..................................................    2060-0104  
86.004-28..................................................    2060-0104  
86.004-38..................................................    2060-0104  
86.004-40..................................................    2060-0104  
86.079-31--86.079-33.......................................    2060-0104  
86.079-39..................................................    2060-0104  
86.080-12..................................................    2060-0104  
86.082-34..................................................    2060-0104  
86.085-37..................................................    2060-0104  
86.090-27..................................................    2060-0104  
86.091-7...................................................    2060-0104  
86.094-21..................................................    2060-0104  
86.094-25..................................................    2060-0104  
86.094-30..................................................    2060-0104  
86.095-14..................................................    2060-0104  
86.095-35..................................................    2060-0104  
86.096-24..................................................    2060-0104  
86.098-23..................................................    2060-0104  
86.099-10..................................................    2060-0104  
86.107-98..................................................    2060-0104  
86.108-00..................................................    2060-0104  
86.111-94..................................................    2060-0104  
86.113-15..................................................    2060-0104  
86.113-94..................................................    2060-0104  
86.129-00..................................................    2060-0104  
86.142-90..................................................    2060-0104  
86.144-94..................................................    2060-0104  
86.150-98..................................................    2060-0104  
86.155-98..................................................    2060-0104  
86.159-08..................................................    2060-0104  
86.160-00..................................................    2060-0104  
86.161-00..................................................    2060-0104  
86.162-03..................................................    2060-0104  
86.163-00..................................................    2060-0104  
86.412-78..................................................    2060-0104  
86.414-78..................................................    2060-0104  
86.415-78..................................................    2060-0104  
86.416-80..................................................    2060-0104  
86.421-78..................................................    2060-0104  
86.423-78..................................................    2060-0104  
86.427-78..................................................    2060-0104  
86.428-80..................................................    2060-0104  
86.429-78..................................................    2060-0104  
86.431-78..................................................    2060-0104  
86.432-78..................................................    2060-0104  
86.434-78..................................................    2060-0104  
86.435-78..................................................    2060-0104  
86.436-78..................................................    2060-0104  
86.437-78..................................................    2060-0104  
86.438-78..................................................    2060-0104  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 61/26886.439-78..................................................    2060-0104  
86.440-78..................................................    2060-0104  
86.445-2006................................................    2060-0104  
86.446-2006................................................    2060-0104  
86.447-2006................................................    2060-0104  
86.448-2006................................................    2060-0104  
86.449.....................................................    2060-0104  
86.513.....................................................    2060-0104  
86.537-90..................................................    2060-0104  
86.542-90..................................................    2060-0104  
86.603-98..................................................    2060-0104  
86.604-84..................................................    2060-0104  
86.605-98..................................................    2060-0104  
86.606-84..................................................    2060-0104  
86.607-84..................................................    2060-0104  
86.609-98..................................................    2060-0104  
86.612-97..................................................    2060-0104  
86.614-84..................................................    2060-0104  
86.615-84..................................................    2060-0104  
86.884-5...................................................    2060-0104  
86.884-7...................................................    2060-0104  
86.884-9...................................................    2060-0104  
86.884-10..................................................    2060-0104  
86.884-12..................................................    2060-0104  
86.884-13..................................................    2060-0104  
86.1106-87.................................................    2060-0104  
86.1107-87.................................................    2060-0104  
86.1108-87.................................................    2060-0104  
86.1110-87.................................................    2060-0104  
86.1111-87.................................................    2060-0104  
86.1113-87.................................................    2060-0104  
86.1114-87.................................................    2060-0104  
86.1805-17.................................................    2060-0104  
86.1806-17.................................................    2060-0104  
86.1809-12.................................................    2060-0104  
86.1811-17.................................................    2060-0104  
86.1823-08.................................................    2060-0104  
86.1826-01.................................................    2060-0104  
86.1829-15.................................................    2060-0104  
86.1839-01.................................................    2060-0104  
86.1840-01.................................................    2060-0104  
86.1842-01.................................................    2060-0104  
86.1843-01.................................................    2060-0104  
86.1844-01.................................................    2060-0104  
86.1845-04.................................................    2060-0104  
86.1847-01.................................................    2060-0104  
86.1862-04.................................................    2060-0104  
86.1920-86.1925............................................    2060-0287  
  
                                * * * * *  
------------------------------------------------------------------------  
                     Fuel Economy of Motor Vehicles  
------------------------------------------------------------------------  
600.005....................................................    2060-0104  
600.006....................................................    2060-0104  
600.007....................................................    2060-0104  
600.010....................................................    2060-0104  
600.113-12.................................................    2060-0104  
600.206-12.................................................    2060-0104  
600.207-12.................................................    2060-0104  
600.209-12.................................................    2060-0104  
600.301--600.314-08........................................    2060-0104  
600.507-12.................................................    2060-0104  
600.509-12.................................................    2060-0104  
600.510-12.................................................    2060-0104  
600.512-12.................................................    2060-0104  
  
                                * * * * *  
------------------------------------------------------------------------  
                  Control of Emissions From Locomotives  
------------------------------------------------------------------------  
1033.925...................................................    2060-0287  
  
                                * * * * *  
------------------------------------------------------------------------  
  Control of Emissions From New and In-Use Marine Compression-Ignition  
                           Engines and Vessels  
------------------------------------------------------------------------  
1042.925...................................................    2060-0827  
  
                                * * * * *  
------------------------------------------------------------------------  
* * * * *  
PART 59--NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR  
CONSUMER AND COMMERCIAL PRODUCTS  
0 
3. The authority citation for part 59 continues to read as follows:  
    Authority:  42 U.S.C. 7414 and 7511b(e).  
[[Page 34357]]  
Subpart F--Control of Evaporative Emissions From New and In-Use  
Portable Fuel Containers  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 62/2680 
4. Amend Sec.  59.626 by revising paragraph (e) to read as follows:  
Sec.  59.626  What emission testing must I perform for my application  
for a certificate of conformity?  
* * * * *  
    (e) We may require you to test units of the same or different  
configuration in addition to the units tested under paragraph (b) of  
this section.  
* * * * *  
0 
5. Amend Sec.  59.628 by revising paragraph (b) to read as follows:  
Sec.  59.628  What records must I keep and what reports must I send to  
EPA? 
* * * * *  
    (b) Keep required data from emission tests and all other  
information specified in this subpart for five years after we issue the  
associated certificate of conformity. If you use the same emission data  
or other information for a later production period, the five-year  
period restarts with each new production period if you continue to rely  
on the information.  
* * * * *  
0 
6. Amend Sec.  59.650 by revising paragraph (c) to read as follows:  
Sec.  59.650  General testing provisions.  
* * * * *  
    (c) The specification for gasoline to be used for testing is given  
in 40 CFR 1065.710(c). Use the grade of gasoline specified for general  
testing. Blend this grade of gasoline with reagent grade ethanol in a  
volumetric ratio of 90.0 percent gasoline to 10.0 percent ethanol to  
achieve a blended fuel that has 10.0 1.0 percent ethanol by  
volume. You may use ethanol that is less pure if you can demonstrate  
that it will not affect your ability to demonstrate compliance with the  
applicable emission standards.  
* * * * *  
0 
7. Amend Sec.  59.653 by revising paragraphs (a)(1) and (3) and  
(a)(4)(ii)(C) to read as follows:  
Sec.  59.653  How do I test portable fuel containers?  
* * * * *  
    (a) * * *  
    (1) Pressure cycling. Perform a pressure test by sealing the  
container and cycling it between +13.8 and -3.4 kPa (+2.0 and -0.5  
psig) for 10,000 cycles at a rate of 60 seconds per cycle. For this  
test, the spout may be removed, and the pressure applied through the  
opening where the spout attaches. The purpose of this test is to  
represent environmental wall stresses caused by pressure changes and  
other factors (such as vibration or thermal expansion). If your  
container cannot be tested using the pressure cycles specified by this  
paragraph (a)(1), you may ask to use special test procedures under  
Sec.  59.652(c).  
* * * * *  
    (3) Slosh testing. Perform a slosh test by filling the portable  
fuel container to 40 percent of its capacity with the fuel specified in  
paragraph (e) of this section and rocking it at a rate of 15 cycles per  
minute until you reach one million total cycles. Use an angle deviation  
of +15[deg] to -15[deg] from level. Take steps to ensure that the fuel  
remains at 40 percent of its capacity throughout the test run.  
    (4) * * *  
    (ii) * * *  
    (C) Actuate the spout by fully opening and closing without  
dispensing fuel. The spout must return to the closed position without  
the aid of the operator (e.g., pushing or pulling the spout closed).  
Repeat for a total of 10 actuations. If at any point the spout fails to  
return to the closed position, the container fails the diurnal test.  
* * * * *  
0 
8. Amend Sec.  59.660 by revising paragraph (b) to read as follows:  
Sec.  59.660  Exemption from the standards.  
* * * * *  
    (b) Manufacturers and other persons subject to the prohibitions in  
Sec.  59.602 may ask us to exempt portable fuel containers to purchase,  
sell, or distribute them for the sole purpose of testing them.  
* * * * *  
0 
9. Amend Sec.  59.664 by revising paragraph (c) to read as follows:  
Sec.  59.664  What are the requirements for importing portable fuel  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 63/268containers into the United States?
* * * * *  
    (c) You may meet the bond requirements of this section by obtaining  
a bond from a third-party surety that is cited in the U.S. Department  
of Treasury Circular 570, ``Companies Holding Certificates of Authority  
as Acceptable Sureties on Federal Bonds and as Acceptable Reinsuring  
Companies'' ( https://www.fiscal.treasury.gov/surety-bonds/circular-570.html ). 
* * * * *  
0 
10. Amend Sec.  59.680 by revising the definition of ``Portable fuel  
container'' to read as follows:  
Sec.  59.680  What definitions apply to this subpart?  
* * * * *  
    Portable fuel container means a reusable container of any color  
that is designed and marketed or otherwise intended for use by  
consumers for receiving, transporting, storing, and dispensing  
gasoline, diesel fuel, or kerosene. For the purposes of this subpart,  
all utility jugs that are red, yellow, or blue in color are deemed to  
be portable fuel containers, regardless of how they are labeled or  
marketed.  
* * * * *  
PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES  
0 
11. The authority citation for part 60 continues to read as follows:  
    Authority:  42 U.S.C. 7401 et seq.  
0 
12. Amend Sec.  60.4200 by revising paragraph (d) to read as follows:  
Sec.  60.4200  Am I subject to this subpart?  
* * * * *  
    (d) Stationary CI ICE may be eligible for exemption from the  
requirements of this subpart as described in 40 CFR part 1068, subpart  
C, except that owners and operators, as well as manufacturers, may be  
eligible to request an exemption for national security.  
* * * * *  
0 
13. Amend Sec.  60.4201 by revising paragraphs (a), (d) introductory  
text, (f) introductory text, and (h) to read as follows:  
Sec.  60.4201  What emission standards must I meet for non-emergency  
engines if I am a stationary CI internal combustion engine  
manufacturer?  
    (a) Stationary CI internal combustion engine manufacturers must  
certify their 2007 model year and later non-emergency stationary CI ICE  
with a maximum engine power less than or equal to 2,237 kilowatt (KW)  
(3,000 horsepower (HP)) and a displacement of less than 10 liters per  
cylinder to the certification emission standards for new nonroad CI  
engines in 40 CFR 1039.101, 1039.102, 1039.104, 1039.105, 1039.107, and  
1039.115 and 40 CFR part 1039, appendix I, as applicable, for all  
pollutants, for the same model year and maximum engine power.  
* * * * *  
    (d) Stationary CI internal combustion engine manufacturers must  
certify the following non-emergency stationary CI ICE to the  
appropriate Tier 2 emission standards for new marine CI engines as  
described in 40 CFR part 1042, appendix I, for all pollutants, for the  
same displacement and rated power:
* * * * *  
[[Page 34358]]  
    (f) Notwithstanding the requirements in paragraphs (a) through (c)  
of this section, stationary non-emergency CI ICE identified in  
paragraphs (a) and (c) of this section may be certified to the  
provisions of 40 CFR part 1042 for commercial engines that are  
applicable for the engine's model year, displacement, power density,  
and maximum engine power if the engines will be used solely in either  
or both of the following locations:  
* * * * *  
    (h) Stationary CI ICE certified to the standards in 40 CFR part  
1039 and equipped with auxiliary emission control devices (AECDs) as  
specified in 40 CFR 1039.665 must meet the Tier 1 certification  
emission standards for new nonroad CI engines in 40 CFR part 1039,  
appendix I, while the AECD is activated during a qualified emergency  
situation. A qualified emergency situation is defined in 40 CFR  
1039.665. When the qualified emergency situation has ended and the AECD  
is deactivated, the engine must resume meeting the otherwise applicable  
emission standard specified in this section.  
0 
14. Amend Sec.  60.4202 by revising paragraphs (a)(1)(i), (a)(2),  
(b)(2), (e) introductory text, and (g) introductory text to read as  
follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 64/268Sec.  60.4202  What emission standards must I meet for emergency  
engines if I am a stationary CI internal combustion engine  
manufacturer?  
    (a) * * *  
    (1) * * *  
    (i) The Tier 2 emission standards for new nonroad CI engines for  
the appropriate rated power as described in 40 CFR part 1039, appendix  
I, for all pollutants and the smoke standards as specified in 40 CFR  
1039.105 for model year 2007 engines; and  
* * * * *  
    (2) For engines with a rated power greater than or equal to 37 KW  
(50 HP), the Tier 2 or Tier 3 emission standards for new nonroad CI  
engines for the same rated power as described in 40 CFR part 1039,  
appendix I, for all pollutants and the smoke standards as specified in  
40 CFR 1039.105 beginning in model year 2007.  
    (b) * * *  
    (2) For 2011 model year and later, the Tier 2 emission standards as  
described in 40 CFR part 1039, appendix I, for all pollutants and the  
smoke standards as specified in 40 CFR 1039.105.  
* * * * *  
    (e) Stationary CI internal combustion engine manufacturers must  
certify the following emergency stationary CI ICE that are not fire  
pump engines to the appropriate Tier 2 emission standards for new  
marine CI engines as described in 40 CFR part 1042, appendix I, for all  
pollutants, for the same displacement and rated power:  
* * * * *  
    (g) Notwithstanding the requirements in paragraphs (a) through (d)  
of this section, stationary emergency CI ICE identified in paragraphs  
(a) and (c) of this section may be certified to the provisions of 40  
CFR part 1042 for commercial engines that are applicable for the  
engine's model year, displacement, power density, and maximum engine  
power if the engines will be used solely in either or both of the  
locations identified in paragraphs (g)(1) and (2) of this section.  
Engines that would be subject to the Tier 4 standards in 40 CFR part  
1042 that are used solely in either or both of the locations identified  
in paragraphs (g)(1) and (2) of this section may instead continue to be  
certified to the appropriate Tier 3 standards in 40 CFR part 1042.  
* * * * *  
0 
15. Amend Sec.  60.4204 by revising paragraphs (a) and (f) to read as  
follows:  
Sec.  60.4204  What emission standards must I meet for non-emergency  
engines if I am an owner or operator of a stationary CI internal  
combustion engine?  
    (a) Owners and operators of pre-2007 model year non-emergency  
stationary CI ICE with a displacement of less than 10 liters per  
cylinder must comply with the emission standards in table 1 to this  
subpart. Owners and operators of pre-2007 model year non-emergency  
stationary CI ICE with a displacement of greater than or equal to 10  
liters per cylinder and less than 30 liters per cylinder must comply  
with the Tier 1 emission standards in 40 CFR part 1042, appendix I.  
* * * * *  
    (f) Owners and operators of stationary CI ICE certified to the  
standards in 40 CFR part 1039 and equipped with AECDs as specified in  
40 CFR 1039.665 must meet the Tier 1 certification emission standards  
for new nonroad CI engines in 40 CFR part 1039, appendix I, while the  
AECD is activated during a qualified emergency situation. A qualified  
emergency situation is defined in 40 CFR 1039.665. When the qualified  
emergency situation has ended and the AECD is deactivated, the engine  
must resume meeting the otherwise applicable emission standard  
specified in this section.  
0 
16. Amend Sec.  60.4205 by revising paragraph (a) to read as follows:  
Sec.  60.4205  What emission standards must I meet for emergency  
engines if I am an owner or operator of a stationary CI internal  
combustion engine?  
    (a) Owners and operators of pre-2007 model year emergency  
stationary CI ICE with a displacement of less than 10 liters per  
cylinder that are not fire pump engines must comply with the emission  
standards in Table 1 to this subpart. Owners and operators of pre-2007  
model year emergency stationary CI ICE with a displacement of greater  
than or equal to 10 liters per cylinder and less than 30 liters per  
cylinder that are not fire pump engines must comply with the Tier 1  
emission standards in 40 CFR part 1042, appendix I.  
* * * * *  
0 
17. Amend Sec.  60.4210 by revising paragraphs (a) and (b), (c)  
introductory text, (c)(3), (d), (i), and (j) and adding paragraph (k)  
to read as follows:  
Sec.  60.4210  What are my compliance requirements if I am a stationary  
CI internal combustion engine manufacturer?  
    (a) Stationary CI internal combustion engine manufacturers must  
certify their stationary CI ICE with a displacement of less than 10  
liters per cylinder to the emission standards specified in Sec. Sec.   6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 65/26860.4201(a) through (c) and 60.4202(a), (b), and (d) using the  
certification procedures required in 40 CFR part 1039, subpart C, and  
must test their engines as specified in 40 CFR part 1039. For the  
purposes of this subpart, engines certified to the standards in Table 1  
to this subpart shall be subject to the same certification procedures  
required for engines certified to the Tier 1 standards in 40 CFR part  
1039, appendix I. For the purposes of this subpart, engines certified  
to the standards in Table 4 to this subpart shall be subject to the  
same certification procedures required for engines certified to the  
Tier 1 standards in 40 CFR part 1039, appendix I, except that engines  
with NFPA nameplate power of less than 37 KW (50 HP) certified to model  
year 2011 or later standards shall be subject to the same requirements  
as engines certified to the standards in 40 CFR part 1039.  
    (b) Stationary CI internal combustion engine manufacturers must  
certify their stationary CI ICE with a displacement of greater than or  
equal to 10 liters per cylinder and less than 30 liters per cylinder to  
the emission standards specified in Sec. Sec.  60.4201(d) and (e) and  
60.4202(e) and (f) using the certification procedures required in 40  
CFR part 1042, subpart C, and must test their engines as specified in  
40 CFR part 1042.  
[[Page 34359]]  
    (c) Stationary CI internal combustion engine manufacturers must  
meet the requirements of 40 CFR 1039.120, 1039.125, 1039.130, and  
1039.135 and 40 CFR part 1068 for engines that are certified to the  
emission standards in 40 CFR part 1039. Stationary CI internal  
combustion engine manufacturers must meet the corresponding provisions  
of 40 CFR part 1042 for engines that would be covered by that part if  
they were nonroad (including marine) engines. Labels on such engines  
must refer to stationary engines, rather than or in addition to nonroad  
or marine engines, as appropriate. Stationary CI internal combustion  
engine manufacturers must label their engines according to paragraphs  
(c)(1) through (3) of this section.  
* * * * *  
    (3) Stationary CI internal combustion engines manufactured after  
January 1, 2007 (for fire pump engines, after January 1 of the year  
listed in table 3 to this subpart, as applicable) must be labeled  
according to paragraphs (c)(3)(i) through (iii) of this section.  
    (i) Stationary CI internal combustion engines that meet the  
requirements of this subpart and the corresponding requirements for  
nonroad (including marine) engines of the same model year and HP must  
be labeled according to the provisions in 40 CFR part 1039 or 1042, as  
appropriate.  
    (ii) Stationary CI internal combustion engines that meet the  
requirements of this subpart, but are not certified to the standards  
applicable to nonroad (including marine) engines of the same model year  
and HP must be labeled according to the provisions in 40 CFR part 1039  
or 1042, as appropriate, but the words ``stationary'' must be included  
instead of ``nonroad'' or ``marine'' on the label. In addition, such  
engines must be labeled according to 40 CFR 1039.20.  
    (iii) Stationary CI internal combustion engines that do not meet  
the requirements of this subpart must be labeled according to 40 CFR  
1068.230 and must be exported under the provisions of 40 CFR 1068.230.  
    (d) An engine manufacturer certifying an engine family or families  
to standards under this subpart that are identical to standards  
applicable under 40 CFR part 1039 or 1042 for that model year may  
certify any such family that contains both nonroad (including marine)  
and stationary engines as a single engine family and/or may include any  
such family containing stationary engines in the averaging, banking,  
and trading provisions applicable for such engines under those parts.  
* * * * *  
    (i) The replacement engine provisions of 40 CFR 1068.240 are  
applicable to stationary CI engines replacing existing equipment that  
is less than 15 years old.  
    (j) Stationary CI ICE manufacturers may equip their stationary CI  
internal combustion engines certified to the emission standards in 40  
CFR part 1039 with AECDs for qualified emergency situations according  
to the requirements of 40 CFR 1039.665. Manufacturers of stationary CI  
ICE equipped with AECDs as allowed by 40 CFR 1039.665 must meet all the  
requirements in 40 CFR 1039.665 that apply to manufacturers.  
Manufacturers must document that the engine complies with the Tier 1  
standard in 40 CFR part 1039, appendix I, when the AECD is activated.  
Manufacturers must provide any relevant testing, engineering analysis,  
or other information in sufficient detail to support such statement  
when applying for certification (including amending an existing  
certificate) of an engine equipped with an AECD as allowed by 40 CFR  
1039.665.  
    (k) Manufacturers of any size may certify their emergency  
stationary CI internal combustion engines under this section using  
assigned deterioration factors established by EPA, consistent with 40  
CFR 1039.240 and 1042.240.  
0 
18. Amend Sec.  60.4211 by revising paragraphs (a)(3) and (b)(1) to  
read as follows:  
Sec.  60.4211  What are my compliance requirements if I am an owner or  
operator of a stationary CI internal combustion engine?  
    (a) * * *  
    (3) Meet the requirements of 40 CFR part 1068, as they apply to  
you. 
    (b) * * *  
    (1) Purchasing an engine certified to emission standards for the  
same model year and maximum engine power as described in 40 CFR parts  
1039 and 1042, as applicable. The engine must be installed and  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 66/268configured according to the manufacturer's specifications.  
* * * * *  
0 
19. Amend Sec.  60.4212 by revising paragraphs (a) and (c) and removing  
the undesignated paragraph following the equation in paragraph (c) to  
read as follows:  
Sec.  60.4212  What test methods and other procedures must I use if I  
am an owner or operator of a stationary CI internal combustion engine  
with a displacement of less than 30 liters per cylinder?  
* * * * *  
    (a) The performance test must be conducted according to the in-use  
testing procedures in 40 CFR part 1039, subpart F, for stationary CI  
ICE with a displacement of less than 10 liters per cylinder, and  
according to 40 CFR part 1042, subpart F, for stationary CI ICE with a  
displacement of greater than or equal to 10 liters per cylinder and  
less than 30 liters per cylinder. Alternatively, stationary CI ICE that  
are complying with Tier 2 or Tier 3 emission standards as described in  
40 CFR part 1039, appendix I, or with Tier 2 emission standards as  
described in 40 CFR part 1042, appendix I, may follow the testing  
procedures specified in Sec.  60.4213, as appropriate.  
* * * * *  
    (c) Exhaust emissions from stationary CI ICE subject to Tier 2 or  
Tier 3 emission standards as described in 40 CFR part 1039, appendix I,  
or Tier 2 emission standards as described in 40 CFR part 1042, appendix  
I, must not exceed the NTE numerical requirements, rounded to the same  
number of decimal places as the applicable standard, determined from  
the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.275  
Where: 
STD = The standard specified for that pollutant in 40 CFR part 1039  
or 1042, as applicable.  
* * * * *  
0 
20. Amend Sec.  60.4216 by revising paragraphs (b) and (c) to read as  
follows:  
Sec.  60.4216  What requirements must I meet for engines used in  
Alaska? 
* * * * *  
    (b) Except as indicated in paragraph (c) of this section,  
manufacturers, owners and operators of stationary CI ICE with a  
displacement of less than 10 liters per cylinder located in remote  
areas of Alaska may meet the requirements of this subpart by  
manufacturing and installing engines meeting the Tier 2 or Tier 3  
emission standards described in 40 CFR part 1042 for the same model  
year, displacement, and maximum engine power, as appropriate, rather  
than the otherwise  
[[Page 34360]]  
applicable requirements of 40 CFR part 1039, as indicated in Sec. Sec.   
60.4201(f) and 60.4202(g).  
    (c) Manufacturers, owners, and operators of stationary CI ICE that  
are located in remote areas of Alaska may choose to meet the applicable  
emission standards for emergency engines in Sec. Sec.  60.4202 and  
60.4205, and not those for non-emergency engines in Sec. Sec.  60.4201  
and 60.4204, except that for 2014 model year and later nonemergency CI  
ICE, the owner or operator of any such engine must have that engine  
certified as meeting at least the Tier 3 PM standards identified in  
appendix I of 40 CFR part 1039 or in 40 CFR 1042.101.  
* * * * *  
0 
21. Amend Sec.  60.4219 by revising the definition for ``Certified  
emissions life'' to read as follows:  
Sec.  60.4219  What definitions apply to this subpart?  
* * * * *  
    Certified emissions life means the period during which the engine  
is designed to properly function in terms of reliability and fuel  
consumption, without being remanufactured, specified as a number of  
hours of operation or calendar years, whichever comes first. The values  
for certified emissions life for stationary CI ICE with a displacement  
of less than 10 liters per cylinder are given in 40 CFR 1039.101(g).  
The values for certified emissions life for stationary CI ICE with a  
displacement of greater than or equal to 10 liters per cylinder and  
less than 30 liters per cylinder are given in 40 CFR 1042.101(e).  
* * * * *  
0 
22. Amend Sec.  60.4230 by revising paragraph (e) to read as follows:  
Sec.  60.4230  Am I subject to this subpart?  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 67/268* * * * *  
    (e) Stationary SI ICE may be eligible for exemption from the  
requirements of this subpart as described in 40 CFR part 1068, subpart  
C (or the exemptions described in 40 CFR parts 1048 and 1054, for  
engines that would need to be certified to standards in those parts),  
except that owners and operators, as well as manufacturers, may be  
eligible to request an exemption for national security.  
* * * * *  
0 
23. Amend Sec.  60.4231 by revising paragraphs (a) through (d) to read  
as follows:  
Sec.  60.4231  What emission standards must I meet if I am a  
manufacturer of stationary SI internal combustion engines or equipment  
containing such engines?  
    (a) Stationary SI internal combustion engine manufacturers must  
certify their stationary SI ICE with a maximum engine power less than  
or equal to 19 KW (25 HP) manufactured on or after July 1, 2008 to the  
certification emission standards and other requirements for new nonroad  
SI engines in 40 CFR part 1054, as follows:  
------------------------------------------------------------------------  
                                                        the engine must  
                                                      meet the following  
                                                         non-handheld  
                                   and manufacturing  emission standards  
 If engine displacement is . . .    dates are . . .    identified in 40  
                                                       CFR part 1054 and  
                                                            related  
                                                         requirements:  
------------------------------------------------------------------------  
(1) Below 225 cc................  July 1, 2008 to     Phase 2.  
                                   December 31, 2011.  
(2) Below 225 cc................  January 1, 2012 or  Phase 3.  
                                   later.  
(3) At or above 225 cc..........  July 1, 2008 to     Phase 2.  
                                   December 31, 2010.  
(4) At or above 225 cc..........  January 1, 2011 or  Phase 3.  
                                   later.  
------------------------------------------------------------------------  
    (b) Stationary SI internal combustion engine manufacturers must  
certify their stationary SI ICE with a maximum engine power greater  
than 19 KW (25 HP) (except emergency stationary ICE with a maximum  
engine power greater than 25 HP and less than 130 HP) that use gasoline  
and that are manufactured on or after the applicable date in Sec.   
60.4230(a)(2), or manufactured on or after the applicable date in Sec.   
60.4230(a)(4) for emergency stationary ICE with a maximum engine power  
greater than or equal to 130 HP, to the certification emission  
standards and other requirements for new nonroad SI engines in 40 CFR  
part 1048. Stationary SI internal combustion engine manufacturers must  
certify their emergency stationary SI ICE with a maximum engine power  
greater than 25 HP and less than 130 HP that use gasoline and that are  
manufactured on or after the applicable date in Sec.  60.4230(a)(4) to  
the Phase 1 emission standards in 40 CFR part 1054, appendix I,  
applicable to class II engines, and other requirements for new nonroad  
SI engines in 40 CFR part 1054. Stationary SI internal combustion  
engine manufacturers may certify their stationary SI ICE with a maximum  
engine power less than or equal to 30 KW (40 HP) with a total  
displacement less than or equal to 1,000 cubic centimeters (cc) that  
use gasoline to the certification emission standards and other  
requirements as appropriate for new nonroad SI engines in 40 CFR part  
1054. 
    (c) Stationary SI internal combustion engine manufacturers must  
certify their stationary SI ICE with a maximum engine power greater  
than 19 KW (25 HP) (except emergency stationary ICE with a maximum  
engine power greater than 25 HP and less than 130 HP) that are rich  
burn engines that use LPG and that are manufactured on or after the  
applicable date in Sec.  60.4230(a)(2), or manufactured on or after the  
applicable date in Sec.  60.4230(a)(4) for emergency stationary ICE  
with a maximum engine power greater than or equal to 130 HP, to the  
certification emission standards and other requirements for new nonroad  
SI engines in 40 CFR part 1048. Stationary SI internal combustion  
engine manufacturers must certify their emergency stationary SI ICE  
greater than 25 HP and less than 130 HP that are rich burn engines that  
use LPG and that are manufactured on or after the applicable date in  
Sec.  60.4230(a)(4) to the Phase 1 emission standards in 40 CFR part  
1054, appendix I, applicable to class II engines, and other  
requirements for new nonroad SI engines in 40 CFR part 1054. Stationary  
SI internal combustion engine manufacturers may certify their  
stationary SI ICE with a maximum engine power less than or equal to 30  
KW (40 HP) with a total displacement less than or equal to 1,000 cc  
that are rich burn engines that use LPG to the certification emission  
standards and other requirements as appropriate for new nonroad SI  
engines in 40 CFR part 1054.  
    (d) Stationary SI internal combustion engine manufacturers who  
choose to certify their stationary SI ICE with a maximum engine power  
greater than 19 KW (25 HP) and less than 75 KW (100 HP) (except  
gasoline and rich burn engines that use LPG and emergency stationary  
ICE with a maximum engine power greater than 25 HP and less than 130  
HP) under the voluntary manufacturer certification program described in  
this subpart must certify those engines to the certification emission  
standards for new nonroad SI engines in 40 CFR part 1048. Stationary SI  
internal combustion engine manufacturers who choose to certify  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 68/268[[Page 34361]]  
their emergency stationary SI ICE greater than 25 HP and less than 130  
HP (except gasoline and rich burn engines that use LPG), must certify  
those engines to the Phase 1 emission standards in 40 CFR part 1054,  
appendix I, applicable to class II engines, for new nonroad SI engines  
in 40 CFR part 1054. Stationary SI internal combustion engine  
manufacturers may certify their stationary SI ICE with a maximum engine  
power less than or equal to 30 KW (40 HP) with a total displacement  
less than or equal to 1,000 cc (except gasoline and rich burn engines  
that use LPG) to the certification emission standards and other  
requirements as appropriate for new nonroad SI engines in 40 CFR part  
1054. For stationary SI ICE with a maximum engine power greater than 19  
KW (25 HP) and less than 75 KW (100 HP) (except gasoline and rich burn  
engines that use LPG and emergency stationary ICE with a maximum engine  
power greater than 25 HP and less than 130 HP) manufactured prior to  
January 1, 2011, manufacturers may choose to certify these engines to  
the standards in Table 1 to this subpart applicable to engines with a  
maximum engine power greater than or equal to 100 HP and less than 500  
HP. 
* * * * *  
0 
24. Revise Sec.  60.4238 to read as follows:  
Sec.  60.4238  What are my compliance requirements if I am a  
manufacturer of stationary SI internal combustion engines <=19 KW (25  
HP) or a manufacturer of equipment containing such engines?  
    Stationary SI internal combustion engine manufacturers who are  
subject to the emission standards specified in Sec.  60.4231(a) must  
certify their stationary SI ICE using the certification and testing  
procedures required in 40 CFR part 1054, subparts C and F.  
Manufacturers of equipment containing stationary SI internal combustion  
engines meeting the provisions of 40 CFR part 1054 must meet the  
provisions of 40 CFR part 1060, subpart C, to the extent they apply to  
equipment manufacturers.  
0 
25. Revise Sec.  60.4239 to read as follows:  
Sec.  60.4239  What are my compliance requirements if I am a  
manufacturer of stationary SI internal combustion engines >19 KW (25  
HP) that use gasoline or a manufacturer of equipment containing such  
engines?  
    Stationary SI internal combustion engine manufacturers who are  
subject to the emission standards specified in Sec.  60.4231(b) must  
certify their stationary SI ICE using the certification procedures  
required in 40 CFR part 1048, subpart C, and must test their engines as  
specified in that part. Stationary SI internal combustion engine  
manufacturers who certify their stationary SI ICE with a maximum engine  
power less than or equal to 30 KW (40 HP) with a total displacement  
less than or equal to 1,000 cc to the certification emission standards  
and other requirements for new nonroad SI engines in 40 CFR part 1054,  
and manufacturers of stationary SI emergency engines that are greater  
than 25 HP and less than 130 HP who meet the Phase 1 emission standards  
in 40 CFR part 1054, appendix I, applicable to class II engines, must  
certify their stationary SI ICE using the certification and testing  
procedures required in 40 CFR part 1054, subparts C and F.  
Manufacturers of equipment containing stationary SI internal combustion  
engines meeting the provisions of 40 CFR part 1054 must meet the  
provisions of 40 CFR part 1060, subpart C, to the extent they apply to  
equipment manufacturers.  
0 
26. Revise Sec.  60.4240 to read as follows:  
Sec.  60.4240  What are my compliance requirements if I am a  
manufacturer of stationary SI internal combustion engines >19 KW (25  
HP) that are rich burn engines that use LPG or a manufacturer of  
equipment containing such engines?
    Stationary SI internal combustion engine manufacturers who are  
subject to the emission standards specified in Sec.  60.4231(c) must  
certify their stationary SI ICE using the certification procedures  
required in 40 CFR part 1048, subpart C, and must test their engines as  
specified in that part. Stationary SI internal combustion engine  
manufacturers who certify their stationary SI ICE with a maximum engine  
power less than or equal to 30 KW (40 HP) with a total displacement  
less than or equal to 1,000 cc to the certification emission standards  
and other requirements for new nonroad SI engines in 40 CFR part 1054,  
and manufacturers of stationary SI emergency engines that are greater  
than 25 HP and less than 130 HP who meet the Phase 1 emission standards  
in 40 CFR part 1054, appendix I, applicable to class II engines, must  
certify their stationary SI ICE using the certification and testing  
procedures required in 40 CFR part 1054, subparts C and F.  
Manufacturers of equipment containing stationary SI internal combustion  
engines meeting the provisions of 40 CFR part 1054 must meet the  
provisions of 40 CFR part 1060, subpart C, to the extent they apply to  
equipment manufacturers.  
0 
27. Amend Sec.  60.4241 by revising paragraphs (a), (b), and (i) to  
read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 69/268Sec.  60.4241  What are my compliance requirements if I am a  
manufacturer of stationary SI internal combustion engines participating  
in the voluntary certification program or a manufacturer of equipment  
containing such engines?  
    (a) Manufacturers of stationary SI internal combustion engines with  
a maximum engine power greater than 19 KW (25 HP) that do not use  
gasoline and are not rich burn engines that use LPG can choose to  
certify their engines to the emission standards in Sec.  60.4231(d) or  
(e), as applicable, under the voluntary certification program described  
in this subpart. Manufacturers who certify their engines under the  
voluntary certification program must meet the requirements as specified  
in paragraphs (b) through (g) of this section. In addition,  
manufacturers of stationary SI internal combustion engines who choose  
to certify their engines under the voluntary certification program,  
must also meet the requirements as specified in Sec.  60.4247.  
Manufacturers of stationary SI internal combustion engines who choose  
not to certify their engines under this section must notify the  
ultimate purchaser that testing requirements apply as described in  
Sec.  60.4243(b)(2); manufacturers must keep a copy of this  
notification for five years after shipping each engine and make those  
documents available to EPA upon request.  
    (b) Manufacturers of engines other than those certified to  
standards in 40 CFR part 1054 must certify their stationary SI ICE  
using the certification procedures required in 40 CFR part 1048,  
subpart C, and must follow the same test procedures that apply to Large  
SI nonroad engines under 40 CFR part 1048, but must use the D-1 cycle  
of International Organization for Standardization 8178-4: 1996(E)  
(incorporated by reference, see Sec.  60.17) or the test cycle  
requirements specified in Table 3 to 40 CFR 1048.505, except that Table  
3 of 40 CFR 1048.505 applies to high load engines only. Manufacturers  
of any size may certify their stationary emergency engines at or above  
130 hp using assigned deterioration factors established by EPA,  
consistent with 40 CFR 1048.240. Stationary SI internal combustion  
engine manufacturers who certify their stationary SI ICE with a maximum  
engine power less than or equal to 30 KW (40 HP) with a total  
displacement less than or equal to 1,000 cc to the certification  
emission standards and other requirements for new nonroad SI  
[[Page 34362]]  
engines in 40 CFR part 1054, and manufacturers of emergency engines  
that are greater than 25 HP and less than 130 HP who meet the Phase 1  
standards in 40 CFR part 1054, appendix I, applicable to class II  
engines, must certify their stationary SI ICE using the certification  
and testing procedures required in 40 CFR part 1054, subparts C and F.  
Manufacturers of equipment containing stationary SI internal combustion  
engines meeting the provisions of 40 CFR part 1054 must meet the  
provisions of 40 CFR part 1060, subpart C, to the extent they apply to  
equipment manufacturers.  
* * * * *  
    (i) For engines being certified to the voluntary certification  
standards in Table 1 of this subpart, the VOC measurement shall be made  
by following the procedures in 40 CFR part 1065, subpart C, to  
determine the total NMHC emissions. As an alternative, manufacturers  
may measure ethane, as well as methane, for excluding such levels from  
the total VOC measurement.  
0 
28. Revise Sec.  60.4242 to read as follows:  
Sec.  60.4242  What other requirements must I meet if I am a  
manufacturer of stationary SI internal combustion engines or equipment  
containing stationary SI internal combustion engines or a manufacturer  
of equipment containing such engines?  
    (a) Stationary SI internal combustion engine manufacturers must  
meet the provisions of 40 CFR parts 1048, 1054, and 1068, as  
applicable, except that engines certified pursuant to the voluntary  
certification procedures in Sec.  60.4241 are subject only to the  
provisions indicated in Sec.  60.4247 and are permitted to provide  
instructions to owners and operators allowing for deviations from  
certified configurations, if such deviations are consistent with the  
provisions of Sec.  60.4241(c) through (f). Manufacturers of equipment  
containing stationary SI internal combustion engines meeting the  
provisions of 40 CFR part 1054 must meet the provisions of 40 CFR part  
1060, as applicable. Labels on engines certified to 40 CFR part 1048  
must refer to stationary engines, rather than or in addition to nonroad  
engines, as appropriate.  
    (b) An engine manufacturer certifying an engine family or families  
to standards under this subpart that are identical to standards  
identified in 40 CFR part 1048 or 1054 for that model year may certify  
any such family that contains both nonroad and stationary engines as a  
single engine family and/or may include any such family containing  
stationary engines in the averaging, banking and trading provisions  
applicable for such engines under those parts. This paragraph (b) also  
applies to equipment or component manufacturers certifying to standards  
under 40 CFR part 1060.  
    (c) Manufacturers of engine families certified to 40 CFR part 1048  
may meet the labeling requirements referred to in paragraph (a) of this  
section for stationary SI ICE by either adding a separate label  
containing the information required in paragraph (a) of this section or  
by adding the words ``and stationary'' after the word ``nonroad'' to  
the label.  
    (d) For all engines manufactured on or after January 1, 2011, and  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 70/268for all engines with a maximum engine power greater than 25 HP and less  
than 130 HP manufactured on or after July 1, 2008, a stationary SI  
engine manufacturer that certifies an engine family solely to the  
standards applicable to emergency engines must add a permanent label  
stating that the engines in that family are for emergency use only. The  
label must be added according to the labeling requirements specified in  
40 CFR 1048.135(b).  
    (e) All stationary SI engines subject to mandatory certification  
that do not meet the requirements of this subpart must be labeled and  
exported according to 40 CFR 1068.230. Manufacturers of stationary  
engines with a maximum engine power greater than 25 HP that are not  
certified to standards and other requirements under 40 CFR part 1048  
are subject to the labeling provisions of 40 CFR 1048.20 pertaining to  
excluded stationary engines.  
    (f) For manufacturers of gaseous-fueled stationary engines required  
to meet the warranty provisions in 40 CFR 1054.120, we may establish an  
hour-based warranty period equal to at least the certified emissions  
life of the engines (in engine operating hours) if we determine that  
these engines are likely to operate for a number of hours greater than  
the applicable useful life within 24 months. We will not approve an  
alternate warranty under this paragraph (f) for nonroad engines. An  
alternate warranty period approved under this paragraph (f) will be the  
specified number of engine operating hours or two years, whichever  
comes first. The engine manufacturer shall request this alternate  
warranty period in its application for certification or in an earlier  
submission. We may approve an alternate warranty period for an engine  
family subject to the following conditions:  
    (1) The engines must be equipped with non-resettable hour meters.  
    (2) The engines must be designed to operate for a number of hours  
substantially greater than the applicable certified emissions life.  
    (3) The emission-related warranty for the engines may not be  
shorter than any published warranty offered by the manufacturer without  
charge for the engines. Similarly, the emission-related warranty for  
any component shall not be shorter than any published warranty offered  
by the manufacturer without charge for that component.  
0 
29. Amend Sec.  60.4243 by revising paragraph (f) to read as follows:  
Sec.  60.4243  What are my compliance requirements if I am an owner or  
operator of a stationary SI internal combustion engine?  
* * * * *  
    (f) If you are an owner or operator of a stationary SI internal  
combustion engine that is less than or equal to 500 HP and you purchase  
a non-certified engine or you do not operate and maintain your  
certified stationary SI internal combustion engine and control device  
according to the manufacturer's written emission-related instructions,  
you are required to perform initial performance testing as indicated in  
this section, but you are not required to conduct subsequent  
performance testing unless the stationary engine undergoes rebuild,  
major repair or maintenance. Engine rebuilding means to overhaul an  
engine or to otherwise perform extensive service on the engine (or on a  
portion of the engine or engine system). For the purpose of this  
paragraph (f), perform extensive service means to disassemble the  
engine (or portion of the engine or engine system), inspect and/or  
replace many of the parts, and reassemble the engine (or portion of the  
engine or engine system) in such a manner that significantly increases  
the service life of the resultant engine.  
* * * * *  
0 
30. Amend Sec.  60.4245 by revising paragraph (a)(3) to read as  
follows:  
Sec.  60.4245  What are my notification, reporting, and recordkeeping  
requirements if I am an owner or operator of a stationary SI internal  
combustion engine?  
* * * * *  
    (a) * * *  
    (3) If the stationary SI internal combustion engine is a certified  
engine, documentation from the manufacturer that the engine is  
certified to meet the emission standards and information as required in  
40 CFR parts 1048, 1054, and 1060, as applicable.  
* * * * *  
0 
31. Amend Sec.  60.4247 by revising paragraph (a) to read as follows:  
[[Page 34363]]  
Sec.  60.4247  What parts of the mobile source provisions apply to me  
if I am a manufacturer of stationary SI internal combustion engines or  
a manufacturer of equipment containing such engines?  
    (a) Manufacturers certifying to emission standards in 40 CFR part  
1054 must meet the provisions of 40 CFR part 1054. Note that 40 CFR  
part 1054, appendix I, describes various provisions that do not apply  
for engines meeting Phase 1 standards in 40 CFR part 1054.  
Manufacturers of equipment containing stationary SI internal combustion  
engines meeting the provisions of 40 CFR part 1054 must meet the  
provisions of 40 CFR part 1060 to the extent they apply to equipment  
manufacturers.  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 71/2680 
32. Amend Sec.  60.4248 by revising the definition for ``Certified  
emissions life'' and ``Certified stationary internal combustion  
engine'' to read as follows:  
Sec.  60.4248  What definitions apply to this subpart?  
* * * * *  
    Certified emissions life means the period during which the engine  
is designed to properly function in terms of reliability and fuel  
consumption, without being remanufactured, specified as a number of  
hours of operation or calendar years, whichever comes first. The values  
for certified emissions life for stationary SI ICE with a maximum  
engine power less than or equal to 19 KW (25 HP) are given in 40 CFR  
1054.107 and 1060.101, as appropriate. The values for certified  
emissions life for stationary SI ICE with a maximum engine power  
greater than 19 KW (25 HP) certified to 40 CFR part 1048 are given in  
40 CFR 1048.101(g). The certified emissions life for stationary SI ICE  
with a maximum engine power greater than 75 KW (100 HP) certified under  
the voluntary manufacturer certification program of this subpart is  
5,000 hours or 7 years, whichever comes first. You may request in your  
application for certification that we approve a shorter certified  
emissions life for an engine family. We may approve a shorter certified  
emissions life, in hours of engine operation but not in years, if we  
determine that these engines will rarely operate longer than the  
shorter certified emissions life. If engines identical to those in the  
engine family have already been produced and are in use, your  
demonstration must include documentation from such in-use engines. In  
other cases, your demonstration must include an engineering analysis of  
information equivalent to such in-use data, such as data from research  
engines or similar engine models that are already in production. Your  
demonstration must also include any overhaul interval that you  
recommend, any mechanical warranty that you offer for the engine or its  
components, and any relevant customer design specifications. Your  
demonstration may include any other relevant information. The certified  
emissions life value may not be shorter than any of the following:  
    (1) 1,000 hours of operation.  
    (2) Your recommended overhaul interval.  
    (3) Your mechanical warranty for the engine.  
    Certified stationary internal combustion engine means an engine  
that belongs to an engine family that has a certificate of conformity  
that complies with the emission standards and requirements in this  
part, or of 40 CFR part 1048 or 1054, as appropriate.  
* * * * *  
PART 85--CONTROL OF AIR POLLUTION FROM MOBILE SOURCES  
0 
33. The authority citation for part 85 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
Subpart O--[Removed and Reserved]  
0 
34. Remove and reserve subpart O, consisting of Sec. Sec.  85.1401  
through 85.1415.  
0 
35. Amend Sec.  85.1501 by revising paragraph (a) to read as follows:  
Sec.  85.1501  Applicability.  
    (a) Except where otherwise indicated, this subpart is applicable to  
motor vehicles offered for importation or imported into the United  
States for which the Administrator has promulgated regulations under 40  
CFR part 86, subpart D or S, prescribing emission standards, but which  
are not covered by certificates of conformity issued under section  
206(a) of the Clean Air Act (i.e., which are nonconforming vehicles as  
defined in Sec.  85.1502), as amended, and part 86 at the time of  
conditional importation. Compliance with regulations under this subpart  
shall not relieve any person or entity from compliance with other  
applicable provisions of the Clean Air Act. This subpart no longer  
applies for heavy-duty engines certified under 40 CFR part 86, subpart  
A; references in this subpart to ``engines'' therefore apply only for  
replacement engines intended for installation in motor vehicles that  
are subject to this subpart.  
* * * * *  
0 
36. Amend Sec.  85.1511 by adding introductory text and paragraph  
(b)(5) to read as follows:  
Sec.  85.1511  Exemptions and exclusions.  
    The exemption provisions of 40 CFR part 1068, subpart D, apply  
instead of the provisions of this section for heavy-duty motor vehicles  
and heavy-duty motor vehicle engines regulated under 40 CFR part 86,  
subpart A, and 40 CFR parts 1036 and 1037. The following provisions  
apply for other motor vehicles and motor vehicle engines:  
* * * * *  
    (b) * * *  
    (5) Export exemption. Vehicles may qualify for a temporary  
exemption under the provisions of 40 CFR 1068.325(d).  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 72/2680 
37. Revise Sec.  85.1514 to read as follows:  
Sec.  85.1514  Treatment of confidential information.  
    The provisions of 40 CFR 1068.10 apply for information you consider  
confidential.  
0 
38. Amend Sec.  85.1701 by revising paragraph (a)(1) to read as  
follows:  
Sec.  85.1701  General applicability.  
    (a) * * *  
    (1) Beginning January 1, 2014, the exemption provisions of 40 CFR  
part 1068, subpart C, apply instead of the provisions of this subpart  
for heavy-duty motor vehicle engines regulated under 40 CFR part 86,  
subpart A, except that the nonroad competition exemption of 40 CFR  
1068.235 and the nonroad hardship exemption provisions of 40 CFR  
1068.245, 1068.250, and 1068.255 do not apply for motor vehicle  
engines. Note that the provisions for emergency vehicle field  
modifications in Sec.  85.1716 continue to apply for heavy-duty  
engines.  
* * * * *  
0 
39. Revise Sec.  85.1712 to read as follows:  
Sec.  85.1712  Treatment of confidential information.  
    The provisions of 40 CFR 1068.10 apply for information you consider  
confidential.  
0 
40. Revise Sec.  85.1801 to read as follows:  
Sec.  85.1801  Applicability and definitions.  
    (a) The recall provisions of 40 CFR part 1068, subpart E, apply  
instead of the provisions of this subpart for heavy-duty motor vehicles  
and heavy-duty motor vehicle engines regulated under 40 CFR part 86,  
subpart A, and 40 CFR parts 1036 and 1037. The provisions of this  
subpart apply for other motor vehicles and motor vehicle engines.  
    (b) For the purposes of this subpart, except as otherwise provided,  
words 
[[Page 34364]]  
shall be defined as provided for by sections 214 and 302 of the Clean  
Air Act, 42 U.S.C. 1857, as amended.  
    (1) Act shall mean the Clean Air Act, 42 U.S.C. 1857, as amended.  
    (2) Days shall mean calendar days.  
0 
41. Revise Sec.  85.1807 to read as follows:  
Sec.  85.1807  Public hearings.  
    Manufacturers may request a hearing as described in 40 CFR part  
1068, subpart G.  
0 
42. Revise Sec.  85.1808 to read as follows:  
Sec.  85.1808  Treatment of confidential information.  
    The provisions of 40 CFR 1068.10 apply for information you consider  
confidential.  
0 
43. Amend Sec.  85.1902 by revising paragraph (b)(2) to read as  
follows:  
Sec.  85.1902  Definitions.  
* * * * *  
    (b) * * *  
    (2) A defect in the design, materials, or workmanship in one or  
more emission-related parts, components, systems, software, or elements  
of design which must function properly to ensure continued compliance  
with greenhouse gas emission standards in 40 CFR part 86.  
* * * * *  
0 
44. Amend Sec.  85.2102 by revising paragraph (a)(18) and adding and  
reserving paragraph (b) to read as follows:  
Sec.  85.2102  Definitions.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 73/268    (a) * * *  
    (18) MOD Director has the meaning given for ``Designated Compliance  
Officer'' in 40 CFR 1068.30.  
    (b) [Reserved]  
0 
45. Amend Sec.  85.2115 by revising paragraph (a)(4) to read as  
follows:  
Sec.  85.2115  Notification of intent to certify.  
    (a) * * *  
    (4) Two complete and identical copies of the notification and any  
subsequent industry comments on any such notification shall be  
submitted by the aftermarket manufacturer to: MOD Director.  
* * * * *  
0 
46. Revise Sec.  85.2301 to read as follows:  
Sec.  85.2301  Applicability.  
    The definitions provided by this subpart are effective February 23,  
1995 and apply to all motor vehicles regulated under 40 CFR part 86,  
subpart S, and to highway motorcycles regulated under 40 CFR part 86,  
subparts E and F. The definitions and related provisions in 40 CFR  
parts 1036, 1037, and 1068 apply instead of the provisions in this  
subpart for heavy-duty motor vehicles and heavy-duty motor vehicle  
engines regulated under 40 CFR part 86, subpart A, and 40 CFR parts  
1036 and 1037.  
PART 86--CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES  
AND ENGINES  
0 
47. The authority citation for part 86 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
48. Section 86.1 is amended by:  
0 
a. Revising the last sentence of paragraph (a);  
0 
b. Redesignating paragraphs (b)(19) through (21) as paragraphs (b)(21)  
through (23); and  
0 
c. Adding new paragraphs (b)(19) and (20).  
    The revision and additions read as follows:  
Sec.  86.1  Incorporation by reference.  
    (a) * * * For information on the availability of this material at  
NARA, email fedreg.legal@nara.gov , or go to www.archives.gov/federal-register/cfr/ibr-locations.html . 
    (b) * * *  
    (19) ASTM D5769-20, Standard Test Method for Determination of  
Benzene, Toluene, and Total Aromatics in Finished Gasolines by Gas  
Chromatography/Mass Spectrometry, approved June 1, 2020 (``ASTM5769''),  
IBR approved for Sec. Sec.  86.113-04(a), 86.213(a), and 86.513(a).  
    (20) ASTM D6550-20, Standard Test Method for Determination of  
Olefin Content of Gasolines by Supercritical-Fluid Chromatography,  
approved July 1, 2020 (``ASTM D6550''), IBR approved for Sec. Sec.   
86.113-04(a), 86.213(a), and 86.513(a).  
* * * * *  
0 
49. Section 86.004-15 is amended by revising paragraph (a)(1) to read  
as follows:  
Sec.  86.004-15  NOX plus NMHC and particulate averaging, trading, and  
banking for heavy-duty engines.  
    (a) Overview. (1) Heavy-duty engines eligible for NO X  
plus NMHC and particulate averaging, trading and banking programs are  
described in the applicable emission standards sections in this  
subpart. For manufacturers not selecting Options 1 or 2 contained in  
Sec.  86.005-10(f), the ABT program requirements contained in Sec.   
86.000-15 apply for 2004 model year Otto-cycle engines, rather than the  
provisions contained in this section. Participation in these programs  
is voluntary.  
* * * * *  
0 
50. Section 86.010-18 is amended by--  
0 
a. Revising paragraphs (g)(2)(ii)(B) and (g)(2)(iii)(C).  
0 
b. Adding paragraph (g)(2)(iii)(D).  
0 
c. Removing and reserving paragraph (l)(2)(ii).  
0 
d. Revising paragraphs (p)(3) and (4).  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 74/268    The revisions and additions read as follows:  
Sec.  86.010-18  On-board Diagnostics for engines used in applications  
greater than 14,000 pounds GVWR.  
* * * * *  
    (g) * * *  
    (2) * * *  
    (ii) * * *  
    (B) For model years 2013 and later, on engines equipped with  
sensors that can detect combustion or combustion quality (e.g., for use  
in engines with homogeneous charge compression ignition (HCCI) control  
systems), the OBD system must detect a misfire malfunction when the  
percentage of misfire is 5 percent or greater.  
    (iii) * * *  
    (C) For model years 2013 through 2018, on engines equipped with  
sensors that can detect combustion or combustion quality, the OBD  
system must monitor continuously for engine misfire when positive  
torque is between 20 and 75 percent of peak torque, and engine speed is  
less than 75 percent of maximum engine speed. If a monitoring system  
cannot detect all misfire patterns under all required engine speed and  
load conditions, the manufacturer may request that the Administrator  
approve the monitoring system nonetheless. In evaluating the  
manufacturer's request, the Administrator will consider the following  
factors: The magnitude of the region(s) in which misfire detection is  
limited; the degree to which misfire detection is limited in the  
region(s) (i.e., the probability of detection of misfire events); the  
frequency with which said region(s) are expected to be encountered in-  
use; the type of misfire patterns for which misfire detection is  
troublesome; and demonstration that the monitoring technology employed  
is not inherently incapable of detecting misfire under required  
conditions (i.e., compliance can be achieved on other engines). The  
evaluation will be based on the following misfire patterns: Equally  
spaced misfire occurring on randomly selected cylinders; single  
cylinder continuous misfire; and, paired cylinder (cylinders firing at  
the same crank angle) continuous misfire.  
[[Page 34365]]  
    (D) For 20 percent of 2019 model year, 50 percent of 2020 model,  
and 100 percent of 2021 and later model year diesel engines (percentage  
based on the manufacturer's projected sales volume of all diesel  
engines subject to this regulation) equipped with sensors that can  
detect combustion or combustion quality, the OBD system must monitor  
continuously for engine misfire under all positive torque engine speed  
conditions except within the following range: The engine operating  
region bound by the positive torque line (i.e., engine torque with  
transmission in neutral) and the two following points: engine speed of  
50 percent of maximum engine speed with the engine torque at the  
positive torque line, and 100 percent of the maximum engine speed with  
the engine torque at 10 percent of peak torque above the positive  
torque line. If a monitoring system cannot detect all misfire patterns  
under all required engine speed and load conditions, the manufacturer  
may request that the Administrator approve the monitoring system  
nonetheless. In evaluating the manufacturer's request, the  
Administrator will consider the following factors: The magnitude of the  
region(s) in which misfire detection is limited; the degree to which  
misfire detection is limited in the region(s) (i.e., the probability of  
detection of misfire events); the frequency with which said region(s)  
are expected to be encountered in-use; the type of misfire patterns for  
which misfire detection is troublesome; and demonstration that the  
monitoring technology employed is not inherently incapable of detecting  
misfire under required conditions (i.e., compliance can be achieved on  
other engines). The evaluation will be based on the following misfire  
patterns: Equally spaced misfire occurring on randomly selected  
cylinders; single cylinder continuous misfire; and, paired cylinder  
(cylinders firing at the same crank angle) continuous misfire.  
* * * * *  
    (p) * * *  
    (3) For model years 2016 through 2018. (i) On the engine ratings  
tested according to paragraph (l)(2)(iii) of this section, the  
certification emissions thresholds shall apply in-use.  
    (ii) On the manufacturer's remaining engine ratings, separate in-  
use emissions thresholds shall apply. These thresholds are determined  
by doubling the applicable thresholds as shown in Table 1 of paragraph  
(g) of this section and Table 2 of paragraph (h) of this section. The  
resultant thresholds apply only in-use and do not apply for  
certification or selective enforcement auditing.  
    (iii) For monitors subject to meeting the minimum in-use monitor  
performance ratio of 0.100 in paragraph (d)(1)(ii) of this section, the  
OBD system shall not be considered noncompliant unless a representative  
sample indicates the in-use ratio is below 0.088 except for filtering  
performance monitors for PM filters (paragraph (g)(8)(ii)(A) of this  
section) and missing substrate monitors (paragraph (g)(8)(ii)(D) of  
this section) for which the OBD system shall not be considered  
noncompliant unless a representative sample indicates the in-use ratio  
is below 0.050.  
    (iv) An OBD system shall not be considered noncompliant solely due  
to a failure or deterioration mode of a monitored component or system  
that could not have been reasonably foreseen to occur by the  
manufacturer.  
    (4) For model years 2019 and later. (i) On all engine ratings, the  
certification emissions thresholds shall apply in-use.  
    (ii) For monitors subject to meeting the minimum in-use monitor  
performance ratio of 0.100 in paragraph (d)(1)(ii) of this section, the  
OBD system shall not be considered noncompliant unless a representative  
sample indicates the in-use ratio is below 0.088.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 75/268    (iii) An OBD system shall not be considered noncompliant solely due  
to a failure or deterioration mode of a monitored component or system  
that the manufacturer could not have reasonably foreseen.  
* * * * *  
0 
51. Section 86.113-04 is amended by revising paragraph (a)(1) to read  
as follows:  
Sec.  86.113-04  Fuel specifications.  
* * * * *  
    (a) * * *  
    (1) Gasoline meeting the following specifications, or substantially  
equivalent specifications approved by the Administrator, must be used  
for exhaust and evaporative testing:  
   Table 1 to Sec.   86.113-04--Test Fuel Specifications for Gasoline  
                             Without Ethanol  
------------------------------------------------------------------------  
                                                            Reference  
            Item                       Regular             procedure 1  
------------------------------------------------------------------------  
Research octane, Minimum 2..  93......................  ASTM D2699  
Octane sensitivity 2........  7.5.....................  ASTM D2700  
Distillation Range ([deg]F):  
    Evaporated initial        75-95...................  ASTM D86  
     boiling point 3.  
    10% evaporated..........  120-135.................  
    50% evaporated..........  200-230.................  
    90% evaporated..........  300-325.................  
    Evaporated final boiling  415 Maximum.............  
     point.  
Total Aromatic Hydrocarbon    35% Maximum.............  ASTM D1319 or  
 (vol %).                                                ASTM D5769  
Olefins (vol %) 4...........  10% Maximum.............  ASTM D1319 or  
                                                         ASTM D6550  
Lead, g/gallon (g/liter),     0.050 (0.013)...........  ASTM D3237  
 Maximum.  
Phosphorous, g/gallon (g/     0.005 (0.0013)..........  ASTM D3231  
 liter), Maximum.  
Total sulfur, wt. % 5.......  0.0015-0.008............  ASTM D2622  
Dry Vapor Pressure            60.0-63.4 (8.7-9.2).....  ASTM D5191  
 Equivalent (DVPE), kPa  
 (psi) 6.  
------------------------------------------------------------------------  
1 Incorporated by reference, see Sec.   86.1.  
2 Octane specifications are optional for manufacturer testing.  
3 For testing at altitudes above 1,219 m (4,000 feet), the specified  
  range is 75-105 [deg]F.  
4 ASTM D6550 prescribes measurement of olefin concentration in mass %.  
  Multiply this result by 0.857 and round to the first decimal place to  
  determine the olefin concentration in volume %.  
5 Sulfur concentration will not exceed 0.0045 weight percent for EPA  
  testing.  
6 For testing unrelated to evaporative emission control, the specified  
  range is 54.8-63.7 kPa (8.0-9.2 psi). For testing at altitudes above  
  1,219 m (4,000 feet), the specified range is 52.0-55.4 kPa (7.6-8.0  
  psi). Calculate dry vapor pressure equivalent, DVPE, based on the  
  measured total vapor pressure, pT, using the following equation: DVPE  
  (kPa) = 0.956 [middot] pT-2.39 (or DVPE (psi) = 0.956 [middot] pT-  
  0.347). DVPE is intended to be equivalent to Reid Vapor Pressure using  
  a different test method.  
[[Page 34366]]  
* * * * *  
0 
52. Section 86.129-00 is amended by revising paragraph (f)(1)(ii)(C) to  
read as follows:  
Sec.  86.129-00  Road load power, test weight, and inertia weight class  
determination.  
* * * * *  
    (f)(1) * * *  
    (ii) * * *  
    (C) Regardless of other requirements in this section relating to  
the testing of HLDTs, for Tier 2 and Tier 3 HLDTs, the test weight  
basis for FTP and SFTP testing (both US06 and SC03), if applicable, is  
the vehicle curb weight plus 300 pounds. For MDPVs certified to  
standards in bin 11 in Tables S04-1 and 2 in Sec.  86.1811-04, the test  
weight basis must be adjusted loaded vehicle weight (ALVW) as defined  
in this part.  
* * * * *  
0 
53. Section 86.130-96 is amended by revising paragraph (a) to read as  
follows:  
Sec.  86.130-96  Test sequence; general requirements.  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 76/268    (a)(1) Gasoline- and methanol-fueled vehicles. The test sequence  
shown in Figure 1 of 40 CFR 1066.801 shows the steps encountered as the  
test vehicle undergoes the procedures subsequently described to  
determine conformity with the standards set forth. The full three-  
diurnal sequence depicted in Figure 1 of 40 CFR 1066.801 tests vehicles  
for all sources of evaporative emissions. The supplemental two-diurnal  
test sequence is designed to verify that vehicles sufficiently purge  
their evaporative canisters during the exhaust emission test. Sections  
86.132-96, 86.133-96, and 86.138-96 describe the separate  
specifications of the supplemental two-diurnal test sequence.  
    (2) Gaseous-fueled vehicles. The test sequence shown in Figure 1 of  
40 CFR 1066.801 shows the steps encountered as the test vehicle  
undergoes the procedures subsequently described to determine conformity  
with the standards set forth, with the exception that the fuel drain  
and fill and precondition canister steps are not required for gaseous-  
fueled vehicles. In addition, the supplemental two-diurnal test and the  
running loss test are not required.  
* * * * *  
0 
54. Section 86.213 is amended by revising paragraph (a)(2) to read as  
follows:  
Sec.  86.213  Fuel specifications.
    (a) * * *  
    (2) You may use the test fuel specified in this paragraph (a)(2)  
for vehicles that are not yet subject to exhaust testing with an  
ethanol-blend test fuel under Sec.  86.113. Manufacturers may certify  
based on this fuel using carryover data until testing with the ethanol-  
blend test fuel is required. The following specifications apply for  
gasoline test fuel without ethanol:  
        Table 1 of Sec.   86.213--Cold Temperature Test Fuel Specifications for Gasoline Without Ethanol  
----------------------------------------------------------------------------------------------------------------  
                                                                                           Reference procedure 1  
                Item                          Regular                    Premium  
----------------------------------------------------------------------------------------------------------------  
(RON+MON)/2 2......................  87.8 0.3......  92.3 0.5.....  ASTM D2699  
                                                                                          ASTM D2700  
Sensitivity 3......................  7.5......................  7.5.....................  ASTM D2699  
                                                                                          ASTM D2700  
Distillation Range ([deg]F):  
    Evaporated initial boiling       76-96....................  76-96...................  ASTM D86  
     point.  
    10% evaporated.................  98-118...................  105-125.................  
    50% evaporated.................  179-214..................  195-225.................  
    90% evaporated.................  316-346..................  316-346.................  
    Evaporated final boiling point.  413 Maximum..............  413 Maximum.............  
Total Aromatic Hydrocarbon (vol %).  26.4 4.0......  32.0 4.0.....  ASTM D1319 or ASTM  
                                                                                           D5769  
Olefins (vol %) 4..................  12.5 5.0......  10.5 5.0.....  ASTM D1319 or ASTM  
                                                                                           D6550  
Lead, g/gallon.....................  0.01, Maximum............  0.01, Maximum...........  ASTM D3237  
Phosphorous, g/gallon..............  0.005 Maximum............  0.005 Maximum...........  ASTM D3231  
Total sulfur, wt. % 3..............  0.0015-0.008.............  0.0015-0.008............  ASTM D2622  
RVP, psi...........................  11.5 0.3......  11.5 0.3.....  ASTM D5191  
----------------------------------------------------------------------------------------------------------------  
1 Incorporated by reference, see Sec.   86.1.  
2 Octane specifications are optional for manufacturer testing. The premium fuel specifications apply for  
  vehicles designed to use high-octane premium fuel.  
3 Sulfur concentration will not exceed 0.0045 weight percent for EPA testing.  
4 ASTM D6550 prescribes measurement of olefin concentration in mass %. Multiply this result by 0.857 and round  
  to the first decimal place to determine the olefin concentration in volume %.  
* * * * *  
Sec.  86.401-97  [Removed]  
0 
55. Remove Sec.  86.401-97.  
0 
56. Amend Sec.  86.408-78 by adding paragraphs (c) and (d) to read as  
follows:  
Sec.  86.408-78  General standards; increase in emissions; unsafe  
conditions.  
* * * * *  
    (c) If a new motorcycle is designed to require manual adjustment to  
compensate for changing altitude, the manufacturer must include the  
appropriate instructions in the application for certification. EPA will  
review the instructions to ensure that properly adjusted motorcycles  
will meet emission standards at both low altitude and high altitude.  
    (d) An action to install parts, modify engines, or perform other  
adjustments to compensate for changing altitude is not prohibited under  
42 U.S.C. 7522 as long as it is done consistent with the manufacturer's  
instructions.  
Sec.  86.413-78  [Removed]  
0 
57. Remove Sec.  86.413-78.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 77/2680 
58. Amend Sec.  86.419-2006 by revising paragraph (b) introductory text  
to read as follows:  
Sec.  86.419-2006  Engine displacement, motorcycle classes.  
* * * * *  
    (b) Motorcycles will be divided into classes and subclasses based  
on engine displacement.  
* * * * *  
0 
59. Amend Sec.  86.427-78 by revising paragraph (a)(1) to read as  
follows:  
[[Page 34367]]  
Sec.  86.427-78  Emission tests.  
    (a)(1) Each test vehicle shall be driven with all emission control  
systems installed and operating for the following total test distances,  
or for such lesser distances as the Administrator may agree to as  
meeting the objectives of this procedure. (See Sec.  86.419 for class  
explanation.)  
                     Table 1 to Sec.   86.427-78--Test Specifications by Displacement Class  
----------------------------------------------------------------------------------------------------------------  
                                                             Total test        Minimum test  
                   Displacement class                         distance           distance      Minimum number of  
                                                            (kilometers)       (kilometers)          tests  
----------------------------------------------------------------------------------------------------------------  
I-A....................................................              6,000              2,500                  4  
I-B....................................................              6,000              2,500                  4  
II.....................................................              9,000              2,500                  4  
III....................................................             15,000              3,500                  4  
----------------------------------------------------------------------------------------------------------------  
* * * * *  
0 
60. Amend Sec.  86.435-78 by revising paragraph (b)(1) to read as  
follows:  
Sec.  86.435-78  Extrapolated emission values.  
* * * * *  
    (b) * * *  
    (1) If the useful life emissions are at or below the standards,  
certification will be granted.  
* * * * *  
0 
61. Amend Sec.  86.436-78 by revising paragraph (d) to read as follows:  
Sec.  86.436-78  Additional service accumulation.  
* * * * *  
    (d) To qualify for certification:  
    (1) The full life emission test results must be at or below the  
standards in this subpart; and  
    (2) The deterioration line must be below the standard at the  
minimum test distance and the useful life, or all points used to  
generate the line, must be at or below the standard.  
* * * * *  
0 
62. Amend Sec.  86.513 by revising paragraph (a)(1) and adding  
paragraph (a)(3) to read as follows:  
Sec.  86.513  Fuel and engine lubricant specifications.  
    (a) * * *  
    (1) Use gasoline meeting the following specifications for exhaust  
and evaporative emission testing:  
       Table 1 of Sec.   86.513--Gasoline Test Fuel Specifications  
------------------------------------------------------------------------  
            Item                        Value              Procedure 1  
------------------------------------------------------------------------  
Distillation Range:  
    1. Initial boiling        23.9-35.0 2.............  ASTM D86  
     point, [deg]C.  
    2. 10% point, [deg]C....  48.9-57.2...............  
    3. 50% point, [deg]C....  93.3-110.0..............  
    4. 90% point, [deg]C....  148.9-162.8.............  
    5. End point, [deg]C....  212.8 maximum...........  
Total aromatic hydrocarbon,   35 maximum..............  ASTM D1319 or  
 volume %.                                               ASTM D5769  
Olefins, volume % 3.........  10 maximum..............  ASTM D1319 or  
                                                         ASTM D6550  
Lead (organic), g/liter.....  0.013 maximum...........  ASTM D3237  
Phosphorous, g/liter........  0.0013 maximum..........  ASTM D3231  
Sulfur, weight %............  0.008 maximum...........  ASTM D2622  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 78/268Dry Vapor Pressure            55.2 to 63.4 4..........  ASTM D5191  
 Equivalent (DVPE), kPa.  
------------------------------------------------------------------------  
1 Incorporated by reference, see Sec.   86.1.  
2 For testing at altitudes above 1,219 m, the specified initial boiling  
  point range is (23.9 to 40.6) [deg]C.  
3 ASTM D6550 prescribes measurement of olefin concentration in mass %.  
  Multiply this result by 0.857 and round to the first decimal place to  
  determine the olefin concentration in volume %.  
4 For testing at altitudes above 1,219 m, the specified volatility range  
  is 52 to 55 kPa. Calculate dry vapor pressure equivalent, DVPE, based  
  on the measured total vapor pressure, pT, using the following  
  equation: DVPE (kPa) = 0.956 [middot] pT-2.39 (or DVPE (psi) = 0.956  
  [middot] pT-0.347). DVPE is intended to be equivalent to Reid Vapor  
  Pressure using a different test method.  
* * * * *  
    (3) Manufacturers may alternatively use ethanol-blended gasoline  
meeting the specifications described in 40 CFR 1065.710(b) for general  
testing without our advance approval. Manufacturers using the ethanol-  
blended fuel for certifying a given engine family may also use it for  
any testing for that engine family under this part. If manufacturers  
use the ethanol-blended fuel for certifying a given engine family, EPA  
may use the ethanol-blended fuel or the neat gasoline test fuel  
specified in this section for that engine family. Manufacturers may  
also request to use fuels meeting alternate specifications as described  
in 40 CFR 1065.701(b).  
* * * * *  
0 
63. Revise Sec.  86.531-78 to read as follows:  
Sec.  86.531-78  Vehicle preparation.  
    (a) The manufacturer shall provide additional fittings and  
adapters, as required by the Administrator, to accommodate a fuel drain  
at the lowest point possible in the tank(s) as installed on the  
vehicle, and to provide for exhaust sample collection.  
    (b) Connect the motorcycle's exhaust system to the analyzer for all  
exhaust emission measurements. Seal all known leaks in the exhaust  
system. Make sure any remaining leaks do not affect the demonstration  
that the motorcycle complies with standards in subpart E of this part.  
0 
64. Revise Sec.  86.1362 to read as follows:  
Sec.  86.1362  Steady-state testing with a ramped-modal cycle.  
    (a) This section describes how to test engines under steady-state  
conditions. Perform ramped-modal testing as described in 40 CFR  
1036.505 and 40 CFR part 1065, except as specified in this section.  
[[Page 34368]]  
    (b) Measure emissions by testing the engine on a dynamometer with  
the following ramped-modal duty cycle to determine whether it meets the  
applicable steady-state emission standards in this part and 40 CFR part  
1036: 
[[Page 34369]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.009  
[[Page 34370]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.010  
BILLING CODE 6560-50-C  
[[Page 34371]]  
Subpart P--[Removed and Reserved]  
0 
65. Remove and reserve subpart P.  
Subpart Q--[Removed and Reserved]  
0 
66. Remove and reserve subpart Q.  
0 
67. Amend Sec.  86.1803-01 by revising the definitions for ``Heavy-duty  
vehicle'' and ``Light-duty truck'' to read as follows:  
Sec.  86.1803-01  Definitions.  
* * * * *  
    Heavy-duty vehicle means any complete or incomplete motor vehicle  
rated at more than 8,500 pounds GVWR. Heavy-duty vehicle also includes  
incomplete vehicles that have a curb weight above 6,000 pounds or a  
basic vehicle frontal area greater than 45 square feet. Note that MDPVs  
are heavy-duty vehicles that are in many cases subject to requirements  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 79/268that apply for light-duty trucks.  
* * * * *  
    Light-duty truck means any motor vehicle that is not a heavy-duty  
vehicle, but is:  
    (1) Designed primarily for purposes of transportation of property  
or is a derivation of such a vehicle; or  
    (2) Designed primarily for transportation of persons and has a  
capacity of more than 12 persons; or  
    (3) Available with special features enabling off-street or off-  
highway operation and use.  
* * * * *  
0 
68. Amend Sec.  86.1811-17 by revising paragraph (b)(8)(iii)(C) to read  
as follows:  
Sec.  86.1811-17  Exhaust emission standards for light-duty vehicles,  
light-duty trucks and medium-duty passenger vehicles.  
* * * * *  
    (b) * * *  
    (8) * * *  
    (iii) * * *  
    (C) Vehicles must comply with the Tier 2 SFTP emission standards  
for NMHC + NO X and CO for 4,000-mile testing that are  
specified in Sec.  86.1811-04(f)(1) if they are certified to  
transitional Bin 85 or Bin 110 standards, or if they are certified  
based on a fuel without ethanol, or if they are not certified to the  
Tier 3 p.m. standard. Note that the standards in this paragraph  
(b)(8)(iii)(C) apply under this section for alternative fueled  
vehicles, for flexible fueled vehicles when operated on a fuel other  
than gasoline or diesel fuel, and for MDPVs, even though these vehicles  
were not subject to the SFTP standards in the Tier 2 program.  
* * * * *  
0 
69. Amend Sec.  86.1813-17 by revising the introductory text and  
paragraph (a)(2)(i) introductory text to read as follows:  
Sec.  86.1813-17  Evaporative and refueling emission standards.  
    Vehicles must meet evaporative and refueling emission standards as  
specified in this section. These emission standards apply for heavy  
duty vehicles above 14,000 pounds GVWR as specified in Sec.  86.1801.  
These emission standards apply for total hydrocarbon equivalent (THCE)  
measurements using the test procedures specified in subpart B of this  
part, as appropriate. Note that Sec.  86.1829 allows you to certify  
without testing in certain circumstances. These evaporative and  
refueling emission standards do not apply for electric vehicles, fuel  
cell vehicles, or diesel-fueled vehicles, except as specified in  
paragraph (b) of this section. Unless otherwise specified, MDPVs are  
subject to all the same provisions of this section that apply to LDT4.  
    (a) * * *  
    (2) * * *  
    (i) The emission standard for the sum of diurnal and hot soak  
measurements from the two-diurnal test sequence and the three-diurnal  
test sequence is based on a fleet average in a given model year. You  
must specify a family emission limit (FEL) for each evaporative family.  
The FEL serves as the emission standard for the evaporative family with  
respect to all required diurnal and hot soak testing. Calculate your  
fleet-average emission level as described in Sec.  86.1860 based on the  
FEL that applies for low-altitude testing to show that you meet the  
specified standard. For multi-fueled vehicles, calculate fleet-average  
emission levels based only on emission levels for testing with  
gasoline. You may generate emission credits for banking and trading and  
you may use banked or traded credits for demonstrating compliance with  
the diurnal plus hot soak emission standard for vehicles required to  
meet the Tier 3 standards, other than gaseous-fueled vehicles, as  
described in Sec.  86.1861 starting in model year 2017. You comply with  
the emission standard for a given model year if you have enough credits  
to show that your fleet-average emission level is at or below the  
applicable standard. You may exchange credits between or among  
evaporative families within an averaging set as described in Sec.   
86.1861. Separate diurnal plus hot soak emission standards apply for  
each evaporative/refueling emission family as shown for high-altitude  
conditions. The sum of diurnal and hot soak measurements may not exceed  
the following Tier 3 standards:  
* * * * *  
0 
70. Amend Sec.  86.1817-05 by revising paragraph (a)(1) to read as  
follows:  
Sec.  86.1817-05  Complete heavy-duty vehicle averaging, trading, and  
banking program.  
    (a) * * *  
    (1) Complete heavy-duty vehicles eligible for the NO X  
averaging, trading, and banking program are described in the applicable  
emission standards section of this subpart. Participation in this  
averaging, trading, and banking program is voluntary.  
* * * * *  
0 
71. Amend Sec.  86.1818-12 by revising paragraph (d) to read as  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 80/268follows:  
Sec.  86.1818-12  Greenhouse gas emission standards for light-duty  
vehicles, light-duty trucks, and medium-duty passenger vehicles.  
* * * * *  
    (d) In-use CO 2 exhaust emission standards. The in-use  
CO2 exhaust emission standard shall be the combined city/  
highway carbon-related exhaust emission value calculated for the  
appropriate vehicle carline/subconfiguration according to the  
provisions of Sec.  600.113-12(g)(4) of this chapter adjusted by the  
deterioration factor from Sec.  86.1823-08(m). Multiply the result by  
1.1 and round to the nearest whole gram per mile. For in-use vehicle  
carlines/subconfigurations for which a combined city/highway carbon-  
related exhaust emission value was not determined under Sec.  600.113-  
12(g)(4) of this chapter, the in-use CO 2 exhaust emission  
standard shall be the combined city/highway carbon-related exhaust  
emission value calculated according to the provisions of Sec.  600.208  
of this chapter for the vehicle model type (except that total model  
year production data shall be used instead of sales projections)  
adjusted by the deterioration factor from Sec.  86.1823-08(m). Multiply  
the result by 1.1 and round to the nearest whole gram per mile. For  
vehicles that are capable of operating on multiple fuels, except plug-  
in hybrid electric vehicles, a separate in-use standard shall be  
determined for each fuel that the vehicle is capable of operating on.  
The standards in this paragraph (d) apply to in-use testing performed  
by the manufacturer pursuant to regulations at Sec. Sec.  86.1845 and  
86.1846 and to in-use testing performed by EPA.  
* * * * *  
0 
72. Amend Sec.  86.1838-01 by revising paragraph (c)(2)(iii) to read as  
follows:  
[[Page 34372]]  
Sec.  86.1838-01  Small-volume manufacturer certification procedures.  
* * * * *  
    (c) * * *  
    (2) * * *  
    (iii) The provisions of Sec.  86.1845-04(c)(2) that require one  
vehicle of each test group during high mileage in-use verification  
testing to have a minimum odometer mileage of 75 percent of the full  
useful life mileage do not apply.  
* * * * *  
0 
73. Amend Sec.  86.1868-12 by revising paragraph (g) introductory text  
and adding paragraph (g)(5) to read as follows:  
Sec.  86.1868-12  CO2 credits for improving the efficiency of air  
conditioning systems.  
* * * * *  
    (g) AC17 validation testing and reporting requirements. For 2020  
and later model years, manufacturers must validate air conditioning  
credits by using the AC17 Test Procedure in 40 CFR 1066.845 as follows:  
* * * * *  
    (5) AC17 testing requirements apply as follows for electric  
vehicles and plug-in hybrid electric vehicles:  
    (i) Manufacturers may omit AC17 testing for electric vehicles.  
Electric vehicles may qualify for air conditioning efficiency credits  
based on identified technologies, without testing. The application for  
certification must include a detailed description of the vehicle's air  
conditioning system and identify any technology items eligible for air  
conditioning efficiency credits. Include additional supporting  
information to justify the air conditioning credit for each technology.  
    (ii) The provisions of paragraph (g)(5)(i) of this section also  
apply for plug-in hybrid electric vehicles if they have an all electric  
range of at least 60 miles (combined city and highway) after adjustment  
to reflect actual in-use driving conditions (see 40 CFR 600.311(j)),  
and they do not rely on the engine to cool the vehicle's cabin for the  
ambient and driving conditions represented by the AC17 test.  
    (iii) If AC17 testing is required for plug-in hybrid electric  
vehicles, perform this testing in charge-sustaining mode.  
* * * * *  
0 
74. Part 88 is revised to read as follows:  
PART 88--CLEAN-FUEL VEHICLES  
Sec. 
88.1 General applicability.  
88.2 through 88.3 [Reserved]  
    Authority:  42 U.S.C. 7410, 7418, 7581, 7582, 7583, 7584, 7586,  
7588, 7589, 7601(a).  
Sec.  88.1  General applicability.
    (a) The Clean Air Act includes provisions intended to promote the  
development and sale of clean-fuel vehicles (see 42 U.S.C. 7581-7589).  
This takes the form of credit incentives for State Implementation  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 81/268Plans. The specified clean-fuel vehicle standards to qualify for these  
credits are now uniformly less stringent than the emission standards  
that apply for new vehicles and new engines under 40 CFR parts 86 and  
1036. 
    (b) The following provisions apply for purposes of State  
Implementation Plans that continue to reference the Clean Fuel Fleet  
Program:  
    (1) Vehicles and engines certified to current emission standards  
under 40 CFR part 86 or 1036 are deemed to also meet the Clean Fuel  
Fleet standards as Ultra Low-Emission Vehicles.  
    (2) Vehicles and engines meeting requirements as specified in  
paragraph (a)(1) of this section with a fuel system designed to not  
vent fuel vapors to the atmosphere are also deemed to meet the Clean  
Fuel Fleet standards as Inherently Low-Emission Vehicles. This  
paragraph (b)(2) applies for vehicles using diesel fuel, liquefied  
petroleum gas, or compressed natural gas. It does not apply for  
vehicles using gasoline, ethanol, methanol, or liquefied natural gas.  
    (3) The following types of vehicles qualify as Zero Emission  
Vehicles:  
    (i) Electric vehicles (see 40 CFR 86.1803-01).  
    (ii) Any other vehicle with a fuel that contains no carbon or  
nitrogen compounds, that has no evaporative emissions, and that burns  
without forming oxides of nitrogen, carbon monoxide, formaldehyde,  
particulate matter, or hydrocarbon compounds. This paragraph (b)(3)(i)  
applies equally for all engines installed on the vehicle.  
Sec.  Sec.  88.2 through 88.3   [Reserved]  
0 
75. Part 89 is revised to read as follows:  
PART 89--CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD  
COMPRESSION-IGNITION ENGINES  
Sec. 
89.1 Applicability.  
89.2 through 89.3 [Reserved]  
    Authority:  42 U.S.C. 7401-7671q.  
Sec.  89.1  Applicability.  
    The Environmental Protection Agency adopted emission standards for  
model year 1996 and later nonroad compression-ignition engines under  
this part. EPA has migrated regulatory requirements for these engines  
to 40 CFR part 1039, with additional testing and compliance provisions  
in 40 CFR parts 1065 and 1068. The Tier 1, Tier 2, and Tier 3 standards  
originally adopted in this part are identified in 40 CFR part 1039,  
appendix I. See 40 CFR 1039.1 for information regarding the timing of  
the transition to 40 CFR part 1039, and for information regarding  
regulations that continue to apply for engines that manufacturers  
originally certified or otherwise produced under this part.  
Sec.  Sec.  89.2 through 89.3   [Reserved]  
0 
76. Part 90 is revised to read as follows:  
PART 90--CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES  
AT OR BELOW 19 KILOWATTS  
Sec. 
90.1 Applicability.  
90.2 through 90.3 [Reserved]  
    Authority:  42 U.S.C. 7401-7671q.  
Sec.  90.1  Applicability.  
    The Environmental Protection Agency adopted emission standards for  
model year 1997 and later nonroad spark-ignition engines below 19 kW  
under this part. EPA has migrated regulatory requirements for these  
engines to 40 CFR part 1054, with additional testing and compliance  
provisions in 40 CFR parts 1065 and 1068. The Phase 1 and Phase 2  
standards originally adopted in this part are identified in 40 CFR part  
1054, appendix I. See 40 CFR 1054.1 for information regarding the  
timing of the transition to 40 CFR part 1054, and for information  
regarding regulations that continue to apply for engines that  
manufacturers originally certified or otherwise produced under this  
part. 
Sec.  Sec.  90.2 through 90.3  [Reserved]  
0 
77. Part 91 is revised to read as follows:  
PART 91--CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES  
Sec. 
91.1 Applicability.  
91.2 through 91.3 [Reserved]  
    Authority:  42 U.S.C. 7401-7671q.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 82/268Sec.  91.1  Applicability.  
    The Environmental Protection Agency adopted emission standards for  
model year 1998 and later marine spark-ignition engines under this  
part, except that the standards of this part did not apply to  
sterndrive/inboard engines. EPA has migrated regulatory requirements  
for these engines to 40 CFR part 1045, with additional testing  
[[Page 34373]]  
and compliance provisions in 40 CFR parts 1065 and 1068. The standards  
originally adopted in this part are identified in 40 CFR part 1045,  
appendix I. See 40 CFR 1045.1 for information regarding the timing of  
the transition to 40 CFR part 1045, and for information regarding  
regulations that continue to apply for engines that manufacturers  
originally certified or otherwise produced under this part.  
Sec.  Sec.  91.2 through 91.3  [Reserved]  
0 
78. Part 92 is revised to read as follows:  
PART 92--CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE  
ENGINES 
Sec. 
92.1 Applicability.  
92.2 through 92.3 [Reserved]  
    Authority:  42 U.S.C. 7401-7671q.  
Sec.  92.1  Applicability.  
    The Environmental Protection Agency first adopted emission  
standards for freshly manufactured and remanufactured locomotives under  
this part in 1998. EPA has migrated regulatory requirements for these  
engines to 40 CFR part 1033, with additional testing and compliance  
provisions in 40 CFR parts 1065 and 1068. The Tier 0, Tier 1, and Tier  
2 standards originally adopted in this part are identified in 40 CFR  
part 1033, appendix I. See 40 CFR 1033.1 for information regarding the  
timing of the transition to 40 CFR part 1033, and for information  
regarding regulations that continue to apply for engines that  
manufacturers originally certified or otherwise produced or  
remanufactured under this part. Emission standards started to apply for  
locomotive and locomotive engines if they were--  
    (a) Manufactured on or after January 1, 2000;  
    (b) Manufactured on or after January 1, 1973 and remanufactured on  
or after January 1, 2000; or  
    (c) Manufactured before January 1, 1973 and upgraded on or after  
January 1, 2000.  
Sec.  Sec.  92.2 through 92.3  [Reserved]  
0 
79. Part 94 is revised to read as follows:  
PART 94--CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION  
ENGINES 
Sec. 
94.1 Applicability.  
94.2 through 94.3 [Reserved]  
    Authority:  42 U.S.C. 7401-7671q.  
Sec.  94.1  Applicability.  
    The Environmental Protection Agency adopted emission standards for  
model year 2004 and later marine compression-ignition engines under  
this part. EPA has migrated regulatory requirements for these engines  
to 40 CFR part 1042, with additional testing and compliance provisions  
in 40 CFR parts 1065 and 1068. The Tier 1 and Tier 2 standards  
originally adopted in this part are identified in 40 CFR part 1042,  
appendix I. See 40 CFR 1042.1 for information regarding the timing of  
the transition to 40 CFR part 1042, and for information regarding  
regulations that continue to apply for engines that manufacturers  
originally certified or otherwise produced under this part.  
Sec.  Sec.  94.2 through 94.3  [Reserved]  
PART 1027--FEES FOR VEHICLE AND ENGINE COMPLIANCE PROGRAMS  
0 
80. The authority citation for part 1027 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
81. The heading for part 1027 is revised to read as set forth above.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 83/2680 
82. Amend Sec.  1027.101 by:  
0 
a. Revising paragraph (a); and  
0 
b. Removing and reserving paragraph (b).  
    The revision reads as follows:
Sec.  1027.101  To whom do these requirements apply?  
    (a) This part prescribes fees manufacturers must pay for activities  
related to EPA's motor vehicle and engine compliance program (MVECP).  
This includes activities related to approving certificates of  
conformity and performing tests and taking other steps to verify  
compliance with emission standards in this part. You must pay fees as  
described in this part if you are a manufacturer of any of the  
following products:  
    (1) Motor vehicles and motor vehicle engines we regulate under 40  
CFR part 86. This includes light-duty vehicles, light-duty trucks,  
medium-duty passenger vehicles, highway motorcycles, and heavy-duty  
highway engines and vehicles.  
    (2) The following nonroad engines and equipment:  
    (i) Locomotives and locomotive engines we regulate under 40 CFR  
part 1033.  
    (ii) Nonroad compression-ignition engines we regulate under 40 CFR  
part 1039.  
    (iii) Marine compression-ignition engines we regulate under 40 CFR  
part 1042 or 1043.  
    (iv) Marine spark-ignition engines and vessels we regulate under 40  
CFR part 1045 or 1060. We refer to these as Marine SI engines.  
    (v) Nonroad spark-ignition engines above 19 kW we regulate under 40  
CFR part 1048. We refer to these as Large SI engines.  
    (vi) Recreational vehicles we regulate under 40 CFR part 1051.  
    (vii) Nonroad spark-ignition engines and equipment at or below 19  
kW we regulate under 40 CFR part 1054 or 1060. We refer to these as  
Small SI engines.  
    (3) The following stationary internal combustion engines:  
    (i) Stationary compression-ignition engines we certify under 40 CFR  
part 60, subpart IIII.  
    (ii) Stationary spark-ignition engines we certify under 40 CFR part  
60, subpart JJJJ.  
    (4) Portable fuel containers we regulate under 40 CFR part 59,  
subpart F.  
* * * * *  
0 
83. Revise Sec.  1027.105 to read as follows:  
Sec.  1027.105  How much are the fees?  
    (a) Fees are determined based on the date we receive a complete  
application for certification. Each reference to a year in this subpart  
refers to the calendar year, unless otherwise specified. Paragraph (b)  
of this section specifies baseline fees that apply for certificates  
received in 2020. See paragraph (c) of this section for provisions  
describing how we calculate fees for 2021 and later years.  
    (b) The following baseline fees apply for each application for  
certification:  
    (1) Except as specified in paragraph (b)(2) of this section for  
Independent Commercial Importers, the following fees apply in 2020 for  
motor vehicles and motor vehicle engines:  
------------------------------------------------------------------------  
            Category 1                Certificate type          Fee  
------------------------------------------------------------------------  
(i) Light-duty vehicles, light-     Federal.............         $27,347  
 duty trucks, medium-duty  
 passenger vehicle, and complete  
 heavy-duty highway vehicles.  
[[Page 34374]]  
  
(ii) Light-duty vehicles, light-    California-only.....          14,700  
 duty trucks, medium-duty  
 passenger vehicle, and complete  
 heavy-duty highway vehicles.  
(iii) Heavy-duty highway engine...  Federal.............          56,299  
(iv) Heavy-duty highway engine....  California-only.....             563  
(v) Heavy-duty vehicle............  Evap................             563  
(vi) Highway motorcycle, including  All.................           1,852  
 Independent Commercial Importers.
------------------------------------------------------------------------  
\1\ The specified categories include engines and vehicles that use all  
  applicable fuels.  
    (2) A fee of $87,860 applies in 2020 for Independent Commercial  
Importers with respect to the following motor vehicles:  
    (i) Light-duty vehicles and light-duty trucks.  
    (ii) Medium-duty passenger vehicles.  
    (iii) Complete heavy-duty highway vehicles.  
    (3) The following fees apply in 2020 for nonroad and stationary  
engines, vehicles, equipment, and components:  
------------------------------------------------------------------------  
            Category 1                Certificate type          Fee  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 84/268------------------------------------------------------------------------  
(i) Locomotives and locomotive      All.................            $563  
 engines.  
(ii) Marine compression-ignition    All, including EIAPP             563  
 engines and stationary  
 compression-ignition engines with
 per-cylinder displacement at or  
 above 10 liters.  
(iii) Other nonroad compression-    All.................           2,940  
 ignition engines and stationary  
 compression-ignition engines with
 per-cylinder displacement below  
 10 liters.  
(iv) Large SI engines and           All.................             563  
 stationary spark-ignition engines
 above 19 kW.  
(v) Marine SI engines. Small SI     Exhaust only........             563  
 engines, and stationary spark-  
 ignition engines at or below 19  
 kW. 
(vi) Recreational vehicles........  Exhaust (or combined             563  
                                     exhaust and evap).  
(vii) Equipment and fuel-system     Evap (where separate             397  
 components associated with          certification is  
 nonroad and stationary spark-       required).  
 ignition engines, including  
 portable fuel containers..  
------------------------------------------------------------------------  
    (c) We will calculate adjusted fees for 2021 and later years based  
on changes in the Consumer Price Index and the number of certificates.  
We will announce adjusted fees for a given year by March 31 of the  
preceding year.  
    (1) We will adjust the values specified in paragraph (b) of this  
section for years after 2020 as follows:  
    (i) Use the following equation for certification related to  
evaporative emissions from nonroad and stationary engines when a  
separate fee applies for certification to evaporative emission  
standards:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.011  
Where: 
Certificate FeeCY = Fee per certificate for a given year.  
Op = operating costs are all of EPA's nonlabor costs for each  
category's compliance program, including any fixed costs associated  
with EPA's testing laboratory, as described in paragraph (d)(1) of  
this section.  
L = the labor costs, to be adjusted by the Consumer Price Index, as  
described in paragraph (d)(1) of this section.  
CPICY-2 = the Consumer Price Index for the month of  
November two years before the applicable calendar year, as described  
in paragraph (d)(2) of this section.  
CPI2006 = 201.8. This is based on the October 2006 value  
of the Consumer Price Index. as described in paragraph (d)(2) of  
this section  
OH = 1.169. This is based on EPA overhead, which is applied to all  
costs. 
cert#MY-2 = the total number of certificates issued for a  
fee category in the model year two years before the calendar year  
for the applicable fees as described in paragraph (d)(3) of this  
section.  
cert#MY-3 = the total number of certificates issued for a  
fee category in the model year three years before the calendar year  
for the applicable fees as described in paragraph (d)(3) of this  
section.  
    (ii) Use the following equation for all other certificates:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.012  
     
Where: 
CPI2002 = 180.9. This is based on the December 2002 value  
of the Consumer Price Index as described in paragraph (d)(2) of this  
section.  
    (2) The fee for any year will remain at the previous year's amount  
until the value calculated in paragraph (c)(1) of this section differs  
by at least $50 from the amount specified for the previous year.  
    (d) Except as specified in Sec.  1027.110(a) for motor vehicles and  
motor vehicle engines, we will use the following values to determine  
adjusted fees using the equation in paragraph (c) of this section:  
    (1) The following values apply for operating costs and labor costs:  
[[Page 34375]]  
------------------------------------------------------------------------  
       Engine or vehicle category               Op               L  
------------------------------------------------------------------------  
(i) Light-duty, medium-duty passenger,        $3,322,039      $2,548,110  
 and complete heavy-duty highway vehicle  
 certification..........................  
(ii) Light-duty, medium-duty passenger,        2,858,223       2,184,331  
 and complete heavy-duty highway vehicle  
 in-use testing.........................  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 85/268(iii) Independent Commercial Importers           344,824         264,980  
 identified in paragraph (b)(2) of this  
 section................................  
(iv) Highway motorcycles................         225,726         172,829  
(v) Heavy-duty highway engines..........       1,106,224       1,625,680  
(vi) Nonroad compression-ignition                486,401         545,160  
 engines that are not locomotive or  
 marine engines, and stationary  
 compression-ignition engines with per-  
 cylinder displacement below 10 liters..  
(vii) Evaporative certificates related             5,039         236,670  
 to nonroad and stationary engines......  
(viii) All other........................         177,425         548,081  
------------------------------------------------------------------------  
    (2) The applicable Consumer Price Index is based on the values  
published by the Bureau of Labor Statistics for All Urban Consumers at  
https://www.usinflationcalculator.com/ under ``Inflation and Prices''  
and ``Consumer Price Index Data from 1913 to. . . .''. For example, we  
calculated the 2006 fees using the Consumer Price Index for November  
2004, which is 191.0.  
    (3) Fee categories for counting the number of certificates issued  
are based on the grouping shown in paragraph (d)(1) of this section.  
0 
84. Amend Sec.  1027.110 by revising paragraph (a) introductory text to  
read as follows:  
Sec.  1027.110  What special provisions apply for certification related  
to motor vehicles?  
    (a) We will adjust fees for light-duty, medium-duty passenger, and  
complete heavy-duty highway vehicles as follows:  
* * * * *  
0 
85. Amend Sec.  1027.125 by revising paragraph (e) to read as follows:  
Sec.  1027.125  Can I get a refund?  
* * * * *  
    (e) Send refund and correction requests online at www.Pay.gov , or  
as specified in our guidance.  
* * * * *  
0 
86. Amend Sec.  1027.130 by revising paragraphs (a) and (b) to read as  
follows:  
Sec.  1027.130  How do I make a fee payment?  
    (a) Pay fees to the order of the Environmental Protection Agency in  
U.S. dollars using electronic funds transfer or any method available  
for payment online at www.Pay.gov , or as specified in EPA guidance.  
    (b) Submit a completed fee filing form at www.Pay.gov . 
* * * * *  
0 
87. Amend Sec.  1027.135 by revising paragraph (b) to read as follows:  
Sec.  1027.135  What provisions apply to a deficient filing?  
* * * * *  
    (b) We will hold a deficient filing along with any payment until we  
receive a completed form and full payment. If the filing remains  
deficient at the end of the model year, we will continue to hold any  
funds associated with the filing so you can make a timely request for a  
refund. We will not process an application for certification if the  
associated filing is deficient.  
0 
88. Revise Sec.  1027.155 to read as follows:  
Sec.  1027.155  What abbreviations apply to this subpart?  
    The following symbols, acronyms, and abbreviations apply to this  
part: 
                       Table 1 to Sec.   1027.155  
------------------------------------------------------------------------  
  
------------------------------------------------------------------------  
CFR..............................  Code of Federal Regulations.  
CPI..............................  Consumer Price Index.  
EPA..............................  U.S. Environmental Protection Agency.  
Evap.............................  Evaporative emissions.  
EIAPP............................  Engine International Air Pollution  
                                    Prevention (from MARPOL Annex VI).  
ICI..............................  Independent Commercial Importer.  
MVECP............................  Motor vehicle and engine compliance  
                                    program.  
MY...............................  Model year.  
U.S..............................  United States.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 86/268------------------------------------------------------------------------  
PART 1033--CONTROL OF EMISSIONS FROM LOCOMOTIVES  
0 
89. The authority citation for part 1033 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
90. Amend Sec.  1033.150 by:  
0 
a. Removing and reserving paragraphs (a) and (d).  
0 
b. Revising paragraph (e) introductory text.  
0 
c. Removing and reserving paragraphs (h) through (j).  
0 
d. Removing paragraphs (l) and (m).  
    The revision reads as follows:
Sec.  1033.150  Interim provisions.  
* * * * *  
    (e) Producing switch locomotives using certified nonroad engines.  
You may use the provisions of this paragraph (e) to produce any number  
of freshly manufactured or refurbished switch locomotives in model  
years 2008 through 2017. Locomotives produced under this paragraph (e)  
are exempt from the standards and requirements of this part subject to  
the following provisions:  
* * * * *  
0 
91. Revise Sec.  1033.255 to read as follows:  
Sec.  1033.255  EPA decisions.  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Clean Air  
Act, we will issue a certificate of conformity for the engine family  
for that model year. We may make the approval subject to additional  
conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce locomotives for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all locomotives being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Clean Air Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Act. Note that these are also violations of 40 CFR  
1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
[[Page 34376]]  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1033.920).  
0 
92. Amend Sec.  1033.601 by revising paragraphs (c)(4) and (5) to read  
as follows:  
Sec.  1033.601  General compliance provisions.  
* * * * *  
    (c) * * *  
    (4) The provisions for importing engines and equipment under the  
identical configuration exemption of 40 CFR 1068.315(h) do not apply  
for locomotives.  
    (5) The provisions for importing engines and equipment under the  
ancient engine exemption of 40 CFR 1068.315(i) do not apply for  
locomotives.  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 87/2680 
93. Amend Sec.  1033.701 by revising paragraph (k)(1) to read as  
follows:  
Sec.  1033.701  General provisions.  
* * * * *  
    (k) * * *  
    (1) You may retire emission credits generated from any number of  
your locomotives. This may be considered donating emission credits to  
the environment. Identify any such credits in the reports described in  
Sec.  1033.730. Locomotives must comply with the applicable FELs even  
if you donate or sell the corresponding emission credits under this  
paragraph (k). Those credits may no longer be used by anyone to  
demonstrate compliance with any EPA emission standards.  
* * * * *  
0 
94. Amend Sec.  1033.740 by revising the introductory text and  
paragraph (a) to read as follows:  
Sec.  1033.740  Credit restrictions.  
    Use of emission credits generated under this part is restricted  
depending on the standards against which they were generated.  
    (a) Pre-2008 credits. NO X and PM credits generated  
before model year 2008 may be used under this part in the same manner  
as NOX and PM credits generated under this part.  
* * * * *  
0 
95. Amend Sec.  1033.901 by revising paragraph (1) of the definition of  
``New'' to read as follows:  
Sec.  1033.901  Definitions.  
* * * * *  
    New, * * *  
    (1) A locomotive or engine is new if its equitable or legal title  
has never been transferred to an ultimate purchaser. Where the  
equitable or legal title to a locomotive or engine is not transferred  
prior to its being placed into service, the locomotive or engine ceases  
to be new when it is placed into service. A locomotive or engine also  
becomes new if it is remanufactured or refurbished (as defined in this  
section). A remanufactured locomotive or engine ceases to be new when  
placed back into service. With respect to imported locomotives or  
locomotive engines, the term ``new locomotive'' or ``new locomotive  
engine'' also means a locomotive or locomotive engine that is not  
covered by a certificate of conformity under this part or 40 CFR part  
92 at the time of importation, and that was manufactured or  
remanufactured after January 1, 2000, which would have been applicable  
to such locomotive or engine had it been manufactured or remanufactured  
for importation into the United States. Note that replacing an engine  
in one locomotive with an unremanufactured used engine from a different  
locomotive does not make a locomotive new.  
* * * * *  
0 
96. Amend Sec.  1033.925 by revising paragraph (e) introductory text to  
read as follows:  
Sec.  1033.925  Reporting and recordkeeping requirements.  
* * * * *  
    (e) Under the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the  
Office of Management and Budget approves the reporting and  
recordkeeping specified in the applicable regulations in this chapter.  
The following items illustrate the kind of reporting and recordkeeping  
we require for locomotives regulated under this part:  
* * * * *  
PART 1036--CONTROL OF EMISSIONS FROM NEW AND IN-USE HEAVY-DUTY  
HIGHWAY ENGINES  
0 
97. The authority citation for part 1036 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
98. Amend Sec.  1036.1 by adding paragraph (b)(3) to read as follows:  
Sec.  1036.1  Does this part apply for my engines?  
* * * * *  
    (b) * * *  
    (3) The provisions of Sec.  1036.501(h)(1) apply.  
* * * * *  
0 
99. Amend Sec.  1036.108 by revising paragraph (a) to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 88/268Sec.  1036.108  Greenhouse gas emission standards.  
* * * * *  
    (a) Emission standards. The emission standards in this paragraph  
(a) apply for engines and optionally powertrains measured using the  
test procedures specified in subpart F of this part as follows:  
    (1) CO 2 emission standards in this paragraph (a)(1)  
apply based on testing as specified in subpart F of this part. The  
applicable test cycle for measuring CO 2 emissions differs  
depending on the engine family's primary intended service class and the  
extent to which the engines will be (or were designed to be) used in  
tractors. For medium and heavy heavy-duty engines certified as tractor  
engines, measure CO 2 emissions using the steady-state duty  
cycle specified in Sec.  1036.501 (referred to as the Supplemental  
Emission Test, or SET, even though emission sampling involves  
measurements from discrete modes). This testing with the SET duty cycle  
is intended for engines designed to be used primarily in tractors and  
other line-haul applications. Note that the use of some SET-certified  
tractor engines in vocational applications does not affect your  
certification obligation under this paragraph (a)(1); see other  
provisions of this part and 40 CFR part 1037 for limits on using  
engines certified to only one cycle. For medium and heavy heavy-duty  
engines certified as both tractor and vocational engines, measure  
CO2 emissions using the steady-state duty cycle and the  
transient duty cycle (sometimes referred to as the Federal Test  
Procedure (FTP) engine cycle) specified in Sec.  1036.501. Testing with  
both SET and FTP duty cycles is intended for engines that are designed  
for use in both tractor and vocational applications. For all other  
engines (including engines meeting spark-ignition standards), measure  
CO2 emissions using the appropriate transient duty cycle  
specified in Sec.  1036.501.  
    (i) The CO 2 standard is 627 g/hp[middot]hr for all  
spark-ignition engines for model years 2016 through 2020. This standard  
continues to apply in later model years for all spark-ignition engines  
that are not heavy heavy-duty engines.  
    (ii) The following CO 2 standards apply for compression-  
ignition engines (in g/hp[middot]hr):  
[[Page 34377]]  
               Table 1 of Sec.   1036.108--Compression-Ignition Engine Standards for MY 2014-2020  
----------------------------------------------------------------------------------------------------------------  
                                                  Medium  heavy-   Heavy  heavy-  
           Model years             Light  heavy-       duty-           duty-      Medium  heavy-   Heavy  heavy-  
                                       duty         vocational      vocational     duty- tractor   duty- tractor  
----------------------------------------------------------------------------------------------------------------  
2014-2016.......................             600             600             567             502             475  
2017-2020.......................             576             576             555             487             460  
----------------------------------------------------------------------------------------------------------------  
    (iii) The following CO 2 standards apply for compression-  
ignition engines and all heavy heavy-duty engines (in g/hp[middot]hr):  
             Table 2 of Sec.   1036.108--Compression-Ignition Engine Standards for MY 2021 and Later  
----------------------------------------------------------------------------------------------------------------  
                                                  Medium  heavy-   Heavy  heavy-  
           Model years             Light  heavy-       duty-           duty-      Medium  heavy-   Heavy  heavy-  
                                       duty         vocational      vocational     duty- tractor   duty- tractor  
----------------------------------------------------------------------------------------------------------------  
2021-2023.......................             563             545             513             473             447  
2024-2026.......................             555             538             506             461             436  
2027 and later..................             552             535             503             457             432  
----------------------------------------------------------------------------------------------------------------  
    (iv) You may certify spark-ignition engines to the compression-  
ignition standards for the appropriate model year under this paragraph  
(a). If you do this, those engines are treated as compression-ignition  
engines for all the provisions of this part.  
    (2) The CH4 emission standard is 0.10 g/hp[middot]hr when measured  
over the applicable transient duty cycle specified in 40 CFR part 86,  
subpart N. This standard begins in model year 2014 for compression-  
ignition engines and in model year 2016 for spark-ignition engines.  
Note that this standard applies for all fuel types just like the other  
standards of this section.  
    (3) The N 2O emission standard is 0.10 g/hp[middot]hr  
when measured over the transient duty cycle specified in 40 CFR part  
86, subpart N. This standard begins in model year 2014 for compression-  
ignition engines and in model year 2016 for spark-ignition engines.  
* * * * *  
0 
100. Amend Sec.  1036.150 by revising paragraphs (e), (g), and (p)(2)  
and adding paragraph (q) to read as follows:  
Sec.  1036.150  Interim provisions.  
* * * * *  
    (e) Alternate phase-in standards. Where a manufacturer certifies  
all of its model year 2013 compression-ignition engines within a given  
primary intended service class to the applicable alternate standards of  
this paragraph (e), its compression-ignition engines within that  
primary intended service class are subject to the standards of this  
paragraph (e) for model years 2013 through 2016. This means that once a  
manufacturer chooses to certify a primary intended service class to the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 89/268standards of this paragraph (e), it is not allowed to opt out of these  
standards. Engines certified to these standards are not eligible for  
early credits under paragraph (a) of this section.  
                            Table 1 of Sec.   1036.150--Alternate Phase-In Standards  
----------------------------------------------------------------------------------------------------------------  
          Vehicle type              Model years        LHD Engines        MHD Engines           HHD Engines  
----------------------------------------------------------------------------------------------------------------  
Tractors.......................  2013-2015........  NA...............  512 g/hphr.......  485 g/hphr.  
                                 2016 and later     NA...............  487 g/hphr.......  460 g/hphr.  
                                  \1\.  
Vocational.....................  2013-2015........  618 g/hphr.......  618 g/hphr.......  577 g/hphr.  
                                 2016 through       576 g/hphr.......  576 g/hphr.......  555 g/hphr.  
                                  20201.  
----------------------------------------------------------------------------------------------------------------  
\1\ These alternate standards for 2016 and later are the same as the otherwise applicable standards for 2017  
  through 2020.  
* * * * *  
    (g) Assigned deterioration factors. You may use assigned  
deterioration factors (DFs) without performing your own durability  
emission tests or engineering analysis as follows:  
    (1) You may use an assigned additive DF of 0.0 g/hp-hr for  
CO2 emissions from engines that do not use advanced or off-  
cycle technologies. If we determine it to be consistent with good  
engineering judgment, we may allow you to use an assigned additive DF  
of 0.0 g/hp-hr for CO 2 emissions from your engines with  
advanced or off-cycle technologies.  
    (2) You may use an assigned additive DF of 0.010 g/hphr for N2O  
emissions from any engine through model year 2021, and 0.020 g/hp-hr  
for later model years.  
    (3) You may use an assigned additive DF of 0.020 g/hp-hr for CH4  
emissions from any engine.  
* * * * *  
    (p) * * *  
    (2) You may certify your model year 2024 through 2026 engines to  
the following alternative standards:  
[[Page 34378]]  
               Table 2 of Sec.   1036.150--Alternative Standards for Model Years 2024 Through 2026  
----------------------------------------------------------------------------------------------------------------  
                                               Medium  heavy-   Heavy  heavy-  
                 Model years                       duty-            duty-        Medium  heavy-   Heavy  heavy-  
                                                 vocational       vocational     duty- tractor    duty- tractor  
----------------------------------------------------------------------------------------------------------------  
2024-2026...................................             542              510              467              442  
----------------------------------------------------------------------------------------------------------------  
    (q) Confirmatory testing of fuel maps defined in Sec.  1036.503(b).  
For model years 2021 and later, where the results from Eq. 1036.235-1  
for a confirmatory test is less than or equal to 2.0%, we will not  
replace the manufacturer's fuel maps.  
0 
101. Amend Sec.  1036.225 by revising paragraphs (e) and (f)(1) to read  
as follows:  
Sec.  1036.225  Amending my application for certification.  
* * * * *  
    (e) The amended application applies starting with the date you  
submit the amended application, as follows:  
    (1) For engine families already covered by a certificate of  
conformity, you may start producing a new or modified engine  
configuration any time after you send us your amended application and  
before we make a decision under paragraph (d) of this section. However,  
if we determine that the affected engines do not meet applicable  
requirements in this part, we will notify you to cease production of  
the engines and may require you to recall the engines at no expense to  
the owner. Choosing to produce engines under this paragraph (e) is  
deemed to be consent to recall all engines that we determine do not  
meet applicable emission standards or other requirements in this part  
and to remedy the nonconformity at no expense to the owner. If you do  
not provide information required under paragraph (c) of this section  
within 30 days after we request it, you must stop producing the new or  
modified engines.  
    (2) [Reserved]  
    (f) * * *  
    (1) You may ask to raise your FEL for your engine family at any  
time before the end of the model year. In your request, you must show  
that you will still be able to meet the emission standards as specified  
in subparts B and H of this part. Use the appropriate FELs/FCLs with  
corresponding production volumes to calculate emission credits for the  
model year, as described in subpart H of this part.  
* * * * *  
0 
102. Amend Sec.  1036.230 by revising paragraph (d) and adding  
paragraph (f) to read as follows:  
Sec.  1036.230  Selecting engine families.  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 90/268    (d) Except as described in paragraph (f) of this section, engine  
configurations within an engine family must use equivalent greenhouse  
gas emission controls. Unless we approve it, you may not produce  
nontested configurations without the same emission control hardware  
included on the tested configuration. We will only approve it if you  
demonstrate that the exclusion of the hardware does not increase  
greenhouse gas emissions.  
* * * * *  
    (f) Engine families may be divided into subfamilies with respect to  
compliance with CO 2 standards.  
0 
103. Amend Sec.  1036.235 by revising the introductory text and  
paragraphs (b) and (c) to read as follows:  
Sec.  1036.235  Testing requirements for certification.  
    This section describes the emission testing you must perform to  
show compliance with the greenhouse gas emission standards in Sec.   
1036.108. When testing hybrid powertrains substitute ``hybrid  
powertrain'' for ``engine'' as it applies to requirements for  
certification.  
* * * * *  
    (b) Test your emission-data engines using the procedures and  
equipment specified in subpart F of this part. In the case of dual-fuel  
and flexible-fuel engines, measure emissions when operating with each  
type of fuel for which you intend to certify the engine. (Note:  
Measurement of criteria emissions from flexible-fuel engines generally  
involves operation with the fuel mixture that best represents in-use  
operation, or with the fuel mixture with the highest emissions.)  
Measure CO 2, CH4, and N2O emissions  
using the specified duty cycle(s), including cold-start and hot-start  
testing as specified in 40 CFR part 86, subpart N. The following  
provisions apply regarding test cycles for demonstrating compliance  
with tractor and vocational standards:  
    (1) If you are certifying the engine for use in tractors, you must  
measure CO 2 emissions using the applicable SET specified in  
Sec.  1036.501, and measure CH 4 and N2O emissions  
using the specified transient cycle.  
    (2) If you are certifying the engine for use in vocational  
applications, you must measure CO 2, CH4, and  
N2O emissions using the specified transient duty cycle,  
including cold-start and hot-start testing as specified in Sec.   
1036.501.  
    (3) You may certify your engine family for both tractor and  
vocational use by submitting CO 2 emission data from both SET  
and transient cycle testing and specifying FCLs for both.  
    (4) Some of your engines certified for use in tractors may also be  
used in vocational vehicles, and some of your engines certified for use  
in vocational may be used in tractors. However, you may not knowingly  
circumvent the intent of this part (to reduce in-use emissions of  
CO2) by certifying engines designed for tractors or  
vocational vehicles (and rarely used in the other application) to the  
wrong cycle. For example, we would generally not allow you to certify  
all your engines to the SET without certifying any to the transient  
cycle. 
    (c) We may perform confirmatory testing by measuring emissions from  
any of your emission-data engines. If your certification includes  
powertrain testing as specified in Sec.  1036.630, this paragraph (c)  
also applies for the powertrain test results.  
    (1) We may decide to do the testing at your plant or any other  
facility. If we do this, you must deliver the engine to a test facility  
we designate. The engine you provide must include appropriate  
manifolds, aftertreatment devices, electronic control units, and other  
emission-related components not normally attached directly to the  
engine block. If we do the testing at your plant, you must schedule it  
as soon as possible and make available the instruments, personnel, and  
equipment we need.  
    (2) If we measure emissions on your engine, the results of that  
testing become the official emission results for the engine as  
specified in this paragraph (c). Unless we later invalidate these data,  
we may decide not to consider your data in determining if your engine  
family meets applicable requirements in this part.  
    (3) Before we test one of your engines, we may set its adjustable  
parameters to any point within the physically adjustable ranges.  
[[Page 34379]]  
    (4) Before we test one of your engines, we may calibrate it within  
normal production tolerances for anything we do not consider an  
adjustable parameter. For example, we may calibrate it within normal  
production tolerances for an engine parameter that is subject to  
production variability because it is adjustable during production, but  
is not considered an adjustable parameter (as defined in Sec.   
1036.801) because it is permanently sealed. For parameters that relate  
to a level of performance that is itself subject to a specified range  
(such as maximum power output), we will generally perform any  
calibration under this paragraph (c)(4) in a way that keeps performance  
within the specified range.  
    (5) We may use our emission test results for steady-state, idle,  
cycle-average and powertrain fuel maps defined in Sec.  1036.503(b) as  
the official emission results. We will not replace individual points  
from your fuel map.  
    (i) We will determine fuel masses, m fuel[cycle] , and  
mean idle fuel mass flow rates, mi fuelidle , if applicable,  
using the method described in Sec.  1036.535(h).  
    (ii) We will perform this comparison using the weighted results  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 91/268from GEM, using vehicles that are appropriate for the engine under  
test. For example, we may select vehicles that the engine went into for  
the previous model year.  
    (iii) If you supply cycle-average engine fuel maps for the highway  
cruise cycles instead of generating a steady-state fuel map for these  
cycles, we may perform a confirmatory test of your engine fuel maps for  
the highway cruise cycles by either of the following methods:  
    (A) Directly measuring the highway cruise cycle-average fuel maps.  
    (B) Measuring a steady-state fuel map as described in paragraph  
(c)(5) of this section and using it in GEM to create our own cycle-  
average engine fuel maps for the highway cruise cycles.  
    (iv) We will replace fuel maps as a result of confirmatory testing  
as follows:  
    (A) Weight individual duty cycle results using the vehicle  
categories determined in paragraph (c)(5)(i) of this section and  
respective weighting factors in Table 1 of 40 CFR 1037.510 to determine  
a composite CO 2 emission value for each vehicle  
configuration; then repeat the process for all the unique vehicle  
configurations used to generate the manufacturer's fuel maps.  
    (B) The average percent difference between fuel maps is calculated  
using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.013  
Where: 
i = an indexing variable that represents one individual weighted  
duty cycle result for a vehicle configuration.  
N = total number of vehicle configurations.  
eCO2compEPA i = unrounded composite mass of CO 2  
emissions in g/ton-mile for vehicle configuration i for the EPA  
confirmatory test.  
eCO2compManu i = unrounded composite mass of  
CO2 emissions in g/ton-mile for vehicle configuration i  
for the manufacturer-declared map.
    (C) Where the unrounded average percent difference between our  
composite weighted fuel map and the manufacturer's is greater than or  
equal to 0%, we will not replace the manufacturer's maps, and we will  
consider an individual engine to have passed the fuel map confirmatory  
test. 
* * * * *  
0 
104. Revise Sec.  1036.255 to read as follows:  
Sec.  1036.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Act, we  
will issue a certificate of conformity for the engine family for that  
model year. We may make the approval subject to additional conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Act. Note that these are also violations of 40 CFR  
1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1036.820).  
0 
105. Revise the heading for subpart D to read as follows:  
Subpart D--Testing Production Engines and Hybrid Powertrains  
0 
106. Amend Sec.  1036.301 by revising paragraph (b)(2) to read as  
follows:  
[[Page 34380]]  
Sec.  1036.301  Measurements related to GEM inputs in a selective  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 92/268enforcement audit.  
* * * * *  
    (b) * * *  
    (2) Evaluate cycle-average fuel maps by running GEM based on  
simulated vehicle configurations representing the interpolated center  
of every group of four test points that define a boundary of cycle work  
and average engine speed divided by average vehicle speed. These  
simulated vehicle configurations are defined from the four surrounding  
points based on averaging values for vehicle mass, drag area (if  
applicable), tire rolling resistance, tire size, and axle ratio. The  
regulatory subcategory is defined by the regulatory subcategory of the  
vehicle configuration with the greatest mass from those four test  
points. Figure 1 of this section illustrates a determination of vehicle  
configurations for engines used in tractors and Vocational Heavy-Duty  
Vehicles (HDV) using a fixed tire size (see Sec.  1036.540(c)(3)(iii)).  
The vehicle configuration from the upper-left quadrant is defined by  
values for Tests 1, 2, 4, and 5 from Table 3 of Sec.  1036.540.  
Calculate vehicle mass as the average of the values from the four  
tests. Determine the weight reduction needed for GEM to simulate this  
calculated vehicle mass by comparing the average vehicle mass to the  
default vehicle mass for the vehicle subcategory from the four points  
that has the greatest mass, with the understanding that two-thirds of  
weight reduction for tractors is applied to vehicle weight and one-  
third is understood to represent increased payload. This is expressed  
mathematically as M avg = Msubcategory  - \2/3\  
[middot] M reduction , which can be solved for Mreduction. For  
vocational vehicles, half of weight reduction is applied to vehicle  
weight and half is understood to represent increased payload. Use the  
following values for default vehicle masses by vehicle subcategory:  
 Table 1 of Sec.   1036.301--Default Vehicle Mass by Vehicle Subcategory  
------------------------------------------------------------------------  
                                                               Default  
                    Vehicle subcategory                        vehicle  
                                                              mass  (kg)  
------------------------------------------------------------------------  
Vocational Light HDV.......................................        7,257  
Vocational Medium HDV......................................       11,408  
Class 7 Mid-Roof Day Cab...................................       20,910  
Class 8 Mid-Roof Day Cab...................................       29,529  
Class 8 High-Roof Sleeper Cab..............................       31,978  
Heavy-Haul Tractor.........................................       53,750  
------------------------------------------------------------------------  
* * * * *  
0 
107. Amend Sec.  1036.501 by revising paragraph (g) and adding  
paragraph (h) to read as follows:  
Sec.  1036.501  How do I run a valid emission test?  
* * * * *  
    (g) The following additional provisions apply for testing to  
demonstrate compliance with the emission standards in Sec.  1036.108  
for model year 2016 through 2020 engines:  
    (1) Measure CO 2, CH4, and N2O  
emissions using the transient cycle specified in either 40 CFR 86.1333  
or Sec.  1036.510.  
    (2) For engines subject to SET testing under Sec.  1036.108(a)(1),  
measure CO 2 emissions using the SET specified in 40 CFR  
86.1362.  
    (h) The following additional provisions apply for testing to  
demonstrate compliance with the emission standards in Sec.  1036.108  
for model year 2021 and later engines:  
    (1) If your engine is intended for installation in a vehicle  
equipped with stop-start technology, you may turn the engine off during  
the idle portions of the duty cycle to represent in-use operation,  
consistent with good engineering judgment. We recommend installing an  
engine starter motor and allowing the engine's Electronic Control Unit  
(ECU) to control the engine stop and start events.  
    (2) For engines subject to SET testing under Sec.  1036.108(a)(1),  
use one of the following methods to measure CO 2 emissions:  
    (i) Use the SET duty cycle specified in Sec.  1036.505 using either  
continuous or batch sampling.  
    (ii) Measure CO 2 emissions over the SET duty cycle  
specified in 40 CFR 86.1362 using continuous sampling. Integrate the  
test results by mode to establish separate emission rates for each mode  
(including the transition following each mode, as applicable). Apply  
the CO2 weighting factors specified in 40 CFR 86.1362 to  
calculate a composite emission result.  
    (3) Measure CO 2, CH4, and N2O  
emissions over the transient cycle specified in either 40 CFR 86.1333  
or Sec.  1036.510.  
    (4) Measure or calculate emissions of criteria pollutants  
corresponding to your measurements to demonstrate compliance with  
CO2 standards in subpart B of this part. These test results  
are not subject to the duty-cycle standards of 40 CFR part 86, subpart  
A. 
0 
108. Add Sec.  1036.503 to read as follows:  
Sec.  1036.503  Engine data and information for vehicle certification.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 93/268    You must give vehicle manufacturers information as follows so they  
can certify model year 2021 and later vehicles:  
    (a) Identify engine make, model, fuel type, combustion type, engine  
family name, calibration identification, and engine displacement. Also  
identify which standards the engines meet.  
    (b) This paragraph (b) describes four different methods to generate  
engine fuel maps. For engines without hybrid components or mild hybrid  
where you choose not to include hybrid components in the test, you must  
generate fuel maps using either paragraph (b)(1) or (2) of this  
section. For mild hybrid engines where you choose to include the hybrid  
components in the test and for hybrid engines, you must generate fuel  
maps using paragraph (b)(4) of this section. For all other hybrids,  
powertrains, and for vehicles where the transmission is not automatic,  
automated manual, manual, or dual-clutch you must use paragraph (b)(3)  
of this section.  
    (1) Combined steady-state and cycle-average. Determine steady-state  
engine fuel maps and fuel consumption at idle as described in Sec.   
1036.535(b) and (c) respectively, and determine cycle-average engine  
fuel maps as described in Sec.  1036.540, excluding cycle-average fuel  
maps for highway cruise cycles.  
    (2) Cycle-average. Determine fuel consumption at idle as described  
in Sec.  1036.535(c) and (d), and determine cycle-average engine fuel  
maps as described in Sec.  1036.540, including cycle-average engine  
fuel maps for highway cruise cycles. In this case, you do not need to  
determine steady-state engine fuel maps under Sec.  1036.535(b). Fuel  
mapping for highway cruise cycles using cycle-average testing is an  
alternate method, which means that we may do confirmatory testing based  
on steady-state fuel mapping for highway cruise cycles even if you do  
not; however, we will use the steady-state fuel maps to create cycle-  
average fuel maps. In Sec.  1036.540 we define the vehicle  
configurations for testing; we may add more vehicle configurations to  
better represent your engine's operation for the range of vehicles in  
which your engines will be installed (see 40 CFR 1065.10(c)(1)).  
    (3) Powertrain. Generate a powertrain fuel map as described in 40  
CFR 1037.550. In this case, you do not need to perform fuel mapping  
under Sec.  1036.535 or Sec.  1036.540. The option in 40 CFR  
1037.550(b)(2) is only allowed for hybrid powertrain testing.  
    (4) Hybrid engine. Determine fuel consumption at idle as described  
in Sec.  1036.535(c) and (d), and determine cycle-average engine fuel  
maps as described in Sec.  1037.550, including cycle-average engine  
fuel maps for highway cruise cycles.  
[[Page 34381]]  
    (c) Provide the following information if you generate engine fuel  
maps using either paragraph (b)(1), (2), or (4) of this section:  
    (1) Full-load torque curve for installed engines, and the full-load  
torque curve of the engine (parent engine) with the highest fueling  
rate that shares the same engine hardware, including the turbocharger,  
as described in 40 CFR 1065.510. You may use 40 CFR 1065.510(b)(5)(i)  
for engines subject to spark-ignition standards. Measure the torque  
curve for hybrid engines that have an RESS as described in 40 CFR  
1065.510(g)(2) with the hybrid system active. For hybrid engines that  
do not include an RESS follow 40 CFR 1065.510(b)(5)(ii).  
    (2) Motoring torque map as described in 40 CFR 1065.510(c)(2) and  
(5) for conventional and hybrid engines, respectively. For engines with  
a low-speed governor, remove data points where the low speed governor  
is active. If you don't know when the low-speed governor is active, we  
recommend removing all points below 40 r/min above the low warm idle  
speed. 
    (3) Declared engine idle speed. For vehicles with manual  
transmissions, this is the engine speed with the transmission in  
neutral. For all other vehicles, this is the engine's idle speed when  
the transmission is in drive.  
    (4) The engine idle speed during the transient cycle-average fuel  
map. 
    (5) The engine idle torque during the transient cycle-average fuel  
map. 
    (d) If you generate powertrain fuel maps using paragraph (b)(3) of  
this section, determine the system continuous rated power according to  
Sec.  1036.527.  
0 
109. Revise Sec.  1036.505 to read as follows:  
Sec.  1036.505  Supplemental emission test.  
    (a) Starting in model year 2021, you must measure CO 2  
emissions using the SET duty cycle in 40 CFR 86.1362 as described in  
Sec.  1036.501, or using the SET duty cycle in this section.  
    (b) Perform SET testing with one of the following procedures:  
    (1) For engine testing, the SET duty cycle is based on normalized  
speed and torque values relative to certain maximum values. Denormalize  
torque as described in 40 CFR 1065.610(d). Denormalize speed as  
described in 40 CFR 1065.512.  
    (2) For hybrid powertrain and hybrid engine testing, follow 40 CFR  
1037.550 to carry out the test, but do not compensate the duty cycle  
for the distance driven as described in 40 CFR 1037.550(g)(4), for  
hybrid engines select the transmission from Table 1 of Sec.  1036.540  
substituting ``engine'' for ``vehicle'' and ``highway cruise cycle''  
for ``SET'', and cycles do not follow 40 CFR 1037.550(j). For cycles  
that begin with a set of contiguous idle points, leave the transmission  
in neutral or park for the full initial idle segment. Place the  
transmission into drive within 5 seconds of the first nonzero vehicle  
speed setpoint. Place the transmission into park or neutral when the  
cycle reaches SET mode 14. Use the following vehicle parameters in  
place of those in 40 CFR 1037.550 to define the vehicle model in 40 CFR  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 94/2681037.550(a)(3):  
    (i) Determine the vehicle test mass, M, as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.014  
     
Where: 
Pcontrated  = the continuous rated power of the hybrid  
system determined in Sec.  1036.527.  
Pcontrated  = 350.1 kW  
M = 15.1[middot]350.1\1.31\ = 32499 kg  
    (ii) Determine the vehicle frontal area, A front, as  
follows:  
    (A) For M <= 18050 kg:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.015  
     
Example:  
M = 16499 kg  
Afront = -169 [middot] 10-8 [middot] 16499\2\ +  
6.33 [middot] 10-4 [middot] 16499 + 1.67 = 7.51 m\2\  
    (B) For M > 18050 kg, A front = 7.59 m\2\.  
    (iii) Determine the vehicle drag area, C dA, as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.016  
     
Where: 
g = gravitational constant = 9.80665 m/s\2\.  
[rho] = air density at reference conditions. Use [rho] = 1.1845 kg/  
m\3\. 
[GRAPHIC] [TIFF OMITTED] TR29JN21.017  
    (iv) Determine the coefficient of rolling resistance,  
Crr, as follows:  
[[Page 34382]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.018  
    (vii) Select a drive axle ratio, k a, that represents the  
worst-case pair of drive axle ratio and tire size for CO 2  
expected for vehicles in which the powertrain will be installed. This  
is typically the highest numeric axle ratio.  
    (viii) Select a tire radius, r, that represents the worst-case pair  
of tire size and drive axle ratio for CO 2 expected for  
vehicles in which the powertrain will be installed. This is typically  
the smallest tire radius.  
    (ix) If you are certifying a hybrid powertrain system without the  
transmission, use a default transmission efficiency of 0.95. If you  
certify with this configuration, you must use 40 CFR 1037.550(a)(3)(ii)  
to create the vehicle model along with its default transmission shift  
strategy. Use the transmission parameters defined in Table 1 of Sec.   
1036.540 to determine transmission type and gear ratio. For Light and  
Medium HDVs, use the Light and Medium HDV parameters for the FTP and  
SET. For Tractors and Heavy HDVs, use the Tractor and Heavy HDV  
transient cycle parameters for the FTP and the Tractor and Heavy HDV  
highway cruise cycle parameters for the SET.  
    (x) Select axle efficiency, Eff axle, according to 40 CFR  
1037.550.  
    (c) Measure emissions using the SET duty cycle shown in Table 1 of  
this section to determine whether engines and hybrid powertrains meet  
the steady-state compression-ignition standards specified in subpart B  
of this part. Table 1 of this section specifies settings for engine and  
hybrid powertrain testing, as follows:  
    (1) The duty cycle for testing engines involves a schedule of  
normalized engine speed and torque values.  
    (2) The duty cycle for hybrid powertrain testing involves a  
schedule of vehicle speeds and road grade.  
    (i) Determine road grade at each point based on the continuous  
rated power of the hybrid powertrain system, P contrated , in  
kW determined in Sec.  1036.527, the vehicle speed (A, B, or C) in mi/  
hr for a given SET mode, v ref[speed] , and the specified road  
grade coefficients using the following equation:  
[[Page 34383]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.019  
Example for SET mode 3a in Table 1 to this section:  
Pcontrated  = 345.2 kW  
vrefB = 59.3 mi/hr  
Road grade = 8.296 [middot] 10-9 [middot] 345.2\3\ + (-4.752  
[middot] 10-7) [middot] 345.2\2\ [middot] 59.3 + 1.291  
[middot] 10-5 [middot] 345.2\2\ + 2.88 [middot]  
10-4 [middot] 59.3\2\ [middot] 4.524 [middot]  
10-4 [middot] 345.2 [middot] 59.3 + (-1.802 [middot]  
10-2) [middot] 345.2 + (-1.83 [middot] 10-1)  
[middot] 59.3 + 8.81 = 0.53%  
    (ii) Use the vehicle C speed determined in Sec.  1036.527 and  
determine the vehicle A and B speeds as follows:  
    (A) Determine vehicle A speed using the following equation:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.020  
     6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 95/268[[Page 34384]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.021  
[[Page 34385]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.022  
[[Page 34386]]  
0 
110. Revise Sec.  1036.510 to read as follows:  
Sec.  1036.510  Transient testing.
    (a) Measure emissions by testing the engine or hybrid powertrain on  
a dynamometer with one of the following transient duty cycles to  
determine whether it meets the transient emission standards in subpart  
B of this part:  
    (1) For spark-ignition engines, use the transient duty cycle  
described in paragraph (a) of appendix B of this part.  
    (2) For compression-ignition engines, use the transient duty cycle  
described in paragraph (b) of appendix B of this part.  
    (3) For spark-ignition hybrid powertrains, use the transient duty  
cycle described in paragraph (a) of appendix B of this part.  
    (4) For compression-ignition hybrid powertrains, use the transient  
duty cycle described in paragraph (b) of appendix B of this part.  
    (b) Perform the following depending on if you are testing engines  
or hybrid powertrains:  
    (1) For engine testing, the transient duty cycles are based on  
normalized speed and torque values relative to certain maximum values.  
Denormalize torque as described in 40 CFR 1065.610(d). Denormalize  
speed as described in 40 CFR 1065.512.  
    (2) For hybrid powertrain testing, follow Sec.  1036.505(b)(2) to  
carry out the test except replace P contrated  with  
Prated, the peak rated power determined in Sec.  1036.527,  
keep the transmission in drive for all idle segments after the initial  
idle segment, and for hybrid engines select the transmission from Table  
1 of Sec.  1036.540 substituting ``engine'' for ``vehicle''. You may  
request to change the engine commanded torque at idle to better  
represent curb idle transmission torque (CITT).  
    (c) The transient test sequence consists of an initial run through  
the transient duty cycle from a cold start, 20 minutes with no engine  
operation, then a final run through of the same transient duty cycle.  
Emissions from engine starting is part of the both the cold and hot  
test intervals. Calculate the total emission mass of each constituent,  
m, and the total work, W, over each test interval according to 40 CFR  
1065.650. Calculate the official transient emission result from the  
cold-start and hot-start test intervals using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.023  
    (d) Calculate cycle statistics and compare with the established  
criteria as specified in 40 CFR 1065.514 for engines and 40 CFR  
1037.550 for hybrid powertrains to confirm that the test is valid.  
0 
111. Amend Sec.  1036.525 by revising paragraphs (a), (d) introductory  
text, and (d)(4) to read as follows:  
Sec.  1036.525  Hybrid engines.  
    (a) For model years 2014 through 2020, if your engine system  
includes features that recover and store energy during engine motoring  
operation, test the engine as described in paragraph (d) of this  
section. For purposes of this section, features that recover energy  
between the engine and transmission are considered related to engine  
motoring.  
* * * * *  
    (d) Measure emissions using the same procedures that apply for  
testing non-hybrid engines under this part, except as specified in this  
part and 40 CFR part 1065. For SET testing, deactivate the hybrid  
features unless we specify otherwise. The following provisions apply  
for testing hybrid engines:  
* * * * *  
    (4) Limits on braking energy. Calculate brake energy fraction,  
xb, as follows:  
    (i) Calculate x b as the integrated negative work over  
the cycle divided by the integrated positive work over the cycle  
according to Eq. 1036.525-1. Calculate the brake energy limit for the  
engine, x bl, according to Eq. 1036.525-2. If x b  
is less than or equal to x bl, use the integrated positive  
work for your emission calculations. If x b is greater than  
xbl use Eq. 1036.525-3 to calculate an adjusted value for  
cycle work, W cycle, and use W cycle as the work  
value for calculating emission results. You may set an instantaneous  
brake target that will prevent x b from being larger than  
xbl to avoid the need to subtract extra brake work from  
positive work.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.024  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 96/268Where: 
Wneg = the negative work over the cycle.  
Wpos = the positive work over the cycle.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.025  
Where: 
Pmax = the maximum power of the engine with the hybrid  
system engaged, in kW.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.026  
Where: 
Wcycle = cycle work when x b is greater than  
xbl. 
Example:  
Wneg = 4.69 kW-hr  
Wpos = 14.67 kW-hr  
Pmax = 223 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.027  
xbl = 4.158 [middot] 10-4 [middot] 223 + 0.2247 =  
0.317423  
since xb > xbl; 
Wcycle = 14.67-([verbar]4.69[verbar]-0.317423 [middot]  
0.317423 [middot] 14.67) = 14.6365 kW-hr  
    (ii) Convert from g/kW-hr to g/hp-hr as the final step in  
calculating emission results.  
* * * * *  
0 
112. Add Sec.  1036.527 to read as follows:  
Sec.  1036.527  Powertrain system rated power determination.  
    This section describes how to determine the peak and continuous  
rated power of conventional and hybrid powertrain systems and the  
vehicle speed for carrying out testing according  
[[Page 34387]]  
to Sec. Sec.  1036.505 and 1036.510 and 40 CFR 1037.550.  
    (a) Set up the powertrain according to 40 CFR 1037.550, but use the  
vehicle parameters in Sec.  1036.505(b)(2), except replace  
Pcontrated  with the manufacturer declared system peak power  
and use applicable automatic transmission for the engine. Note that if  
you repeat the system rated power determination as described in  
paragraph (f)(4) of this section, use the measured system peak power in  
place of P contrated . 
    (b) Prior to the start of each test interval verify the following:  
    (1) The state-of-charge of the rechargeable energy storage system  
(RESS) is >=90% of the operating range between the minimum and maximum  
RESS energy levels specified by the manufacturer.  
    (2) The conditions of all hybrid system components are within their  
normal operating range as declared by the manufacturer.  
    (3) RESS restrictions (e.g., power limiting, thermal limits, etc.)  
are not active.  
    (c) Carry out the test as follows:  
    (1) Warm up the powertrain by operating it. We recommend operating  
the powertrain at any vehicle speed and road grade that achieves  
approximately 75% of its expected maximum power. Continue the warm-up  
until the engine coolant, block, or head absolute temperature is within  
2% of its mean value for at least 2 min or until the engine  
thermostat controls engine temperature.  
    (2) Start the test by keying on the powertrain and letting it sit  
at 0 mi/hr for 50 seconds.  
    (3) Set maximum driver demand for a full load acceleration at 6%  
road grade starting at an initial vehicle speed of 0 mi/hr.  
    (4) 268 seconds after the initiation of paragraph (c)(3) of this  
section, linearly ramp the grade from 6% to 0% over 300 seconds. Stop  
the test after the vehicle speed has stopped increasing above the  
maximum value observed during the test.  
    (d) Record the powertrain system angular speed and torque values  
measured at the dynamometer at 100 Hz and use these in conjunction with  
the vehicle model to calculate P sys,vehicle . 
    (e) Calculate the system power, P sys, for each data  
point as follows:  
    (1) For testing with the speed and torque measurements at the  
transmission input shaft, P sys is equal to the calculated  
vehicle system peak power, P sys,vehicle , determined in  
paragraphs (c) through (d) of this section.  
    (2) For testing with the speed and torque measurements at the axle  
input shaft or the wheel hubs, determine P sys using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.028  
Where: 
Psys,vehicle  = the calculated vehicle system peak power.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 97/268[egr]trans = the default transmission efficiency = 0.95.  
[egr]axle = the default axle efficiency. Set this value =  
1 for speed and torque measurement at the axle input shaft or =  
0.955 at the wheel hubs.  
Example:  
Psys,vehicle  = 317.6 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.029  
    (f) The system peak rated power, P rated, is the highest  
calculated P sys where the coefficient of variation (COV)  
<2%. The COV is determined as follows:  
    (1) Calculate the standard deviation, [sigma](t).  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.030  
     
Where: 
N = the number of measurement intervals = 20.  
Psysi = the N samples in the 100 Hz signal previously  
used to calculate the respective P[mu](t) values at the time step t.  
P[mu](t) = the power vector from the results of each test run that  
is determined by a moving averaging of 20 consecutive samples of  
Psys in the 100 Hz that converts P[mu](t) to a 5 Hz signal.  
    (2) The resulting 5 Hz power and covariance signals are used to  
determine system rated power.  
    (3) The coefficient of variation COV(t) shall be calculated as the  
ratio of the standard deviation, [sigma](t), to the mean value of  
power, P[mu](t), for each time step t.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.031  
    (4) If the determined system peak rated power is not within 3% of the system peak rated power as declared by the  
manufacturer, you must repeat the procedure in paragraphs (a) through  
(f)(3) of this section using the measured system peak rated power  
determined in paragraph (f) of this section instead of the manufacturer  
declared value. The result from this repeat is the final determined  
system peak rated power.  
    (5) If the determined system peak rated power is within 3% of the system peak rated power as declared by the  
manufacturer, the declared system peak rated power shall be used.  
    (g) Determine continuous rated power as follows:  
    (1) For conventional powertrains, P contrated  equals  
Prated. 
    (2) For hybrid powertrains, continuous rated power,  
Pcontrated , is the maximum measured power from the data  
collected in paragraph (c)(3) of this section that meets the  
requirements in paragraph (f) of this section.  
    (h) Vehicle C speed, [nu] refC, is determined as follows:  
    (1) For powertrains where P sys is greater than 0.98  
[middot] P contrated  in top gear at more than one vehicle  
speed, [nu] refC is the average of the minimum and maximum  
vehicle speeds from the data collected in paragraph (c)(4) of this  
section that meets the requirements in paragraph (f) of this section.  
    (2) For powertrains where P sys is not greater than 0.98  
[middot] P contrated  in top gear at more than one vehicle  
speed, [nu] refC is the maximum vehicle speed from the data  
collected in paragraph (c)(4) of this section that meets the  
requirements in paragraph (f) of this section where P sys is  
great than 0.98 [middot] P contrated . 
0 
113. Revise Sec.  1036.530 to read as follows:  
Sec.  1036.530  Calculating greenhouse gas emission rates.  
    This section describes how to calculate official emission results  
for CO2, CH4, and N2O. 
    (a) Calculate brake-specific emission rates for each applicable  
duty cycle as specified in 40 CFR 1065.650. Apply infrequent  
regeneration adjustment factors to your CO 2 emission results  
for each duty cycle as described in 40 CFR 86.004-28 starting in model  
year 2021. You may optionally apply infrequent regeneration adjustment  
factors for CH 4 and N2O. 
    (b) Adjust CO 2 emission rates calculated under paragraph  
(a) of this section for measured test fuel properties as specified in  
this paragraph (b). This adjustment is intended to make official  
emission results independent of differences in test fuels within a fuel  
type. Use good engineering judgment to develop and apply testing  
protocols to  
[[Page 34388]]  
minimize the impact of variations in test fuels.  
    (1) Determine your test fuel's mass-specific net energy content,  
Emfuelmeas , also known as lower heating value, in MJ/kg,  
expressed to at least three decimal places. Determine  
Emfuelmeas  as follows:  
    (i) For liquid fuels, determine E mfuelmeas  according to  
ASTM D4809 (incorporated by reference in Sec.  1036.810). Have the  
sample analyzed by at least three different labs and determine the  
final value of your test fuel's E mfuelmeas  as the median all  
of the lab results you obtained. If you have results from three  
different labs, we recommend you screen them to determine if additional  
observations are needed. To perform this screening, determine the  
absolute value of the difference between each lab result and the  
average of the other two lab results. If the largest of these three  
resulting absolute value differences is greater than 0.297 MJ/kg, we  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 98/268recommend you obtain additional results prior to determining the final  
value of E mfuelmeas . 
    (ii) For gaseous fuels, determine E mfuelmeas  according  
to ASTM D3588 (incorporated by reference in Sec.  1036.810).  
    (2) Determine your test fuel's carbon mass fraction, w C,  
as described in 40 CFR 1065.655(d), expressed to at least three decimal  
places; however, you must measure fuel properties rather than using the  
default values specified in Table 1 of 40 CFR 1065.655.  
    (i) For liquid fuels, have the sample analyzed by at least three  
different labs and determine the final value of your test fuel's  
wC as the median of all of the lab results you obtained. If  
you have results from three different labs, we recommend you screen  
them to determine if additional observations are needed. To perform  
this screening, determine the absolute value of the difference between  
each lab result and the average of the other two lab results. If the  
largest of these three resulting absolute value differences is greater  
than 1.56 percent carbon, we recommend you obtain additional results  
prior to determining the final value of w C. 
    (ii) For gaseous fuels, have the sample analyzed by a single lab  
and use that result as your test fuel's w C. 
    (3) If, over a period of time, you receive multiple fuel deliveries  
from a single stock batch of test fuel, you may use constant values for  
mass-specific energy content and carbon mass fraction, consistent with  
good engineering judgment. To use this paragraph (b)(3), you must  
demonstrate that every subsequent delivery comes from the same stock  
batch and that the fuel has not been contaminated.  
    (4) Correct measured CO 2 emission rates as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.032  
     
Where: 
eCO2 = the calculated CO 2 emission result.  
Emfuelmeas  = the mass-specific net energy content of the  
test fuel as determined in paragraph (b)(1) of this section. Note  
that dividing this value by w Cmeas (as is done in this  
equation) equates to a carbon-specific net energy content having the  
same units as E mfuelCref . 
EmfuelCref  = the reference value of carbon-mass-specific  
net energy content for the appropriate fuel type, as determined in  
Table 1 of this section.  
wCmeas = carbon mass fraction of the test fuel (or  
mixture of test fuels) as determined in paragraph (b)(2) of this  
section.  
Example:  
eCO2 = 630.0 g/hp[middot]hr  
Emfuelmeas  = 42.528 MJ/kg  
EmfuelCref  = 49.3112 MJ/kgC  
wCmeas = 0.870  
[GRAPHIC] [TIFF OMITTED] TR29JN21.033  
eCO2cor = 624.5 g/hp[middot]hr  
                              Table 1 to Sec.   1036.530--Reference Fuel Properties  
----------------------------------------------------------------------------------------------------------------  
                                                      Reference fuel carbon-mass-        Reference fuel carbon  
                  Fuel type \a\                       specific net energy content,     mass fraction, wCref \b\  
                                                        EmfuelCref, (MJ/kgC) \b\  
----------------------------------------------------------------------------------------------------------------  
Diesel fuel......................................                           49.3112                       0.874  
Gasoline.........................................                           50.4742                       0.846  
Natural Gas......................................                           66.2910                       0.750  
LPG..............................................                           56.5218                       0.820  
Dimethyl Ether...................................                           55.3886                       0.521  
High-level ethanol-gasoline blends...............                           50.3211                       0.576  
----------------------------------------------------------------------------------------------------------------  
\a\ For fuels that are not listed, you must ask us to approve reference fuel properties.  
\b\ For multi-fuel streams, such as natural gas with diesel fuel pilot injection, use good engineering judgment  
  to determine blended values for EmfuelCref and wCref using the values in this table.  
    (c) Your official emission result for each pollutant equals your  
calculated brake-specific emission rate multiplied by all applicable  
adjustment factors, other than the deterioration factor.  
0 
114. Revise Sec.  1036.535 to read as follows:  
Sec.  1036.535  Determining steady-state engine fuel maps and fuel  
consumption at idle.  
    This section describes how to determine an engine's steady-state  
fuel map and fuel consumption at idle for model year 2021 and later  
vehicles. Vehicle manufacturers may need these values to demonstrate  
compliance with emission standards under 40 CFR part 1037 as described  
in Sec.  1036.510.  
    (a) General test provisions. Perform fuel mapping using the  
procedure described in paragraph (b) of this section to establish  
measured fuel-consumption rates at a range of engine speed and load  
settings. Measure fuel consumption at idle using the procedure  
described in paragraph (c) of this section. If you perform cycle-  
average mapping for highway cruise cycles as described in Sec.   
1036.540, omit mapping under paragraph (b) of the section and instead  
perform mapping as described in paragraph (d) of this section. Use  
these measured fuel-consumption values to declare fuel-consumption  
rates for certification as described in paragraph (e) of this section.  
    (1) Map the engine's torque curve and declare engine idle speed as  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 99/268described in Sec.  1036.503(c)(1) and (3), and perform emission  
measurements as described in 40 CFR 1065.501 and 1065.530 for discrete-  
mode steady-state testing. This section uses engine parameters and  
variables that are consistent with 40 CFR part 1065.  
    (2) Measure NO X emissions for each specified sampling  
period in g/s. You  
[[Page 34389]]  
may perform these measurements using a NO X emission-  
measurement system that meets the requirements of 40 CFR part 1065,  
subpart J. Include these measured NO X values any time you  
report to us your fuel consumption values from testing under this  
section. If a system malfunction prevents you from measuring  
NOX emissions during a test under this section but the test  
otherwise gives valid results, you may consider this a valid test and  
omit the NO X emission measurements; however, we may require  
you to repeat the test if we determine that you inappropriately voided  
the test with respect to NO X emission measurement.  
    (b) Steady-state fuel mapping. Determine fuel-consumption rates for  
each engine configuration over a series of steady-state engine  
operating points consisting of pairs of speed and torque points as  
described in this paragraph (b). You may use shared data across an  
engine platform to the extent that the fuel-consumption rates remain  
valid. For example, if you test a high-output configuration and create  
a different configuration that uses the same fueling strategy but  
limits the engine operation to be a subset of that from the high-output  
configuration, you may use the fuel-consumption rates for the reduced  
number of mapped points for the low-output configuration, as long as  
the narrower map includes at least 70 points. Perform fuel mapping as  
follows:  
    (1) Generate the sequence of steady-state engine operating points  
as follows:  
    (i) Determine the required steady-state engine operating points as  
follows:  
    (A) For engines with an adjustable warm idle speed setpoint, select  
the following speed setpoints: Minimum warm idle speed,  
fnidlemin , the highest speed above maximum power at which  
70% of maximum power occurs, n hi, and eight (or more)  
equally spaced points between f nidlemin  and nhi.  
(See 40 CFR 1065.610(c)). For engines without an adjustable warm idle  
speed replace minimum warm idle speed with warm idle speed,  
fnidle. 
    (B) Select the following torque setpoints at each of the selected  
speed setpoints: Zero (T = 0), maximum mapped torque,  
Tmax mapped , and eight (or more) equally spaced points  
between T = 0 and T max mapped . For each of the selected  
speed setpoints, replace any torque setpoints that are above the mapped  
torque at the selected speed setpoint, T max, minus 5 percent  
of Tmax mapped , with one test point at T max. 
    (ii) Select any additional (optional) steady-state engine operating  
points consistent with good engineering judgment. For example you may  
select additional points when linear interpolation between the defined  
points is not a reasonable assumption for determining fuel consumption  
from the engine. For each additional speed setpoint, increments between  
torque setpoints must be no larger than one-ninth of  
Tmax,mapped  and we recommend including a torque setpoint of  
Tmax. If you select a maximum torque setpoint less than  
Tmax, use good engineering judgment to select your maximum  
torque setpoint to avoid unrepresentative data. Note that if the test  
points were added for the child rating, they should still be reported  
in the parent fuel map. We will select at least as many points as you.  
    (iii) Set the run order for all of the steady-state engine  
operating points (both required and optional) as described in this  
paragraph (b)(1)(iii). Arrange the list of steady-state engine  
operating points such that the resulting list of paired speed and  
torque setpoints begins with the highest speed setpoint and highest  
torque setpoint followed by decreasing torque setpoints at the highest  
speed setpoint. This will be followed by the next lowest speed setpoint  
and the highest torque setpoint at that speed setpoint continuing  
through all the steady-state engine operating points and ending with  
the lowest speed (f nidlemin ) and torque setpoint (T = 0).  
The following figure provides an example of this array of points and  
run order.  
[[Page 34390]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.034  
    (iv) The steady-state engine operating points that have the highest  
torque setpoint for a given speed setpoint are optional reentry points  
into the steady-state-fuel-mapping sequence, should you need to pause  
or interrupt the sequence during testing.  
    (v) The steady-state engine operating points that have the lowest  
torque setpoint for a given speed setpoint are optional exit points  
from the steady-state-fuel-mapping sequence, should you need to pause  
or interrupt the sequence during testing.  
    (2) If the engine has an adjustable warm idle speed setpoint, set  
it to its minimum value, f nidlemin . 
    (3) During each test interval, control speed within 1%  
of nhi and engine torque within 5% of  
Tmax mapped  except for the following cases where both  
setpoints cannot be achieved because the steady-state engine operating  
point is near an engine operating boundary:  
    (i) For steady-state engine operating points that cannot be  
achieved and the operator demand stabilizes at minimum; control the  
dynamometer so it gives priority to follow the torque setpoint and let  
the engine govern the speed (see 40 CFR 1065.512(b)(1)). In this case,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 100/268the tolerance on speed control in paragraph (b)(3) of this section does  
not apply and engine torque is controlled to within 25  
N[middot]m.  
    (ii) For steady-state engine operating points that cannot be  
achieved and the operator demand stabilizes at maximum and the speed  
setpoint is below 90% of n hi; control the dynamometer so it  
gives priority to follow the speed setpoint and let the engine govern  
the torque (see 40 CFR 1065.512(b)(2)). In this case, the tolerance on  
torque control given in paragraph (b)(3) of this section does not  
apply. 
    (iii) For steady-state engine operating points that cannot be  
achieved and the operator demand stabilizes at maximum and the speed  
setpoint is at or above 90% of n hi; control the dynamometer  
so it gives priority to follow the torque setpoint and let the engine  
govern the speed (see 40 CFR 1065.512(b)(1)). In this case, the  
tolerance on speed control given in paragraph (b)(3) of this section  
does not apply.  
    (iv) For the steady-state engine operating points at the minimum  
speed setpoint and maximum torque setpoint, you may select a  
dynamometer control mode that gives priority to speed and an engine  
control mode that gives priority to torque. In this case, if the  
operator demand stabilizes at minimum or maximum, the tolerance on  
torque control in paragraph (b)(3) of this section does not apply.  
    (4) You may select the appropriate dynamometer and engine control  
modes in real-time or at any time prior based on various factors  
including the operating setpoint location relative to an engine  
operating boundary. Warm-up the engine as described in 40 CFR  
1065.510(b)(2).  
    (5) Within 60 seconds after concluding the warm-up, linearly ramp  
the speed and torque setpoints over 5 seconds to the first steady-state  
engine operating point from paragraph (b)(1) of this section.  
    (6) Operate the engine at the steady-state engine operating point  
for (70 1) seconds, and then start the test interval and  
record measurements using one of the following methods. You must also  
measure and report NO X emissions over each test interval as  
described in paragraph (a)(2) of this section. If you use redundant  
systems for the determination of fuel consumption, for example  
combining measurements of  
[[Page 34391]]  
dilute and raw emissions when generating your map, follow the  
requirements of 40 CFR 1065.201(d).  
    (i) Indirect measurement of fuel flow. Record speed and torque and  
measure emissions and other inputs needed to run the chemical balance  
in 40 CFR 1065.655(c) for a (30 1) second test interval;  
determine the corresponding mean values for the test interval. For  
dilute sampling of emissions, in addition to the background measurement  
provisions described in 40 CFR 1065.140 you may do the following:  
    (A) If you use batch sampling to measure background emissions, you  
may sample periodically into the bag over the course of multiple test  
intervals and read them as allowed in paragraph (b)(7)(i) of this  
section. If you use this paragraph (b)(6)(i)(A), you must apply the  
same background readings to correct emissions from each of the  
applicable test intervals.  
    (B) You may determine background emissions by sampling from the  
dilution air during the non-test interval periods in the test sequence,  
including pauses allowed in paragraph (b)(7)(i) of this section. If you  
use this paragraph (b)(6)(i)(B), you must allow sufficient time for  
stabilization of the background measurement; followed by an averaging  
period of at least 30 seconds. Use the average of the most recent pre-  
test interval and the next post-test interval background readings to  
correct each test interval. The most recent pre-test interval  
background reading must be taken no greater than 30 minutes prior to  
the start of the first applicable test interval and the next post-test  
interval background reading must be taken no later than 30 minutes  
after the end of the last applicable test interval. Background readings  
must be taken prior to the test interval for each reentry point and  
after the test interval for each exit point or more frequently.  
    (ii) Direct measurement of fuel flow. Record speed and torque and  
measure fuel consumption with a fuel flow meter for a (30 1) second test interval; determine the corresponding mean values  
for the test interval.  
    (7) After completing the test interval described in paragraph  
(b)(6) of this section, linearly ramp the speed and torque setpoints  
over 5 seconds to the next steady-state engine operating point.  
    (i) You may pause the steady-state-fuel-mapping sequence at any of  
the reentry points (as noted in paragraph (b)(1)(iv) of this section)  
to calibrate emission-measurement instrumentation; to read and evacuate  
background bag samples collected over the course of multiple test  
intervals; or to sample the dilution air for background emissions. This  
paragraph (b)(7)(i) allows you to spend more than the 70 seconds noted  
in paragraph (b)(6) of this section.  
    (ii) If an infrequent regeneration event occurs, interrupt the  
steady-state-fuel-mapping sequence and allow the regeneration event to  
finish. You may continue to operate at the steady-state engine  
operating point where the event began or, using good engineering  
judgment, you may transition to another operating condition to reduce  
the regeneration event duration. You may complete any post-test  
interval activities to validate test intervals prior to the most recent  
reentry point. Once the regeneration event is finished, linearly ramp  
the speed and torque setpoints over 5 seconds to the most recent  
reentry point described in paragraph (b)(1)(iv) of this section, and  
restart the steady-state-fuel-mapping sequence by repeating the steps  
in paragraphs (b)(6) and (7) of this section for all the remaining  
steady-state engine operating points. Operate at the reentry point for  
longer than the 70 seconds in paragraph (b)(6), as needed, to bring the  
aftertreatment to representative thermal conditions. Void all test  
intervals in the steady-state-fuel-mapping sequence beginning with the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 101/268reentry point and ending with the steady-state engine operating point  
where the regeneration event began.  
    (iii) You may interrupt the steady-state-fuel-mapping sequence  
after any of the exit points described in paragraph (b)(1)(v) of this  
section. To restart the steady-state-fuel-mapping sequence; begin with  
paragraph (b)(4) of this section and continue with paragraph (b)(5) of  
this section, except that the steady-state engine operating point is  
the next reentry point, not the first operating point from paragraph  
(b)(1) of this section. Follow paragraphs (b)(6) and (7) of this  
section until all remaining steady-state engine operating points are  
tested. 
    (iv) If the steady-state-fuel-mapping sequence is interrupted due  
test equipment or engine malfunction, void all test intervals in the  
steady-state-fuel-mapping sequence beginning with the most recent  
reentry point as described in paragraph (b)(1)(iv) of this section.  
Complete any post-test interval activities to validate test intervals  
prior to the most recent reentry point. Correct the malfunction and  
restart the steady-state-fuel-mapping sequence as described in  
paragraph (b)(7)(iii) of this section.  
    (v) If any steady-state engine test interval is voided, void all  
test intervals in the steady-state-fuel-mapping sequence beginning with  
the most recent reentry point as described in paragraph (b)(1)(iv) of  
this section and ending with the next exit point as described in  
paragraph (b)(1)(v) of this section. Rerun that segment of the steady-  
state-fuel-mapping sequence. If multiple test intervals are voided in  
multiple speed setpoints, you may exclude the speed setpoints where all  
of the test intervals were valid from the rerun sequence. Rerun the  
steady-state-fuel-mapping sequence as described in paragraph  
(b)(7)(iii) of this section.  
    (8) If you determine fuel-consumption rates using emission  
measurements from the raw or diluted exhaust, calculate the mean fuel  
mass flow rate, mi fuel, for each point in the fuel map using  
the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.035  
Where: 
mifuel = mean fuel mass flow rate for a given fuel map  
setpoint, expressed to at least the nearest 0.001 g/s.  
MC = molar mass of carbon.  
wCmeas = carbon mass fraction of fuel (or mixture of test  
fuels) as determined in 40 CFR 1065.655(d), except that you may not  
use the default properties in Table 1 of 40 CFR 1065.655 to  
determine [alpha], [beta], and w C for liquid fuels. You  
may not account for the contribution to [alpha], [beta], [gamma],  
and [delta] of diesel exhaust fluid or other non-fuel fluids  
injected into the exhaust.  
niexh = the mean raw exhaust molar flow rate from which  
you measured emissions according to 40 CFR 1065.655.  
[[Page 34392]]  
xCcombdry  = the mean concentration of carbon from fuel  
and any injected fluids in the exhaust per mole of dry exhaust as  
determined in 40 CFR 1065.655(c).  
xH2Oexhdry  = the mean concentration of H 2O in  
exhaust per mole of dry exhaust as determined in 40 CFR 1065.655(c).  
miCO2DEF = the mean CO 2 mass emission rate  
resulting from diesel exhaust fluid decomposition as determined in  
paragraph (b)(9) of this section. If your engine does not use diesel  
exhaust fluid, or if you choose not to perform this correction, set  
miCO2DEF equal to 0.  
MCO2 = molar mass of carbon dioxide.  
Example:  
MC = 12.0107 g/mol  
wCmeas = 0.869  
niexh = 25.534 mol/s  
xCcombdry  = 0.002805 mol/mol  
xH2Oexhdry  = 0.0353 mol/mol  
miCO2DEF = 0.0726 g/s  
MCO2 = 44.0095 g/mol  
[GRAPHIC] [TIFF OMITTED] TR29JN21.036  
    (9) If you determine fuel-consumption rates using emission  
measurements with engines that utilize diesel exhaust fluid for  
NOX control, correct for the mean CO 2 mass  
emissions resulting from diesel exhaust fluid decomposition at each  
fuel map setpoint using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.037  
Where: 
miDEF = the mean mass flow rate of injected urea solution  
diesel exhaust fluid for a given sampling period, determined  
directly from the electronic control module, or measured separately,  
consistent with good engineering judgment.  
MCO2 = molar mass of carbon dioxide.  
wCH4N2O = mass fraction of urea in diesel exhaust fluid  
aqueous solution. Note that the subscript ``CH4N2O'' refers to urea  
as a pure compound and the subscript ``DEF'' refers to the aqueous  
urea diesel exhaust fluid as a solution of urea in water. You may  
use a default value of 32.5% or use good engineering judgment to  
determine this value based on measurement.  
MCH4N2O = molar mass of urea.  
Example:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 102/268miDEF = 0. 304 g/s  
MCO2 = 44.0095 g/mol  
wCH4N2O = 32.5% = 0.325  
MCH4N2O = 60.05526 g/mol  
[GRAPHIC] [TIFF OMITTED] TR29JN21.038  
    (c) Fuel consumption at idle. Determine fuel-consumption rates for  
engines certified for installation in vocational vehicles for each  
engine configuration over a series of engine-idle operating points  
consisting of pairs of speed and torque points as described in this  
paragraph (c). You may use shared data across engine configurations,  
consistent with good engineering judgment. Perform measurements as  
follows:  
    (1) Determine the required engine-idle operating points as follows:  
    (i) Select the following two speed setpoints:  
    (A) Engines with an adjustable warm idle speed setpoint: Minimum  
warm idle speed, f nidlemin , and the maximum warm idle speed,  
fnidlemax . 
    (B) Engines without an adjustable warm idle speed setpoint: Warm  
idle speed (with zero torque on the primary output shaft),  
fnidle, and 1.15 times f nidle. 
    (ii) Select the following two torque setpoints at each of the  
selected speed setpoints: 0 and 100 N[middot]m.  
    (iii) You may run these four engine-idle operating points in any  
order. 
    (2) Control speed and torque as follows:  
    (i) Engines with an adjustable warm idle speed setpoint. For the  
warm-up in paragraph (c)(3) of this section and the transition in  
paragraph (c)(4) of this section control both speed and torque. At any  
time prior to reaching the next engine-idle operating point, set the  
engine's adjustable warm idle speed setpoint to the speed setpoint of  
the next engine-idle operating point in the sequence. This may be done  
before or during the warm-up or during the transition. Near the end of  
the transition period control speed and torque as described in  
paragraph (b)(3)(i) of this section. Once the transition is complete;  
set the operator demand to minimum to allow the engine governor to  
control speed; and control torque with the dynamometer as described in  
paragraph (b)(3) of this section.  
    (ii) Engines without an adjustable warm idle speed setpoint.  
Control speed and torque with operator demand and the dynamometer for  
the engine-idle operating points at the higher speed setpoint as  
described in paragraph (b)(3) of this section. Both the speed and  
torque tolerances apply for these points because they are not near the  
engine's operating boundary and are achievable. Control speed and  
torque for the engine-idle operating points at the lower speed setpoint  
as described in paragraph (c)(2)(i) of this section except for setting  
the engine's adjustable warm idle speed setpoint.  
    (3) Warm-up the engine as described in 40 CFR 1065.510(b)(2).  
    (4) After concluding the warm-up procedure, linearly ramp the speed  
and torque setpoints over 20 seconds to operate the engine at the next  
engine-idle operating point from paragraph (c)(1) of this section.  
    (5) Operate the engine at the engine-idle operating point for (180  
1) seconds, and then start the test interval and record  
measurements using one of the following methods. You must also measure  
and report NO X emissions over each test interval as  
described in paragraph (a)(2) of this section. If you use redundant  
systems for the determination of fuel consumption, for example  
combining measurements of dilute and raw emissions when generating your  
map, follow the requirements of 40 CFR 1065.201(d).  
    (i) Indirect measurement of fuel flow. Record speed and torque and  
measure emissions and other inputs needed to run the chemical balance  
in 40 CFR 1065.655(c) for a (600 1) second test interval;  
determine the corresponding mean values for the test interval. We  
[[Page 34393]]  
will use an average of indirect measurement of fuel flow with dilute  
sampling and direct sampling. For dilute sampling of emissions, measure  
background according to the provisions described in 40 CFR 1065.140,  
but read the background as described in paragraph (c)(7)(i) of this  
section. If you use batch sampling to measure background emissions, you  
may sample periodically into the bag over the course of multiple test  
intervals and read them as allowed in paragraph (b)(7)(i) of this  
section. If you use this paragraph (c)(5)(i), you must apply the same  
background readings to correct emissions from each of the applicable  
test intervals. Note that the minimum dilution ratio requirements for  
PM sampling in 40 CFR 1065.140(e)(2) do not apply. We recommend  
minimizing the CVS flow rate to minimize errors due to background  
correction consistent with good engineering judgment and operational  
constraints such as minimum flow rate for good mixing.  
    (ii) Direct measurement of fuel flow. Record speed and torque and  
measure fuel consumption with a fuel flow meter for a (600 1) second test interval; determine the corresponding mean values  
for the test interval.  
    (6) After completing the test interval described in paragraph  
(c)(5) of this section, repeat the steps in paragraphs (c)(3) through  
(5) of this section for all the remaining engine-idle operating points.  
After completing the test interval on the last engine-idle operating  
point, the fuel-consumption-at-idle sequence is complete.  
    (7) The following provisions apply for interruptions in the fuel-  
consumption-at-idle sequence in a way that is intended to produce  
results equivalent to running the sequence without interruption:  
    (i) You may pause the fuel-consumption-at-idle sequence after each  
test interval to calibrate emission-measurement instrumentation and to  
read and evacuate background bag samples collected over the course of a  
single test interval. This paragraph (c)(7)(i) allows you to shut-down  
the engine or to spend more time at the speed/torque idle setpoint  
after completing the test interval before transitioning to the step in  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 103/268paragraph (c)(3) of this section.  
    (ii) If an infrequent regeneration event occurs, interrupt the  
fuel-consumption-at-idle sequence and allow the regeneration event to  
finish. You may continue to operate at the engine-idle operating point  
where the event began or, using good engineering judgment, you may  
transition to another operating condition to reduce the regeneration  
event duration. If the event occurs during a test interval, void that  
test interval. Once the regeneration event is finished, restart the  
fuel-consumption-at-idle sequence by repeating the steps in paragraphs  
(c)(3) through (5) of this section for all the remaining engine-idle  
operating points.  
    (iii) You may interrupt the fuel-consumption-at-idle sequence after  
any of the test intervals. Restart the fuel-consumption-at-idle  
sequence by repeating the steps in paragraphs (c)(3) through (5) of  
this section for all the remaining engine-idle operating points.  
    (iv) If the fuel-consumption-at-idle sequence is interrupted due to  
test equipment or engine malfunction, correct the malfunction and  
restart the fuel-consumption-at-idle sequence by repeating the steps in  
paragraphs (c)(3) through (5) of this section for all the remaining  
engine-idle operating points. If the malfunction occurred during a test  
interval, void that test interval.
    (v) If any idle test intervals are voided, repeat the steps in  
paragraphs (c)(3) through (5) of this section for each of the voided  
engine-idle operating points.  
    (8) Correct the measured or calculated mean fuel mass flow rate,  
mifuel at each of the engine-idle operating points to  
account for mass-specific net energy content as described in paragraph  
(b)(13) of this section.  
    (d) Steady-state fuel maps used for cycle-average fuel mapping of  
the cruise cycles. Determine fuel-consumption rates for each engine  
configuration over a series of steady-state engine operating points  
near idle as described in this paragraph (d). You may use shared data  
across an engine platform to the extent that the fuel-consumption rates  
remain valid.  
    (1) Perform steady-state fuel mapping as described in paragraph (b)  
of this section with the following exceptions:  
    (i) All the required steady-state engine operating points as  
described in paragraph (b)(1)(i) of this section are optional.  
    (ii) Select speed setpoints to cover the range of idle speeds  
expected as follows:  
    (A) The minimum number of speed setpoints is two.  
    (B) For engines with an adjustable warm idle speed setpoint, the  
minimum speed setpoint must be equal to the minimum warm idle speed,  
fnidlemin , and the maximum speed setpoint must be equal to  
or greater than the maximum warm idle speed, f nidlemax . The  
minimum speed setpoint for engines without an adjustable warm idle  
speed setpoint, must be equal to the warm idle speed (with zero torque  
on the primary output shaft), f nidle, and the maximum speed  
setpoint must be equal to or greater than 1.15 times the warm idle  
speed, f nidle. 
    (iii) Select torque setpoints at each speed setpoint to cover the  
range of idle torques expected as follows:  
    (A) The minimum number of torque setpoints at each speed setpoint  
is three. Note that you must meet the minimum torque spacing  
requirements described in paragraph (b)(1)(ii) of this section.  
    (B) The minimum torque setpoint at each speed setpoint is zero.  
    (C) The maximum torque setpoint at each speed setpoint must be  
greater than or equal to the estimated maximum torque at warm idle (in-  
drive) conditions, T idlemaxest , using the following  
equation. For engines with an adjustable warm idle speed setpoint,  
evaluate T idlemaxest  at the maximum warm idle speed,  
fnidlemax . For engines without an adjustable warm idle speed  
setpoint, use the warm idle speed (with zero torque on the primary  
output shaft), f nidle. 
[GRAPHIC] [TIFF OMITTED] TR29JN21.039  
Where: 
Tfnstall = the maximum engine torque at  
fnstall. 
fnidle = the applicable engine idle speed as described in  
this paragraph (d).  
fnstall = the stall speed of the torque converter; use  
fntest or 2250 r/min, whichever is lower.  
Pacc = accessory power for the vehicle class; use 1500 W  
for Vocational Light HDV, 2500 W for Vocational Medium HDV, and 3500  
W for Tractors and Vocational Heavy HDV.  
Example:  
Tfnstall = 1870 N[middot]m  
fntest = 1740.8 r/min = 182.30 rad/s  
fnstall = 1740.8 r/min = 182.30 rad/s  
fnidle = 700 r/min = 73.30 rad/s  
Pacc = 1500 W  
[GRAPHIC] [TIFF OMITTED] TR29JN21.040  
[[Page 34394]]  
    (2) Remove the points from the default map that are below 115% of  
the maximum speed and 115% of the maximum torque of the boundaries of  
the points measured in paragraph (d)(1) of this section.  
    (3) Add the points measured in paragraph (d)(1) of this section.  
    (e) Carbon balance verification. The provisions related to carbon  
balance verification in Sec.  1036.543 apply to test intervals in this  
section.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 104/268    (f) Correction for net energy content. Correct the measured or  
calculated mean fuel mass flow rate, mi fuel at each engine  
operating condition as specified in paragraphs (b), (c), and (d) of  
this section to a mass-specific net energy content of a reference fuel  
using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.041  
Where: 
Emfuelmeas  = the mass-specific net energy content of the  
test fuel as determined in Sec.  1036.530(b)(1).  
EmfuelCref  = the reference value of carbon-mass-specific  
net energy content for the appropriate fuel. Use the values shown in  
Table 1 of Sec.  1036.530 for the designated fuel types, or values  
we approve for other fuel types.  
wCref = the reference value of carbon mass fraction for  
the test fuel as shown in Table 1 of Sec.  1036.530 for the  
designated fuels. For other fuels, use the reference carbon mass  
fraction of diesel fuel for engines subject to compression-ignition  
standards, and use the reference carbon mass fraction of gasoline  
for engines subject to spark-ignition standards.  
Example:  
mifuel = 0.933 g/s  
Emfuelmeas  = 42.7984 MJ/kgC  
EmfuelCref  = 49.3112 MJ/kgC  
wCref = 0.874  
[GRAPHIC] [TIFF OMITTED] TR29JN21.042  
    (g) Measured vs. declared fuel-consumption rates. Select fuel-  
consumption rates in g/s to characterize the engine's fuel maps. These  
declared values may not be lower than any corresponding measured values  
determined in paragraphs (b) through (d) of this section. This includes  
if you use multiple measurement methods as allowed in paragraph (b)(7)  
of this section. You may select any value that is at or above the  
corresponding measured value. These declared fuel-consumption rates,  
which serve as emission standards under Sec.  1036.108, are the values  
that vehicle manufacturers will use for certification under 40 CFR part  
1037. Note that production engines are subject to GEM cycle-weighted  
limits as described in Sec.  1036.301. If you perform the carbon  
balance error verification in Sec.  1036.543, for each fuel map data  
point: 
    (1) If you pass the [isin] rC verification, you must  
declare fuel-consumption rates no lower than the average of the direct  
and indirect fuel measurements.  
    (2) If you pass either the [isin] aC verification or  
[isin]aCrate verification and fail the [isin] rC  
verification, you must declare fuel-consumption rates no lower than the  
indirect fuel measurement.  
    (3) If you don't pass the [isin] rC, [isin] aC,  
and [isin] aCrate verifications, you must declare fuel-  
consumption rates no lower than the highest rate for the direct and  
indirect fuel measurements.  
    (h) EPA measured fuel-consumption rates. If we pass the carbon mass  
relative error for a test interval ([isin] rC) verification,  
the official fuel-consumption rate result will be the average of the  
direct and indirect fuel measurements. If we pass either the carbon  
mass absolute error for a test interval ([isin] aC)  
verification or carbon mass rate absolute error for a test interval  
([isin]aCrate) verification and fail the [isin] rC  
verification, the official fuel-consumption rate result will be the  
indirect fuel measurement.  
0 
115. Revise Sec.  1036.540 to read as follows:  
Sec.  1036.540  Determining cycle-average engine fuel maps.  
    (a) Overview. This section describes how to determine an engine's  
cycle-average fuel maps for model year 2021 and later vehicles with  
transient cycles. This section may also apply for highway cruise cycles  
as described in Sec.  1036.510. Vehicle manufacturers may need cycle-  
average fuel maps for transient duty cycles, highway cruise cycles, or  
both to demonstrate compliance with emission standards under 40 CFR  
part 1037. Generating cycle-average engine fuel maps consists of the  
following steps:  
    (1) Determine the engine's torque maps as described in Sec.   
1036.510(a).  
    (2) Determine the engine's steady-state fuel map and fuel  
consumption at idle as described in Sec.  1036.535.  
    (3) Simulate several different vehicle configurations using GEM  
(see 40 CFR 1037.520) to create new engine duty cycles, as described in  
paragraph (c) of this section. The transient vehicle duty cycles for  
this simulation are in 40 CFR part 1037, appendix I; the highway cruise  
cycles with grade are in 40 CFR part 1037, appendix IV. Note that GEM  
simulation relies on vehicle service classes as described in 40 CFR  
1037.140.  
    (4) Test the engines using the new duty cycles to determine fuel  
consumption, cycle work, and average vehicle speed as described in  
paragraph (d) of this section and establish GEM inputs for those  
parameters for further vehicle simulations as described in paragraph  
(e) of this section.  
    (b) General test provisions. The following provisions apply for  
testing under this section:  
    (1) To perform fuel mapping under this section for hybrid engines,  
make sure the engine and its hybrid features are appropriately  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 105/268configured to represent the hybrid features in your testing.  
    (2) Measure NO X emissions for each specified sampling  
period in grams. You may perform these measurements using a  
NOX emission-measurement system that meets the requirements  
of 40 CFR part 1065, subpart J. Include these measured NO X  
values any time you report to us your fuel consumption values from  
testing under this section. If a system malfunction prevents you from  
measuring NO X emissions during a test under this section but  
the test otherwise gives valid results, you may consider this a valid  
test and omit the NO X emission measurements; however, we may  
require you to repeat the test if we determine that you inappropriately  
voided the test with respect to NO X emission measurement.  
    (3) This section uses engine parameters and variables that are  
consistent with 40 CFR part 1065.  
    (4) For variable-speed gaseous-fueled engines with a single-point  
fuel injection system, apply all of the following statistical criteria  
to validate the transient duty cycle in 40 CFR part 1037, appendix I:  
                                           Table 1 to Sec.   1036.540  
----------------------------------------------------------------------------------------------------------------  
              Parameter                         Speed                    Torque                   Power  
----------------------------------------------------------------------------------------------------------------  
Slope, a1............................  0.950 <= a1 <=1.030....  0.830 <= a1 <=1.030....  0.830 <= a1 <=1.030.  
Absolute value of intercept,           <=10% of warm idle.....  <=3% of maximum mapped   <=2% of maximum mapped  
 [bond]a0[bond].                                                 torque.                  power.  
[[Page 34395]]  
  
Standard error of the estimate, SEE..  <=5% of maximum test     <=15% of maximum mapped  <=15% of maximum mapped  
                                        speed.                   torque.                  power.  
Coefficient of determination, r2.....  >=0.970................  >=0.700................  >=0.750.  
----------------------------------------------------------------------------------------------------------------  
    (c) Create engine duty cycles. Use GEM to simulate several  
different vehicle configurations to create transient and highway cruise  
engine duty cycles corresponding to each vehicle configuration, as  
follows:  
    (1) Set up GEM to simulate vehicle operation based on your engine's  
torque maps, steady-state fuel maps, engine minimum warm-idle speed and  
fuel consumption at idle as described in paragraphs (a)(1) and (2) of  
this section, as well as 40 CFR 1065.405(b). For engines without an  
adjustable warm idle speed replace minimum warm idle speed with warm  
idle speed, f nidle. 
    (2) Set up GEM with transmission parameters for different vehicle  
service classes and vehicle duty cycles as described in Table 2 of this  
section. For automatic transmissions set neutral idle to ``Y'' in the  
vehicle file. These values are based on automatic or automated manual  
transmissions, but they apply for all transmission types.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.043  
[[Page 34396]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.044  
Where: 
fn[speed]  = engine's angular speed as determined in  
paragraph (c)(3)(ii) or (iii) of this section.  
ktopgear = transmission gear ratio in the highest  
available gear from Table 2 of this section (for powertrain testing  
use actual top gear ratio).  
vref = reference speed. Use 65 mi/hr for the transient  
cycle and the 65 mi/hr highway cruise cycle, and use 55 mi/hr for  
the 55 mi/hr highway cruise cycle.
[GRAPHIC] [TIFF OMITTED] TR29JN21.045  
Example for a vocational Light HDV or vocational Medium HDV with a 6-  
speed automatic transmission at B speed (Test 3 or 4 in Table 3 of this  
section):  
fnrefB = 1870 r/min = 31.17 r/s  
kaB = 4.0 
ktopgear = 0.61 
vref = 65 mi/hr = 29.06 m/s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.046  
    (ii) Test at least eight different vehicle configurations for  
engines that will be installed in vocational Light HDV or vocational  
Medium HDV using vehicles in Table 3 of this section. For example, if  
your engines will be installed in vocational Medium HDV and vocational  
Heavy HDV, you might select Tests 2, 4, 6, and 8 of Table 3 of this  
section to represent vocational Medium HDV and Tests 2, 3, 4, 6, and 9  
of Table 4 of this section to represent vocational Heavy HDV. You may  
test your engine using additional vehicle configurations with different  
ka and Crr values to represent a wider range of  
in-use vehicle configurations. For all vehicle configurations set the  
drive axle configuration to 4x2. For powertrain testing, set  
Mrotating  to 340 kg and Eff axle to 0.955 for all  
vehicle configurations. Set the axle ratio, k a, and tire  
size, 
[GRAPHIC] [TIFF OMITTED] TR29JN21.047  
for each vehicle configuration based on the corresponding designated  
engine speed (f nrefA, fnrefB, fnrefC,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 106/268or fntest) at 65 mi/hr for the transient cycle and the 65  
mi/hr highway cruise cycle, and at 55 mi/hr for the 55 mi/hr highway  
cruise cycle. These vehicle speeds apply equally for engines subject to  
spark-ignition standards. Use the following  
[[Page 34397]]  
settings specific to each vehicle configuration:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.048  
    (iii) Test nine different vehicle configurations for engines that  
will be installed in vocational Heavy HDV and for tractors that are not  
heavy-haul tractors. Test six different vehicle configurations for  
heavy-haul tractors. You may test your engines for additional  
configurations with different k a, CdA, and  
Crr values to represent a wider range of in-use vehicle  
configurations. Set C rr to 6.9 for all nine defined vehicle  
configurations. For class 7 and 8 vehicle configurations set the drive  
axle configuration to 4x2 and 6x4 respectively. For powertrain testing,  
set Effaxle to 0.955 for all vehicle configurations. Set the  
axle ratio, k a, and tire size,  
[GRAPHIC] [TIFF OMITTED] TR29JN21.049  
for each vehicle configuration based on the corresponding designated  
engine speed (B, f ntest, or the minimum NTE exclusion speed  
as determined in 40 CFR 86.1370(b)(1)) at 65 mi/hr for the transient  
duty cycle and the 65 mi/hr highway cruise duty cycle, and at 55 mi/hr  
for the 55 mi/hr highway cruise duty cycle. Use the settings specific  
to each vehicle configuration as shown in Table 4 or Table 5 of this  
section, as appropriate. Engines subject to testing under both Tables 4  
and 5 of this section need not repeat overlapping vehicle  
configurations, so complete fuel mapping requires testing 12 (not 15)  
vehicle configurations for those engines. However, the preceding  
sentence does not apply if you choose to create two separate maps from  
the vehicle configurations defined in Tables 4 and 5 of this section.  
Note that M rotating  is needed for powertrain testing but not  
for engine testing. Tables 4 and 5 follow:  
[[Page 34398]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.050  
[GRAPHIC] [TIFF OMITTED] TR29JN21.051  
    (iv) If the engine will be installed in a combination of vehicles  
defined in paragraphs (c)(3)(ii) and (iii) of this section, use good  
engineering judgment to select at least nine vehicle configurations  
from Tables 3 and 4 of this section that best represent the range of  
vehicles your engine will be sold in. If there are not nine  
representative configurations you must add vehicles, that you define,  
to reach a total of at least nine vehicles. For example, if your  
engines will be installed in vocational Medium HDV and vocational Heavy  
HDV, select Tests 2, 4, 6 and 8 of Table 3 of this section to represent  
Medium HDV and Tests 3, 6, and 9 of Table 4 of this section to  
represent vocational Heavy HDV and add two more vehicles that you  
define. You may test your engine using additional vehicle  
configurations with different k a and Crr values  
to represent a wider range of in-use vehicle configurations.  
    (v) Use the defined values in Tables 2 through 5 of this section to  
set up GEM with the correct regulatory subcategory and vehicle weight  
reduction, if applicable, to achieve the target vehicle mass, M, for  
each test.  
    (4) Use the GEM output of instantaneous engine speed and engine  
flywheel torque for each of the vehicle configurations to generate a 10  
Hz transient duty cycle corresponding to each vehicle configuration  
operating over each vehicle duty cycle.  
    (d) Test the engine with GEM cycles. Test the engine over each of  
the transient engine duty cycles generated in paragraph (c) of this  
section as follows:  
    (1) Determine the sequence of engine duty cycles (both required and  
optional) for the cycle-average-fuel-mapping sequence as follows:  
    (i) Sort the list of engine duty cycles into three separate groups  
by vehicle duty cycle; transient vehicle duty cycle, 55 mi/hr highway  
cruise duty cycle, and the 65 mi/hr highway cruise duty cycle.  
    (ii) Within each group of engine duty cycles derived from the same  
vehicle duty cycle, order the duty cycles as follows: Select the engine  
duty cycle with the highest reference cycle work; followed by the cycle  
with the lowest cycle work; followed by the cycle with next highest  
cycle work; followed by the  
[[Page 34399]]  
cycle with the next lowest cycle work; until all the cycles are  
selected.  
    (iii) For each engine duty cycle, preconditioning cycles will be  
needed to start the cycle-average-fuel-mapping sequence.  
    (A) For the first and second cycle in each sequence, the two  
preconditioning cycles are the first cycle in the sequence, the  
transient vehicle duty cycle with the highest reference cycle work.  
This cycle is run twice for preconditioning prior to starting the  
sequence for either of the first two cycles.  
    (B) For all other cycles, the two preconditioning cycles are the  
previous two cycles in the sequence.  
    (2) If the engine has an adjustable warm idle speed setpoint, set  
it to its minimum value, f nidlemin . 
    (3) During each test interval, control speed and torque to meet the  
cycle validation criteria in 40 CFR 1065.514, except as noted in this  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 107/268paragraph (d)(3). Note that 40 CFR part 1065 does not allow subsampling  
of the 10 Hz GEM generated reference cycle. If the range of reference  
speeds is less than 10 percent of the mean reference speed, you only  
need to meet the standard error of the estimate in Table 2 of 40 CFR  
1065.514 for the speed regression.
    (4) Warm-up the engine as described in 40 CFR 1065.510(b)(2).  
    (5) Transition between duty cycles as follows:  
    (i) For transient duty cycles, start the next cycle within 10  
seconds after the conclusion of the preceding cycle. Note that this  
paragraph (d)(5)(i) applies to transitioning from both the  
preconditioning cycles and tests for record.  
    (ii) For cruise cycles, linearly ramp to the next cycle over 5  
seconds and stabilize for 15 seconds prior to starting the next cycle.  
Note that this paragraph (d)(5)(ii) applies to transitioning from both  
the preconditioning cycles and tests for record.  
    (6) Operate the engine over the engine duty cycle and record  
measurements using one of the methods described in paragraph (d)(6)(i)  
or (ii) of this section. You must also measure and report  
NOX emissions over each test interval as described in  
paragraph (a)(2) of this section. If you use redundant systems for the  
determination of fuel consumption, for example combining measurements  
of dilute and raw emissions when generating your map, follow the  
requirements of 40 CFR 1065.201(d).  
    (i) Indirect measurement of fuel flow. Record speed and torque and  
measure emissions and other inputs needed to run the chemical balance  
in 40 CFR 1065.655(c) for the test interval defined by the first engine  
duty cycle; determine the corresponding mean values for the test  
interval. For dilute sampling of emissions, in addition to the  
background measurement provisions described in 40 CFR 1065.140, you may  
do the following:  
    (A) Measure background as described in Sec.  1036.535(b)(7)(i)(A)  
but read the background as described in paragraph (d)(9)(i) of this  
section.  
    (B) Measure background as described in Sec.  1036.535(b)(7)(i)(B)  
but read the background as described in paragraph (d)(9)(i) of this  
section.  
    (ii) Direct measurement of fuel flow. Record speed and torque and  
measure fuel consumption with a fuel flow meter for the test interval  
defined by the first engine duty cycle; determine the corresponding  
mean values for the test interval.
    (7) Repeat the steps in paragraph (d)(6) of this section for all  
the remaining engine duty cycles.  
    (8) Repeat the steps in paragraphs (d)(4) through (7) of this  
section for all the applicable groups of duty cycles (e.g., transient  
vehicle duty cycle, 55 mi/hr highway cruise duty cycle, and the 65 mi/  
hr highway cruise duty cycle).  
    (9) The following provisions apply for interruptions in the cycle-  
average-fuel-mapping sequence in a way that is intended to produce  
results equivalent to running the sequence without interruption:  
    (i) You may pause the cycle-average-fuel-mapping sequence after  
each test interval to calibrate emission-measurement instrumentation,  
to read and evacuate background bag samples collected over the course  
of multiple test intervals, or to sample the dilution air for  
background emissions. This paragraph (d)(9)(i) requires you to shut-  
down the engine during the pause. If the pause is longer than 30  
minutes, restart the engine and restart the cycle-average-fuel-mapping  
sequence at the step in paragraph (d)(4) of this section. Otherwise,  
restart the engine and restart the cycle-average-fuel-mapping sequence  
at the step in paragraph (d)(5) of this section.  
    (ii) If an infrequent regeneration event occurs, interrupt the  
cycle-average-fuel-mapping sequence and allow the regeneration event to  
finish. You may continue to operate the engine over the engine duty  
cycle where the event began or, using good engineering judgment, you  
may transition to another operating condition to reduce the  
regeneration event duration.  
    (A) Determine which cycles in the sequence to void as follows:  
    (1) If the regeneration event began during a test interval, the  
cycle associated with that test interval must be voided.  
    (2) If you used dilute sampling to measure emissions and you used  
batch sampling to measure background emissions that were sampled  
periodically into the bag over the course of multiple test intervals  
and you are unable to read the background bag (e.g., sample volume too  
small), void all cycles associated with that background bag.  
    (3) If you used dilute sampling to measure emissions and you used  
the option to sample periodically from the dilution air and you did not  
meet all the requirements for this option as described in paragraph  
(d)(6)(i)(B) of this section, void all cycles associated with those  
background readings.  
    (4) If the regeneration event began during a non-test-interval  
period of the sequence and the provisions in paragraphs  
(d)(9)(ii)(A)(2) and (3) of this section do not apply, you do not need  
to void any cycles.  
    (B) Determine the cycle to restart the sequence. Identify the cycle  
associated with the last valid test interval. The next cycle in the  
sequence is the cycle to be used to restart the sequence.  
    (C) Once the regeneration event is finished, restart the sequence  
at the cycle determined in paragraph (d)(9)(ii)(B) of this section  
instead of the first cycle of the sequence. If the engine is not  
already warm, restart the sequence at paragraph (d)(4) of this section.  
Otherwise, restart at paragraph (d)(5) of this section.  
    (iii) If the cycle-average-fuel-mapping sequence is interrupted due  
to test equipment or engine malfunction, correct the malfunction and  
follow the steps in paragraphs (d)(9)(ii)(A) through (C) of this  
section to restart the sequence. Treat the detection of the malfunction  
as the beginning of the regeneration event.  
    (iv) If any test interval in the cycle-average-fuel-mapping  
sequence is voided, you must rerun that test interval as described in  
this paragraph (d)(9)(iv). You may rerun the whole sequence or any  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 108/268contiguous part of the sequence. If you end up with multiple valid test  
intervals for a given cycle, use the last valid test interval for  
determining the cycle-average fuel map. If the engine has been shut-  
down for more than 30 minutes or if it is not already warm, restart the  
sequence at paragraph (d)(4) of this section. Otherwise, restart at  
paragraph (d)(5) of this section. Repeat the steps in paragraphs (d)(6)  
and (7) of this section until you complete the whole sequence or part  
of the sequence.  
[[Page 34400]]  
The following examples illustrate possible scenarios for completing  
only part of the sequence:  
    (A) If you voided only the test interval associated with the fourth  
cycle in the sequence, you may restart the sequence using the second  
and third cycles as the preconditioning cycles and stop after  
completing the test interval associated with the fourth cycle.  
    (B) If you voided the test intervals associated with the fourth and  
sixth cycles, you may restart the sequence using the second and third  
cycles as the preconditioning cycles and stop after completing the test  
interval associated with the sixth cycle. If the test interval  
associated with the fifth cycle in this sequence was valid, it must be  
used for determining the cycle-average fuel map instead of the original  
one. 
    (10) For plug-in hybrid engines, precondition the battery and then  
complete all back-to-back tests for each vehicle configuration  
according to 40 CFR 1066.501 before moving to the next vehicle  
configuration.  
    (11) You may send signals to the engine controller during the test,  
such as current transmission gear and vehicle speed, if that allows  
engine operation during the test to better represent in-use operation.  
    (12) For hybrid powertrains with no plug-in capability, correct for  
the net energy change of the energy storage device as described in 40  
CFR 1066.501. For plug-in hybrid engines, follow 40 CFR 1066.501 to  
determine End-of-Test for charge-depleting operation; to do this, you  
must get our advance approval for a utility factor curve. We will  
approve your utility factor curve if you can show that you created it  
from sufficient in-use data of vehicles in the same application as the  
vehicles in which the plug-in hybrid electric vehicle (PHEV) engine  
will be installed.  
    (13) Calculate the fuel mass flow rate, m fuel, for each  
duty cycle using one of the following equations:  
    (i) Determine fuel-consumption rates using emission measurements  
from the raw or diluted exhaust, calculate the mass of fuel for each  
duty cycle, m fuel[cycle] , as follows:  
    (A) For calculations that use continuous measurement of emissions  
and continuous CO 2 from urea, calculate  
mfuel[cycle]  using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.052  
Where: 
MC = molar mass of carbon.  
wCmeas = carbon mass fraction of fuel (or mixture of test  
fuels) as determined in 40 CFR 1065.655(d), except that you may not  
use the default properties in Table 1 of 40 CFR 1065.655 to  
determine [alpha], [beta], and w C for liquid fuels.  
i = an indexing variable that represents one recorded emission  
value. 
N = total number of measurements over the duty cycle.  
nexh = exhaust molar flow rate from which you measured  
emissions.  
xCcombdry  = amount of carbon from fuel and any injected  
fluids in the exhaust per mole of dry exhaust as determined in 40  
CFR 1065.655(c).  
xH2Oexhdry  = amount of H 2O in exhaust per mole  
of exhaust as determined in 40 CFR 1065.655(c).  
[Delta]t = 1/f record 
MCO2 = molar mass of carbon dioxide.  
mCO2DEFi = mass emission rate of CO 2 resulting  
from diesel exhaust fluid decomposition over the duty cycle as  
determined from Sec.  1036.535(b)(7). If your engine does not  
utilize diesel exhaust fluid for emission control, or if you choose  
not to perform this correction, set m CO2DEFi equal to 0.  
Example:  
MC = 12.0107 g/mol  
wCmeas = 0.867  
N = 6680  
nexh1 = 2.876 mol/s  
nexh2 = 2.224 mol/s  
xCcombdry1  = 2.61[middot]10-\3\ mol/mol  
xCcombdry2  = 1.91[middot]10-\3\ mol/mol  
xH2Oexh1 = 3.53[middot]10-\2\ mol/mol  
xH2Oexh2 = 3.13[middot]10-\2\ mol/mol  
frecord = 10 Hz  
[Delta]t = 1/10 = 0.1 s  
MCO2 = 44.0095 g/mol  
mCO2DEF1 = 0.0726 g/s  
mCO2DEF2 = 0.0751 g/s  
BILLING CODE 6560-50-P  
[[Page 34401]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.053  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 109/268BILLING CODE 6560-50-C  
    (ii) Manufacturers may choose to measure fuel mass flow rate.  
Calculate the mass of fuel for each duty cycle,  
mfuel[cycle] , as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.054  
Where: 
i = an indexing variable that represents one recorded value.  
N = total number of measurements over the duty cycle. For batch fuel  
mass measurements, set N = 1.  
mfueli = the fuel mass flow rate, for each point, i,  
starting from i = 1.  
[Delta]t = 1/f record 
[[Page 34402]]  
frecord = the data recording frequency.  
Example:  
N = 6680  
mfuel1 = 1.856 g/s  
mfuel2 = 1.962 g/s  
frecord = 10 Hz  
[Delta]t = 1/10 = 0.1 s  
mfueltransient  = (1.856 + 1.962 + . . . +  
mfuel6680 ) [middot] 0.1  
mfueltransient  = 111.95 g  
    (14) The provisions related to carbon balance error verification in  
Sec.  1036.543 apply to test intervals in this section.  
    (15) Correct the measured or calculated fuel mass flow rate,  
mfuel, for each test result to a mass-specific net energy  
content of a reference fuel as described in Sec.  1036.535(e),  
replacing with mi fuel in Eq. 1036.535-4.  
    (16) For engines designed for plug-in hybrid electric vehicles, the  
mass of fuel for each cycle, m fuel[cycle] , is the utility  
factor-weighted fuel mass. This is done by calculating m fuel  
for the full charge-depleting and charge-sustaining portions of the  
test and weighting the results, using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.055  
Where: 
mfuel[cycle],CD  = total mass of fuel for all the tests in  
the charge-depleting portion of the test.  
UFD,CD = utility factor fraction at distance  
DCD as determined by interpolating the approved utility  
factor curve.  
mfuel[cycle],CS  = total mass of fuel for all the tests in  
the charge-sustaining portion of the test.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.056  
Where: 
v = vehicle velocity at each time step. For tests completed under  
this section, v is the vehicle velocity in the GEM duty-cycle file.  
For tests under 40 CFR 1037.550, v is the vehicle velocity as  
determined by Eq. 1037.550-1 of 40 CFR 1037.550. Note that this  
should include complete and incomplete charge-depleting tests.  
    (e) Determine GEM inputs. Use the results of engine testing in  
paragraph (d) of this section to determine the GEM inputs for the  
transient duty cycle and optionally for each of the highway cruise  
cycles corresponding to each simulated vehicle configuration as  
follows:  
    (1) Your declared fuel mass consumption, m fuel[cycle] .  
Using the calculated fuel mass consumption values described in  
paragraph (d) of this section, declare values using the method  
described in Sec.  1036.535(g).  
    (2) We will determine m fuel[cycle]  values using the  
method described in Sec.  1036.535(h).  
    (3) Engine output speed per unit vehicle speed,  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.057  
     
by taking the average engine speed measured during the engine test  
while the vehicle is moving and dividing it by the average vehicle  
speed provided by GEM. Note that the engine cycle created by GEM has a  
flag to indicate when the vehicle is moving.  
    (4) Positive work determined according to 40 CFR part 1065,  
W[cycle], by using the engine speed and engine torque  
measured during the engine test while the vehicle is moving. Note that  
the engine cycle created by GEM has a flag to indicate when the vehicle  
is moving.  
    (5) The engine idle speed and torque, by taking the average engine  
speed and torque measured during the engine test while the vehicle is  
not moving. Note that the engine cycle created by GEM has a flag to  
indicate when the vehicle is moving.  
    (6) The following table illustrates the GEM data inputs  
corresponding to the different vehicle configurations for a given duty  
cycle: 
[GRAPHIC] [TIFF OMITTED] TR29JN21.058  
[[Page 34403]]  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 110/2680 
116. Add Sec.  1036.543 to read as follows:  
Sec.  1036.543  Carbon balance error verification.  
    A carbon balance error verification compares independent  
assessments of the flow of carbon through the system (engine plus  
aftertreatment). We will, and you may optionally, verify carbon balance  
error according to 40 CFR 1065.543. This section applies to all test  
intervals in Sec. Sec.  1036.535(b), (c), and (d) and 1036.540 and 40  
CFR 1037.550.  
0 
117. Amend Sec.  1036.620 by revising paragraphs (a) and (b)(1)(iii) to  
read as follows:  
Sec.  1036.620  Alternate CO2 standards based on model year 2011  
compression-ignition engines.  
* * * * *  
    (a) The standards of this section are determined from the measured  
emission rate of the test engine of the applicable baseline 2011 engine  
family or families as described in paragraphs (b) and (c) of this  
section. Calculate the CO 2 emission rate of the baseline  
test engine using the same equations used for showing compliance with  
the otherwise applicable standard. The alternate CO 2  
standard for light and medium heavy-duty vocational-certified engines  
(certified for CO 2 using the transient cycle) is equal to  
the baseline emission rate multiplied by 0.975. The alternate  
CO2 standard for tractor-certified engines (certified for  
CO2 using the SET duty cycle) and all other heavy heavy-duty  
engines is equal to the baseline emission rate multiplied by 0.970. The  
in-use FEL for these engines is equal to the alternate standard  
multiplied by 1.03.  
    (b) * * *  
    (1) * * *  
    (iii) Calculate separate adjustments for emissions over the SET  
duty cycle and the transient cycle.  
* * * * *  
0 
118. Amend Sec.  1036.701 by revising paragraphs (i) and (j) to read as  
follows:  
Sec.  1036.701  General provisions.  
* * * * *  
    (i) Unless the regulations in this part explicitly allow it, you  
may not calculate Phase 1 credits more than once for any emission  
reduction. For example, if you generate Phase 1 CO 2 emission  
credits for a hybrid engine under this part for a given vehicle, no one  
may generate CO 2 emission credits for that same hybrid  
engine and the associated vehicle under 40 CFR part 1037. However,  
Phase 1 credits could be generated for identical vehicles using engines  
that did not generate credits under this part.  
    (j) Credits you generate with compression-ignition engines in 2020  
and earlier model years may be used in model year 2021 and later as  
follows:  
    (1) For credit-generating engines certified to the tractor engine  
standards in Sec.  1036.108, you may use credits calculated relative to  
the tractor engine standards.  
    (2) For credit-generating engines certified to the vocational  
engine standards in Sec.  1036.108, you may optionally carry over  
adjusted vocational credits from an averaging set, and you may use  
credits calculated relative to the emission levels in the following  
table: 
   Table 1 of Sec.   1036.701--Emission Levels for Credit Calculation  
------------------------------------------------------------------------  
        Medium heavy-duty  engines            Heavy heavy-duty engines  
------------------------------------------------------------------------  
558 g/hp[middot]hr........................  525 g/hp[middot]hr.  
------------------------------------------------------------------------  
* * * * *  
0 
119. Amend Sec.  1036.705 by revising paragraphs (b)(2) and (5) to read  
as follows:  
Sec.  1036.705  Generating and calculating emission credits.  
* * * * *  
    (b) * * *  
    (2) For tractor engines:  
Emission credits (Mg) = (Std-FCL) [middot] (CF) [middot] (Volume)  
[middot] (UL) [middot] (10-6) 
Where: 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 111/268Std = the emission standard, in g/hp-hr, that applies under subpart  
B of this part for engines not participating in the ABT program of  
this subpart (the ``otherwise applicable standard'').  
FCL = the Family Certification Level for the engine family, in g/hp-  
hr, measured over the SET duty cycle rounded to the same number of  
decimal places as the emission standard.  
CF = a transient cycle conversion factor (hp-hr/mile), calculated by  
dividing the total (integrated) horsepower-hour over the duty cycle  
(average of tractor-engine configurations weighted by their  
production volumes) by 6.3 miles for engines subject to spark-  
ignition standards and 6.5 miles for engines subject to compression-  
ignition standards. This represents the average work performed by  
tractor engines in the family over the mileage represented by  
operation over the duty cycle. Note that this calculation requires  
you to use the transient cycle conversion factor even for engines  
certified to standards based on the SET duty cycle.  
Volume = the number of tractor engines eligible to participate in  
the averaging, banking, and trading program within the given engine  
family during the model year, as described in paragraph (c) of this  
section.  
UL = the useful life for the given engine family, in miles.  
* * * * *  
    (5) You may generate CO 2 emission credits from a model  
year 2021 or later medium heavy-duty engine family subject to spark-  
ignition standards for exchanging with other engine families only if  
the engines in the family are gasoline-fueled. You may generate  
CO2 credits from non-gasoline engine families only for the  
purpose of offsetting CH 4 and/or N 2O emissions  
within the same engine family as described in paragraph (d) of this  
section.  
* * * * *  
0 
120. Amend Sec.  1036.801 by:  
0 
a. Revising the definitions for ``Auxiliary emission control device'',  
``Heavy-duty vehicle'', and ``Hybrid''.  
0 
b. Adding definitions for ``Hybrid engine'', ``Hybrid powertrain'', and  
``Mild hybrid'' in alphabetical order.  
0 
c. Revising the definition for ``Steady-state''.  
    The revisions and additions read as follows:  
Sec.  1036.801   Definitions.  
* * * * *  
    Auxiliary emission control device means any element of design that  
senses temperature, motive speed, engine speed (r/min), transmission  
gear, or any other parameter for the purpose of activating, modulating,  
delaying, or deactivating the operation of any part of the emission  
control system.  
* * * * *  
    Heavy-duty vehicle means any motor vehicle above 8,500 pounds GVWR.  
An incomplete vehicle is also a heavy-duty vehicle if it has a curb  
weight above 6,000 pounds or a basic vehicle frontal area greater than  
45 square feet. Curb weight and basic vehicle frontal area have the  
meaning given in 40 CFR 86.1803-01.  
    Hybrid means an engine or 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 that certain  
provisions in this part treat hybrid engines and hybrid powertrains  
intended for vehicles that include regenerative braking different than  
those intended for vehicles 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  
[[Page 34404]]  
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.  
    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 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.  
* * * * *  
    Mild hybrid means a hybrid engine or powertrain with regenerative  
braking capability where the system recovers less than 20 percent of  
the total braking energy over the transient cycle defined in appendix I  
of 40 CFR part 1037.  
* * * * *  
    Steady-state has the meaning given in 40 CFR 1065.1001. This  
includes fuel mapping and idle testing where engine speed and load are  
held at a finite set of nominally constant values.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 112/268* * * * *  
0 
121. Amend Sec.  1036.805 by revising paragraphs (b) through (f) and  
adding paragraph (g) to read as follows:  
Sec.  1036.805  Symbols, abbreviations, and acronyms.  
* * * * *  
    (b) Symbols for quantities. This part uses the following symbols  
and units of measure for various quantities:  
                               Table 2 to Sec.   1036.805--Symbols for Quantities  
----------------------------------------------------------------------------------------------------------------  
                                                                                             Unit in terms of SI  
          Symbol                 Quantity                Unit               Unit symbol           base units  
----------------------------------------------------------------------------------------------------------------  
[alpha]..................  atomic hydrogen-to-   mole per mole.......  mol/mol.............  1.
                            carbon ratio.  
[Agr]....................  Area................  square meter........  m2..................  m2.  
[beta]...................  atomic oxygen-to-     mole per mole.......  mol/mol.............  1.
                            carbon ratio.  
Cd[Agr]..................  drag area...........  meter squared.......  m2..................  m2.  
Crr......................  coefficient of        kilogram per metric   kg/tonne............  10-3.  
                            rolling resistance.   ton.  
D........................  distance............  miles or meters.....  mi or m.............  m.
[egr]....................  efficiency..........  
[isin]...................  Difference or error  
                            quantity.  
e........................  mass weighted         grams/ton-mile......  g/ton-mi............  g/kg-km.  
                            emission result.  
Eff......................  efficiency..........  
Em.......................  mass-specific net     megajoules/kilogram.  MJ/kg...............  m2[middot]s-2.  
                            energy content.  
fn.......................  angular speed         revolutions per       r/min...............  [pi][middot]30[midd  
                            (shaft).              minute.                                     ot]s-1.  
g........................  gravitational         meters per second     m/s2................  m[middot]s-2.  
                            acceleration.         squared.  
i........................  indexing variable...  
ka.......................  drive axle ratio....  ....................  ....................  1.
ktopgear.................  highest available  
                            transmission gear.  
m........................  Mass................  pound mass or         lbm or kg...........  kg.  
                                                  kilogram.  
M........................  molar mass..........  gram per mole.......  g/mol...............  10-  
                                                                                              3[middot]kg[middot  
                                                                                              ]mol-1.  
M........................  vehicle mass........  kilogram............  kg..................  kg.  
Mrotating................  inertial mass of      kilogram............  kg..................  kg.  
                            rotating components.  
N........................  total number in a  
                            series.  
P........................  Power...............  kilowatt............  kW..................  103[middot]m2[middo  
                                                                                              t]kg[middot]s-3.  
[rho]....................  mass density........  kilogram per cubic    kg/m3...............  m-3[middot]kg.  
                                                  meter.  
r........................  tire radius.........  meter...............  m...................  m.
SEE......................  standard error of  
                            the estimate.  
[sigma]..................  standard deviation..  
T........................  torque (moment of     newton meter........  N[middot]m..........  m2[middot]kg[middot  
                            force).                                                           ]s-2.  
t........................  Time................  second..............  s...................  s.
[Delta]t.................  time interval,        second..............  s...................  s.
                            period, 1/frequency.  
UF.......................  utility factor......  
v........................  Speed...............  miles per hour or     mi/hr or m/s........  m[middot]s-1.  
                                                  meters per second.  
W........................  Work................  kilowatt-hour.......  kW[middot]hr........  3.6[middot]m2[middo  
                                                                                              t]kg[middot]s-1.  
wC.......................  carbon mass fraction  gram/gram...........  g/g.................  1.
wCH4N2O..................  urea mass fraction..  gram/gram...........  g/g.................  1.
x........................  amount of substance   mole per mole.......  mol/mol.............  1.
                            mole fraction.  
xb.......................  brake energy  
                            fraction.  
xbl......................  brake energy limit..  
----------------------------------------------------------------------------------------------------------------  
    (c) Superscripts. This part uses the following superscripts for  
modifying quantity symbols:  
                Table 3 to Sec.   1036.805--Superscripts  
------------------------------------------------------------------------  
                Superscript                            Meaning  
------------------------------------------------------------------------  
overbar (such as y).......................  arithmetic mean.  
overdot (such as y).......................  quantity per unit time.  
------------------------------------------------------------------------  
    (d) Subscripts. This part uses the following subscripts for  
modifying quantity symbols:  
[[Page 34405]]  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 113/268                 Table 4 to Sec.   1036.805--Subscripts  
------------------------------------------------------------------------  
          Subscript                             Meaning  
------------------------------------------------------------------------  
65...........................  65 miles per hour.  
A............................  A speed.  
A............................  absolute (e.g., absolute difference or  
                                error).  
Acc..........................  accessory.  
App..........................  approved.  
Axle.........................  axle.  
B............................  B speed.  
C............................  C speed.  
C............................  carbon mass.  
Ccombdry.....................  carbon from fuel per mole of dry exhaust.  
CD...........................  charge-depleting.  
CO2DEF.......................  CO2 resulting from diesel exhaust fluid  
                                decomposition.  
comb.........................  combustion.  
comp.........................  composite.  
Cor..........................  corrected.  
CS...........................  charge-sustaining.  
Cycle........................  test cycle.  
DEF..........................  diesel exhaust fluid.  
engine.......................  engine.  
Exh..........................  raw exhaust.  
Front........................  frontal.  
Fuel.........................  fuel.  
H2Oexhaustdry................  H2O in exhaust per mole of exhaust.  
Hi...........................  high.  
I............................  an individual of a series.  
Idle.........................  idle.  
M............................  mass.  
Max..........................  maximum.  
mapped.......................  mapped.  
Meas.........................  measured quantity.  
Neg..........................  negative.  
Pos..........................  positive.  
R............................  relative (e.g., relative difference or  
                                error).  
Rate.........................  rate (divided by time).  
Rated........................  rated.  
record.......................  record.  
Ref..........................  reference quantity.  
speed........................  speed.  
Stall........................  stall.  
Test.........................  test.  
Tire.........................  tire.  
transient....................  transient.  
[Mgr]........................  vector.  
vehicle......................  vehicle.  
------------------------------------------------------------------------  
    (e) Other acronyms and abbreviations. This part uses the following  
additional abbreviations and acronyms:  
      Table 5 to Sec.   1036.805--Other Acronyms and Abbreviations  
------------------------------------------------------------------------  
           Acronym                              Meaning  
------------------------------------------------------------------------  
ABT..........................  averaging, banking, and trading.  
AECD.........................  auxiliary emission control device.  
ASTM.........................  American Society for Testing and  
                                Materials.  
BTU..........................  British thermal units.  
CD...........................  charge-depleting.  
CFR..........................  Code of Federal Regulations.  
CI...........................  Compression-ignition.  
COV..........................  coefficient of variation.  
CS...........................  charge-sustaining.  
DEF..........................  diesel exhaust fluid.  
DF...........................  deterioration factor.  
DOT..........................  Department of Transportation.  
E85..........................  gasoline blend including nominally 85  
                                percent denatured ethanol.  
ECU..........................  Electronic Control Unit.  
EPA..........................  Environmental Protection Agency.  
FCL..........................  Family Certification Level.  
[[Page 34406]]  
  
FEL..........................  Family Emission Limit.  
GEM..........................  Greenhouse gas Emissions Model.  
g/hp-hr......................  grams per brake horsepower-hour.  
GVWR.........................  gross vehicle weight rating.  
HDV..........................  heavy-duty vehicle.  
LPG..........................  liquefied petroleum gas.  
NARA.........................  National Archives and Records  
                                Administration.  
NHTSA........................  National Highway Traffic Safety  
                                Administration.  
NTE..........................  not-to-exceed.  
RESS.........................  rechargeable energy storage system.  
RMC..........................  ramped-modal cycle.  
SCR..........................  selective catalytic reduction.  
SEE..........................  standard error of the estimate.  
SET..........................  Supplemental Emission Test.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 114/268SI...........................  spark-ignition.  
U.S..........................  United States.  
U.S.C........................  United States Code.  
------------------------------------------------------------------------  
    (f) Constants. This part uses the following constants:  
                  Table 6 to Sec.   1036.805--Constants  
------------------------------------------------------------------------  
       Symbol                Quantity                    Value  
------------------------------------------------------------------------  
g..................  gravitational constant.  9.80665 m[middot]s-2  
------------------------------------------------------------------------  
    (g) Prefixes. This part uses the following prefixes to define a  
quantity:  
                  Table 7 to Sec.   1036.805--Prefixes  
------------------------------------------------------------------------  
       Symbol                Quantity                    Value  
------------------------------------------------------------------------  
[micro]............  micro..................  10-6  
m..................  milli..................  10-3  
c..................  centi..................  10-2  
k..................  kilo...................  103  
M..................  mega...................  106  
------------------------------------------------------------------------  
0 
122. Revise Sec.  1036.810 to read as follows:  
Sec.  1036.810  Incorporation by reference.  
    Certain material is incorporated by reference into this part with  
the approval of the Director of the Federal Register under 5 U.S.C.  
552(a) and 1 CFR part 51. To enforce any edition other than that  
specified in this section, the Environmental Protection Agency must  
publish a document in the Federal Register and the material must be  
available to the public. All approved material is available for  
inspection at U.S. EPA, Air and Radiation Docket and Information  
Center, WJC West Building, Room 3334, 1301 Constitution Ave. NW,  
Washington, DC 20460, www.epa.gov/dockets , (202) 202-1744, and is  
available from the sources listed in this section. It is also available  
for inspection at the National Archives and Records Administration  
(NARA). For information on the availability of this material at NARA,  
call 202-741-6030, or go to www.archives.gov/federal-register/cfr/ibr-locations.html . 
    (a) ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West  
Conshohocken, PA 19428-2959, (877) 909-2786, www.astm.org/ . 
    (1) ASTM D3588-98 (Reapproved 2017)e1, Standard Practice for  
Calculating Heat Value, Compressibility Factor, and Relative Density of  
Gaseous Fuels, approved April 1, 2017, (``ASTM D3588''), IBR approved  
for Sec.  1036.530(b).  
    (2) ASTM D4809-13, Standard Test Method for Heat of Combustion of  
Liquid Hydrocarbon Fuels by Bomb Calorimeter (Precision Method),  
approved May 1, 2013, (``ASTM D4809''), IBR approved for Sec.   
1036.530(b).  
    (b) National Institute of Standards and Technology, 100 Bureau  
Drive, Stop 1070, Gaithersburg, MD 20899-1070, (301) 975-6478, or  
www.nist.gov . 
    (1) NIST Special Publication 811, Guide for the Use of the  
International System of Units (SI), 2008 Edition, March 2008, IBR  
approved for Sec.  1036.805.  
    (2) [Reserved]  
0 
123. Amend Sec.  1036.825 by revising paragraph (a) to read as follows:  
Sec.  1036.825  Reporting and recordkeeping requirements.  
    (a) This part includes various requirements to submit and record  
data or other information. Unless we specify otherwise, store required  
records in any format and on any media and keep them readily available  
for eight years after you send an associated application for  
certification, or eight years after you generate the data if they do  
not support an application for certification. We may review these  
records at any time. You must promptly give us organized, written  
records in English if we ask for them. We may require you to submit  
written records in an electronic format.  
* * * * *  
Appendix I to Part 1036 [Redesignated as Appendix C to Part 1036]  
0 
124. Redesignate appendix I to part 1036 as appendix C to part 1036.  
0 
125. Add appendix A to part 1036 to read as follows:  
Appendix A to Part 1036--Summary of Previous Emission Standards  
    The following standards, which EPA originally adopted under 40  
CFR part 85 or 86, apply to compression-ignition engines produced  
before model year 2007 and to spark-ignition engines produced before  
model year 2008:  
    (a) Smoke. Smoke standards applied for compression-ignition  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 115/268engines based on opacity measurement using the test procedures in 40  
CFR part 86, subpart I, as follows:  
    (1) Engines were subject to the following smoke standards for  
model years 1970 through 1973:  
    (i) 40 percent during the engine acceleration mode.  
    (ii) 20 percent during the engine lugging mode.  
    (2) The smoke standards in 40 CFR 86.11 started to apply in  
model year 1974.  
    (b) Idle CO. A standard of 0.5 percent of exhaust gas flow at  
curb idle applied through model year 2016 to the following engines:  
    (1) Spark-ignition engines with aftertreatment starting in model  
year 1987. This standard applied only for gasoline-fueled engines  
through model year 1997. Starting in model year 1998, the same  
standard applied for engines fueled by methanol, LPG, and natural  
gas. The idle CO standard no longer applied for engines certified to  
meet onboard diagnostic requirements starting in model year 2005.  
    (2) Methanol-fueled compression-ignition engines starting in  
model year 1990. This  
[[Page 34407]]  
standard also applied for natural gas and LPG engines starting in  
model year 1997. The idle CO standard no longer applied for engines  
certified to meet onboard diagnostic requirements starting in model  
year 2007.  
    (c) Crankcase emissions. The requirement to design engines to  
prevent crankcase emissions applied starting with the following  
engines:  
    (1) Spark-ignition engines starting in model year 1968. This  
standard applied only for gasoline-fueled engines through model year  
1989, and applied for spark-ignition engines using other fuels  
starting in model year 1990.  
    (2) Naturally aspirated diesel-fueled engines starting in model  
year 1985.  
    (3) Methanol-fueled compression-ignition engines starting in  
model year 1990.  
    (4) Naturally aspirated gaseous-fueled engines starting in model  
year 1997, and all other gaseous-fueled engines starting in 1998.  
    (d) Early steady-state standards. The following criteria  
standards applied to heavy-duty engines based on steady-state  
measurement procedures:  
               Table 1 to Appendix A--Early Steady-State Emission Standards for Heavy-Duty Engines  
----------------------------------------------------------------------------------------------------------------  
                                                                               Pollutant  
           Model year                    Fuel        -----------------------------------------------------------  
                                                              HC               NOX + HC               CO  
----------------------------------------------------------------------------------------------------------------  
1970-1973.......................  gasoline..........  275 ppm...........  ..................  1.5 volume  
                                                                                               percent.  
1974-1978.......................  gasoline and        ..................  16 g/hp[middot]hr.  40 g/hp[middot]hr.  
                                   diesel.  
1979-1984 a.....................  gasoline and        ..................  5 g/hp[middot]hr    25 g/hp[middot]hr.  
                                   diesel.                                 for diesel, 5.0 g/  
                                                                           hp[middot]hr for  
                                                                           gasoline.  
----------------------------------------------------------------------------------------------------------------  
a An optional NOX + HC standard of 10 g/hp[middot]hr applied in 1979 through 1984 in conjunction with a separate  
  HC standard of 1.5 g/hp[middot]hr.  
    (e) Transient emission standards for spark-ignition engines. The  
following criteria standards applied for spark-ignition engines  
based on transient measurement using the test procedures in 40 CFR  
part 86, subpart N. Starting in model year 1991, manufacturers could  
generate or use emission credits for NO X and  
NOX + NMHC standards. Table 2 to this appendix follows:  
               Table 2 to Appendix A--Transient Emission Standards for Spark-Ignition Engines a b  
----------------------------------------------------------------------------------------------------------------  
                                                                    Pollutant (g/hp[middot]hr)  
                   Model year                    ---------------------------------------------------------------  
                                                        HC              CO              NOX         NOX + NMHC  
----------------------------------------------------------------------------------------------------------------  
1985-1987.......................................             1.1            14.4            10.6  ..............  
1988-1990.......................................             1.1            14.4             6.0  ..............  
1991-1997.......................................             1.1            14.4             5.0  ..............  
1998-2004 \c\...................................             1.1            14.4             4.0  ..............  
2005-2007.......................................  ..............            14.4  ..............         \d\ 1.0  
----------------------------------------------------------------------------------------------------------------  
\a\ Standards applied only for gasoline-fueled engines through model year 1989. Standards started to apply for  
  methanol in model year 1990, and for LPG and natural gas in model year 1998.  
\b\ Engines intended for installation only in heavy-duty vehicles above 14,000 pounds GVWR were subject to an HC  
  standard of 1.9 g/hp[middot]hr for model years 1987 through 2004, and a CO standard of 37.1 g/hp[middot]hr for  
  model years 1987 through 2007. In addition, for model years 1987 through 2007, up to 5 percent of a  
  manufacturer's sales of engines intended for installation in heavy-duty vehicles at or below 14,000 pounds  
  GVWR could be certified to the alternative HC and CO standards.  
\c\ For natural gas engines in model years 1998 through 2004, the NOX standard was 5.0 g/hp[middot]hr; the HC  
  standards were 1.7 g/hp[middot]hr for engines intended for installation only in vehicles above 14,000 pounds  
  GVWR, and 0.9 g/hp[middot]hr for other engines.  
\d\ Manufacturers could delay the 1.0 g/hp[middot]hr NOX + NMHC standard until model year 2008 by meeting an  
  alternate NOX + NMHC standard of 1.5 g/hp[middot]hr applied for model years 2004 through 2007.  
    (f) Transient emission standards for compression-ignition  
engines. The following criteria standards applied for compression-  
ignition engines based on transient measurement using the test  
procedures in 40 CFR part 86, subpart N. Starting in model year  
1991, manufacturers could generate or use emission credits for  
NOX, NOX + NMHC, and PM standards. Table 3 to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 116/268this appendix follows:  
             Table 3 to Appendix A--Transient Emission Standards for Compression-Ignition Engines a  
----------------------------------------------------------------------------------------------------------------  
                                                           Pollutant (g/hp[middot]hr)  
          Model year           ---------------------------------------------------------------------------------  
                                      HC              CO              NOX         NOX + NMHC           PM  
----------------------------------------------------------------------------------------------------------------  
1985-1987.....................             1.3            15.5            10.7  ..............  ................  
1988-1989.....................             1.3            15.5            10.7  ..............  0.60.  
1990..........................             1.3            15.5             6.0  ..............  0.60.  
1991-1992.....................             1.3            15.5             5.0  ..............  0.25.  
1993..........................             1.3            15.5             5.0  ..............  0.25 truck, 0.10  
                                                                                                 bus.  
1994-1995.....................             1.3            15.5             5.0  ..............  0.10 truck, 0.07  
                                                                                                 urban bus.  
1996-1997.....................             1.3            15.5             5.0  ..............  0.10 truck, 0.05  
                                                                                                 urban bus.\b\  
1998-2003.....................             1.3            15.5             4.0  ..............  0.10 truck, 0.05  
                                                                                                 urban bus.\b\  
2004-2006.....................  ..............            15.5  ..............         \c\ 2.4  0.10 truck, 0.05  
                                                                                                 urban bus.\b\  
----------------------------------------------------------------------------------------------------------------  
\a\ Standards applied only for diesel-fueled engines through model year 1989. Standards started to apply for  
  methanol in model year 1990, and for LPG and natural gas in model year 1997. An alternate HC standard of 1.2 g/  
  hp[middot]hr applied for natural gas engines for model years 1997 through 2003.  
\b\ The in-use PM standard for urban bus engines in model years 1996 through 2006 was 0.07 g/hp[middot]hr.  
[[Page 34408]]  
  
\c\ An optional NOX + NMHC standard of 2.5 g/hp[middot]hr applied in 2004 through 2006 in conjunction with a  
  separate NMHC standard of 0.5 g/hp[middot]hr.  
0 
126. Add appendix B to part 1036 to read as follows:  
Appendix B to Part 1036--Transient Duty Cycles  
    (a) This appendix specifies transient duty cycles for the engine  
and powertrain testing described in Sec.  1036.510, as follows:  
    (1) The transient duty cycle for testing engines involves a  
schedule of normalized engine speed and torque values.  
    (2) The transient duty cycles for powertrain testing involves a  
schedule of vehicle speeds and road grade. Determine road grade at  
each point based on the peak rated power of the powertrain system,  
Prated, determined in Sec.  1036.527 and road grade  
coefficients using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.059  
    (b) The following transient duty cycle applies for spark-  
ignition engines and powertrains:  
BILLING CODE 6560-50-P  
[GRAPHIC] [TIFF OMITTED] TR29JN21.060  
[[Page 34409]]  
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[[Page 34433]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.085  
    (c) The following transient duty cycle applies for compression  
ignition engines and powertrains:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.086  
[[Page 34434]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.087  
[[Page 34435]]  
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[[Page 34440]]  
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[[Page 34443]]  
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[[Page 34448]]  
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[[Page 34458]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.111  
BILLING CODE 6560-50-C  
[[Page 34459]]  
PART 1037--CONTROL OF EMISSIONS FROM NEW HEAVY-DUTY MOTOR VEHICLES  
0 
127. The authority citation for part 1037 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
128. Amend Sec.  1037.103 by revising paragraph (c) to read as follows:  
Sec.  1037.103  Evaporative and refueling emission standards.  
* * * * *  
    (c) Compliance demonstration. You may provide a statement in the  
application for certification that vehicles above 14,000 pounds GVWR  
comply with evaporative and refueling emission standards in this  
section instead of submitting test data if you include an engineering  
analysis describing how vehicles include design parameters, equipment,  
operating controls, or other elements of design that adequately  
demonstrate that vehicles comply with the standards throughout the  
useful life. We would expect emission control components and systems to  
exhibit a comparable degree of control relative to vehicles that comply  
based on testing. For example, vehicles that comply under this  
paragraph (c) should rely on comparable material specifications to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 120/268limit fuel permeation, and components should be sized and calibrated to  
correspond with the appropriate fuel capacities, fuel flow rates, purge  
strategies, and other vehicle operating characteristics. You may  
alternatively show that design parameters are comparable to those for  
vehicles at or below 14,000 pounds GVWR certified under 40 CFR part 86,  
subpart S.  
* * * * *  
0 
129. Amend Sec.  1037.105 by revising paragraph (h)(1) to read as  
follows:  
Sec.  1037.105  CO2 emission standards for vocational vehicles.  
* * * * *  
    (h) * * *  
    (1) The following alternative emission standards apply by vehicle  
type and model year as follows:  
                          Table 5 of Sec.   1037.105--Phase 2 Custom Chassis Standards  
                                                  [g/ton-mile]  
----------------------------------------------------------------------------------------------------------------  
                Vehicle type a                  Assigned vehicle service class     MY 2021-2026      MY 2027+  
----------------------------------------------------------------------------------------------------------------  
School bus...................................  Medium HDV......................              291             271  
Motor home...................................  Medium HDV......................              228             226  
Coach bus....................................  Heavy HDV.......................              210             205  
Other bus....................................  Heavy HDV.......................              300             286  
Refuse hauler................................  Heavy HDV.......................              313             298  
Concrete mixer...............................  Heavy HDV.......................              319             316  
Mixed-use vehicle............................  Heavy HDV.......................              319             316  
Emergency vehicle............................  Heavy HDV.......................              324             319  
----------------------------------------------------------------------------------------------------------------  
a Vehicle types are generally defined in Sec.   1037.801. ``Other bus'' includes any bus that is not a school  
  bus or a coach bus. A ``mixed-use vehicle'' is one that meets at least one of the criteria specified in Sec.  
  1037.631(a)(1) and at least one of the criteria in Sec.   1037.631(a)(2), but not both.  
* * * * *  
0 
130. Amend Sec.  1037.106 by revising paragraphs (b) and (f)(2)(i) to  
read as follows:  
Sec.  1037.106  Exhaust emission standards for tractors above 26,000  
pounds GVWR.  
* * * * *  
    (b) The CO 2 standards for tractors above 26,000 pounds  
GVWR in Table 1 of this section apply based on modeling and testing as  
described in subpart F of this part. The provisions of Sec.  1037.241  
specify how to comply with the standards in this paragraph (b).  
            Table 1 of Sec.   1037.106--CO2 Standards for Class 7 and Class 8 Tractors by Model Year  
                                                  [g/ton-mile]  
----------------------------------------------------------------------------------------------------------------  
                                    Phase 1         Phase 1         Phase 2         Phase 2          Phase 2  
                                 standards for   standards for   standards for   standards for    standards for  
         Subcategory a            model years     model years     model years     model years    model year 2027  
                                   2014-2016       2017-2020       2021-2023       2024-2026        and later  
----------------------------------------------------------------------------------------------------------------  
Class 7 Low-Roof (all cab                  107             104           105.5            99.8              96.2  
 styles)......................  
Class 7 Mid-Roof (all cab                  119             115           113.2           107.1             103.4  
 styles)......................  
Class 7 High-Roof (all cab                 124             120           113.5           106.6             100.0  
 styles)......................  
Class 8 Low-Roof Day Cab......              81              80            80.5            76.2              73.4  
Class 8 Low-Roof Sleeper Cab..              68              66            72.3            68.0              64.1  
Class 8 Mid-Roof Day Cab......              88              86            85.4            80.9              78.0  
Class 8 Mid-Roof Sleeper Cab..              76              73            78.0            73.5              69.6  
Class 8 High-Roof Day Cab.....              92              89            85.6            80.4              75.7  
Class 8 High-Roof Sleeper Cab.              75              72            75.7            70.7              64.3  
Heavy-Haul Tractors...........  ..............  ..............            52.4            50.2              48.3  
----------------------------------------------------------------------------------------------------------------  
a Subcategory terms are defined in Sec.   1037.801.  
* * * * *  
    (f) * * *  
    (2) * * *  
    (i) If you certify all your Class 7 tractors to Class 8 standards,  
you may use these Heavy HDV credits without restriction. This paragraph  
(f)(2)(i) applies equally for hybrid and electric vehicles.  
* * * * *  
0 
131. Amend Sec.  1037.115 by revising paragraph (e) to read as follows:  
Sec.  1037.115  Other requirements.  
* * * * *  
    (e) Air conditioning leakage. Loss of refrigerant from your air  
conditioning systems may not exceed a total leakage rate of 11.0 grams  
per year or a percent leakage rate of 1.50 percent per year,  
[[Page 34460]]  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 121/268whichever is greater. Calculate the total leakage rate in g/year as  
specified in 40 CFR 86.1867-12(a). Calculate the percent leakage rate  
as: [total leakage rate (g/yr)] / [total refrigerant capacity (g)] x  
100. Round your percent leakage rate to the nearest one-hundredth of a  
percent. This paragraph (e) applies for all refrigerants.  
    (1) This paragraph (e) is intended to address air conditioning  
systems for which the primary purpose is to cool the driver  
compartment. This would generally include all cab-complete pickups and  
vans. This paragraph (e) does not apply for refrigeration units on  
trailers. Similarly, it does not apply for self-contained air  
conditioning used to cool passengers or refrigeration units used to  
cool cargo on vocational vehicles. Air conditioning and refrigeration  
units may be considered self-contained whether or not they draw  
electrical power from engines used to propel the vehicles. For purposes  
of this paragraph (e), a self-contained system is an enclosed unit with  
its own evaporator and condenser even if it draws power from the  
engine. 
    (2) For purposes of this paragraph (e), ``refrigerant capacity'' is  
the total mass of refrigerant recommended by the vehicle manufacturer  
as representing a full charge. Where full charge is specified as a  
pressure, use good engineering judgment to convert the pressure and  
system volume to a mass.  
    (3) If air conditioning systems with capacity above 3,000 grams of  
refrigerant are designed such that a compliance demonstration under 40  
CFR 86.1867-12(a) is impossible or impractical, you may ask to use  
alternative means to demonstrate that your air conditioning system  
achieves an equivalent level of control.  
0 
132. Amend Sec.  1037.120 by revising paragraph (b)(1)(i) and (ii) to  
read as follows:  
Sec.  1037.120  Emission-related warranty requirements.  
* * * * *  
    (b) * * *  
    (1) * * *  
    (i) 5 years or 50,000 miles for Light HDV (except tires).  
    (ii) 5 years or 100,000 miles for Medium HDV and Heavy HDV (except  
tires). 
* * * * *  
Sec.  1037.135  [Amended]  
0 
133. Amend Sec.  1037.135 by removing and reserving paragraph (c)(4).  
0 
134. Amend Sec.  1037.140 by revising paragraphs (g) and (h) to read as  
follows:  
Sec.  1037.140  Classifying vehicles and determining vehicle  
parameters.  
* * * * *  
    (g) The 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 of this part  
apply to both tractors and vocational vehicles, Class 7 tractors are  
considered ``Medium HDV'' and Class 8 tractors are considered ``Heavy  
HDV''. This paragraph (g)(1) applies for electric, hybrid, and non-  
hybrid vehicles.  
    (2) Phase 1 vocational vehicles are divided based on GVWR. ``Light  
HDV'' includes Class 2b through Class 5 vehicles; ``Medium HDV''  
includes Class 6 and Class 7 vehicles; and ``Heavy HDV'' includes Class  
8 vehicles.  
    (3) Phase 2 vocational vehicles propelled by engines subject to the  
spark-ignition standards of 40 CFR part 1036, ``Light HDV'' includes  
Class 2b through Class 5 vehicles, and ``Medium HDV'' includes Class 6  
through Class 8 vehicles.  
    (4) Phase 2 vocational vehicles propelled by engines subject to the  
compression-ignition standards in 40 CFR part 1036 are divided as  
follows:  
    (i) Class 2b through Class 5 vehicles are considered ``Light HDV''.  
    (ii) Class 6 through 8 vehicles are considered ``Heavy HDV'' if the  
installed engine's primary intended service class is heavy heavy-duty  
(see 40 CFR 1036.140).  
    (iii) Class 8 hybrid and electric vehicles are considered ``Heavy  
HDV'', regardless of the engine's primary intended service class.  
    (iv) All other Class 6 through Class 8 vehicles are considered  
``Medium HDV''.  
    (5) In certain circumstances, you may certify vehicles to standards  
that apply for a different vehicle service class. For example, see  
Sec. Sec.  1037.105(g) and 1037.106(f). If you optionally certify  
vehicles to different standards, those vehicles are subject to all the  
regulatory requirements as if the standards were mandatory.  
    (h) Use good engineering judgment to identify the intended  
regulatory subcategory (Urban, Multi-Purpose, or Regional) for each of  
your vocational vehicle configurations based on the expected use of the  
vehicles.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 122/2680 
135. Amend Sec.  1037.150 by revising paragraphs (c), (q)(2), (s), (u),  
(x) introductory text, (y), (z), and (aa) to read as follows:  
Sec.  1037.150  Interim provisions.  
* * * * *  
    (c) Small manufacturers. The following provisions apply for small  
manufacturers:  
    (1) Small manufacturers are not subject to the greenhouse gas  
standards of Sec.  1037.107 for trailers with a date of manufacture  
before January 1, 2019.  
    (2) The greenhouse gas standards of Sec. Sec.  1037.105 and  
1037.106 are optional for small manufacturers producing vehicles with a  
date of manufacture before January 1, 2022. In addition, small  
manufacturers producing vehicles that run on any fuel other than  
gasoline, E85, or diesel fuel may delay complying with every later  
standard under this part by one model year.  
    (3) Qualifying manufacturers must notify the Designated Compliance  
Officer each model year before introducing excluded vehicles into U.S.  
commerce. This notification must include a description of the  
manufacturer's qualification as a small business under 13 CFR 121.201.  
Manufacturers must label excluded vehicles with the following  
statement: ``THIS VEHICLE IS EXCLUDED UNDER 40 CFR 1037.150(c).''  
    (4) Small manufacturers may meet Phase 1 standards instead of Phase  
2 standards in the first year Phase 2 standards apply to them if they  
voluntarily comply with the Phase 1 standards for the full preceding  
year. Specifically, small manufacturers may certify their model year  
2022 vehicles to the Phase 1 greenhouse gas standards of Sec. Sec.   
1037.105 and 1037.106 if they certify all the vehicles from their  
annual U.S.-directed production volume to the Phase 1 standards  
starting on or before January 1, 2021.  
    (5) See paragraphs (r), (t), (y), and (aa) of this section for  
additional allowances for small manufacturers.  
* * * * *  
    (q) * * *  
    (2) For vocational vehicles and tractors subject to Phase 2  
standards, create separate vehicle subfamilies if there is a credit  
multiplier for advanced technology; group those vehicles together in a  
vehicle subfamily if they use the same multiplier.  
* * * * *  
    (s) Confirmatory testing for Falt-aero. If we conduct coastdown  
testing to verify your F alt-aero  value for Phase 2 tractors,  
we will make our determination using the principles of SEA testing in  
Sec.  1037.305. We will not replace your F alt-aero  value if  
the tractor passes. If your tractor fails, we will generate a  
replacement value of F alt-aero  based on at least one  
CdA value and corresponding  
[[Page 34461]]  
effective yaw angle, C eff, from a minimum of 100 valid runs  
using the procedures of Sec.  1037.528(h). Note that we intend to  
minimize the differences between our test conditions and those of the  
manufacturer by testing at similar times of the year where possible and  
the same location where possible and when appropriate.  
* * * * *  
    (u) Streamlined preliminary approval for trailer devices. Before  
January 1, 2018, manufacturers of aerodynamic devices for trailers may  
ask for preliminary EPA approval of compliance data for their devices  
based on qualifying for designation under the SmartWay program based on  
measured C dA values, whether or not that involves testing or  
other methods specified in Sec.  1037.526. Trailer manufacturers may  
certify based on [Delta]C dA values established under this  
paragraph (u) through model year 2020. Manufacturers must perform  
testing as specified in subpart F of this part for any vehicles or  
aerodynamic devices not qualifying for approval under this paragraph  
(u). 
* * * * *  
    (x) Aerodynamic testing for trailers. Section 1037.526 generally  
requires you to adjust [Delta]C dA values from alternate test  
methods to be equivalent to measurements with the primary test method.  
This paragraph (x) describes approximations that we believe are  
consistent with good engineering judgment; however, you may not use  
these approximations where we determine that clear and convincing  
evidence shows that they would significantly overestimate actual  
improvements in aerodynamic performance.  
* * * * *  
    (y) Transition to Phase 2 standards. The following provisions allow  
for enhanced generation and use of emission credits from Phase 1  
tractors and vocational vehicles for meeting the Phase 2 standards:  
    (1) For vocational Light HDV and vocational Medium HDV, emission  
credits you generate 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 Sec.  1037.740(c). For Class 8 vocational vehicles  
with medium heavy-duty engines, we will approve your request to  
generate these credits in and use these credits for the Medium HDV  
averaging set if you show that these vehicles would qualify as Medium  
HDV under the Phase 2 program as described in Sec.  1037.140(g)(4).  
    (2) You may use the off-cycle provisions of Sec.  1037.610 to apply  
technologies to Phase 1 vehicles as follows:  
    (i) You may apply an improvement factor of 0.988 for tractors and  
vocational vehicles with automatic tire inflation systems on all axles.  
    (ii) For vocational vehicles with automatic engine shutdown systems  
that conform with Sec.  1037.660, you may apply an improvement factor  
of 0.95.  
    (iii) For vocational vehicles with stop-start systems that conform  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 123/268with Sec.  1037.660, you may apply an improvement factor of 0.92.  
    (iv) For vocational vehicles with neutral-idle systems conforming  
with Sec.  1037.660, you may apply an improvement factor of 0.98. You  
may adjust this improvement factor if we approve a partial reduction  
under Sec.  1037.660(a)(2); for example, if your design reduces fuel  
consumption by half as much as shifting to neutral, you may apply an  
improvement factor of 0.99.  
    (3) Small manufacturers may generate emission credits for natural  
gas-fueled vocational vehicles as follows:  
    (i) Small manufacturers may certify their vehicles instead of  
relying on the exemption of paragraph (c) of this section. The  
provisions of this part apply for such vehicles, except as specified in  
this paragraph (y)(3).  
    (ii) Use GEM version 2.0.1 to determine a CO 2 emission  
level for your vehicle, then multiply this value by the engine's FCL  
for CO2 and divide by the engine's applicable CO 2  
emission standard.  
    (4) Phase 1 vocational vehicle credits that small manufacturers  
generate may be used through model year 2027.  
    (z) Constraints for vocational regulatory subcategories. The  
following provisions apply to determinations of vocational regulatory  
subcategories as described in Sec.  1037.140:  
    (1) Select the Regional regulatory subcategory if you certify the  
engine based on testing only with the Supplemental Emission Test.  
    (2) Select the Regional regulatory subcategory for coach buses and  
motor homes you certify under Sec.  1037.105(b).  
    (3) You may not select the Urban regulatory subcategory for any  
vehicle with a manual or single-clutch automated manual transmission.  
    (4) Starting in model year 2024, you must select the Regional  
regulatory subcategory for any vehicle with a manual transmission.  
    (5) You may select the Multi-purpose regulatory subcategory for any  
vocational vehicle, except as specified in paragraphs (z)(1) through  
(3) of this section.  
    (6) You may not select the Urban regulatory subcategory for any  
vehicle with a manual or single-clutch automated manual transmission.  
    (7) You may select the Urban regulatory subcategory for a hybrid  
vehicle equipped with regenerative braking, unless it is equipped with  
a manual transmission.  
    (8) You may select the Urban regulatory subcategory for any vehicle  
with a hydrokinetic torque converter paired with an automatic  
transmission, or a continuously variable automatic transmission, or a  
dual-clutch transmission with no more than two consecutive forward  
gears between which it is normal for both clutches to be momentarily  
disengaged.  
    (aa) Custom-chassis standards. The following provisions apply  
uniquely to small manufacturers under the custom-chassis standards of  
Sec.  1037.105(h):  
    (1) You may use emission credits generated under Sec.  1037.105(d),  
including banked or traded credits from any averaging set. Such credits  
remain subject to other limitations that apply under subpart H of this  
part. 
    (2) You may produce up to 200 drayage tractors in a given model  
year to the standards described in Sec.  1037.105(h) for ``other  
buses''. The limit in this paragraph (aa)(2) applies with respect to  
vehicles produced by you and your affiliated companies. Treat these  
drayage tractors as being in their own averaging set.  
0 
136. Amend Sec.  1037.201 by revising paragraph (h) to read as follows:  
Sec.  1037.201  General requirements for obtaining a certificate of  
conformity.  
* * * * *  
    (h) The certification and testing provisions of 40 CFR part 86,  
subpart S, apply instead of the provisions of this subpart relative to  
the evaporative and refueling emission standards specified in Sec.   
1037.103, except that Sec.  1037.243 describes how to demonstrate  
compliance with evaporative emission standards. For vehicles that do  
not use an evaporative canister for controlling diurnal emissions, you  
may certify with respect to exhaust emissions and use the provisions of  
Sec.  1037.622 to let a different company certify with respect to  
evaporative emissions.  
* * * * *  
0 
137. Amend Sec.  1037.205 by revising paragraphs (e) and (f) to read as  
follows:  
Sec.  1037.205  What must I include in my application?  
* * * * *  
    (e) Describe any test equipment and procedures that you used,  
including any special or alternate test procedures you used (see Sec.   
1037.501). Include information describing the procedures  
[[Page 34462]]  
you used to determine C dA values as specified in Sec. Sec.   
1037.525 through 1037.527. Describe which type of data you are using  
for engine fuel maps (see 40 CFR 1036.503). If your trailer  
certification relies on approved data from device manufacturers,  
identify the device and device manufacturer.  
    (f) Describe how you operated any emission-data vehicle before  
testing, including the duty cycle and the number of vehicle operating  
miles used to stabilize emission-related performance. Explain why you  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 124/268selected the method of service accumulation. Describe any scheduled  
maintenance you did, and any practices or specifications that should  
apply for our testing.  
* * * * *  
0 
138. Amend Sec.  1037.225 by revising paragraph (e) to read as follows:  
Sec.  1037.225  Amending applications for certification.  
* * * * *  
    (e) The amended application applies starting with the date you  
submit the amended application, as follows:  
    (1) For vehicle families already covered by a certificate of  
conformity, you may start producing a new or modified vehicle  
configuration any time after you send us your amended application and  
before we make a decision under paragraph (d) of this section. However,  
if we determine that the affected vehicles do not meet applicable  
requirements in this part, we will notify you to cease production of  
the vehicles and may require you to recall the vehicles at no expense  
to the owner. Choosing to produce vehicles under this paragraph (e) is  
deemed to be consent to recall all vehicles that we determine do not  
meet applicable emission standards or other requirements in this part  
and to remedy the nonconformity at no expense to the owner. If you do  
not provide information required under paragraph (c) of this section  
within 30 days after we request it, you must stop producing the new or  
modified vehicles.  
    (2) [Reserved]  
* * * * *  
0 
139. Amend Sec.  1037.230 by revising paragraph (a)(2) to read as  
follows:  
Sec.  1037.230  Vehicle families, sub-families, and configurations.  
    (a) * * *  
    (2) Apply subcategories for tractors (other than vocational  
tractors) as shown in Table 2 of this section.  
    (i) For vehicles certified to the optional tractor standards in  
Sec.  1037.670, assign the subcategories as described in Sec.   
1037.670.  
    (ii) For vehicles intended for export to Canada, you may assign the  
subcategories as specified in the Canadian regulations.  
    (iii) Table 2 follows:  
            Table 2 of Sec.   1037.230--Tractor Subcategories  
------------------------------------------------------------------------  
  
------------------------------------------------------------------------  
Class 7                                           Class 8  
------------------------------------------------------------------------  
Low-roof tractors...............  Low-roof day cabs.  Low-roof sleeper  
                                                       cabs.  
Mid-roof tractors...............  Mid-roof day cabs.  Mid-roof sleeper  
                                                       cabs.  
High-roof tractors..............  High-roof day cabs  High-roof sleeper  
                                                       cabs.  
                                 ---------------------------------------  
                                    Heavy-haul tractors (starting with  
                                                 Phase 2).  
------------------------------------------------------------------------  
* * * * *  
0 
140. Amend Sec.  1037.231 by revising paragraph (b)(7) to read as  
follows:  
Sec.  1037.231  Powertrain families.  
* * * * *  
    (b) * * *  
    (7) Number of available forward gears, and transmission gear ratio  
for each available forward gear, if applicable. Count forward gears as  
being available only if the vehicle has the hardware and software to  
allow operation in those gears.  
* * * * *  
0 
141. Amend Sec.  1037.235 by revising paragraphs (a), (c)(2), and (h)  
to read as follows:  
Sec.  1037.235  Testing requirements for certification.  
* * * * *  
    (a) Select emission-data vehicles that represent production  
vehicles and components for the vehicle family consistent with the  
specifications in Sec. Sec.  1037.205(o), 1037.515, and 1037.520. Where  
the test results will represent multiple vehicles or components with  
different emission performance, use good engineering judgment to select  
worst-case emission data vehicles or components. In the case of  
powertrain testing under Sec.  1037.550, select a test engine, test  
hybrid components, test axle, and test transmission as applicable, by  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 125/268considering the whole range of vehicle models covered by the powertrain  
family and the mix of duty cycles specified in Sec.  1037.510. If the  
powertrain has more than one transmission calibration, for example  
economy vs. performance, you may weight the results from the powertrain  
testing in Sec.  1037.550 by the percentage of vehicles in the family  
by prior model year for each configuration. This can be done, for  
example, through the use of survey data or based on the previous model  
year's sales volume. Weight the results of M fuel[cycle] , 
[GRAPHIC] [TIFF OMITTED] TR29JN21.112  
and W[cycle] from Table 2 of Sec.  1037.550 according to the  
percentage of vehicles in the family that use each transmission  
calibration.  
* * * * *  
    (c) * * *  
    (2) If we measure emissions (or other parameters, as applicable)  
from your vehicle or component, the results of that testing become the  
official emission results for the vehicle or component. Note that  
changing the official emission result does not necessarily require a  
change in the declared modeling input value. These results will only  
affect your vehicle FEL if the results of our confirmatory testing  
result in a GEM vehicle emission value that is higher than the vehicle  
FEL declared by the manufacturer. Unless we later invalidate these  
data, we may decide not to consider your data in determining if your  
vehicle family meets applicable requirements in this part.  
* * * * *  
    (h) You may ask us to use analytically derived GEM inputs for  
untested configurations (such as untested axle ratios within an axle  
family) as identified in subpart F of this part based on interpolation  
of all relevant measured values for related configurations, consistent  
with good engineering judgment. We may establish specific approval  
criteria based on prevailing industry practice. If we allow this, we  
may test any configuration. We  
[[Page 34463]]  
may also require you to test any configuration as part of a selective  
enforcement audit.  
0 
142. Amend Sec.  1037.243 by revising paragraph (c) to read as follows:  
Sec.  1037.243  Demonstrating compliance with evaporative emission  
standards.  
* * * * *  
    (c) Apply deterioration factors to measured emission levels for  
comparing to the emission standard in subpart B of this part. Establish  
an additive deterioration factor based on an engineering analysis that  
takes into account the expected aging from in-use vehicles.  
* * * * *  
0 
143. Revise Sec.  1037.255 to read as follows:  
Sec.  1037.255  What decisions may EPA make regarding my certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
vehicle family meets all the requirements of this part and the Act, we  
will issue a certificate of conformity for the vehicle family for that  
model year. We may make the approval subject to additional conditions.  
    (b) We may deny an application for certification if we determine  
that a vehicle family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny an application or suspend or revoke a  
certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce vehicles for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all vehicles being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Act. Note that these are also violations of 40 CFR  
1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1037.820).  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 126/2680 
144. Amend Sec.  1037.301 by revising paragraph (b) to read as follows:  
Sec.  1037.301  Overview of measurements related to GEM inputs in a  
selective enforcement audit.  
* * * * *  
    (b) A selective enforcement audit for this part consists of  
performing measurements with production vehicles relative to one or  
more declared values for GEM inputs, and using those measured values in  
place of your declared values to run GEM. Except as specified in this  
subpart, the vehicle is considered passing if the new modeled emission  
result is at or below the modeled emission result corresponding to the  
declared GEM inputs. If you report an FEL for the vehicle configuration  
before the audit, we will instead consider the vehicle passing if the  
new cycle-weighted emission result is at or below the FEL.  
* * * * *  
0 
145. Amend Sec.  1037.305 by revising the introductory text and  
paragraph (a) to read as follows:  
Sec.  1037.305  Audit procedures for tractors--aerodynamic testing.  
    To perform a selective enforcement audit with respect to drag area  
for tractors, use the reference method specified in Sec.  1037.525; we  
may instead require you to use the same method you used for  
certification. The following provisions apply instead of 40 CFR  
1068.415 through 1068.425 for a selective enforcement audit with  
respect to drag area:  
    (a) Determine whether a tractor meets standards as follows:  
    (1) We will select a vehicle configuration for testing. Perform a  
coastdown measurement according to Sec.  1037.528 with the vehicle in  
its production configuration. If the production configuration cannot be  
connected to a standard trailer, you may ask us to approve trailer  
specifications different than Sec.  1037.501(g)(1) based on good  
engineering judgment. Instead of the process described in Sec.   
1037.528(h)(12), determine your test result as described in this  
paragraph (a). You must have an equal number of runs in each direction.  
    (2) Measure a yaw curve for your test vehicle using your alternate  
method according to Sec.  1037.525(b)(3). You do not need to test at  
the coastdown effective yaw angle. You may use a previously established  
yaw curve from your certification testing if it is available.  
    (3) Using the yaw curve, perform a regression using values of drag  
area, CdAalt, and yaw angle, [psi] alt,  
to determine the air-direction correction coefficients, a 0,  
a1, a2, a3, and a4, for the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.113  
    (4) Adjust the drag area value from each coastdown run,  
CdArun, from the yaw angle of each run,  
[psi]run, to 4.5[deg] to represent a wind-  
averaged drag area value, C dAwa by applying Eq.  
1037.305-1 as follows:  
[[Page 34464]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.114  
    (5) Perform additional coastdown measurements until you reach a  
pass or fail decision under this paragraph (a). The minimum number of  
runs to pass is 24. The minimum number of runs to fail is 100.  
    (6) Calculate statistical values to characterize cumulative test  
results at least once per day based on an equal number of coastdown  
runs in each direction. Determine the wind-averaged drag area value for  
the test C dAwa by averaging all  
CdAwa-run values for all days of testing.  
Determine the upper and lower bounds of the drag area value,  
CdAwa-bounded , expressed to two decimal places,  
using a confidence interval as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.115  
Where: 
CdAwa-bounded  = the upper bound,  
CdAwa-upper , and lower bound,  
CdAwa-lower , of the drag area value, where  
CdAwa-upper  is the larger number.  
CdAwa = the average of all  
CdAwa-run values.  
[sigma] = the standard deviation of all  
CdAwa-run values (see 40 CFR 1065.602(c)).  
n = the total number of coastdown runs.  
    (7) Determine compliance based on the values of  
CdAwa-upper  and CdAwa-lower   
relative to the adjusted bin boundary. For purposes of this section,  
the upper limit of a bin is expressed as the specified value plus 0.05  
to account for rounding. For example, for a bin including values of  
5.5-5.9 m2, being above the upper limit means exceeding 5.95  
m2. The vehicle passes or fails relative to the adjusted bin  
boundary based on one of the following criteria:  
    (i) The vehicle passes if C dAwa-upper  is less  
than or equal to the upper limit of the bin to which you certified the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 127/268vehicle.  
    (ii) The vehicle fails if C dAwa-lower  is  
greater than the upper limit of the bin to which you certified the  
vehicle.  
    (iii) The vehicle passes if you perform 100 coastdown runs and  
CdAwa-upper  is greater than and  
CdAwa-lower  is lower than the upper limit of the  
bin to which you certified the vehicle.  
    (iv) The vehicle fails if you choose to stop testing before  
reaching a final determination under this paragraph (a)(7).  
    (v) You may continue testing beyond the stopping point specified in  
this paragraph (a)(7). We may consider the additional data in making  
pass/fail determinations.  
* * * * *  
0 
146. Revise Sec.  1037.320 to read as follows:  
Sec.  1037.320  Audit procedures for axles and transmissions.  
    Selective enforcement audit provisions apply for axles and  
transmissions relative to the efficiency demonstrations of Sec. Sec.   
1037.560 and 1037.565 as specified in this section. The following  
provisions apply instead of 40 CFR 1068.415 through 1068.445 for the  
selective enforcement audit.  
    (a) A selective enforcement audit for axles or transmissions would  
consist of performing measurements with a production axle or  
transmission to determine mean power loss values as declared for GEM  
simulations, and running GEM over one or more applicable duty cycles  
based on those measured values. The axle or transmission is considered  
passing for a given configuration if the new modeled emission result  
for every applicable duty cycle is at or below the modeled emission  
result corresponding to the declared GEM inputs.  
    (b) Run GEM for each applicable vehicle configuration identified in  
40 CFR 1036.540 using the applicable default engine map defined in  
appendix C of 40 CFR part 1036, and the default torque curve given in  
Table 1 of this section for the vehicle class as defined in Sec.   
1037.140(g). For axle testing, this may require omitting several  
vehicle configurations based on selecting axle ratios that correspond  
to the tested axle. For transmission testing, use the test  
transmission's gear ratios in place of the gear ratios defined in 40  
CFR 1036.540. The GEM result for each vehicle configuration counts as a  
separate test for determining whether the family passes the audit.  
    (c) If the initial axle or transmission passes, the family passes  
and no further testing is required. If the initial axle or transmission  
does not pass, select two additional production axles or transmissions,  
as applicable, to perform additional tests. Note that these could be  
different axle and transmission configurations within the family. These  
become official test results for the family. Use good engineering  
judgment to use the results of these tests to update the declared maps  
for the axle or transmission family. For example, if you fail the audit  
test for any of the axles or transmissions tested, the audit result  
becomes the declared map. This may also require revising any  
analytically derived maps.  
[[Page 34465]]  
                       Table 1 to Sec.   1037.320--Default Torque Curves for Vehicle Class  
----------------------------------------------------------------------------------------------------------------  
              Light HDV                       Medium HDV               Heavy HDV           Light HDV and medium  
----------------------------------------------------------------------------------------    HDV spark-ignition  
                                                                                        ------------------------  
                            Engine       Engine      Engine       Engine      Engine       Engine      Engine  
 Engine speed  (r/min)      torque     speed (r/     torque     speed (r/     torque     speed (r/     torque  
                         (N[middot]m)     min)    (N[middot]m)     min)    (N[middot]m)     min)    (N[middot]m)  
----------------------------------------------------------------------------------------------------------------  
750....................         470          600         850          600        1200          600          433  
907....................         579          750         890          750        1320          700          436  
1055...................         721          850        1000          850        1490          800          445  
1208...................         850          950        1200          950        1700          900          473  
1358...................         876         1050        1440         1050        1950         1000          492  
1507...................         866         1100        1520         1100        2090         1100          515  
1660...................         870         1150        1570         1200        2100         1200          526  
1809...................         868         1250        1590         1250        2100         1300          541  
1954...................         869         1300        1590         1300        2093         1400          542  
2105...................         878         1450        1590         1400        2092         1500          542  
2258...................         850         1500        1590         1500        2085         1600          542  
2405...................         800         1600        1540         1520        2075         1700          547  
2556...................         734         1700        1470         1600        2010         1800          550  
2600...................           0         1800        1385         1700        1910         1900          551  
                         ............       1900        1300         1800        1801         2000          554  
                         ............       2000        1220         1900        1640         2100          553  
                         ............       2100        1040         2000        1350         2200          558  
                         ............       2250         590         2100         910         2300          558  
                         ............       2400           0         2250           0         2400          566  
                         ............  .........  ............  .........  ............       2500          571  
                         ............  .........  ............  .........  ............       2600          572  
                         ............  .........  ............  .........  ............       2700          581  
                         ............  .........  ............  .........  ............       2800          586  
                         ............  .........  ............  .........  ............       2900          587  
                         ............  .........  ............  .........  ............       3000          590  
                         ............  .........  ............  .........  ............       3100          591  
                         ............  .........  ............  .........  ............       3200          589  
                         ............  .........  ............  .........  ............       3300          585  
                         ............  .........  ............  .........  ............       3400          584  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 128/268                         ............  .........  ............  .........  ............       3500          582  
                         ............  .........  ............  .........  ............       3600          573  
                         ............  .........  ............  .........  ............       3700          562  
                         ............  .........  ............  .........  ............       3800          555  
                         ............  .........  ............  .........  ............       3900          544  
                         ............  .........  ............  .........  ............       4000          534  
                         ............  .........  ............  .........  ............       4100          517  
                         ............  .........  ............  .........  ............       4200          473  
                         ............  .........  ............  .........  ............       4291          442  
                         ............  .........  ............  .........  ............       4500          150  
----------------------------------------------------------------------------------------------------------------  
0 
147. Amend Sec.  1037.501 by adding paragraph (i) to read as follows:  
Sec.  1037.501  General testing and modeling provisions.  
* * * * *  
    (i) Note that declared GEM inputs for fuel maps and aerodynamic  
drag area typically includes compliance margins to account for testing  
variability; for other measured GEM inputs, the declared values are  
typically the measured values without adjustment.  
0 
148. Amend Sec.  1037.510 by revising paragraphs (a)(2), (c)(3), (d),  
and (e) to read as follows:  
Sec.  1037.510  Duty-cycle exhaust testing.  
* * * * *  
    (a) * * *  
    (2) Perform cycle-average engine fuel mapping as described in 40  
CFR 1036.540. For powertrain testing under Sec.  1037.550 or Sec.   
1037.555, perform testing as described in this paragraph (a)(2) to  
generate GEM inputs for each simulated vehicle configuration, and test  
runs representing different idle conditions. Perform testing as  
follows:  
    (i) Transient cycle. The transient cycle is specified in appendix I  
of this part.  
    (ii) Highway cruise cycles. The grade portion of the route  
corresponding to the 55 mi/hr and 65 mi/hr highway cruise cycles is  
specified in appendix IV of this part. Maintain vehicle speed between -  
1.0 mi/hr and 3.0 mi/hr of the speed setpoint; this speed tolerance  
applies instead of the approach specified in 40 CFR 1066.425(b)(1) and  
(2). 
    (iii) Drive idle. Perform testing at a loaded idle condition for  
Phase 2 vocational vehicles. For engines with an adjustable warm idle  
speed setpoint, test at the minimum warm idle speed and the maximum  
warm idle speed; otherwise simply test at the engine's warm idle speed.  
Warm up the powertrain using the vehicle settings for the Test 1  
vehicle configuration as defined in Table 2 or 3 of 40 CFR 1036.540 by  
operating it at 65 mi/hr for 600 seconds. Linearly ramp the powertrain  
down to zero vehicle speed in 20 seconds. Set the engine to operate at  
idle speed for 90 seconds, with the brake applied and the transmission  
in drive (or clutch depressed for manual transmission), and sample  
emissions to determine mean emission values (in g/s) over the last 30  
seconds of idling.  
    (iv) Parked idle. Perform testing at an unloaded idle condition for  
Phase 2 vocational vehicles. For engines with an adjustable warm idle  
speed setpoint, test at the minimum warm idle speed and the maximum  
warm idle speed; otherwise simply test at the engine's warm idle speed.  
Warm up the powertrain using the vehicle settings for the Test 1  
vehicle configuration by  
[[Page 34466]]  
operating it at 65 mi/hr for 600 seconds. Linearly ramp the powertrain  
down to zero vehicle speed in 20 seconds. Set the engine to operate at  
idle speed for 780 seconds, with the transmission in park (or the  
transmission in neutral with the parking brake applied for manual  
transmissions), and sample emissions to determine mean emission values  
(in g/s) over the last 600 seconds of idling.  
* * * * *  
    (c) * * *  
    (3) Table 1 follows:  
                          Table 1 of Sec.   1037.510--Weighting Factors for Duty Cycles  
----------------------------------------------------------------------------------------------------------------  
                                             Distance-weighted                Time-weighted a          Average  
                                    ----------------------------------------------------------------    speed  
                                                                                                     during non-  
                                      Transient   55 mi/hr   65 mi/hr    Drive    Parked   Non-idle  idle cycles  
                                         (%)       cruise     cruise   idle (%)  idle (%)     (%)     (mi/hr) b  
                                                    (%)        (%)  
----------------------------------------------------------------------------------------------------------------  
Day Cabs...........................          19         17         64  ........  ........  ........  ...........  
Sleeper Cabs.......................           5          9         86  ........  ........  ........  ...........  
Heavy-haul tractors................          19         17         64  ........  ........  ........  ...........  
Vocational--Regional...............          20         24         56         0        25        75        38.41  
Vocational--Multi-Purpose (2b-7)...          54         29         17        17        25        58        23.18  
Vocational--Multi-Purpose (8)......          54         23         23        17        25        58        23.27  
Vocational--Urban (2b-7)...........          92          8          0        15        25        60        16.25  
Vocational--Urban (8)..............          90         10          0        15        25        60        16.51  
Vocational with conventional                 42         21         37  ........  ........  ........  ...........  
 powertrain (Phase 1 only).........  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 129/268Vocational Hybrid Vehicles (Phase 1          75          9         16  ........  ........  ........  ...........  
 only).............................  
----------------------------------------------------------------------------------------------------------------  
a Note that these drive idle and non-idle weighting factors do not reflect additional drive idle that occurs  
  during the transient cycle. The transient cycle does not include any parked idle.  
b These values apply even for vehicles not following the specified speed traces.  
    (d) For transient testing, compare actual second-by-second vehicle  
speed with the speed specified in the test cycle and ensure any  
differences are consistent with the criteria as specified in 40 CFR  
1066.425(b) and (c). If the speeds do not conform to these criteria,  
the test is not valid and must be repeated.  
    (e) Run test cycles as specified in 40 CFR part 1066. For testing  
vehicles equipped with cruise control over the highway cruise cycles,  
you may use the vehicle's cruise control to control the vehicle speed.  
For vehicles equipped with adjustable vehicle speed limiters, test the  
vehicle with the vehicle speed limiter at its highest setting.  
* * * * *  
0 
149. Amend Sec.  1037.515 by revising paragraphs (c) and (d)(2) to read  
as follows:  
Sec.  1037.515  Determining CO2 emissions to show compliance for  
trailers.  
* * * * *  
    (c) Drag area. You may use [Delta]C dA values approved  
under Sec.  1037.211 for device manufacturers if your trailers are  
properly equipped with those devices. Determine [Delta]C dA  
values for other trailers based on testing. Measure C dA and  
determine [Delta]C dA values as described in Sec.   
1037.526(a). You may use [Delta]C dA values from one trailer  
configuration to represent any number of additional trailers based on  
worst-case testing. This means that you may apply [Delta]C dA  
values from your measurements to any trailer models of the same  
category with drag area at or below that of the tested configuration.  
For trailers in the short dry box vans and short refrigerated box vans  
that are not 28 feet long, apply the [Delta]C dA value  
established for a comparable 28-foot trailer model; you may use the  
same devices designed for 28-foot trailers or you may adapt those  
devices as appropriate for the different trailer length, consistent  
with good engineering judgment. For example, 48-foot trailers may use  
longer side skirts than the skirts that were tested with a 28-foot  
trailer. Trailer and device manufacturers may seek preliminary approval  
for these adaptations. Determine bin levels based on  
[Delta]C dA test results as described in the following table:  
  Table 2 of Sec.   1037.515--Bin Determinations for Trailers Based on  
                        Aerodynamic Test Results  
                           [[Delta]CdA in m2]  
------------------------------------------------------------------------  
                                                          And use the  
                                                        following value  
    If a trailer's measured     Designate the trailer   for [Delta]CDA .  
      [Delta]CDA is . . .              as . . .               . .  
  
------------------------------------------------------------------------  
<=0.09........................  Bin I................                0.0  
0.10-0.39.....................  Bin II...............                0.1  
0.40-0.69.....................  Bin III..............                0.4  
0.70-0.99.....................  Bin IV...............                0.7  
1.00-1.39.....................  Bin V................                1.0  
1.40-1.79.....................  Bin VI...............                1.4  
>=1.80........................  Bin VII..............                1.8  
------------------------------------------------------------------------  
    (d) * * *  
    (2) Apply weight reductions for other components made with light-  
weight materials as shown in the following table:  
[[Page 34467]]  
       Table 3 of Sec.   1037.515--Weight Reductions for Trailers  
                                [pounds]  
------------------------------------------------------------------------  
                                                       Weight  reduction  
           Component                   Material             (pounds)  
------------------------------------------------------------------------  
Structure for Suspension        Aluminum.............                280  
 Assembly a.  
Hub and Drum (per axle).......  Aluminum.............                 80  
Floor b.......................  Aluminum.............                375  
Floor b.......................  Composite (wood and                  245  
                                 plastic).  
Floor Crossmembers b..........  Aluminum.............                250  
Landing Gear..................  Aluminum.............                 50  
Rear Door.....................  Aluminum.............                187  
Rear Door Surround............  Aluminum.............                150  
Roof Bows.....................  Aluminum.............                100  
Side Posts....................  Aluminum.............                300  
Slider Box....................  Aluminum.............                150  
Upper Coupler Assembly........  Aluminum.............                430  
------------------------------------------------------------------------  
\a\ For tandem-axle suspension sub-frames made of aluminum, apply a  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 130/268  weight reduction of 280 pounds. Use good engineering judgment to  
  estimate a weight reduction for using aluminum sub-frames with other  
  axle configurations.  
\b\ Calculate a smaller weight reduction for short trailers by  
  multiplying the indicated values by 0.528 (28/53).  
* * * * *  
0 
150. Revise Sec.  1037.520 to read as follows:  
Sec.  1037.520  Modeling CO2 emissions to show compliance for  
vocational vehicles and tractors.  
    This section describes how to use the Greenhouse gas Emissions  
Model (GEM) (incorporated by reference in Sec.  1037.810) to show  
compliance with the CO 2 standards of Sec. Sec.  1037.105 and  
1037.106 for vocational vehicles and tractors. Use GEM version 2.0.1 to  
demonstrate compliance with Phase 1 standards; use GEM Phase 2, Version  
3.5.1 to demonstrate compliance with Phase 2 standards. Use good  
engineering judgment when demonstrating compliance using GEM. See Sec.   
1037.515 for calculation procedures for demonstrating compliance with  
trailer standards.  
    (a) General modeling provisions. To run GEM, enter all applicable  
inputs as specified by the model.  
    (1) GEM inputs apply for Phase 1 standards as follows:  
    (i) Model year and regulatory subcategory (see Sec.  1037.230).  
    (ii) Coefficient of aerodynamic drag or drag area, as described in  
paragraph (b) of this section (tractors only).  
    (iii) Steer and drive tire rolling resistance, as described in  
paragraph (c) of this section.  
    (iv) Vehicle speed limit, as described in paragraph (d) of this  
section (tractors only).  
    (v) Vehicle weight reduction, as described in paragraph (e) of this  
section (tractors only for Phase 1).  
    (vi) Automatic engine shutdown systems, as described in Sec.   
1037.660 (only for Class 8 sleeper cabs). Enter a GEM input value of  
5.0 g/ton-mile, or an adjusted value as specified in Sec.  1037.660.  
    (2) For Phase 2 vehicles, the GEM inputs described in paragraphs  
(a)(1)(i) through (v) of this section continue to apply. Note that the  
provisions in this part related to vehicle speed limiters and automatic  
engine shutdown systems are available for vocational vehicles in Phase  
2. The rest of this section describes additional GEM inputs for  
demonstrating compliance with Phase 2 standards. Simplified versions of  
GEM apply for limited circumstances as follows:  
    (i) You may use default engine fuel maps for glider kits as  
described in Sec.  1037.635.  
    (ii) If you certify vehicles to the custom-chassis standards  
specified in Sec.  1037.105(h), run GEM by identifying the vehicle type  
and entering ``NA'' instead of what would otherwise apply for, tire  
revolutions per mile, engine information, transmission information,  
drive axle ratio, axle efficiency, and aerodynamic improvement as  
specified in paragraphs (c)(1), (f), (g)(1) and (3), (i), and (m) of  
this section, respectively. Incorporate other GEM inputs as specified  
in this section.  
    (b) Coefficient of aerodynamic drag and drag area for tractors.  
Determine the appropriate drag area, C dA, for tractors as  
described in this paragraph (b). Use the recommended method or an  
alternate method to establish a value for C dA, expressed in  
m\2\ to one decimal place, as specified in Sec.  1037.525. Where we  
allow you to group multiple configurations together, measure  
CdA of the worst-case configuration.  
    (1) Except as specified in paragraph (b)(2) of this section,  
determine the Phase 1 bin level for your vehicle based on measured  
CdA values as shown in the following tables:  
                      Table 1 to Sec.   1037.520--Cd Inputs for Phase 1 High-Roof Tractors  
----------------------------------------------------------------------------------------------------------------  
                                                                                      If your  
                                                                                   measured  CDA   Then your CD  
                 Tractor type                               Bin level               (M2) is . .   input is . . .  
  
  
----------------------------------------------------------------------------------------------------------------  
High-Roof Day Cabs............................  Bin I...........................           >=8.0            0.79  
                                                Bin II..........................         7.1-7.9            0.72  
                                                Bin III.........................         6.2-7.0            0.63  
                                                Bin IV..........................         5.6-6.1            0.56  
                                                Bin V...........................           <=5.5            0.51  
High-Roof Sleeper Cabs........................  Bin I...........................           >=7.6            0.75  
                                                Bin II..........................         6.8-7.5            0.68  
[[Page 34468]]  
  
                                                Bin III.........................         6.3-6.7            0.60  
                                                Bin IV..........................         5.6-6.2            0.52  
                                                Bin V...........................           <=5.5            0.47  
----------------------------------------------------------------------------------------------------------------  
                Table 2 to Sec.   1037.520--Cd Inputs for Phase 1 Low-Roof and Mid-Roof Tractors  
----------------------------------------------------------------------------------------------------------------  
                                                                                      If your  
                                                                                   measured  CDA   Then your CD  
                 Tractor type                               Bin level               (M2) is . .   input is . . .  
  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 131/268  
----------------------------------------------------------------------------------------------------------------  
Low-Roof Day and Sleeper Cabs.................  Bin I...........................           >=5.1            0.77  
                                                Bin II..........................           <=5.0            0.71  
Mid-Roof Day and Sleeper Cabs.................  Bin I...........................           >=5.6            0.87  
                                                Bin II..........................           <=5.5            0.82  
----------------------------------------------------------------------------------------------------------------  
    (2) For Phase 1 low- and mid-roof tractors, you may instead  
determine your drag area bin based on the drag area bin of an  
equivalent high-roof tractor. If the high-roof tractor is in Bin I or  
Bin II, then you may assume your equivalent low- and mid-roof tractors  
are in Bin I. If the high-roof tractor is in Bin III, Bin IV, or Bin V,  
then you may assume your equivalent low- and mid-roof tractors are in  
Bin II. 
    (3) For Phase 2 tractors other than heavy-haul tractors, determine  
bin levels and C dA inputs as follows:  
    (i) Determine bin levels for high-roof tractors based on  
aerodynamic test results as specified in Sec.  1037.525 and summarized  
in the following table:  
                     Table 3 to Sec.   1037.520--Bin Determinations for Phase 2 High-Roof Tractors Based on Aerodynamic Test Results  
                                                                      [CdA in m\2\]  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                         Tractor type                             Bin I        Bin II      Bin III       Bin IV       Bin V        Bin VI      Bin VII  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
Day Cabs.....................................................        >=7.2      6.6-7.1      6.0-6.5      5.5-5.9      5.0-5.4      4.5-4.9        <=4.4  
Sleeper Cabs.................................................        >=6.9      6.3-6.8      5.7-6.2      5.2-5.6      4.7-5.1      4.2-4.6        <=4.1  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
    (ii) For low- and mid-roof tractors, you may either use the same  
bin level that applies for an equivalent high-roof tractor as shown in  
Table 3 of this section, or you may determine your bin level based on  
aerodynamic test results as described in Table 4 of this section.  
               Table 4 to Sec.   1037.520--Bin Determinations for Phase 2 Low-Roof and Mid-Roof Tractors Based on Aerodynamic Test Results  
                                                                      [CdA in m\2\]  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                         Tractor type                             Bin I        Bin II      Bin III       Bin IV       Bin V        Bin VI      Bin VII  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
Low-Roof Cabs................................................        >=5.4      4.9-5.3      4.5-4.8      4.1-4.4      3.8-4.0      3.5-3.7        <=3.4  
Mid-Roof Cabs................................................        >=5.9      5.5-5.8      5.1-5.4      4.7-5.0      4.4-4.6      4.1-4.3        <=4.0  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
    (iii) Determine the C dA input according to the tractor's  
bin level as described in the following table:  
                                        Table 5 to Sec.   1037.520--Phase 2 CdA Tractor Inputs Based on Bin Level  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                         Tractor type                             Bin I        Bin II      Bin III       Bin IV       Bin V        Bin VI      Bin VII  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
High-Roof Day Cabs...........................................         7.45         6.85         6.25         5.70         5.20         4.70         4.20  
High-Roof Sleeper Cabs.......................................         7.15         6.55         5.95         5.40         4.90         4.40         3.90  
Low-Roof Cabs................................................         6.00         5.60         5.15         4.75         4.40         4.10         3.80  
Mid-Roof Cabs................................................         7.00         6.65         6.25         5.85         5.50         5.20         4.90  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
[[Page 34469]]  
    (4) Note that, starting in model year 2027, GEM internally reduces  
CdA for high-roof tractors by 0.3 m2 to simulate adding a  
rear fairing to the standard trailer.  
    (c) Tire revolutions per mile and rolling resistance. You must have  
a tire revolutions per mile (TRPM) and a tire rolling resistance level  
(TRRL) for each tire configuration. For purposes of this section, you  
may consider tires with the same SKU number to be the same  
configuration. Determine TRRL input values separately for drive and  
steer tires; determine TRPM only for drive tires.  
    (1) Use good engineering judgment to determine a tire's revolutions  
per mile to the nearest whole number as specified in SAE J1025  
(incorporated by reference in Sec.  1037.810). Note that for tire sizes  
that you do not test, we will treat your analytically derived  
revolutions per mile the same as test results, and we may perform our  
own testing to verify your values. We may require you to test a sample  
of additional tire sizes that we select.  
    (2) Measure tire rolling resistance in kg per metric ton as  
specified in ISO 28580 (incorporated by reference in Sec.  1037.810),  
except as specified in this paragraph (c). Use good engineering  
judgment to ensure that your test results are not biased low. You may  
ask us to identify a reference test laboratory to which you may  
correlate your test results. Prior to beginning the test procedure in  
Section 7 of ISO 28580 for a new bias-ply tire, perform a break-in  
procedure by running the tire at the specified test speed, load, and  
pressure for 60  2 minutes.  
    (3) For each tire design tested, measure rolling resistance of at  
least three different tires of that specific design and size. Perform  
the test at least once for each tire. Calculate the arithmetic mean of  
these results to the nearest 0.1 kg/tonne and use this value or any  
higher value as your GEM input for TRRL. You must test at least one  
tire size for each tire model, and may use engineering analysis to  
determine the rolling resistance of other tire sizes of that model.  
Note that for tire sizes that you do not test, we will treat your  
analytically derived rolling resistances the same as test results, and  
we may perform our own testing to verify your values. We may require  
you to test a small sub-sample of untested tire sizes that we select.  
    (4) If you obtain your test results from the tire manufacturer or  
another third party, you must obtain a signed statement from the party  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 132/268supplying those test results to verify that tests were conducted  
according to the requirements of this part. Such statements are deemed  
to be submissions to EPA.  
    (5) For tires marketed as light truck tires that have load ranges  
C, D, or E, use as the GEM input TRRL multiplied by 0.87.  
    (6) For vehicles with at least three drive axles or for vehicles  
with more than three axles total, use good engineering judgment to  
combine tire rolling resistance into three values (steer, drive 1, and  
drive 2) for use in GEM. This may require performing a weighted average  
of tire rolling resistance from multiple axles based on the typical  
load on each axle. For liftable axles, calculate load- and time-  
weighted values to represent the load and the amount of time these  
tires are in contact with the ground during typical in-use operation.  
    (7) For vehicles with a single rear axle, enter ``NA'' as the TRRL  
value for drive axle 2.  
    (d) Vehicle speed limit. If the vehicles will be equipped with a  
vehicle speed limiter, input the maximum vehicle speed to which the  
vehicle will be limited (in miles per hour rounded to the nearest 0.1  
mile per hour) as specified in Sec.  1037.640. Use good engineering  
judgment to ensure the limiter is tamper resistant. We may require you  
to obtain preliminary approval for your designs.  
    (e) Vehicle weight reduction. Develop a weight-reduction as a GEM  
input as described in this paragraph (e). Enter the sum of weight  
reductions as described in this paragraph (e), or enter zero if there  
is no weight reduction. For purposes of this paragraph (e), high-  
strength steel is steel with tensile strength at or above 350 MPa.  
    (1) Vehicle weight reduction inputs for wheels are specified  
relative to dual-wide tires with conventional steel wheels. For  
purposes of this paragraph (e)(1), an aluminum alloy qualifies as  
light-weight if a dual-wide drive wheel made from this material weighs  
at least 21 pounds less than a comparable conventional steel wheel. The  
inputs are listed in Table 6 of this section. For example, a tractor or  
vocational vehicle with aluminum steer wheels and eight (4x2) dual-wide  
aluminum drive wheels would have an input of 210 pounds (2x21 + 8x21).  
       Table 6 to Sec.   1037.520--Wheel-Related Weight Reductions  
------------------------------------------------------------------------  
                                           Weight            Weight  
                                         reduction--       reduction--  
     Weight-reduction technology       phase 1 (lb per   phase 2 (lb per  
                                           wheel)            wheel)  
------------------------------------------------------------------------  
Wide-Base Single Drive Tire with . .  
 .\a\ 
    Steel Wheel.....................                84                84  
    Aluminum Wheel..................               139               147  
    Light-Weight Aluminum Alloy                    147               147  
     Wheel..........................  
Wide-Base Single Trailer Tire with .  
 . .\a\ 
    Steel Wheel.....................  ................                84  
    Aluminum or Aluminum Alloy Wheel  ................               131  
Steer Tire, Dual-wide Drive Tire, or  
 Dual-wide Trailer Tire with . . .
    High-Strength Steel Wheel.......                 8                 8  
    Aluminum Wheel..................                21                25  
    Light-Weight Aluminum Alloy                     30                25  
     Wheel..........................  
------------------------------------------------------------------------  
\a\ The weight reduction for wide-base tires accounts for reduced tire  
  weight relative to dual-wide tires.  
    (2) Weight reduction inputs for tractor components other than  
wheels are specified in the following table:  
[[Page 34470]]  
     Table 7 to Sec.   1037.520--Nonwheel-Related Weight Reductions From Alternative Materials for Tractors  
                                                    [Pounds]  
----------------------------------------------------------------------------------------------------------------  
                                                                                 High-strength  
                 Weight reduction technologies                     Aluminum          steel        Thermoplastic  
----------------------------------------------------------------------------------------------------------------  
Door..........................................................              20                6  ...............  
Roof..........................................................              60               18  ...............  
Cab rear wall.................................................              49               16  ...............  
Cab floor.....................................................              56               18  ...............  
Hood Support Structure System.................................              15                3  ...............  
Hood and Front Fender.........................................  ..............  ...............               65  
Day Cab Roof Fairing..........................................  ..............  ...............               18  
Sleeper Cab Roof Fairing......................................              75               20               40  
Aerodynamic Side Extender.....................................  ..............  ...............               10  
Fairing Support Structure System..............................              35                6  ...............  
Instrument Panel Support Structure............................               5                1  ...............  
Brake Drums--Drive (set of 4).................................             140               74  ...............  
Brake Drums--Non Drive (set of 2).............................              60               42  ...............  
Frame Rails...................................................             440               87  ...............  
Crossmember--Cab..............................................              15                5  ...............  
Crossmember--Suspension.......................................              25                6  ...............  
Crossmember--Non Suspension (set of 3)........................              15                5  ...............  
Fifth Wheel...................................................             100               25  ...............  
Radiator Support..............................................              20                6  ...............  
Fuel Tank Support Structure...................................              40               12  ...............  
Steps.........................................................              35                6  ...............  
Bumper........................................................              33               10  ...............  
Shackles......................................................              10                3  ...............  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 133/268Front Axle....................................................              60               15  ...............  
Suspension Brackets, Hangers..................................             100               30  ...............  
Transmission Case.............................................              50               12  ...............  
Clutch Housing................................................              40               10  ...............  
Fairing Support Structure System..............................              35                6  ...............  
Drive Axle Hubs (set of 4)....................................              80               20  ...............  
Non Drive Hubs (2)............................................              40                5  ...............  
Two-piece driveshaft..........................................              20                5  ...............  
Transmission/Clutch Shift Levers..............................              20                4  ...............  
----------------------------------------------------------------------------------------------------------------  
    (3) Weight-reduction inputs for vocational-vehicle components other  
than wheels are specified in the following table:  
Table 8 to Sec.   1037.520--Nonwheel-Related Weight Reductions From Alternative Materials for Phase 2 Vocational  
                                                    Vehicles  
                                                  [Pounds] \a\  
----------------------------------------------------------------------------------------------------------------  
                                                                                        Vehicle type  
                                                                          --------------------------------------  
                 Component                             Material                          Medium HDV  
                                                                            Light HDV       \b\       Heavy HDV  
----------------------------------------------------------------------------------------------------------------  
Axle Hubs--Non-Drive......................  Aluminum.....................             40                      40  
Axle Hubs--Non-Drive......................  High Strength Steel..........              5                       5  
Axle--Non-Drive...........................  Aluminum.....................             60                      60  
Axle--Non-Drive...........................  High Strength Steel..........             15                      15  
Brake Drums--Non-Drive....................  Aluminum.....................             60                      60  
Brake Drums--Non-Drive....................  High Strength Steel..........             42                      42  
Axle Hubs--Drive..........................  Aluminum.....................             40                      80  
Axle Hubs--Drive..........................  High Strength Steel..........             10                      20  
Brake Drums--Drive........................  Aluminum.....................             70                     140  
Brake Drums--Drive........................  High Strength Steel..........             37                      74  
Suspension Brackets, Hangers..............  Aluminum.....................             67                     100  
Suspension Brackets, Hangers..............  High Strength Steel..........             20                      30  
----------------------------------------------------------------------------------------------------------------  
Crossmember--Cab..........................  Aluminum.....................           10           15           15  
Crossmember--Cab..........................  High Strength Steel..........            2            5            5  
Crossmember--Non-Suspension...............  Aluminum.....................           15           15           15  
Crossmember--Non-Suspension...............  High Strength Steel..........            5            5            5  
Crossmember--Suspension...................  Aluminum.....................           15           25           25  
Crossmember--Suspension...................  High Strength Steel..........            6            6            6  
Driveshaft................................  Aluminum.....................           12           40           50  
Driveshaft................................  High Strength Steel..........            5           10           12  
Frame Rails...............................  Aluminum.....................          120          300          440  
[[Page 34471]]  
  
Frame Rails...............................  High Strength Steel..........           40           40           87  
----------------------------------------------------------------------------------------------------------------  
\a\ Weight-reduction values apply per vehicle unless otherwise noted.  
\b\ For Medium HDV with 6x4 or 6x2 axle configurations, use the values for Heavy HDV.  
    (4) Apply vehicle weight inputs for changing technology  
configurations as follows:  
    (i) For Class 8 tractors or for Class 8 vocational vehicles with a  
permanent 6x2 axle configuration, apply a weight reduction input of 300  
pounds. However, apply no weight reduction for coach buses certified to  
custom-chassis standards under Sec.  1037.105(h).  
    (ii) For Class 8 tractors with 4x2 axle configuration, apply a  
weight reduction input of 400 pounds.  
    (iii) For tractors with installed engines with displacement below  
14.0 liters, apply a weight reduction of 300 pounds.  
    (iv) For tractors with single-piece driveshafts with a total length  
greater than 86 inches, apply a weight reduction of 43 pounds for steel  
driveshafts and 63 pounds for aluminum driveshafts.  
    (5) You may ask to apply the off-cycle technology provisions of  
Sec.  1037.610 for weight reductions not covered by this paragraph (e).  
    (f) Engine characteristics. Enter information from the engine  
manufacturer to describe the installed engine and its operating  
parameters as described in 40 CFR 1036.503. The fuel-mapping  
information must apply for the vehicle's GVWR; for example, if you  
install a medium heavy-duty engine in a Class 8 vehicle, the engine  
must have additional fuel-mapping information for the heavier vehicle.  
Note that you do not need fuel consumption at idle for tractors.  
    (g) Vehicle characteristics. Enter the following information to  
describe the vehicle and its operating parameters:  
    (1) Transmission make, model, and type. Also identify the gear  
ratio for every available forward gear to two decimal places, the input  
torque limit for each of the forward gears, and, if applicable, the  
lowest gear involving a locked torque converter. Count forward gears as  
being available only if the vehicle has the hardware and software to  
allow operation in those gears. For vehicles with a manual  
transmission, GEM applies a 2% emission increase relative to automated  
manual transmissions. If your vehicle has a dual-clutch transmission,  
use good engineering judgment to determine if it can be accurately  
represented in GEM as an automated manual transmission. We may require  
you to perform a powertrain test with dual-clutch transmissions to show  
that they can be properly simulated as an automated manual  
transmission.  
    (2) Drive axle make, model, and configuration. Select a drive axle  
configuration to represent your vehicle for modeling.  
    (i) 4x2: One drive axle and one non-drive axle. This includes  
vehicles with two drive axles where one of the drive axles is  
disconnectable and that disconnectable drive axle is designed to be  
connected only when the vehicle is driven off-road or in slippery  
conditions if at least one of the following is true:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 134/268    (A) The input and output of the disconnectable axle is mechanically  
disconnected from the drive shaft and the wheels when the axle is in  
4x2 configuration.  
    (B) You provide power loss data generated according to Sec.   
1037.560 for the combination of both drive axles, where the  
disconnectable drive axle is in the disconnected configuration.  
    (ii) 6x2: One drive axle and two non-drive axles.  
    (iii) 6x4: Two or more drive axles, or more than three total axles.  
Note that this includes, for example, a vehicle with two drive axles  
out of four total axles (otherwise known as an 8x4 configuration).  
    (iv) 6x4D: One non-drive axle and two drive axles where one of the  
two drive axles is automatically disconnectable such that the axle can  
switch between 6x2 and 6x4 configurations. You may select this  
configuration only if at least one of the following is true:  
    (A) The input and output of the disconnectable axle is mechanically  
disconnected from the drive shaft and the wheels when the axle is in  
the 6x2 configuration.  
    (B) You provide power loss data generated according to Sec.   
1037.560 for the combination of both drive axles, where the  
disconnectable drive axle is in the disconnected configuration.  
    (3) Drive axle ratio, k a. If a vehicle is designed with  
two or more user-selectable axle ratios, use the drive axle ratio that  
is expected to be engaged for the greatest driving distance. If the  
vehicle does not have a drive axle, such as a hybrid vehicle with  
direct electric drive, let k a = 1.
    (4) GEM inputs associated with powertrain testing include  
powertrain family, transmission calibration identifier, test data from  
Sec.  1037.550, and the powertrain test configuration (dynamometer  
connected to transmission output or wheel hub). You do not need to  
identify or provide inputs for transmission gear ratios, fuel map data,  
or engine torque curves, which would otherwise be required under  
paragraph (f) of this section.  
    (h) Idle speed and idle-reduction technologies. The following  
provisions apply for engine idling:  
    (1) For engines with no adjustable warm idle speed, input vehicle  
idle speed as the manufacturer's declared warm idle speed. For engines  
with adjustable warm idle speed, input your vehicle idle speed as  
follows:  
------------------------------------------------------------------------  
                                                          Your default  
                                  And your engine is      vehicle idle  
  If your vehicle is a . . .       subject to . . .       speed is . .  
                                                              .\1\  
------------------------------------------------------------------------  
(i) Heavy HDV.................  compression-ignition    600 r/min.  
                                 or spark-ignition  
                                 standards.  
(ii) Medium HDV tractor.......  compression-ignition    700 r/min.  
                                 standards.  
(iii) Light HDV or Medium HDV   compression-ignition    750 r/min.  
 vocational vehicle.             standards.  
[[Page 34472]]  
  
(iv) Light HDV or Medium HDV..  spark-ignition          600 r/min.  
                                 standards.  
------------------------------------------------------------------------  
\1\ If the default idle speed is above or below the engine  
  manufacturer's whole range of declared warm idle speeds, use the  
  manufacturer's maximum or minimum declared warm idle speed,  
  respectively, instead of the default value.  
    (2) Identify whether your vehicle has qualifying idle-reduction  
technologies, subject to the qualifying criteria in Sec.  1037.660, as  
follows:  
    (i) Stop-start technology and automatic engine shutdown systems  
apply for vocational vehicles. See paragraph (j) of this section for  
automatic engine shutdown systems for tractors.  
    (ii) Neutral idle applies for tractors and vocational vehicles.  
    (i) Axle, transmission, and torque converter characterization. You  
may characterize the axle, transmission, and torque converter using  
axle efficiency maps as described in Sec.  1037.560, transmission  
efficiency maps as described in Sec.  1037.565, and torque converter  
capacity factors and torque ratios as described in Sec.  1037.570 to  
replace the default values in GEM. If you obtain your test results from  
the axle manufacturer, transmission manufacturer, torque converter  
manufacturer or another third party, you must obtain a signed statement  
from the party supplying those test results to verify that tests were  
conducted according to the requirements of this part. Such statements  
are deemed to be submissions to EPA.  
    (j) Additional reduction technologies. Enter input values in GEM as  
follows to characterize the percentage CO 2 emission  
reduction corresponding to certain technologies and vehicle  
configurations, or enter 0:  
    (1) Intelligent controls. Enter 2 for tractors with predictive  
cruise control. This includes any cruise control system that  
incorporates satellite-based global-positioning data for controlling  
operator demand. For other tractors, enter 1.5 if they have neutral  
coasting, unless good engineering judgment indicates that a lower  
percentage should apply.  
    (2) Accessory load. Enter the following values related to accessory  
loads; if more than one item applies, enter the sum of those values:  
    (i) If vocational vehicles have electrically powered pumps for  
steering, enter 0.5 for vocational vehicles certified with the Regional  
duty cycle, and enter 1 for other vocational vehicles.  
    (ii) If tractors have electrically powered pumps for both steering  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 135/268and engine cooling, enter 1.  
    (iii) If vehicles have a high-efficiency air conditioning  
compressor, enter 0.5 for tractors and vocational Heavy HDV, and enter  
1 for other vocational vehicles. This includes all electrically powered  
compressors. It also include mechanically powered compressors if the  
coefficient of performance improves by 10 percent or greater over the  
baseline design, consistent with the provisions for improved  
evaporators and condensers in 40 CFR 86.1868-12(h)(5).  
    (3) Tire-pressure systems. Enter 1.2 for vehicles with automatic  
tire inflation systems on all axles (1.1 for Multi-Purpose and Urban  
vocational vehicles). Enter 1.0 for vehicles with tire pressure  
monitoring systems on all axles (0.9 for Multi-Purpose and Urban  
vocational vehicles). If vehicles use a mix of the two systems, treat  
them as having only tire pressure monitoring systems.  
    (4) Extended-idle reduction. Enter values as shown in the following  
table for sleeper cabs equipped with idle-reduction technology meeting  
the requirements of Sec.  1037.660 that are designed to automatically  
shut off the main engine after 300 seconds or less:  
      Table 9 to Sec.   1037.520--GEM Input Values for AES Systems  
------------------------------------------------------------------------  
                                                    GEM input values  
                                               -------------------------  
                  Technology                                   Tamper-  
                                                 Adjustable   resistant  
------------------------------------------------------------------------  
Standard AES system...........................            1            4  
With diesel APU...............................            3            4  
With battery APU..............................            5            6  
With automatic stop-start.....................            3            3  
With fuel-operated heater (FOH)...............            2            3  
With diesel APU and FOH.......................            4            5  
With battery APU and FOH......................            5            6  
With stop-start and FOH.......................            4            5  
------------------------------------------------------------------------  
    (5) Other. Additional GEM inputs may apply as follows:  
    (i) Enter 0.9 and 1.7, respectively, for school buses and coach  
buses that have at least seven available forward gears.  
    (ii) If we approve off-cycle technology under Sec.  1037.610 in the  
form of an improvement factor, enter the improvement factor expressed  
as a percentage reduction in CO 2 emissions. (Note: In the  
case of approved off-cycle technologies whose benefit is quantified as  
a g/ton-mile credit, apply the credit to the GEM result, not as a GEM  
input value.)  
    (k) Vehicles with hybrid power take-off. For vocational vehicles,  
determine the delta PTO emission result of your engine and hybrid power  
take-off system as described in Sec.  1037.540.  
    (l) [Reserved]  
    (m) Aerodynamic improvements for vocational vehicles. For  
vocational vehicles certified using the Regional duty cycle, enter  
[Delta]C dA values to account for using aerodynamic devices  
as follows:  
    (1) Enter 0.2 for vocational vehicles with an installed rear  
fairing if the vehicle is at least 7 m long with a minimum frontal area  
of 8 m2. 
    (2) For vehicles at least 11 m long with a minimum frontal area of  
9 m2, enter 0.5 if the vehicle has both skirts and a front  
fairing, and enter 0.3 if it has only one of those devices.  
    (3) You may determine input values for these or other technologies  
based on  
[[Page 34473]]  
aerodynamic measurements as described in Sec.  1037.527.  
    (n) Alternate fuels. For fuels other than those identified in GEM,  
perform the simulation by identifying the vehicle as being diesel-  
fueled if the engine is subject to the compression-ignition standard,  
or as being gasoline-fueled if the engine is subject to the spark-  
ignition standards. Correct the engine or powertrain fuel map for mass-  
specific net energy content as described in 40 CFR 1036.535(b).  
0 
151. Revise Sec.  1037.525 to read as follows:  
Sec.  1037.525  Aerodynamic measurements for tractors.  
    This section describes a methodology for quantifying aerodynamic  
drag for use in determining input values for tractors as described in  
Sec.  1037.520. This coastdown testing is the reference method for  
aerodynamic measurements.  
    (a) General provisions. The GEM input for a tractor's aerodynamic  
performance is a C d value for Phase 1 and a C dA  
value for Phase 2. The input value is measured or calculated for a  
tractor in a specific test configuration with a trailer, such as a  
high-roof tractor with a box van meeting the requirements for the  
standard trailer.  
    (1) Aerodynamic measurements may involve any of several different  
procedures. Measuring with different procedures introduces variability,  
so we identify the coastdown method in Sec.  1037.528 as the primary  
(or reference) procedure. You may use other procedures with our advance  
approval as described in paragraph (d) of this section, but we require  
that you adjust your test results from other test methods to correlate  
with coastdown test results. All adjustments must be consistent with  
good engineering judgment. Submit information describing how you  
quantify aerodynamic drag from coastdown testing, whether or not you  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 136/268use an alternate method.  
    (2) Test high-roof tractors with a standard trailer as described in  
Sec.  1037.501(g)(1). Note that the standard trailer for Phase 1  
tractors is different from that of later model years. Note also that  
GEM may model a different configuration than the test configuration,  
but accounts for this internally. Test low-roof and mid-roof tractors  
without a trailer; however, you may test low-roof and mid-roof tractors  
with a trailer to evaluate off-cycle technologies.  
    (b) Adjustments to correlate with coastdown testing. Adjust  
aerodynamic drag values from alternate methods to be equivalent to the  
corresponding values from coastdown measurements as follows:  
    (1) Determine the functional relationship between your alternate  
method and coastdown testing. Specify this functional relationship as  
Falt-aero  for a given alternate drag measurement method. The  
effective yaw angle, [psi] eff, is assumed to be zero degrees  
for Phase 1. For Phase 2, determine [psi] eff from coastdown  
test results using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.116  
Where: 
CdAcoastdown ([psi]eff) = the  
average drag area measured during coastdown at an effective yaw  
angle, [psi] eff. 
    CdAalt([psi]eff) = the average  
drag area calculated from an alternate drag measurement method at an  
effective yaw angle, [psi] eff. 
    (2) Unless good engineering judgment dictates otherwise, assume  
that coastdown drag is proportional to drag measured using alternate  
methods and apply a constant adjustment factor, F alt-aero ,  
for a given alternate drag measurement method of similar vehicles.  
    (3) Determine F alt-aero  by performing coastdown testing  
and applying your alternate method on the same vehicles. Consider all  
applicable test data including data collected during selective  
enforcement audits. Unless we approve another vehicle, one vehicle must  
be a Class 8 high-roof sleeper cab with a full aerodynamics package  
pulling a standard trailer. Where you have more than one tractor model  
meeting these criteria, use the tractor model with the highest  
projected sales. If you do not have such a tractor model, you may use  
your most comparable tractor model with our prior approval. In the case  
of alternate methods other than those specified in this subpart, good  
engineering judgment may require you to determine your adjustment  
factor based on results from more than the specified minimum number of  
vehicles.  
    (4) Measure the drag area using your alternate method for a Phase 2  
tractor used to determine F alt-aero  with testing at yaw  
angles of 0[deg], 1[deg], 3[deg], 4.5[deg], 6[deg], and 9[deg] (you may  
include additional angles), using direction conventions described in  
Figure 2 of SAE J1252 (incorporated by reference in Sec.  1037.810).  
Also, determine the drag area at the coastdown effective yaw angle,  
CdAalt([psi]eff), by taking the  
average drag area at [psi] eff and -[psi] eff for  
your vehicle using the same alternate method.  
    (5) For Phase 2 testing, determine separate values of  
Falt-aero  for at least one high-roof day cab and one high-  
roof sleeper cab for model year 2021, for at least two high-roof day  
cabs and two high-roof sleeper cabs for model year 2024, and for at  
least three high-roof day cabs and three high-roof sleeper cabs for  
model year 2027. These test requirements are cumulative; for example,  
you may meet these requirements by testing two vehicles to support  
model year 2021 certification and four additional vehicles to support  
model year 2023 certification. For any untested tractor models, apply  
the value of F alt-aero  from the tested tractor model that  
best represents the aerodynamic characteristics of the untested tractor  
model, consistent with good engineering judgment. Testing under this  
paragraph (b)(5) continues to be valid for later model years until you  
change the tractor model in a way that causes the test results to no  
longer represent production vehicles. You must also determine unique  
values of F alt-aero  for low-roof and mid-roof tractors if  
you determine C dA values based on low or mid-roof tractor  
testing as shown in Table 4 of Sec.  1037.520. For Phase 1 testing, if  
good engineering judgment allows it, you may calculate a single,  
constant value of F alt-aero  for your whole product line by  
dividing the coastdown drag area, C dAcoastdown ,  
by drag area from your alternate method, C dAalt. 
    (6) Determine F alt-aero  to at least three decimal  
places. For example, if your coastdown testing results in a drag area  
of 6.430, but your wind tunnel method results in a drag area of 6.200,  
Falt-aero  would be 1.037 (or a higher value you declare).  
    (7) If a tractor and trailer cannot be configured to meet the gap  
requirements specified in Sec.  1037.501(g)(1)(ii), test with the  
trailer positioned as close as possible to the specified gap dimension  
and use good engineering judgment to correct the results to be  
equivalent to a test configuration meeting the specified gap dimension.  
For example, we may allow you to correct your test output using an  
approved alternate method or substitute a test vehicle that is capable  
of meeting the required specifications and is otherwise aerodynamically  
equivalent. This allowance applies for certification, confirmatory  
testing, SEA, and all other testing to demonstrate compliance with  
standards.  
    (8) You may ask us for preliminary approval of your coastdown  
testing under Sec.  1037.210. We may witness the testing.  
[[Page 34474]]  
    (c) Yaw sweep corrections. Aerodynamic features can have a  
different effectiveness for reducing wind-averaged drag than is  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 137/268predicted by zero-yaw drag. The following procedures describe how to  
determine a tractor's C dA values to account for wind-  
averaged drag as specified in Sec.  1037.520:  
    (1) Apply the following method for all Phase 2 testing with an  
alternate method:  
    (i) Calculate the wind-averaged drag area from the alternate  
method, C dAwa-alt, using an average of  
measurements at -4.5 and +4.5 degrees.  
    (ii) Determine your wind-averaged drag area,  
CdAwa, rounded to one decimal place, using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.117  
    (2) Apply the following method for Phase 2 coastdown testing other  
than coastdown testing used to establish F alt-aero : 
    (i) Determine your drag area at the effective yaw angle from  
coastdown, C dAcoastdown ([psi]eff). 
    (ii) Use an alternate method to calculate the ratio of the wind-  
averaged drag area, C dAwa-alt (using an average  
of measurements at -4.5 and +4.5 degrees) to the drag area at the  
effective yaw angle, C dAalt([psi]eff). 
    (iii) Determine your wind-averaged drag area,  
CdAwa, rounded to one decimal place, using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.118  
    (3) Different approximations apply for Phase 1. For Phase 1  
testing, you may correct your zero-yaw drag area as follows if the  
ratio of the zero-yaw drag area divided by yaw-sweep drag area for your  
vehicle is greater than 0.8065 (which represents the ratio expected for  
a typical Class 8 high-roof sleeper cab):  
    (i) Determine the zero-yaw drag area, C dAzero- 
yaw, and the yaw-sweep drag area for your vehicle using the same  
alternate method as specified in this subpart. Measure the drag area  
for 0[deg], -6[deg], and +6[deg]. Use the arithmetic mean of the -  
6[deg] and +6[deg] drag areas as the 6[deg] drag area,  
CdA<plus-minus >6. 
    (ii) Calculate your yaw-sweep correction factor, CF ys,  
using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.119  
    (iii) Calculate your corrected drag area for determining the  
aerodynamic bin by multiplying the measured zero-yaw drag area by  
CFys, as determined using Eq. 1037.525-4, as applicable. You  
may apply the correction factor to drag areas measured using other  
procedures. For example, apply CF ys to drag areas measured  
using the coastdown method. If you use an alternate method, apply an  
alternate correction, F alt-aero , and calculate the final  
drag area using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.120  
    (iv) You may ask us to apply CF ys to similar vehicles  
incorporating the same design features.  
    (v) As an alternative, you may calculate the wind-averaged drag  
area according to SAE J1252 (incorporated by reference in Sec.   
1037.810) and substitute this value into Eq. 1037.525-4 for the 6[deg] drag area.  
    (d) Approval of alternate methods. You must obtain preliminary  
approval before using any method other than coastdown testing to  
quantify aerodynamic drag. We will approve your request if you show  
that your procedures produce data that are the same as or better than  
coastdown testing with respect to repeatability and unbiased  
correlation. Note that the correlation is not considered to be biased  
if there is a bias before correction, but you remove the bias using  
Falt-aero . Send your request for approval to the Designated  
Compliance Officer. Keep records of the information specified in this  
paragraph (d). Unless we specify otherwise, include this information  
with your request. You must provide any information we require to  
evaluate whether you may apply the provisions of this section. Include  
additional information related to your alternate method as described in  
Sec. Sec.  1037.530 through 1037.534. If you use a method other than  
those specified in this subpart, include all the following information,  
as applicable:  
    (1) Official name/title of the procedure.  
    (2) Description of the procedure.  
    (3) Cited sources for any standardized procedures that the method  
is based on.  
    (4) Description and rationale for any modifications/deviations from  
the standardized procedures.  
    (5) Data comparing the procedure to the coastdown reference  
procedure.  
    (6) Additional information specified for the alternate methods  
described in Sec. Sec.  1037.530 through 1037.534 as applicable to this  
method (e.g., source location/address, background/history).  
0 
152. Amend Sec.  1037.528 by revising the introductory text and  
paragraphs (a), (c) introductory text, (e) introductory text, (g)(3)  
introductory text, (h)(3)(i), (h)(6), and (h)(12)(v) to read as  
follows:  
Sec.  1037.528  Coastdown procedures for calculating drag area (CdA).  
    The coastdown procedures in this section describe how to calculate  
drag area, C dA, for Phase 2 tractors, trailers, and  
vocational vehicles, subject to the provisions of Sec. Sec.  1037.525  
through 1037.527. These procedures are considered the reference method  
for tractors, but an alternate method for trailers. Follow the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 138/268provisions of Sections 1 through 9 of SAE J2263 (incorporated by  
reference in Sec.  1037.810), with the clarifications and exceptions  
described in this section. Several of these exceptions are from SAE  
J1263 (incorporated by reference in Sec.  1037.810). The coastdown  
procedures in 40 CFR 1066.310 apply instead of the provisions of this  
section for Phase 1 tractors.  
    (a) The terms and variables identified in this section have the  
meaning given in SAE J1263 and SAE J2263 unless specified otherwise.  
* * * * *  
    (c) The test condition specifications described in Sections 7.1  
through 7.4 of  
[[Page 34475]]  
SAE J1263 apply, with certain exceptions and additional provisions as  
described in this paragraph (c). These conditions apply to each run  
separately.  
* * * * *  
    (e) Measure wind speed, wind direction, air temperature, and air  
pressure at a recording frequency of 10 Hz, in conjunction with time-  
of-day data. Use at least one stationary anemometer and suitable data  
loggers meeting SAE J1263 specifications, subject to the following  
additional specifications for the anemometer placed along the test  
surface:  
* * * * *  
    (g) * * *  
    (3) Correct measured air direction from all the high-speed segments  
using the wind speed and wind direction measurements described in  
paragraph (e) of this section as follows:  
* * * * *  
    (h) * * *  
    (3) * * *  
    (i) Calculate the mean vehicle speed to represent the start point  
of each speed range as the arithmetic average of measured speeds  
throughout the continuous time interval that begins when measured  
vehicle speed is less than 2.00 mi/hr above the nominal starting speed  
point and ends when measured vehicle speed reaches 2.00 mi/hr below the  
nominal starting speed point, expressed to at least two decimal places.  
Calculate the timestamp corresponding to the starting point of each  
speed range as the average timestamp of the interval.  
* * * * *  
    (6) For tractor testing, calculate the tire rolling resistance  
force at high and low speeds for steer, drive, and trailer axle  
positions, F TRR[speed,axle] , and determine  
[Delta]F TRR, the rolling resistance difference between 65  
mi/hr and 15 mi/hr, for each tire as follows:  
    (i) Conduct a stepwise coastdown tire rolling resistance test with  
three tires for each tire model installed on the vehicle using SAE  
J2452 (incorporated by reference in Sec.  1037.810) for the following  
test points (which replace the test points in Table 3 of SAE J2452):  
     Table 1 of Sec.   1037.528--Stepwise Coastdown Test Points for  
       Determining Tire Rolling Resistance as a Function of Speed  
------------------------------------------------------------------------  
                                                              Inflation  
                  Step Number                   Load  (% of    pressure  
                                                    max)      (% of max)  
------------------------------------------------------------------------  
1.............................................           20          100  
2.............................................           55           70  
3.............................................           85          120  
4.............................................           85          100  
5.............................................          100           95  
------------------------------------------------------------------------  
    (ii) Calculate FTRR[speed,axle] using the following equation:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.121  
     
Where: 
nt,[axle]  = number of tires at the axle position.  
p[axle] = the inflation pressure set and measured on the  
tires at the axle position at the beginning of the coastdown test.  
L[axle] = the load over the axle at the axle position on  
the coastdown test vehicle.  
[alpha][axle], [beta] [axle],  
a[axle], b[axle], and c[axle] =  
regression coefficients from SAE J2452 that are specific to axle  
position.  
Example:  
nt,steer = 2 
psteer = 758.4 kPa  
Lsteer = 51421.2 N  
[alpha]steer = -0.2435  
[beta]steer = 0.9576  
asteer = 0.0434  
bsteer = 5.4[middot]10-5 
csteer = 5.53[middot]10-7 
nt,drive = 8 
pdrive = 689.5 kPa  
Ldrive = 55958.4 N  
[alpha]drive = -0.3146  
[beta]drive = 0.9914  
adrive = 0.0504  
bdrive = 1.11[middot]10-4 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 139/268cdrive = 2.86[middot]10-7 
nt,trailer  = 8 
ptrailer = 689.5 kPa  
Ltrailer = 45727.5 N  
[alpha]trailer = -0.3982  
[beta]trailer = 0.9756  
atrailer = 0.0656  
btrailer = 1.51[middot]10-4 
ctrailer = 2.94[middot]10-7 
vseghi = 28.86 m/s = 103.896 km/hr
vseglo = 5.84 m/s = 21.024 km/hr  
[GRAPHIC] [TIFF OMITTED] TR29JN21.122  
FTRRhi,steer  = 365.6 N  
FTRRhi,drive  = 431.4 N  
FTRRhi,trailer  = 231.7 N  
FTRRlo,steer  = 297.8 N  
FTRRlo,drive  = 350.7 N  
FTRRlo,trailer  = 189.0 N  
    (iii) Calculate F TRR[speed]  by summing the tire rolling  
resistance calculations at a given speed for each axle position:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.123  
[[Page 34476]]  
Example:  
FTRRhi = 365.6 + 431.4 + 231.7 = 1028.7 N  
FTRRlo = 297.8 + 350.7 + 189.0 = 837.5 N  
    (iv) Adjust F TRR[speed]  to the ambient temperature  
during the coastdown segment as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.124  
Where: 
    Tseg[speed]  = the average ambient temperature during  
the coastdown segment, in [deg]C.  
Example:  
FTRRhi = 1028.7 N  
FTRRlo = 837.5 N  
Tseghi = 25.5 [deg]C  
Tseglo = 25.1 [deg]C  
FTRRhi,adj  = 1 + 0.006[middot](24-25.5)] = 1019.4 N  
FTRRlo,adj  = 837.5[middot][1 + 0.006[middot](24-25.1] =  
832.0 N 
    (v) Determine the difference in rolling resistance between 65 mph  
and 15 mph, [Delta]F TRR, for each tire. Use good engineering  
judgment to consider the multiple results. For example, you may ignore  
the test results for the tires with the highest and lowest differences  
and use the result from the remaining tire. Determine  
[Delta]F TRR as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.125  
Example:  
[Delta]F TRR = 1019.4-832.0 = 187.4 N  
* * * * *  
    (12) * * *  
    (v) For the same set of points, recalculate the mean  
CdA. This is the final result of the coastdown test,  
CdAcoastdown ([psi]eff). 
* * * * *  
0 
153. Amend Sec.  1037.530 by revising paragraph (d)(7) to read as  
follows:  
Sec.  1037.530  Wind-tunnel procedures for calculating drag area (CdA).  
* * * * *  
    (d) * * *  
    (7) Fan section description: fan type, diameter, power, maximum  
angular speed, maximum speed, support type, mechanical drive, and  
sectional total weight.  
* * * * *  
0 
154. Amend Sec.  1037.532 by revising paragraph (a) to read as follows:  
Sec.  1037.532  Using computational fluid dynamics to calculate drag  
area (CdA).  
* * * * *  
    (a) For Phase 2 vehicles, use SAE J2966 (incorporated by reference  
in Sec.  1037.810), with the following clarifications and exceptions:  
    (1) Vehicles are subject to the requirement to meet standards based  
on the average of testing at yaw angles of +4.5[deg] and -4.5[deg];  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 140/268however, you may submit your application for certification with CFD  
results based on only one of those yaw angles.  
    (2) For CFD code with a Navier-Stokes based solver, follow the  
additional steps in paragraph (d) of this section. For Lattice-  
Boltzmann based CFD code, follow the additional steps in paragraph (e)  
of this section.  
    (3) Simulate a Reynolds number of 5.1 million (based on a 102-inch  
trailer width) and an air speed of 65 mi/hr.  
    (4) Perform an open-road simulation (not the Wind Tunnel  
Simulation).  
    (5) Use a free stream turbulence intensity of 0.0%.  
    (6) Choose time steps that can accurately resolve intrinsic flow  
instabilities, consistent with good engineering judgment.  
    (7) The result must be drag area (C dA), not drag  
coefficient (C d), based on an air speed of 65 mi/hr.  
    (8) Submit information as described in paragraph (g) of this  
section.  
* * * * *  
0 
155. Amend Sec.  1037.534 by revising paragraph (c)(1) and (2),  
(d)(4)(i), and (f)(4)(iv) to read as follows:  
Sec.  1037.534  Constant-speed procedure for calculating drag area  
(CdA). 
* * * * *  
    (c) * * *  
    (1) Measure torque at each of the drive wheels using a hub torque  
meter or a rim torque meter. If testing a tractor with two drive axles,  
you may disconnect one of the drive axles from receiving torque from  
the driveshaft, in which case you would measure torque at only the  
wheels that receive torque from the driveshaft. Set up instruments to  
read engine speed for calculating angular speed at the point of the  
torque measurements, or install instruments for measuring the angular  
speed of the wheels directly.  
    (2) Install instrumentation to measure vehicle speed at 10 Hz, with  
an accuracy and resolution of 0.1 mi/hr. Also install instrumentation  
for reading engine speed from the engine's onboard computer.  
* * * * *  
    (d) * * *  
    (4) * * *  
    (i) Measure the angular speed of the driveshaft, axle, or wheel  
where the torque is measured, or calculate it from engine speed in  
conjunction with gear and axle ratios, as applicable.  
* * * * *  
    (f) * * *  
    (4) * * *  
    (iv) Calculate C dA for each 10 second increment from the  
50 mi/hr and 70 mi/hr test segments using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.126  
Where: 
CdAi[speed] = the mean drag area for each 10  
second increment, i.  
Faero[speed]  = mean aerodynamic force over a given 10  
second increment = F RL[speed]  -FRL10,test . 
Vair[speed]  = mean aerodynamic force over a given 10  
second increment.  
R = specific gas constant = 287.058 J/(kg[middot]K).  
T = mean air temperature.  
pact = mean absolute air pressure.
Example:  
FRL70 = 4310.6 N  
FRL10,test  = 900.1 N  
Faero70 = 4310.6-900.1 = 3410.5 N  
V2air70 = 1089.5 m\2\/s\2\  
R = 287.058 J/(kg[middot]K)  
T = 293.68 K  
pact = 101300 Pa  
[[Page 34477]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.127  
CdAi70 = 5.210 m\2\  
* * * * *  
0 
156. Amend Sec.  1037.540 by revising paragraphs (b)(3) and (8),  
(d)(2), (e)(2), and (f) to read as follows:  
Sec.  1037.540  Special procedures for testing vehicles with hybrid  
power take-off.  
* * * * *  
    (b) * * *  
    (3) Denormalize the PTO duty cycle in appendix II of this part  
using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.128  
Where: 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 141/268prefi = the reference pressure at each point i in the PTO  
cycle. 
pi = the normalized pressure at each point i in the PTO cycle  
(relative to p max). 
pmax = the mean maximum pressure measured in paragraph  
(b)(2) of this section.  
pmin = the mean minimum pressure measured in paragraph  
(b)(2) of this section.  
* * * * *  
    (8) Measured pressures must meet the cycle-validation  
specifications in the following table for each test run over the duty  
cycle: 
  Table 1 of Sec.   1037.540--Statistical Criteria for Validating Each  
                      Test Run Over the Duty Cycle  
------------------------------------------------------------------------  
               Parameter \a\                          Pressure  
------------------------------------------------------------------------  
Slope, a1.................................  0.950 <= a1 <= 1.030.  
Absolute value of intercept,                <=2.0% of maximum mapped  
 [verbar]a0[verbar].                         pressure.  
Standard error of the estimate, SEE.......  <=10% of maximum mapped  
                                             pressure.  
Coefficient of determination, r2..........  >=0.970.  
------------------------------------------------------------------------  
\a\ Determine values for specified parameters as described in 40 CFR  
  1065.514(e) by comparing measured values to denormalized pressure  
  values from the duty cycle in appendix II of this part.  
* * * * *  
    (d) * * *  
    (2) For fractions of a test, use the following equation to  
calculate the time:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.129  
Where: 
i = an indexing variable that represents one recorded value.  
N = number of measurement intervals.  
pcircuit-1, i = normalized pressure command from circuit 1  
of the PTO cycle for each point, i, starting from i = 1.  
pcircuit-2, i = normalized pressure command from circuit 2  
of the PTO cycle for each point, i, starting from i = 1. Let  
pcircuit-2  = 0 if there is only one circuit.  
pcircuit-1  = the mean normalized pressure command from  
circuit 1 over the entire PTO cycle.  
pcircuit-2  = the mean normalized pressure command from  
circuit 2 over the entire PTO cycle. Let p circuit-2  = 0  
if there is only one circuit.  
[Delta]t = the time interval between measurements. For example, at  
100 Hz, [Delta]t = 0.0100 seconds.
* * * * *  
    (e) * * *  
    (2) Divide the CO 2 mass from the PTO cycle by the  
distance determined in paragraph (d)(4) of this section and the  
standard payload as defined in Sec.  1037.801 to get the CO 2  
emission rate in g/ton-mile. For plug-in hybrid electric vehicles  
follow paragraph (f)(3) of this section to calculate utility factor  
weighted CO 2 emissions in g/ton-mile.  
* * * * *  
    (f) For Phase 2, calculate the delta PTO fuel results for input  
into GEM during vehicle certification as follows:  
    (1) Calculate fuel consumption in grams per test,  
mfuelPTO, without rounding, as described in 40 CFR  
1036.540(d)(4) for both the conventional vehicle and the charge-  
sustaining and charge-depleting portions of the test for the hybrid  
vehicle as applicable.  
    (2) Divide the fuel mass by the applicable distance determined in  
paragraph (d)(4) of this section and the appropriate standard payload  
as defined in Sec.  1037.801 to determine the fuel rate in g/ton-mile.  
    (3) For plug-in hybrid electric vehicles calculate the utility  
factor weighted fuel consumption in g/ton-mile, as follows:  
    (i) Determine the utility factor fraction for the PTO system from  
the table in appendix V of this part using interpolation based on the  
total time of the charge-depleting portion of the test as determined in  
paragraphs (c)(6) and (d)(3) of this section.  
    (ii) Weight the emissions from the charge-sustaining and charge-  
depleting portions of the test using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.130  
Where: 
mPTO,CD = mass of fuel per ton-mile while in charge-  
depleting mode.  
UFt,CD = utility factor fraction at time t CD  
as determined in paragraph (f)(3)(i) of this section.  
mPTO,CS = mass of fuel per ton-mile while in charge-  
sustaining mode.  
    (4) Calculate the difference between the conventional PTO emissions  
result and the hybrid PTO emissions result for input into GEM.  
* * * * *  
0 
157. Revise Sec.  1037.550 to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 142/268Sec.  1037.550  Powertrain testing.  
    This section describes the procedure to measure fuel consumption  
and create engine fuel maps by testing a powertrain that includes an  
engine coupled with a transmission, drive axle, and hybrid components  
or any assembly with one or more of those hardware elements. Engine  
fuel maps are part of demonstrating compliance with Phase 2 vehicle  
standards under this part; the powertrain test procedure in this  
section is one option for generating this fuel-mapping information as  
described in 40  
[[Page 34478]]  
CFR 1036.503. Additionally, this powertrain test procedure is one  
option for certifying hybrids to the engine standards in 40 CFR  
1036.108.  
    (a) General provisions. The following provisions apply broadly for  
testing under this section:  
    (1) Measure NO X emissions as described in paragraph (k)  
of this section. Include these measured NO X values any time  
you report to us your greenhouse gas emissions or fuel consumption  
values from testing under this section.  
    (2) The procedures of 40 CFR part 1065 apply for testing in this  
section except as specified. This section uses engine parameters and  
variables that are consistent with 40 CFR part 1065.  
    (3) Powertrain testing depends on models to calculate certain  
parameters. You can use the detailed equations in this section to  
create your own models, or use the GEM HIL model (incorporated by  
reference in Sec.  1037.810) to simulate vehicle hardware elements as  
follows:  
    (i) Create driveline and vehicle models that calculate the angular  
speed setpoint for the test cell dynamometer,  
[fnof]nref,dyno , based on the torque measurement location.  
Use the detailed equations in paragraph (f) of this section, the GEM  
HIL model's driveline and vehicle submodels, or a combination of the  
equations and the submodels. You may use the GEM HIL model's  
transmission submodel in paragraph (f) of this section to simulate a  
transmission only if testing hybrid engines.  
    (ii) Create a driver model or use the GEM HIL model's driver  
submodel to simulate a human driver modulating the throttle and brake  
pedals to follow the test cycle as closely as possible.  
    (iii) Create a cycle-interpolation model or use the GEM HIL model's  
cycle submodel to interpolate the duty-cycles and feed the driver model  
the duty-cycle reference vehicle speed for each point in the duty-  
cycle. 
    (4) The powertrain test procedure in this section is designed to  
simulate operation of different vehicle configurations over specific  
duty cycles. See paragraphs (h) and (j) of this section.  
    (5) For each test run, record engine speed and torque as defined in  
40 CFR 1065.915(d)(5) with a minimum sampling frequency of 1 Hz. These  
engine speed and torque values represent a duty cycle that can be used  
for separate testing with an engine mounted on an engine dynamometer  
under Sec.  1037.551, such as for a selective enforcement audit as  
described in Sec.  1037.301.  
    (6) For hybrid powertrains with no plug-in capability, correct for  
the net energy change of the energy storage device as described in 40  
CFR 1066.501. For PHEV powertrains, follow 40 CFR 1066.501 to determine  
End-of-Test for charge-depleting operation. You must get our approval  
in advance for your utility factor curve; we will approve it if you can  
show that you created it from sufficient in-use data of vehicles in the  
same application as the vehicles in which the PHEV powertrain will be  
installed.  
    (b) Test configuration. Select a powertrain for testing as  
described in Sec.  1037.235 or 40 CFR 1036.235 as applicable. Set up  
the engine according to 40 CFR 1065.110 and 1065.405(b). Set the  
engine's idle speed to the minimum warm-idle speed. If warm idle speed  
is not adjustable, simply let the engine operate at its warm idle  
speed. 
    (1) The default test configuration consists of a powertrain with  
all components upstream of the axle. This involves connecting the  
powertrain's output shaft directly to the dynamometer or to a gear box  
with a fixed gear ratio and measuring torque at the axle input shaft.  
You may instead set up the dynamometer to connect at the wheel hubs and  
measure torque at that location. The preceding sentence may apply if  
your powertrain configuration requires it, such as for hybrid  
powertrains or if you want to represent the axle performance with  
powertrain test results.  
    (2) For testing hybrid engines, connect the engine's crankshaft  
directly to the dynamometer and measure torque at that location.  
    (c) Powertrain temperatures during testing. Cool the powertrain  
during testing so temperatures for oil, coolant, block, head,  
transmission, battery, and power electronics are within the  
manufacturer's expected ranges for normal operation. You may use  
electronic control module outputs to comply with this paragraph (c).  
You may use auxiliary coolers and fans.  
    (d) Engine break in. Break in the engine according to 40 CFR  
1065.405, the axle assembly according to Sec.  1037.560, and the  
transmission according to Sec.  1037.565. You may instead break in the  
powertrain as a complete system using the engine break in procedure in  
40 CFR 1065.405.  
    (e) Dynamometer setup. Set the dynamometer to operate in speed-  
control mode (or torque-control mode for hybrid engine testing at idle,  
including idle portions of transient duty cycles). Record data as  
described in 40 CFR 1065.202. Command and control the dynamometer speed  
at a minimum of 5 Hz, or 10 Hz for testing engine hybrids. Run the  
vehicle model to calculate the dynamometer setpoints at a rate of at  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 143/268least 100 Hz. If the dynamometer's command frequency is less than the  
vehicle model dynamometer setpoint frequency, subsample the calculated  
setpoints for commanding the dynamometer setpoints.  
    (f) Driveline and vehicle model. Use the GEM HIL model's driveline  
and vehicle submodels or the equations in this paragraph (f) to  
calculate the dynamometer speed setpoint, [fnof] nref,dyno ,  
based on the torque measurement location. Note that the GEM HIL model  
is configured to set the accessory load to zero and it comes configured  
with the tire slip model disabled.
    (1) Driveline model with a transmission in hardware. For testing  
with torque measurement at the axle input shaft or wheel hubs,  
calculate, [fnof] nref,dyno , using the GEM HIL model's  
driveline submodel or the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.131  
Where: 
ka[speed]  = drive axle ratio as determined in paragraph  
(h) of this section. Set k a[speed]  equal to 1.0 if torque  
is measured at the wheel hubs.  
vrefi = simulated vehicle reference speed as calculated  
in paragraph (f)(3) of this section.  
r[speed] = tire radius as determined in paragraph (h) of  
this section.  
    (2) Driveline model with a simulated transmission. For testing with  
the torque measurement at the engine's crankshaft,  
[fnof]nref,dyno  is the dynamometer target speed from the GEM  
HIL model's transmission submodel. You may request our approval to  
change the transmission submodel, as long as the changes do not affect  
the gear selection logic. Before testing, initialize the transmission  
model with the engine's measured torque curve and the applicable  
steady-state fuel map from the GEM HIL model. You may request our  
approval to input your own steady-state fuel map. Configure the torque  
converter to simulate neutral idle when using this procedure to  
generate engine fuel maps in 40 CFR 1036.503 or to perform the  
Supplemental Emission Test (SET) testing under 40 CFR 1036.505. You may  
change engine commanded torque at idle to better represent CITT for  
transient testing under 40 CFR 1036.510. You may change the  
[[Page 34479]]  
simulated engine inertia to match the inertia of the engine under test.  
We will evaluate your requests under paragraph (f)(3) of this section  
based on your demonstration that that the adjusted testing better  
represents in-use operation.  
    (i) The transmission submodel needs the following model inputs:  
    (A) Torque measured at the engine's crankshaft.  
    (B) Engine estimated torque determined from the electronic control  
module or by converting the instantaneous operator demand to an  
instantaneous torque in N[middot]m.  
    (C) Dynamometer mode when idling (speed-control or torque-control).  
    (D) Measured engine speed when idling.  
    (E) Transmission output angular speed,  
[fnof]ni,transmission , calculated as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.132  
Where: 
ka[speed]  = drive axle ratio as determined in paragraph  
(h) of this section.  
vrefi = simulated vehicle reference speed as calculated  
in paragraph (f)(3) of this section.  
    r[speed] = tire radius as determined in paragraph (h)  
of this section.  
    (ii) The transmission submodel generates the following model  
outputs:  
    (A) Dynamometer target speed.  
    (B) Dynamometer idle load.  
    (C) Transmission engine load limit.  
    (D) Engine speed target.  
    (3) Vehicle model. Calculate the simulated vehicle reference speed,  
[nu]refi, using the GEM HIL model's vehicle submodel or the equations  
in this paragraph (f)(3):  
[GRAPHIC] [TIFF OMITTED] TR29JN21.133  
Where: 
i = a time-based counter corresponding to each measurement during  
the sampling period. Let v ref1 = 0; start calculations at  
i = 2. A 10-minute sampling period will generally involve 60,000  
measurements.  
T = instantaneous measured torque at the axle input, measured at the  
wheel hubs, or simulated by the GEM HIL model's transmission  
submodel.  
E[fnof][fnof]axle = axle efficiency. Use E[fnof][fnof]axle = 0.955  
for T >= 0, and use E[fnof][fnof]axle = 1/0.955 for T < 0. Use  
E[fnof][fnof]axle = 1.0 if torque is measured at the wheel hubs.  
M = vehicle mass for a vehicle class as determined in paragraph (h)  
of this section.  
g = gravitational constant = 9.80665 m/s2. 
Crr = coefficient of rolling resistance for a vehicle  
class as determined in paragraph (h) of this section.  
Gi-1 = the percent grade interpolated at distance,  
Di-1, from the duty cycle in appendix IV to this part  
corresponding to measurement (i-1).  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 144/268[GRAPHIC] [TIFF OMITTED] TR29JN21.134  
[rho] = air density at reference conditions. Use [rho] = 1.1845 kg/  
m3. 
CdA = drag area for a vehicle class as determined in  
paragraph (h) of this section.  
Fbrake,i-1 = instantaneous braking force 
applied by the driver model.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.135  
[Delta]t = the time interval between measurements. For example, at  
100 Hz, [Delta]t = 0.0100 seconds.
Mrotating  = inertial mass of rotating components. Let  
Mrotating  = 340 kg for vocational Light HDV or vocational  
Medium HDV. See paragraph (h) of this section for tractors and for  
vocational Heavy HDV.  
    (4) Example. The following example illustrates a calculation of  
[fnof]nref,dyno  using paragraph (f)(1) of this section where  
torque is measured at the axle input shaft. This example is for a  
vocational Light HDV or vocational Medium HDV with 6 speed automatic  
transmission at B speed (Test 4 in Table 2 of 40 CFR 1036.540).  
k[alpha]B  = 4.0 
rB = 0.399 m  
T999 = 500.0 N[middot]m  
Crr = 7.7 kg/tonne = 7.7[middot]10-3 kg/kg 
M = 11408 kg  
Cd[Alpha] = 5.4 m\2\  
G999 = 0.39% = 0.0039  
[GRAPHIC] [TIFF OMITTED] TR29JN21.136  
Fbrake,999  = 0 N 
vref,999 = 20.0 m/s  
Fgrade,999  = 11408[middot]9.81[middot]sin (atan(0.0039)) =  
436.5 N 
[Delta]t = 0.0100 s  
Mrotating  = 340 kg  
[[Page 34480]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.137  
    (g) Driver model. Use the GEM HIL model's driver submodel or design  
a driver model to simulate a human driver modulating the throttle and  
brake pedals. In either case, tune the model to follow the test cycle  
as closely as possible meeting the following specifications:  
    (1) The driver model must meet the speed requirements for operation  
over the highway cruise cycles as described in Sec.  1037.510 and for  
operation over the transient cycle as described in 40 CFR 1066.425(b).  
The exceptions in 40 CFR 1066.425(b)(4) apply to the transient cycle  
and the highway cruise cycles.  
    (2) Send a brake signal when operator demand is zero and vehicle  
speed is greater than the reference vehicle speed from the test cycle.  
Include a delay before changing the brake signal to prevent dithering,  
consistent with good engineering judgment.  
    (3) Allow braking only if operator demand is zero.  
    (4) Compensate for the distance driven over the duty cycle over the  
course of the test. Use the following equation to perform the  
compensation in real time to determine your time in the cycle:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.138  
Where: 
vvehicle = measured vehicle speed.
vcycle = reference speed from the test cycle. If  
vcycle,i-1 < 1.0 m/s, set  
vcycle,i-1 =  
vvehicle, i-1. 
    (h) Vehicle configurations to evaluate for generating fuel maps as  
defined in 40 CFR 1036.503. Configure the driveline and vehicle models  
from paragraph (f) of this section in the test cell to test the  
powertrain. Simulate multiple vehicle configurations that represent the  
range of intended vehicle applications. Use at least three equally  
spaced axle ratios or tire sizes and three different road loads (nine  
configurations), or at least four equally spaced axle ratios or tire  
sizes and two different road loads (eight configurations). Select axle  
ratios to represent the full range of expected vehicle installations.  
    (1) Determine the vehicle model inputs for M, M rotating ,  
Cd[Alpha], and C rr for a set of vehicle  
configurations as described in 40 CFR 1036.540(c)(3). Instead of  
selecting axle ratios and tire sizes based on the range of intended  
vehicle applications as described in this paragraph (h), you may select  
axle ratios and tire sizes such that the ratio of engine speed to  
vehicle speed covers the range of ratios of minimum and maximum engine  
speed to vehicle speed when the transmission is in top gear for the  
vehicles in which the powertrain will be installed. Note that you do  
not have to use the same axle ratios and tire sizes for each GEM  
regulatory subcategory.  
    (2) For hybrid powertrain systems where the transmission will be  
simulated, use the transmission parameters defined in Table 1 of 40 CFR  
1036.540 to determine transmission type and gear ratio. Use a fixed  
transmission efficiency of 0.95. The GEM HIL transmission model uses a  
transmission parameter file for each test that includes the  
transmission type, gear ratios, lockup gear, torque limit per gear from  
Table 1 of 40 CFR 1036.540, and the values from 40 CFR 1036.503(b)(4)  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 145/268and (c).  
    (i) [Reserved]  
    (j) Duty cycles to evaluate. Operate the powertrain over each of  
the duty cycles specified in Sec.  1037.510(a)(2), and for each  
applicable vehicle configuration from paragraph (h) of this section.  
Determine cycle-average powertrain fuel maps by testing the powertrain  
using the procedures in 40 CFR 1036.540(d) with the following  
exceptions:  
    (1) Understand ``engine'' to mean ``powertrain''.  
    (2) If the preceding duty cycle does not end at 0 mi/hr, transition  
between duty cycles by decelerating at a rate of 2 mi/hr/s at 0% grade  
until the vehicle reaches zero speed. Shut off the powertrain. Prepare  
the powertrain and test cell for the next duty-cycle. Start the next  
duty-cycle within 60 to 180 seconds after shutting off the powertrain.  
Do not run the powertrain or change its physical state before starting  
the next duty cycle. If the next duty cycle begins at 0 mi/hr vehicle  
speed, key on the vehicle and start the duty-cycle after 10 seconds,  
otherwise key on the vehicle and transition to the next duty cycle by  
accelerating at a rate of 1 mi/hr/s at 0% grade for vehicle  
configurations given in Table 2 of 40 CFR 1036.540 or 2 mi/hr/s at 0%  
grade for vehicle configurations given in Tables 3 and 4 of 40 CFR  
1036.540, then stabilize for 10 seconds at the initial duty cycle  
conditions.  
    (3) Calculate cycle work using GEM or the speed and torque from the  
driveline and vehicle models from paragraph (f) of this section to  
determine the sequence of duty cycles.  
    (4) Calculate the mass of fuel consumed for idle duty cycles as  
described in paragraph (n) of this section.  
    (5) Warm up the powertrain as described in 40 CFR 1036.527(c)(1).  
    (k) Measuring NOX emissions. Measure NO X emissions for  
each sampling period in grams. You may perform these measurements using  
a NOX emission-measurement system that meets the  
requirements of 40 CFR part 1065, subpart J. If a system malfunction  
prevents you from measuring NO X emissions during a test  
under this section but the test otherwise gives valid results, you may  
consider this a valid test and omit the NO X emission  
measurements; however, we may require you to repeat the test if we  
determine that you inappropriately voided the test with respect to  
NOX emission measurement.  
    (l) [Reserved]  
    (m) Measured output speed validation. For each test point, validate  
the measured output speed with the corresponding reference values. If  
the range of reference speed is less than 10  
[[Page 34481]]  
percent of the mean reference speed, you need to meet only the standard  
error of the estimate in Table 1 of this section. You may delete points  
when the vehicle is stopped. If your speed measurement is not at the  
location of f nref, correct your measured speed using the  
constant speed ratio between the two locations. Apply cycle-validation  
criteria for each separate transient or highway cruise cycle based on  
the following parameters:  
  Table 1 of Sec.   1037.550--Statistical Criteria for Validating Duty  
                                 Cycles  
------------------------------------------------------------------------  
                Parameter a                         Speed control  
------------------------------------------------------------------------  
Slope, a;1................................  0.990 <=a1 <=1.010.  
Absolute value of intercept,                <=2.0% of maximum [fnof]nref  
 [verbar]a0[verbar].                         speed.  
Standard error of the estimate, SEE.......  <=2.0% of maximum [fnof]nref  
                                             speed.  
Coefficient of determination, r2..........  >=0.990.  
------------------------------------------------------------------------  
a Determine values for specified parameters as described in 40 CFR  
  1065.514(e) by comparing measured and reference values for  
  [fnof]nref,dyno.  
    (n) Fuel consumption at idle. Determine the mass of fuel consumed  
at idle for the applicable duty cycles described in Sec.   
1037.510(a)(2) as follows:  
    (1) Measure fuel consumption with a fuel flow meter and report the  
mean idle fuel mass flow rate for each duty cycle as applicable,  
mifuelidle . 
    (2) If you do not measure fuel mass flow rate, calculate the idle  
fuel mass flow rate for each duty cycle, mi fuelidle , for  
each set of vehicle settings, as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.140  
Where: 
MC = molar mass of carbon.  
wCmeas = carbon mass fraction of fuel (or mixture of test  
fuels) as determined in 40 CFR 1065.655(d), except that you may not  
use the default properties in Table 1 of 40 CFR 1065.655 to  
determine [alpha], [beta], and w C for liquid fuels.  
niexh = the mean raw exhaust molar flow rate from which  
you measured emissions according to 40 CFR 1065.655.  
xCcombdry  = the mean concentration of carbon from fuel  
and any injected fluids in the exhaust per mole of dry exhaust.  
xH2Oexhdry  = the mean concentration of H 2O in  
exhaust per mole of dry exhaust.  
miCO2DEF = the mean CO 2 mass emission rate  
resulting from diesel exhaust fluid decomposition over the duty  
cycle as determined in 40 CFR 1036.535(b)(7). If your engine does  
not use diesel exhaust fluid, or if you choose not to perform this  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 146/268correction, set mi CO2DEF equal to 0.  
MCO2 = molar mass of carbon dioxide.  
Example:  
MC = 12.0107 g/mol  
wCmeas = 0.867  
niexh = 25.534 mol/s  
xCcombdry  = 2.805[middot]10-3 mol/mol  
xH2Oexhdry  = 3.53[middot]10-2 mol/mol  
miCO2DEF = 0.0726 g/s  
MCO2 = 44.0095  
[GRAPHIC] [TIFF OMITTED] TR29JN21.139  
mifuelidle  = 0.405 g/s = 1458.6 g/hr  
    (o) Create GEM inputs. Use the results of powertrain testing to  
determine GEM inputs for the different simulated vehicle configurations  
as follows:  
    (1) Correct the measured or calculated fuel masses,  
mfuel[cycle] , and mean idle fuel mass flow rates,  
mifuelidle , if applicable, for each test result to a mass-  
specific net energy content of a reference fuel as described in 40 CFR  
1036.535(f), replacing mi fuel with mfuel[cycle]   
where applicable in Eq. 1036.535-4.  
    (2) Declare fuel masses, m fuel[cycle] , in g/cycle. In  
addition, declare mean fuel mass flow rate for each applicable idle  
duty cycle, mi fuelidle . These declared values may not be  
lower than any corresponding measured values determined in this  
section. If you use multiple measurement methods as allowed in 40 CFR  
1036.540(d), follow 40 CFR 1036.535(g) regarding the use of direct and  
indirect fuel measurements and the carbon balance error verification.  
These declared values, which serve as emission standards, collectively  
represent the powertrain fuel map for certification.  
[[Page 34482]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.141  
    (ii) For testing with torque measurement at the wheel hubs, use Eq.  
1037.550-8 setting k a equal to 1.  
    (iii) For testing with torque measurement at the engine's  
crankshaft:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.142  
Where: 
fnengine = average engine speed when vehicle speed is at  
or above 0.100 m/s.  
vref = average simulated vehicle speed at or above 0.100  
m/s. 
Example:  
fnengine = 1870 r/min = 31.17 r/s  
vref = 19.06 m/s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.143  
    (4) Calculate positive work, W [cycle], as the work over  
the duty cycle at the axle input shaft, wheel hubs, or the engine's  
crankshaft, as applicable, when vehicle speed is at or above 0.100 m/s.  
    (5) Calculate engine idle speed, by taking the average engine speed  
measured during the transient cycle test while the vehicle speed is  
below 0.100 m/s.  
    (6) The following table illustrates the GEM data inputs  
corresponding to the different vehicle configurations for a given duty  
cycle: 
[[Page 34483]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.144  
0 
158. Amend Sec.  1037.551 by revising paragraph (b) to read as follows:  
Sec.  1037.551  Engine-based simulation of powertrain testing.  
* * * * *  
    (b) Operate the engine over the applicable engine duty cycles  
corresponding to the vehicle cycles specified in Sec.  1037.510(a)(2)  
for powertrain testing over the applicable vehicle simulations  
described in Sec.  1037.550(i). Warm up the engine to prepare for the  
transient test or one of the highway cruise cycles by operating it one  
time over one of the simulations of the corresponding duty cycle. Warm  
up the engine to prepare for the idle test by operating it over a  
simulation of the 65-mi/hr highway cruise cycle for 600 seconds. Within  
60 seconds after concluding the warm up cycle, start emission sampling  
while the engine operates over the duty cycle. You may perform any  
number of test runs directly in succession once the engine is warmed  
up. Perform cycle validation as described in 40 CFR 1065.514 for engine  
speed, torque, and power.  
* * * * *  
0 
159. Amend Sec.  1037.555 by revising paragraphs (d), (e), and (f) to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 147/268read as follows:  
Sec.  1037.555  Special procedures for testing Phase 1 hybrid systems.  
* * * * *  
    (d) Calculate the transmission output shaft's angular speed target  
for the driver model, f nref,driver , from the linear speed  
associated with the vehicle cycle using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.145  
Where: 
vcyclei = vehicle speed of the test cycle for each point,  
i, starting from i = 1.  
ka = drive axle ratio, as declared by the manufacturer.  
r = radius of the loaded tires, as declared by the manufacturer.  
    (e) Use speed control with a loop rate of at least 100 Hz to  
program the dynamometer to follow the test cycle, as follows:  
    (1) Calculate the transmission output shaft's angular speed target  
for the dynamometer, f nref,dyno , from the measured linear  
speed at the dynamometer rolls using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.146  
[GRAPHIC] [TIFF OMITTED] TR29JN21.147  
Where: 
T = instantaneous measured torque at the transmission output shaft.  
Fbrake = instantaneous brake force applied by the driver  
model to add force to slow down the vehicle.  
t = elapsed time in the driving schedule as measured by the  
dynamometer, in seconds.  
    (2) For each test, validate the measured transmission output  
shaft's speed with the corresponding reference values according to 40  
CFR 1065.514(e). You may delete points when the vehicle is stopped.  
Perform the validation based on speed values at the transmission output  
shaft. For steady-state tests (55 mi/hr and 65 mi/hr cruise), apply  
cycle-validation criteria by treating the sampling periods from the two  
tests as a continuous sampling period. Perform this validation based on  
the following parameters:  
  Table 1 of Sec.   1037.555--Statistical Criteria for Validating Duty  
                                 Cycles  
------------------------------------------------------------------------  
                 Parameter                          Speed control  
------------------------------------------------------------------------  
Slope, a1.................................  0.950 <= a1 <= 1.030.  
Absolute value of intercept,                <=2.0% of maximum test  
 [verbar]a0[verbar].                         speed.  
Standard error of the estimate, SEE.......  <=5% of maximum test speed.  
Coefficient of determination, r\2\........  >=0.970.  
------------------------------------------------------------------------  
    (f) Send a brake signal when operator demand is equal to zero and  
vehicle speed is greater than the reference vehicle speed from the test  
cycle. Set a delay before changing the brake state to prevent the brake  
signal from dithering,  
[[Page 34484]]  
consistent with good engineering judgment.  
* * * * *  
0 
160. Revise Sec.  1037.560 to read as follows:  
Sec.  1037.560  Axle efficiency test.  
    This section describes a procedure for mapping axle efficiency  
through a determination of axle power loss.  
    (a) You may establish axle power loss maps based on testing any  
number of axle configurations within an axle family as specified in  
Sec.  1037.232. You may share data across a family of axle  
configurations, as long as you test the axle configuration with the  
lowest efficiency from the axle family; this will generally involve  
testing the axle with the highest axle ratio. For vehicles with tandem  
drive axles, always test each drive axle separately. For tandem axles  
that can be disconnected, test both single-drive and tandem axle  
configurations. This includes 4x4 axles where one of the axles is  
disconnectable. Alternatively, you may analytically derive power loss  
maps for untested configurations within the same axle family as  
described in paragraph (h) of this section.  
    (b) Prepare an axle assembly for testing as follows:  
    (1) Select an axle assembly with less than 500 hours of operation  
before testing. Assemble the axle in its housing, along with wheel ends  
and bearings.  
    (2) If you have a family of axle assemblies with different axle  
ratios, you may test multiple configurations using a common axle  
housing, wheel ends, and bearings.
    (3) Install the axle assembly on the dynamometer with an input  
shaft angle perpendicular to the axle.  
    (i) For axle assemblies with or without a locking main  
differential, test the axle assembly using one of the following  
methods:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 148/268    (A) Lock the main differential and test it with one electric motor  
on the input shaft and a second electric motor on the output side of  
the output shaft that has the speed-reduction gear attached to it.  
    (B) Test with the main differential unlocked and with one electric  
motor on the input shaft and electric motors on the output sides of  
each of the output shafts.  
    (ii) For drive-through tandem-axle setups, lock the longitudinal  
and inter-wheel differentials.  
    (4) Add gear oil according to the axle manufacturer's instructions.  
If the axle manufacturer specifies multiple gear oils, select the one  
with the highest viscosity at operating temperature. You may use a  
lower-viscosity gear oil if we approve that as critical emission-  
related maintenance under Sec.  1037.125. Fill the gear oil to a level  
that represents in-use operation. You may use an external gear oil  
conditioning system, as long as it does not affect measured values.  
    (5) Install equipment for measuring the bulk temperature of the  
gear oil in the oil sump or a similar location. Report temperature to  
the nearest 0.1 [deg]C.  
    (6) Break in the axle assembly using good engineering judgment.  
Maintain gear oil temperature at or below 100 [deg]C throughout the  
break-in period.  
    (7) You may drain the gear oil following the break-in procedure and  
repeat the filling procedure described in paragraph (b)(4) of this  
section. We will follow your practice for our testing.  
    (c) Measure input and output speed and torque as described in 40  
CFR 1065.210(b). You must use a speed-measurement system that meets an  
accuracy of 0.05% of point. Use torque transducers that  
meet an accuracy requirement of 1.0 N[middot]m for unloaded  
test points and 0.2% of the maximum tested axle input  
torque or output torque, respectively, for loaded test points.  
Calibrate and verify measurement instruments according to 40 CFR part  
1065, subpart D. Command speed and torque at a minimum of 10 Hz, and  
record all data, including bulk oil temperature, as 1 Hz mean values.  
    (d) The test matrix consists of test points representing output  
torque and wheel speed values meeting the following specifications:  
    (1) Output torque includes both loaded and unloaded operation. For  
measurement involving unloaded output torque, also called spin loss  
testing, the wheel end is not connected to the dynamometer and is left  
to rotate freely; in this condition the input torque (to maintain  
constant wheel speed) equals the power loss. Test axles at a range of  
output torque values, as follows:  
    (i) 0, 500, 1000, 2000, 3000, and 4000 N[middot]m for single drive  
axle applications for tractors and for vocational Heavy HDV with a  
single drive axle.  
    (ii) 0, 250, 500, 1000, 1500, and 2000 N[middot]m for tractors, for  
vocational Heavy HDV with tandem drive axles, and for all vocational  
Light HDV or vocational Medium HDV.  
    (iii) You may exclude values that exceed your axle's maximum torque  
rating. 
    (2) Determine maximum wheel speed corresponding to a vehicle speed  
of 65 mi/hr based on the smallest tire (as determined using Sec.   
1037.520(c)(1)) that will be used with the axle. If you do not know the  
smallest tire size, you may use a default size of 650 r/mi. Use wheel  
angular speeds for testing that include 50 r/min and speeds in 100 r/  
min increments that encompass the maximum wheel speed (150, 250, etc.).  
    (3) You may test the axle assembly at additional speed and torque  
setpoints.  
    (e) Determine axle efficiency using the following procedure:  
    (1) Maintain ambient temperature between (15 and 35) [deg]C  
throughout testing. Measure ambient temperature within 1.0 m of the  
axle assembly. Verify that critical axle settings (such as bearing  
preload, backlash, and oil sump level) are within specifications before  
and after testing.  
    (2) Maintain gear oil temperature at (81 to 83) [deg]C. You may  
alternatively specify a lower range by shifting both temperatures down  
by the same amount. We will test your axle assembly using the same  
temperature range you specify for your testing. You may use an external  
gear oil conditioning system, as long as it does not affect measured  
values. 
    (3) Use good engineering judgment to warm up the axle assembly by  
operating it until the gear oil is within the specified temperature  
range. 
    (4) Stabilize operation at each point in the test matrix for at  
least 10 seconds, then measure the input torque, output torque, and  
wheel angular speed for at least 10 seconds. Record arithmetic mean  
values for all three parameters over the measurement period. Calculate  
power loss as described in paragraph (f) of this section based on these  
values for mean input torque, T in, mean output torque,  
Tout, and mean wheel angular speed, f nwheel, at  
each test point.  
    (5) Perform the map sequence described in paragraph (e)(4) of this  
section three times. Remove torque from the input shaft and allow the  
axle to come to a full stop before each repeat measurement.  
    (6) You may need to perform additional testing at a given test  
point based on a calculation of a confidence interval to represent  
repeatability at a 95% confidence level for that test point. If the  
confidence limit is greater than 0.10% for loaded tests or greater than  
0.05% for unloaded tests, perform another repeat of measurements at  
that test point and recalculate the repeatability for the whole set of  
test results. Continue testing until the confidence interval is at or  
below the specified values for all test points. Calculate a confidence  
interval representing the repeatability in establishing a 95%  
confidence level using the following equation:  
[[Page 34485]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.148  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 149/268Where: 
[sigma]Ploss = standard deviation of power loss values at  
a given torque-speed setting (see 40 CFR 1065.602(c)).  
N = number of repeat tests.  
Pmax = maximum output torque setting from the test  
matrix. 
    Example:  
[sigma]Ploss = 0.1650 kW  
N = 3 
P max = 314.2000 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.149  
Confidence Interval = 0.0594%  
    (f) Calculate the mean power loss, P loss, at each test  
point as follows:  
    (1) Calculate P loss for each measurement at each test  
point as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.150  
Where: 
Tin = mean input torque from paragraph (e)(4) of this  
section.  
fnwheel = mean wheel angular speed from paragraph (e)(4)  
of this section in rad/s.  
ka = drive axle ratio, expressed to at least the nearest  
0.001. 
Tout = mean output torque from paragraph (e)(4) of this  
section. Let T out = 0 for all unloaded tests.  
    (2) Calculate P loss as the mean power loss from all  
measurements at a given test point.  
    (3) The following example illustrates a calculation of  
Ploss: 
Tin,1 = 845.10 N[middot]m  
fnwheel,1  = 100.0 r/min = 10.472 rad/s  
ka = 3.731  
Tout,1 = 3000.00 N[middot]m  
Ploss,1 = 845.10 [middot] 10.472 [middot] 3.731 - 3000.00  
[middot] 10.472  
Ploss,1 = 1602.9 W = 1.6029 kW  
Ploss,2 = 1601.9 W = 1.6019 kW  
Ploss,3 = 1603.9 W = 1.6039 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.151  
    (g) Create a table with the mean power loss, P loss,  
corresponding to each test point for input into GEM. Express wheel  
angular speed in r/min to one decimal place; express output torque in  
N[middot]m to two decimal places; express power loss in kW to four  
decimal places.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.279  
    (2) Record declared mean power loss values at or above the  
corresponding value calculated in paragraph (f) of this section. Use  
good engineering judgment to select values that will be at or above the  
mean power loss values for your production axles. Vehicle manufacturers  
will use these declared mean power loss values for certification. For  
vehicles with tandem drive axles, the GEM input is the sum of the power  
loss and output torque from the individual axles. For vehicles with a  
disconnectable axle, GEM uses separate inputs for single and tandem  
drive axle configurations.  
    (h) You may analytically derive axle power loss maps for untested  
configurations within an axle family as follows:  
    (1) Test at least three axle assemblies within the same family  
representing at least the smallest axle ratio, the largest axle ratio,  
and an axle ratio closest to the arithmetic mean from the two other  
tested axle assemblies. Test each axle assembly as described in this  
section at the same speed and torque setpoints.  
    (2) Perform a second-order least-squares regression between  
declared power loss and axle ratio using each speed and torque setpoint  
described in paragraph (d) of this section for your tested axle  
assemblies. Use the declared power loss values from paragraph (g) of  
this section; however, for purposes of analytically deriving power loss  
maps under this paragraph (h), you must select declared values for the  
largest and smallest axle ratios in the axle family that are adjusted  
relative to the calculated values for mean power loss by the same  
multiplier. If the coefficent of the second-order term is negative,  
include testing from additional axle ratios, or increase your declared  
power loss for the largest and smallest axle ratios by the same  
multiplier as needed for the second-order term to become positive.  
    (3) Determine P loss of untested axles for each speed and  
torque setpoint based on a linear relationship between your declared  
power loss and axle ratio as follows:  
    (i) Determine the slope of the correlation line by connecting the  
declared power loss values for the smallest and largest axle ratios.  
[[Page 34486]]  
    (ii) Fix the intercept for the correlation line by shifting it  
upward as needed so all the declared power loss values are on the  
correlation line or below it. Note that for cases involving three  
tested axle assemblies, the correlation line will always include the  
declared power loss for the smallest and largest axle ratio.  
    (4) Select declared values of P loss for untested  
configurations that are at or above the values you determined in  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 150/268paragraph (h)(3) of this section.  
0 
161. Revise Sec.  1037.565 to read as follows:  
Sec.  1037.565  Transmission efficiency test.  
    This section describes a procedure for mapping transmission  
efficiency through a determination of transmission power loss.  
    (a) You may establish transmission power loss maps based on testing  
any number of transmission configurations within a transmission family  
as specified in Sec.  1037.232. You may share data across any  
configurations within the family, as long as you test the transmission  
configuration with the lowest efficiency from the transmission family.  
Alternatively, you may ask us to approve analytically derived power  
loss maps for untested configurations within the same transmission  
family (see Sec.  1037.235(h)).  
    (b) Prepare a transmission for testing as follows:  
    (1) Select a transmission with less than 500 hours of operation  
before testing.  
    (2) Mount the transmission to the dynamometer such that the geared  
shaft in the transmission is aligned with the input shaft from the  
dynamometer.  
    (3) Add transmission oil according to the transmission  
manufacturer's instructions. If the transmission manufacturer specifies  
multiple transmission oils, select the one with the highest viscosity  
at operating temperature. You may use a lower-viscosity transmission  
oil if we approve it as critical emission-related maintenance under  
Sec.  1037.125. Fill the transmission oil to a level that represents  
in-use operation. You may use an external transmission oil conditioning  
system, as long as it does not affect measured values.  
    (4) Include any internal and external pumps for hydraulic fluid and  
lubricating oil in the test. Determine the work required to drive an  
external pump according to 40 CFR 1065.210.  
    (5) Install equipment for measuring the bulk temperature of the  
transmission oil in the oil sump or a similar location.  
    (6) If the transmission is equipped with a torque converter, lock  
it for all testing performed in this section.  
    (7) Break in the transmission using good engineering judgment.  
Maintain transmission oil temperature at (87 to 93) [deg]C for  
automatic transmissions and transmissions having more than two friction  
clutches, and at (77 to 83) [deg]C for all other transmissions. You may  
ask us to approve a different range of transmission oil temperatures if  
you have data showing that it better represents in-use operation.  
    (c) Measure input and output shaft speed and torque as described in  
40 CFR 1065.210(b). You must use a speed measurement system that meets  
an accuracy of 0.05% of point. Accuracy requirements for  
torque transducers depend on the highest loaded transmission input and  
output torque as described in paragraph (d)(2) of this section. Use  
torque transducers for torque input measurements that meet an accuracy  
requirement of 0.2% of the highest loaded transmission  
input for loaded test points and 0.1% of the highest loaded  
transmission input torque for unloaded test points. For torque output  
measurements, torque transducers must meet an accuracy requirement of  
0.2% of the highest loaded transmission output torque for  
each gear ratio. Calibrate and verify measurement instruments according  
to 40 CFR part 1065, subpart D. Command speed and torque at a minimum  
of 10 Hz, and record all data, including bulk oil temperature, at a  
minimum of 1 Hz mean values.  
    (d) Test the transmission at input shaft speeds and torque  
setpoints as described in this paragraph (d). You may exclude lower  
gears from testing; however, you must test all the gears above the  
highest excluded gear. GEM will use default values for any untested  
gears. The test matrix consists of test points representing  
transmission input shaft speeds and torque setpoints meeting the  
following specifications for each tested gear:  
    (1) Test at the following transmission input shaft speeds:  
    (i) 600.0 r/min or transmission input shaft speed when paired with  
the engine operating at idle.  
    (ii) The transmission's maximum rated input shaft speed. You may  
alternatively select a value representing the highest expected in-use  
transmission input shaft speed.  
    (iii) Three equally spaced intermediate speeds. The intermediate  
speed points may be adjusted to the nearest 50 or 100 r/min. You may  
test any number of additional speed setpoints to improve accuracy.  
    (2) Test at certain transmission input torque setpoints as follows:  
    (i) Include one unloaded (zero-torque) setpoint.  
    (ii) Include one loaded torque setpoint between 75% and 105% of the  
transmission's maximum rated input shaft torque. However, you may use a  
lower torque setpoint as needed to avoid exceeding dynamometer torque  
limits, as long as testing accurately represents in-use performance. If  
your loaded torque setpoint is below 75% of the transmission's maximum  
rated input shaft torque, you must demonstrate that the sum of time for  
all gears where demanded engine torque is between your maximum torque  
setpoint and 75% of the transmission's maximum rated input shaft torque  
is no more than 10% of the time for each vehicle drive cycle specified  
in this subpart. This demonstration must be made available upon  
request.  
    (iii) You may test at any number of additional torque setpoints to  
improve accuracy.  
    (iv) Note that GEM calculates power loss between tested or default  
values by linear interpolation, except that GEM may extrapolate outside  
of measured values to account for testing at torque setpoints below 75%  
as specified in paragraph (d)(2)(ii) of this section.  
    (3) In the case of transmissions that automatically go into neutral  
when the vehicle is stopped, also perform tests at 600 r/min and 800 r/  
min with the transmission in neutral and the transmission output fixed  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 151/268at zero speed.  
    (e) Determine transmission efficiency using the following  
procedure:  
    (1) Maintain ambient temperature between (15 and 35) [deg]C  
throughout testing. Measure ambient temperature within 1.0 m of the  
transmission.  
    (2) Maintain transmission oil temperature as described in paragraph  
(b)(7) of this section.  
    (3) Use good engineering judgment to warm up the transmission  
according to the transmission manufacturer's specifications.  
    (4) Perform unloaded transmission tests by disconnecting the  
transmission output shaft from the dynamometer and letting it rotate  
freely. If the transmission adjusts pump pressure based on whether the  
vehicle is moving or stopped, set up the transmission for unloaded  
tests to operate as if the vehicle is moving.  
    (5) For transmissions that have multiple configurations for a given  
gear ratio, such as dual-clutch transmissions that can pre-select an  
upshift or downshift, set the transmission to operate in the  
configuration with the greatest power loss. Alternatively, test  
[[Page 34487]]  
in each configuration and use good engineering judgment to calculate a  
weighted power loss for each test point under this section based on  
field data that characterizes the degree of in-use operation in each  
configuration.  
    (6) For a selected gear, operate the transmission at one of the  
test points from paragraph (d) of this section for at least 10 seconds.  
Measure the speed and torque of the input and output shafts for at  
least 10 seconds. You may omit measurement of output shaft speeds if  
your transmission is configured to not allow slip. Calculate arithmetic  
mean values for mean input shaft torque, T in, mean output  
shaft torque, T out, mean input shaft speed,  
[fnof]nin, and mean output shaft speed,  
[fnof]nout, for each point in the test matrix for each test.  
Repeat this stabilization, measurement, and calculation for the other  
speed and torque setpoints from the test matrix for the selected gear  
in any sequence. Calculate power loss as described in paragraph (f) of  
this section based on mean speed and torque values at each test point.  
    (7) Repeat the procedure described in paragraph (e)(6) of this  
section for all gears, or for all gears down to a selected gear. This  
section refers to an ``operating condition'' to represent operation at  
a test point in a specific gear.  
    (8) Perform the test sequence described in paragraphs (e)(6) and  
(7) of this section three times. You may do this repeat testing at any  
given test point before you perform measurements for the whole test  
matrix. Remove torque from the transmission input shaft and bring the  
transmission to a complete stop before each repeat measurement.  
    (9) You may need to perform additional testing at a given operating  
condition based on a calculation of a confidence interval to represent  
repeatability at a 95% confidence level at that operating condition. If  
the confidence interval is greater than 0.10% for loaded tests or  
greater than 0.05% for unloaded tests, perform another measurement at  
that operating condition and recalculate the repeatability for the  
whole set of test results. Continue testing until the confidence  
interval is at or below the specified values for all operating  
conditions. As an alternative, for any operating condition that does  
not meet this repeatability criterion, you may determine a maximum  
power loss instead of calculating a mean power loss as described in  
paragraph (g) of this section. Calculate a confidence interval  
representing the repeatability in establishing a 95% confidence level  
using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.152  
Where: 
[sigma]Ploss = standard deviation of power loss values at  
a given operating condition (see 40 CFR 1065.602(c)).  
N = number of repeat tests for an operating condition.  
Prated = the transmission's rated input power for a given  
gear. For testing in neutral, use the value of P rated for  
the top gear.  
Example:  
[sigma]Ploss = 0.1200 kW  
N = 3 
Prated = 314.2000 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.153  
Confidence Interval = 0.0432%  
    (f) Calculate the mean power loss, P loss, at each  
operating condition as follows:  
    (1) Calculate P loss for each measurement at each  
operating condition as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.154  
Where: 
Tin = mean input shaft torque from paragraph (e)(6) of  
this section.  
[fnof]nin = mean input shaft speed from paragraph (e)(6)  
of this section in rad/s.  
Tout = mean output shaft torque from paragraph (e)(6) of  
this section. Let T out= 0 for all unloaded tests.  
[fnof]nout = mean output shaft speed from paragraph  
(e)(6) of this section in rad/s. Let [fnof] nout = 0 for  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 152/268all tests with the transmission in neutral. See paragraph (f)(2) of  
this section for calculating [fnof] nout as a function of  
[fnof]nin instead of measuring [fnof] nout. 
    (2) For transmissions that are configured to not allow slip, you  
may calculate [fnof] nout based on the gear ratio using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.155  
Where: 
kg = transmission gear ratio, expressed to at least the  
nearest 0.001.  
    (3) Calculate P loss as the mean power loss from all  
measurements at a given operating condition.  
    (4) The following example illustrates a calculation of  
Ploss: 
Tin,1 = 1000.0 N[middot]m  
[fnof]nin,1 = 1000 r/min = 104.72 rad/sec  
Tout,1 = 2654.5 N[middot]m  
[fnof]nout,1 = 361.27 r/min = 37.832 rad/s  
Ploss,1 = 1000.0[middot]104.72-2654.5[middot]37.832  
Ploss,1 = 4295 W = 4.295 kW  
Ploss,2 = 4285 W = 4.285 kW  
Ploss,3 = 4292 W = 4.292 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.156  
[[Page 34488]]  
    (g) Create a table with the mean power loss, P loss,  
corresponding to each operating condition for input into GEM. Also  
include power loss in neutral for each tested engine's speed, if  
applicable. Express transmission input speed in r/min to one decimal  
place; express input torque in N[middot]m to two decimal places;  
express power loss in kW to four decimal places. Record the following  
values: 
[GRAPHIC] [TIFF OMITTED] TR29JN21.280  
    (2) For any operating condition not meeting the repeatability  
criterion in paragraph (e)(9) of this section, record the maximum value  
of Ploss for that operating condition along with the  
corresponding values of T in, and fnin. 
    (h) Record declared power loss values at or above the corresponding  
value calculated in paragraph (f) of this section. Use good engineering  
judgment to select values that will be at or above the mean power loss  
values for your production transmissions. Vehicle manufacturers will  
use these declared mean power loss values for certification.  
0 
162. Add Sec.  1037.570 to read as follows:  
Sec.  1037.570  Procedures to characterize torque converters.  
    GEM includes input values related to torque converters. This  
section describes a procedure for mapping a torque converter's capacity  
factors and torque ratios over a range of operating conditions. You may  
ask us to approve analytically derived input values based on this  
testing for additional untested configurations as described in Sec.   
1037.235(h).  
    (a) Prepare a torque converter for testing as follows:  
    (1) Select a torque converter with less than 500 hours of operation  
before the start of testing.  
    (2) If the torque converter has a locking feature, unlock it for  
all testing performed under this section. If the torque converter has a  
slipping lockup clutch, you may ask us to approve a different strategy  
based on data showing that it represents better in-use operation.  
    (3) Mount the torque converter with a transmission to the  
dynamometer in series or parallel arrangement or mount the torque  
converter without a transmission to represent a series configuration.  
    (4) Add transmission oil according to the torque converter  
manufacturer's instructions, with the following additional  
specifications:  
    (i) If the torque converter manufacturer specifies multiple  
transmission oils, select the one with the highest viscosity at  
operating temperature. You may use a lower-viscosity transmission oil  
if we approve that as critical emission-related maintenance under Sec.   
1037.125.  
    (ii) Fill the transmission oil to a level that represents in-use  
operation. If you are testing the torque converter without the  
transmission, keep output pressure and the flow rate of transmission  
oil into the torque converter within the torque converter  
manufacturer's limits.  
    (iii) You may use an external transmission oil conditioning system,  
as long as it does not affect measured values.  
    (5) Install equipment for measuring the bulk temperature of the  
transmission oil in the oil sump or a similar location and at the  
torque converter inlet. If the torque converter is tested without a  
transmission, measure the oil temperature at the torque converter  
inlet. 
    (6) Break in the torque converter and transmission (if applicable)  
using good engineering judgment. Maintain transmission oil temperature  
at (87 to 93) [deg]C. You may ask us to approve a different range of  
transmission oil temperatures if you have data showing that it better  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 153/268represents in-use operation.  
    (b) Measure pump and turbine shaft speed and torque as described in  
40 CFR 1065.210(b). You must use a speed measurement system that meets  
an accuracy of 0.1% of point or 1 r/min,  
whichever is greater. Use torque transducers that meet an accuracy of  
1.0% of the torque converter's maximum rated input and  
output torque, respectively. Calibrate and verify measurement  
instruments according to 40 CFR part 1065, subpart D. Command speed and  
torque at a minimum of 10 Hz. Record all speed and torque data at a  
minimum of 1 Hz mean values. Note that this section relies on the  
convention of describing the input shaft as the pump and the output  
shaft as the turbine shaft.  
    (c) Determine torque converter characteristics based on a test  
matrix using either constant input speed or constant input torque as  
follows:  
    (1) Constant input speed. Test at constant input speed as follows:  
    (i) Select a fixed pump speed, [fnof] npum, between (1000  
and 2000) r/min.  
    (ii) Test the torque converter at multiple speed ratios, v, in the  
range of v = 0.00 to v = 0.95. Use a step width of 0.10 for the range  
of v = 0.00 to 0.60 and 0.05 for the range of v = 0.60 to 0.95.  
Calculate speed ratio, v, as turbine shaft speed divided by pump speed.  
    (2) Constant input torque. Test at constant input torque as  
follows:  
    (i) Set the pump torque, T pum, to a fixed positive value  
at [fnof] npum = 1000 r/min with the torque converter's  
turbine shaft locked in a non-rotating state (i.e., turbine's speed,  
ntur, = 0 r/min).  
    (ii) Test the torque converter at multiple speed ratios, v, in the  
range of v = 0.00 up to a value of [fnof] ntur that covers  
the usable range of v. Use a step width of 0.10 for the range of v =  
0.00 to 0.60 and 0.05 for the range of v = 0.60 to 0.95.  
    (3) You may limit the maximum speed ratio to a value below 0.95 if  
you have data showing this better represents in-use operation. You must  
use the step widths defined in paragraph (c)(1) or (2) of this section  
and include the upper limit as a test point. If you choose a value less  
than 0.60, you must test at least seven evenly distributed points  
between v = 0 and your new upper speed ratio.  
    (d) Characterize the torque converter using the following  
procedure:  
[[Page 34489]]  
    (1) Maintain ambient temperature between (15 and 35) [deg]C  
throughout testing. Measure ambient temperature within 1.0 m of the  
torque converter.  
    (2) Maintain transmission oil temperature as described in paragraph  
(a)(6) of this section. You may use an external transmission oil  
conditioning system, as long as it does not affect measured values.  
    (3) Use good engineering judgment to warm up the torque converter  
according to the torque converter manufacturer's specifications.  
    (4) Test the torque converter at constant input speed or constant  
input torque as described in paragraph (c) of this section. Operate the  
torque converter at v = 0.00 for (5 to 60) seconds, then measure pump  
torque, turbine shaft torque, angular pump speed, angular turbine shaft  
speed, and the transmission oil temperature at the torque converter  
inlet for (5 to 15) seconds. Calculate arithmetic mean values for pump  
torque, T pum, turbine shaft torque, T tur, angular  
pump speed, f npum, and angular turbine shaft speed,  
fntur, over the measurement period. Repeat this  
stabilization, measurement, and calculation for the other speed ratios  
from the test matrix in order of increasing speed ratio. Adjust the  
speed ratio by increasing the angular turbine shaft speed.  
    (5) Complete a test run by performing the test sequence described  
in paragraph (d)(4) of this section two times.  
    (6) Invalidate the test run if the difference between the pair of  
mean torque values for the repeat tests at any test point differ by  
more than 1 N[middot]m or by more than 5% of  
the average of those two values. This paragraph (d)(6) applies  
separately for mean pump torque and mean turbine shaft torque at each  
test point.  
    (7) Invalidate the test run if any calculated value for mean  
angular pump speed does not stay within 5 r/min of the  
speed setpoint or if any calculated value for mean pump torque does not  
stay within 5 N[middot]m of the torque setpoint.  
    (e) Calculate the mean torque ratio, l, at each tested speed ratio,  
v, as follows:  
    (1) Calculate [mu] at each tested speed ratio as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.157  
     
Where: 
Ttur = mean turbine shaft torque from paragraph (d)(4) of  
this section.  
Tpum = mean pump torque from paragraph (d)(4) of this  
section.  
    (2) Calculate l as the average of the two values of [mu] at each  
tested speed ratio.  
    (3) The following example illustrates a calculation of l:  
Ttur,v=0,1  = 332.4 N[middot]m  
Tpum,v=0,1  = 150.8 N[middot]m  
Ttur,v=0,2  = 333.6 N[middot]m  
Tpum,v=0,2  = 150.3 N[middot]m  
[GRAPHIC] [TIFF OMITTED] TR29JN21.158  
    (f) Calculate the mean capacity factor, k, at each tested speed  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 154/268ratio, v, as follows:  
    (1) Calculate k at each tested speed ratio as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.159  
     
Where: 
fnpum = mean angular pump speed from paragraph (d)(4) of  
this section.  
Tpum = mean pump torque from paragraph (d)(4) of this  
section.  
    (2) Calculate k as the average of the two values of K at each  
tested speed ratio.  
    (3) The following example illustrates a calculation of k:  
fnpum,v=0,1 fnpum,v=0,2  = 1000.0 r/min  
Tpum,v=0,1  = 150.8 N[middot]m  
[GRAPHIC] [TIFF OMITTED] TR29JN21.160  
    (g) Create a table of GEM inputs showing l and k at each tested  
speed ratio, v. Express l to two decimal places; express k to one  
decimal place; express v to two decimal places.  
0 
163. Amend Sec.  1037.601 by revising paragraph (a)(2) to read as  
follows:  
Sec.  1037.601  General compliance provisions.  
    (a) * * *  
    (2) The provisions of 40 CFR 1068.105(a) apply for vehicle  
manufacturers installing engines certified under 40 CFR part 1036 as  
further limited by this paragraph (a)(2). If new engine emission  
standards apply in a given model year, you may install normal  
inventories of engines from the preceding model year under the  
provisions of 40 CFR 1068.105(a) through March 31 of that year without  
our approval; you may not install such engines after March 31 of that  
year unless we approve it in advance. Installing such engines after  
March 31 without our prior approval is  
[[Page 34490]]  
considered to be prohibited stockpiling of engines. In a written  
request for our approval, you must describe how your circumstances led  
you and your engine supplier to have normal inventories of engines that  
were not used up in the specified time frame. We will approve your  
request for up to three additional months to install engines under this  
paragraph (a)(2) if we determine that the excess inventory is a result  
of unforeseeable circumstances and should not be considered  
circumvention of emission standards. We will limit this approval to a  
certain number of engines consistent with your normal production and  
inventory practices. Note that 40 CFR 1068.105(a) allows vehicle  
manufacturers to use up only normal inventories of engines meeting less  
stringent standards; if, for example, a vehicle manufacturer's normal  
practice is to receive a shipment of engines every two weeks, it will  
deplete its potential to install previous-tier engines under this  
paragraph (a)(2) well before March 31 in the year that new standards  
apply. 
* * * * *  
0 
164. Amend Sec.  1037.615 by revising paragraph (f) to read as follows:  
Sec.  1037.615  Advanced technologies.  
* * * * *  
    (f) For electric vehicles and for fuel cells powered by hydrogen,  
calculate CO 2 credits using an FEL of 0 g/ton-mile.  
* * * * *  
0 
165. Amend Sec.  1037.621 by revising paragraph (g) introductory text  
to read as follows:  
Sec.  1037.621  Delegated assembly.  
* * * * *  
    (g) We may allow certifying vehicle manufacturers to authorize  
dealers or distributors to reconfigure/recalibrate vehicles after the  
vehicles have been introduced into commerce if they have not yet been  
delivered to the ultimate purchaser as follows:  
* * * * *  
0 
166. Amend Sec.  1037.635 by revising paragraph (c)(1) introductory  
text to read as follows:  
Sec.  1037.635  Glider kits and glider vehicles.  
* * * * *  
    (c) * * *  
    (1) The allowance in this paragraph (c) applies only for the  
following engines:  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 155/2680 
167. Amend Sec.  1037.660 by revising paragraphs (a)(2) and (b) to read  
as follows:  
Sec.  1037.660  Idle-reduction technologies.  
* * * * *  
    (a) * * *  
    (2) Neutral idle. Phase 2 vehicles with hydrokinetic torque  
converters paired with automatic transmissions qualify for neutral-idle  
credit in GEM modeling if the transmission reduces torque equivalent to  
shifting into neutral throughout the interval during which the  
vehicle's brake pedal is depressed and the vehicle is at a zero-speed  
condition (beginning within five seconds of the vehicle reaching zero  
speed with the brake depressed). If a vehicle reduces torque partially  
but not enough to be equivalent to shifting to neutral, you may use the  
provisions of Sec.  1037.610(g) to apply for an appropriate partial  
emission reduction; this may involve A to B testing with the powertrain  
test procedure in Sec.  1037.550 or the spin-loss portion of the  
transmission efficiency test in Sec.  1037.565.  
* * * * *  
    (b) Override conditions. The system may limit activation of the  
idle-reduction technology while any of the conditions of this paragraph  
(b) apply. These conditions allow the system to delay engine shutdown,  
adjust engine restarting, or delay disengaging transmissions, but do  
not allow for resetting timers. Engines may restart and transmissions  
may re-engage during override conditions if the vehicle is set up to do  
this automatically. We may approve additional override criteria as  
needed to protect the engine and vehicle from damage and to ensure safe  
vehicle operation.  
    (1) For AES systems on tractors, the system may delay shutdown--  
    (i) When an exhaust emission control device is regenerating. The  
period considered to be regeneration for purposes of this allowance  
must be consistent with good engineering judgment and may differ in  
length from the period considered to be regeneration for other  
purposes. For example, in some cases it may be appropriate to include a  
cool down period for this purpose but not for infrequent regeneration  
adjustment factors.  
    (ii) When the vehicle's main battery state-of-charge is not  
sufficient to allow the main engine to be restarted.  
    (iii) When the vehicle's transmission, fuel, oil, or engine coolant  
temperature is too low or too high according to the manufacturer's  
specifications for protecting against system damage. This allows the  
engine to continue operating until it is in a predefined temperature  
range, within which the shutdown sequence of paragraph (a) of this  
section would resume.  
    (iv) When the vehicle's main engine is operating in power take-off  
(PTO) mode. For purposes of this paragraph (b), an engine is considered  
to be in PTO mode when a switch or setting designating PTO mode is  
enabled.  
    (v) When external ambient conditions prevent managing cabin  
temperatures for the driver's safety.  
    (vi) When necessary while servicing the vehicle, provided the  
deactivation of the AES system is accomplished using a diagnostic scan  
tool. The system must be automatically reactivated when the engine is  
shut down for more than 60 minutes.  
    (2) For AES systems on vocational vehicles, the system may limit  
activation--  
    (i) When any condition specified in paragraphs (b)(1)(i) through  
(v) of this section applies.  
    (ii) When the engine compartment is open.  
    (3) For neutral idle, the system may delay shifting the  
transmission to neutral--  
    (i) When the system meets the PTO conditions specified in paragraph  
(b)(1)(iv) of this section.  
    (ii) When the transmission is in reverse gear.  
    (iii) When the vehicle is ascending or descending a road with grade  
at or above 6.0%.  
    (4) For stop-start, the system may limit activation--  
    (i) When any condition specified in paragraph (b)(2) or (b)(3)(ii)  
or (iii) of this section applies.  
    (ii) When air brake pressure is too low according to the  
manufacturer's specifications for maintaining vehicle-braking  
capability.  
    (iii) When an automatic transmission is in ``park'' or ``neutral''  
and the parking brake is engaged.  
    (iv) When recent vehicle speeds indicate an abnormally high  
shutdown and restart frequency, such as with congested driving. For  
example, a vehicle not exceeding 10 mi/hr for the previous 300 seconds  
or since the most recent engine start would be a proper basis for  
overriding engine shutdown. You may also design this override to  
protect against system damage or malfunction of safety systems.  
    (v) When the vehicle detects that a system or component is worn or  
malfunctioning in a way that could reasonably prevent the engine from  
restarting, such as low battery voltage.  
    (vi) When the steering angle is at or near the limit of travel.  
    (vii) When flow of diesel exhaust fluid is limited due to freezing.  
    (viii) When a sensor failure could prevent the anti-lock braking  
system from properly detecting vehicle speed.  
[[Page 34491]]  
    (ix) When a protection mode designed to prevent component failure  
is active.  
    (x) When a fault on a system component needed for starting the  
engine is active.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 156/268* * * * *  
0 
168. Amend Sec.  1037.665 by revising paragraph (c) to read as follows:  
Sec.  1037.665  Production and in-use tractor testing.  
* * * * *  
    (c) We may approve your request to perform alternative testing that  
will provide equivalent or better information compared to the specified  
testing. For example, we may allow you to provide CO 2 data  
from in-use operation or from manufacturer-run on-road testing as long  
as it allows for reasonable year-to-year comparisons and includes  
testing from production vehicles. We may also direct you to do less  
testing than we specify in this section.  
* * * * *  
0 
169. Amend Sec.  1037.670 by revising paragraphs (a) and (b) to read as  
follows:  
Sec.  1037.670  Optional CO2 emission standards for tractors at or  
above 120,000 pounds GCWR.  
    (a) You may certify tractors at or above 120,000 pounds GCWR to the  
following CO 2 standards instead of the Phase 2  
CO2 standards of Sec.  1037.106:  
        Table 1 of Sec.   1037.670--Optional Phase 2 CO2 Standards for Tractors Above 120,000 Pounds GCWR  
                                                [g/ton-mile] \a\  
----------------------------------------------------------------------------------------------------------------  
                                                                 Model years      Model years      Model years  
                         Subcategory                              2021-2023        2024-2026      2026 and later  
----------------------------------------------------------------------------------------------------------------  
Heavy Class 8 Low-Roof Day Cab...............................             53.5             50.8             48.9  
Heavy Class 8 Low-Roof Sleeper Cab...........................             47.1             44.5             42.4  
Heavy Class 8 Mid-Roof Day Cab...............................             55.6             52.8             50.8  
Heavy Class 8 Mid-Roof Sleeper Cab...........................             49.6             46.9             44.7  
Heavy Class 8 High-Roof Day Cab..............................             54.5             51.4             48.6  
Heavy Class 8 High-Roof Sleeper Cab..........................             47.1             44.2             41.0  
----------------------------------------------------------------------------------------------------------------  
\a\ Note that these standards are not directly comparable to the standards for Heavy-Haul Tractors in Sec.  
  1037.106 because GEM handles aerodynamic performance differently for the two sets of standards.  
    (b) Determine subcategories as described in Sec.  1037.230 for  
tractors that are not heavy-haul tractors. For example, the subcategory  
for tractors that would otherwise be considered Class 8 low-roof day  
cabs would be Heavy Class 8 Low-Roof Day Cabs and would be identified  
as HC8_DC_LR for the GEM run.  
* * * * *  
0 
170. Amend Sec.  1037.701 by revising paragraphs (h) and (i) to read as  
follows:  
Sec.  1037.701  General provisions.  
* * * * *  
    (h) See Sec.  1037.740 for special credit provisions that apply for  
credits generated under 40 CFR 86.1819-14 (k)(7), 40 CFR 1036.615, or  
Sec.  1037.615.  
    (i) Unless the regulations in this part explicitly allow it, you  
may not calculate Phase 1 credits more than once for any emission  
reduction. For example, if you generate Phase 1 CO 2 emission  
credits for a given hybrid vehicle under this part, no one may generate  
CO2 emission credits for the associated hybrid engine under  
40 CFR part 1036. However, Phase 1 credits could be generated for  
identical engines used in vehicles that did not generate credits under  
this part.  
* * * * *  
0 
171. Amend Sec.  1037.705 by revising paragraph (c)(2) to read as  
follows:  
Sec.  1037.705  Generating and calculating emission credits.  
* * * * *  
    (c) * * *  
    (2) Exported vehicles, even if they are certified under this part  
and labeled accordingly.  
* * * * *  
0 
172. Amend Sec.  1037.740 by revising paragraph (b)(1) to read as  
follows:  
Sec.  1037.740  Restrictions for using emission credits.  
* * * * *  
    (b) * * *  
    (1) The maximum amount of credits you may bring into the following  
service class groups is 60,000 Mg per model year:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 157/268    (i) Spark-ignition engines, light heavy-duty compression-ignition  
engines, and Light HDV. This group comprises the averaging set listed  
in paragraphs (a)(1) of this section and the averaging set listed in 40  
CFR 1036.740(a)(1) and (2).  
    (ii) Medium heavy-duty compression-ignition engines and Medium HDV.  
This group comprises the averaging sets listed in paragraph (a)(2) of  
this section and 40 CFR 1036.740(a)(3).  
    (iii) Heavy heavy-duty compression-ignition engines and Heavy HDV.  
This group comprises the averaging sets listed in paragraph (a)(3) of  
this section and 40 CFR 1036.740(a)(4).  
* * * * *  
0 
173. Amend Sec.  1037.801 by--  
0 
a. Revising the definitions for ``Auxiliary emission control device'',  
``Compression-ignition'', and ``Electric vehicle''.  
0 
b. Adding a definition for ``Electronic control module'' in  
alphabetical order.  
0 
c. Revising the definitions for ``Gear ratio or Transmission gear  
ratio, kg'' and ``Heavy-duty vehicle''.  
0 
d. Adding a definition for ``High-strength steel'' in alphabetical  
order. 
0 
e. Revising the definitions for ``Hybrid engine or hybrid powertrain'',  
``Hybrid vehicle'', ``Light-duty truck'', ``Low rolling resistance  
tire'', ``Model year'', and ``Small manufacturer''.  
0 
f. Adding a definition for ``Tonne'' in alphabetical order.  
    The revisions and additions read as follows:  
Sec.  1037.801  Definitions.  
* * * * *  
    Auxiliary emission control device means any element of design that  
senses temperature, motive speed, engine speed (r/min), transmission  
gear, or any other parameter for the purpose of activating, modulating,  
delaying, or deactivating the operation of any part of the emission  
control system.  
* * * * *  
    Compression-ignition has the meaning given in Sec.  1037.101.  
* * * * *  
    Electric vehicle means a motor vehicle that does not include an  
engine, and is powered solely by an external source of electricity and/  
or solar power. Note that this definition does not include hybrid  
electric vehicles or fuel-cell vehicles that use a chemical fuel such  
as gasoline, diesel fuel, or hydrogen. Electric vehicles may also be  
referred to  
[[Page 34492]]  
as all-electric vehicles to distinguish them from hybrid vehicles.  
    Electronic control module has the meaning given in 40 CFR  
1065.1001.  
* * * * *  
    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.  
* * * * *  
    Heavy-duty vehicle means any trailer and any other motor vehicle  
that has a GVWR above 8,500 pounds. An incomplete vehicle is also a  
heavy-duty vehicle if it has a curb weight above 6,000 pounds or a  
basic vehicle frontal area greater than 45 square feet.  
* * * * *  
    High-strength steel has the meaning given in Sec.  1037.520.  
    Hybrid engine or hybrid powertrain means an engine or 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 other examples of systems that qualify as hybrid engines or  
powertrains are systems that recover kinetic energy and use it to power  
an electric heater in the aftertreatment. Note that certain provisions  
in this part treat hybrid engines and hybrid powertrains intended for  
vehicles that include regenerative braking different than those  
intended for vehicles that do not include regenerative braking.  
    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 other examples of systems that qualify as hybrid engines or  
powertrains are systems that recover kinetic energy and use it to power  
an electric heater in the aftertreatment. Note that certain provisions  
in this part treat hybrid vehicles that include regenerative braking  
different than those that do not include regenerative braking.  
* * * * *  
    Light-duty truck means any motor vehicle that is not a heavy-duty  
vehicle, but is:  
    (1) Designed primarily for purposes of transportation of property  
or is a derivation of such a vehicle; or  
    (2) Designed primarily for transportation of persons and has a  
capacity of more than 12 persons; or  
    (3) Available with special features enabling off-street or off-  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 158/268highway operation and use.  
* * * * *  
    Low rolling resistance tire means a tire on a vocational vehicle  
with a TRRL at or below of 7.7 kg/tonne, a steer tire on a tractor with  
a TRRL at or below 7.7 kg/tonne, a drive tire on a tractor with a TRRL  
at or below 8.1 kg/tonne, a tire on a non-box trailer with a TRRL at or  
below of 6.5 kg/tonne, or a tire on a box van with a TRRL at or below  
of 6.0 kg/tonne.  
* * * * *  
    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, model year means the manufacturer's annual  
new model production period based on the vehicle's date of manufacture,  
where the model year is the calendar year corresponding to the date of  
manufacture, except as follows:  
    (i) The vehicle's model year may be designated as the year before  
the calendar year corresponding to the date of manufacture if the  
engine's model year is also from an earlier year. You may ask us to  
extend your prior model year certificate to include such vehicles. Note  
that Sec.  1037.601(a)(2) limits the extent to which vehicle  
manufacturers may install engines built in earlier calendar years.  
    (ii) The vehicle's model year may be designated as the year after  
the calendar year corresponding to the vehicle's date of manufacture.  
For example, a manufacturer may produce a new vehicle by installing the  
engine in December 2023 and designating it as a model year 2024  
vehicle.  
    (2) For trailers and 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 and 40 CFR part 85, subpart X. 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 vehicle  
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 redesignate 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.  
* * * * *  
    Small manufacturer means a manufacturer meeting the small business  
criteria specified in 13 CFR 121.201 for vocational vehicles and  
tractors (NAICS code 336120) or for trailers (NAICS code 336212). The  
employee and revenue limits apply to the total number employees and  
total revenue together for affiliated companies.  
* * * * *  
    Tonne means metric ton, which is exactly 1000 kg.  
* * * * *  
0 
174. Amend Sec.  1037.805 by revising paragraphs (b), (c), (d), (e),  
and (f) to read as follows:  
Sec.  1037.805  Symbols, abbreviations, and acronyms.  
* * * * *  
    (b) Symbols for quantities. This part uses the following symbols  
and units of measure for various quantities:  
[[Page 34493]]  
                               Table 2 to Sec.   1037.805--Symbols for Quantities  
----------------------------------------------------------------------------------------------------------------  
                                                                                                Unit in terms of  
         Symbol                  Quantity                   Unit               Unit symbol       SI base units  
----------------------------------------------------------------------------------------------------------------  
A......................  vehicle frictional load  pound force or newton..  lbf or N..........  kg[middot]m[middo  
                                                                                                t]s-2.  
a......................  axle position  
                          regression  
                          coefficient.  
[alpha]................  atomic hydrogen-to-      mole per mole..........  mol/mol...........  1.  
                          carbon ratio.  
[alpha]................  axle position  
                          regression  
                          coefficient.  
[alpha]0...............  intercept of air speed  
                          correction.  
[alpha]1...............  slope of air speed  
                          correction.  
[alpha]g...............  acceleration of Earth's  meters per second        m/s2..............  m[middot]s-2.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 159/268                          gravity.                 squared.  
[alpha]0...............  intercept of least  
                          squares regression.  
[alpha]1...............  slope of least squares  
                          regression.  
B......................  vehicle load from drag   pound force per mile     lbf/(mi/hr) or      kg[middot]s-1.  
                          and rolling resistance.  per hour or newton       N[middot]s/m.  
                                                   second per meter.  
b......................  axle position  
                          regression  
                          coefficient.  
[beta].................  atomic oxygen-to-carbon  mole per mole..........  mol/mol...........  1.  
                          ratio.  
[beta].................  axle position  
                          regression  
                          coefficient.  
[beta]0................  intercept of air  
                          direction correction.  
[beta]1................  slope of air direction  
                          correction.  
C......................  vehicle-specific         pound force per mile     lbf/mph2 or         kg[middot]m-1.  
                          aerodynamic effects.     per hour squared or      N[middot]s2/m2.  
                                                   newton-second squared  
                                                   per meter squared.  
c......................  axle position  
                          regression  
                          coefficient.  
ci.....................  axle test regression  
                          coefficients.  
Ci.....................  constant.
[Delta]CdA.............  differential drag area.  meter squared..........  m2................  m2.  
CdA....................  drag area..............  meter squared..........  m2................  m2.  
Cd.....................  drag coefficient.  
CF.....................  correction factor.  
Crr....................  coefficient of rolling   kilogram per metric ton  kg/tonne..........  10-3.  
                          resistance.  
D......................  distance...............  miles or meters........  mi or m...........  m.  
e......................  mass-weighted emission   grams/ton-mile.........  g/ton-mi..........  g/kg-km.  
                          result.  
E[fnof][fnof]..........  efficiency.  
F......................  adjustment factor.  
F......................  force..................  pound force or newton..  lbf or N..........  kg[middot]m[middo  
                                                                                                t]s-2.  
fn.....................  angular speed (shaft)..  revolutions per minute.  r/min.............  [pi][middot]30[mi  
                                                                                                ddot]s-1.  
G......................  road grade.............  percent................  %.................  10-2.  
g......................  gravitational            meters per second        m/s2..............  m[middot]s-2.  
                          acceleration.            squared.  
h......................  elevation or height....  meters.................  m.................  m.  
i......................  indexing variable.  
ka.....................  drive axle ratio.......  .......................  ..................  1.  
kd.....................  transmission gear  
                          ratio.  
ktopgear...............  highest available  
                          transmission gear.  
L......................  load over axle.........  pound force or newton..  lbf or N..........  kg[middot]m[middo  
                                                                                                t]s-2.  
m......................  mass...................  pound mass or kilogram.  lbm or kg.........  kg.  
M......................  molar mass.............  gram per mole..........  g/mol.............  10-  
                                                                                                3[middot]kg[midd  
                                                                                                ot]mol-1.  
M......................  vehicle mass...........  kilogram...............  kg................  kg.  
Me.....................  vehicle effective mass.  kilogram...............  kg................  kg.  
Mrotating..............  inertial mass of         kilogram...............  kg................  kg.  
                          rotating components.  
N......................  total number in series.  
n......................  number of tires.  
n......................  amount of substance      mole per second........  mol/s.............  mol[middot]s-1.  
                          rate.  
P......................  power..................  kilowatt...............  kW................  103[middot]m2[mid  
                                                                                                dot]kg[middot]s-  
                                                                                                3.  
p......................  pressure...............  pascal.................  Pa................  kg[middot]m-  
                                                                                                1[middot]s-2.  
[rho]..................  mass density...........  kilogram per cubic       kg/m3.............  kg[middot]m-3.  
                                                   meter.  
PL.....................  payload................  tons...................  ton...............  kg.  
[phi]..................  direction..............  degrees................  [deg].............  [deg].  
c......................  direction..............  degrees................  [deg].............  [deg].  
r......................  tire radius............  meter..................  m.................  m.  
r2.....................  coefficient of  
                          determination.  
Re#....................  Reynolds number.  
SEE....................  standard error of the  
                          estimate.  
[sigma]................  standard deviation.  
TRPM...................  tire revolutions per     revolutions per mile...  r/mi.  
                          mile.  
TRRL...................  tire rolling resistance  kilogram per metric ton  kg/tonne..........  10-3.  
                          level.  
T......................  absolute temperature...  kelvin.................  K.................  K.  
T......................  Celsius temperature....  degree Celsius.........  [deg]C............  K-273.15.  
T......................  torque (moment of        newton meter...........  N[middot]m........  m2[middot]kg[midd  
                          force).                                                               ot]s-2.  
t......................  time...................  hour or second.........  hr or s...........  s.  
[Delta]t...............  time interval, period,   second.................  s.................  s.  
                          1/frequency.  
UF.....................  utility factor.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 160/268v......................  speed..................  miles per hour or        mi/hr or m/s......  m[middot]s-1.  
                                                   meters per second.  
w......................  weighting factor.  
w......................  wind speed.............  miles per hour.........  mi/hr.............  m[middot]s-1.  
[[Page 34494]]  
  
W......................  work...................  kilowatt-hour..........  kW[middot]hr......  3.6[middot]m2[mid  
                                                                                                dot]kg[middot]s-  
                                                                                                1.  
wC.....................  carbon mass fraction...  gram/gram..............  g/g...............  1.  
WR.....................  weight reduction.......  pound mass.............  lbm...............  kg.  
x......................  amount of substance      mole per mole..........  mol/mol...........  1.  
                          mole fraction.  
----------------------------------------------------------------------------------------------------------------  
    (c) Superscripts. This part uses the following superscripts for  
modifying quantity symbols:  
                Table 3 to Sec.   1037.805--Superscripts  
------------------------------------------------------------------------  
                Superscript                            Meaning  
------------------------------------------------------------------------  
overbar (such as y).......................  arithmetic mean.  
Double overbar (such as y)................  arithmetic mean of  
                                             arithmetic mean.  
overdot (such as y).......................  quantity per unit time.  
------------------------------------------------------------------------  
    (d) Subscripts. This part uses the following subscripts for  
modifying quantity symbols:  
                 Table 4 to Sec.   1037.805--Subscripts  
------------------------------------------------------------------------  
          Subscript                             Meaning  
------------------------------------------------------------------------  
6................  6[deg] yaw angle sweep.  
A............................  A speed.  
air..........................  air.  
aero.........................  aerodynamic.  
alt..........................  alternative.  
act..........................  actual or measured condition.  
air..........................  air.  
axle.........................  axle.  
B............................  B speed.  
brake........................  brake.  
C............................  C speed.  
Ccombdry.....................  carbon from fuel per mole of dry exhaust.  
CD...........................  charge-depleting.  
circuit......................  circuit.  
CO2DEF.......................  CO2 resulting from diesel exhaust fluid  
                                decomposition.  
CO2PTO.......................  CO2 emissions for PTO cycle.  
coastdown....................  coastdown.  
comp.........................  composite.  
CS...........................  charge-sustaining.  
cycle........................  test cycle.  
drive........................  drive axle  
drive-idle...................  idle with the transmission in drive.  
driver.......................  driver.  
dyno.........................  dynamometer.  
effective....................  effective.  
end..........................  end.  
eng..........................  engine.  
event........................  event.  
fuel.........................  fuel.  
full.........................  full.  
grade........................  grade.  
H2Oexhaustdry................  H2O in exhaust per mole of exhaust.  
hi...........................  high.  
i............................  an individual of a series.  
idle.........................  idle.  
in...........................  inlet.  
inc..........................  increment.  
lo...........................  low.  
loss.........................  loss.  
max..........................  maximum.  
meas.........................  measured quantity.  
med..........................  median.  
min..........................  minimum.  
moving.......................  moving.  
out..........................  outlet.  
P............................  power.  
pair.........................  pair of speed segments.  
parked-idle..................  idle with the transmission in park.  
partial......................  partial.  
[[Page 34495]]  
  
ploss........................  power loss.  
plug-in......................  plug-in hybrid electric vehicle.  
powertrain...................  powertrain.  
PTO..........................  power take-off.  
rated........................  rated speed.  
record.......................  record.  
ref..........................  reference quantity.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 161/268RL...........................  road load.  
rotating.....................  rotating.  
seg..........................  segment.  
speed........................  speed.  
spin.........................  axle spin loss.  
start........................  start.  
steer........................  steer axle.  
t............................  tire.  
test.........................  test.  
th...........................  theoretical.  
total........................  total.  
trac.........................  traction.  
trac10.......................  traction force at 10 mi/hr.  
trailer......................  trailer axle.  
transient....................  transient.  
TRR..........................  tire rolling resistance.  
urea.........................  urea.  
veh..........................  vehicle.  
w............................  wind.  
wa...........................  wind average.  
yaw..........................  yaw angle.  
ys...........................  yaw sweep.  
zero.........................  zero quantity.  
------------------------------------------------------------------------  
    (e) Other acronyms and abbreviations. This part uses the following  
additional abbreviations and acronyms:  
      Table 5 to Sec.   1037.805--Other Acronyms and Abbreviations  
------------------------------------------------------------------------  
           Acronym                              Meaning  
------------------------------------------------------------------------  
ABT..........................  averaging, banking, and trading.  
AECD.........................  auxiliary emission control device.  
AES..........................  automatic engine shutdown.  
APU..........................  auxiliary power unit.  
CD...........................  charge-depleting.  
CFD..........................  computational fluid dynamics.  
CFR..........................  Code of Federal Regulations.  
CITT.........................  curb idle transmission torque.  
CS...........................  charge-sustaining.  
DOT..........................  Department of Transportation.  
ECM..........................  electronic control module.  
EPA..........................  Environmental Protection Agency.  
FE...........................  fuel economy.  
FEL..........................  Family Emission Limit.  
GAWR.........................  gross axle weight rating.  
GCWR.........................  gross combination weight rating.  
GEM..........................  greenhouse gas emission model.  
GVWR.........................  gross vehicle weight rating.  
Heavy HDV....................  Heavy heavy-duty vehicle (see Sec.  
                                1037.140).  
HVAC.........................  heating, ventilating, and air  
                                conditioning.  
ISO..........................  International Organization for  
                                Standardization.  
Light HDV....................  Light heavy-duty vehicle (see Sec.  
                                1037.140).  
Medium HDV...................  Medium heavy-duty vehicle (see Sec.  
                                1037.140).  
NARA.........................  National Archives and Records  
                                Administration.  
NHTSA........................  National Highway Transportation Safety  
                                Administration.  
PHEV.........................  plug-in hybrid electric vehicle.  
PTO..........................  power take-off.  
RESS.........................  rechargeable energy storage system.  
SAE..........................  Society of Automotive Engineers.  
SEE..........................  standard error of the estimate.  
SKU..........................  stock-keeping unit.  
[[Page 34496]]  
  
TRPM.........................  tire revolutions per mile.  
TRRL.........................  tire rolling resistance level.  
U.S.C........................  United States Code.  
VSL..........................  vehicle speed limiter.  
------------------------------------------------------------------------  
    (f) Constants. This part uses the following constants:  
                  Table 6 to Sec.   1037.805--Constants  
------------------------------------------------------------------------  
        Symbol                  Quantity                  Value  
------------------------------------------------------------------------  
g.....................  gravitational constant.  9.80665 m[middot]s-2.  
R.....................  specific gas constant..  287.058 J/  
                                                  (kg[middot]K).  
------------------------------------------------------------------------  
* * * * *  
0 
175. Revise Sec.  1037.810 to read as follows:  
Sec.  1037.810  Incorporation by reference.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 162/268    (a) Certain material is incorporated by reference into this part  
with the approval of the Director of the Federal Register under 5  
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that  
specified in this section, the Environmental Protection Agency must  
publish a document in the Federal Register and the material must be  
available to the public. All approved material is available for  
inspection at EPA Docket Center, WJC West Building, Room 3334, 1301  
Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets ,  
(202) 202-1744, and is available from the sources listed in this  
section. It is also available for inspection at the National Archives  
and Records Administration (NARA). For information on the availability  
of this material at NARA, email fedreg.legal@nara.gov , call 202-741-  
6030, or go to www.archives.gov/federal-register/cfr/ibr-locations.html . 
    (b) International Organization for Standardization, Case Postale  
56, CH-1211 Geneva 20, Switzerland, (41) 22749 0111, www.iso.org , or  
central@iso.org . 
    (1) ISO 28580:2009(E) ``Passenger car, truck and bus tyres--Methods  
of measuring rolling resistance--Single point test and correlation of  
measurement results'', First Edition, July 1, 2009, (``ISO 28580''),  
IBR approved for Sec.  1037.520(c).  
    (2) [Reserved]  
    (c) U.S. EPA, Office of Air and Radiation, 2565 Plymouth Road, Ann  
Arbor, MI 48105, www.epa.gov . 
    (1) Greenhouse gas Emissions Model (GEM), Version 2.0.1, September  
2012 (``GEM version 2.0.1''), IBR approved for Sec.  1037.520.  
    (2) Greenhouse gas Emissions Model (GEM) Phase 2, Version 3.5.1,  
November 2020 (``GEM Phase 2, Version 3.5.1''); IBR approved for Sec.   
1037.520.  
    (3) GEM's MATLAB/Simulink Hardware-in-Loop model, Version 3.8,  
December 2020 (``GEM HIL model''); IBR approved for Sec.  1037.550(a).  
    Note 1 to paragraph (c): The computer code for these models is  
available as noted in paragraph (a) of this section. A working  
version of the software is also available for download at https://www.epa.gov/regulations-emissions-vehicles-and-engines/greenhouse-gas-emissions-model-gem
    (d) National Institute of Standards and Technology, 100 Bureau  
Drive, Stop 1070, Gaithersburg, MD 20899-1070, (301) 975-6478, or  
www.nist.gov . 
    (1) NIST Special Publication 811, Guide for the Use of the  
International System of Units (SI), 2008 Edition, March 2008, IBR  
approved for Sec.  1037.805.  
    (2) [Reserved]  
    (e) SAE International, 400 Commonwealth Dr., Warrendale, PA 15096-  
0001, (877) 606-7323 (U.S. and Canada) or (724) 776-4970 (outside the  
U.S. and Canada), http://www.sae.org . 
    (1) SAE J1025, Test Procedures for Measuring Truck Tire Revolutions  
Per Kilometer/Mile, Stabilized August 2012, (``SAE J1025''), IBR  
approved for Sec.  1037.520(c).  
    (2) SAE J1252, SAE Wind Tunnel Test Procedure for Trucks and Buses,  
Revised July 2012, (``SAE J1252''), IBR approved for Sec. Sec.   
1037.525(b) and 1037.530(a).  
    (3) SAE J1263, Road Load Measurement and Dynamometer Simulation  
Using Coastdown Techniques, revised March 2010, (``SAE J1263''), IBR  
approved for Sec. Sec.  1037.528 introductory text, (a), (b), (c), (e),  
and (h) and 1037.665(a).  
    (4) SAE J1594, Vehicle Aerodynamics Terminology, Revised July 2010,  
(``SAE J1594''), IBR approved for Sec.  1037.530(d).  
    (5) SAE J2071, Aerodynamic Testing of Road Vehicles--Open Throat  
Wind Tunnel Adjustment, Revised June 1994, (``SAE J2071''), IBR  
approved for Sec.  1037.530(b).  
    (6) SAE J2263, Road Load Measurement Using Onboard Anemometry and  
Coastdown Techniques, Revised December 2008, (``SAE J2263''), IBR  
approved for Sec. Sec.  1037.528 introductory text, (a), (b), (d), and  
(f) and 1037.665(a).  
    (7) SAE J2343, Recommended Practice for LNG Medium and Heavy-Duty  
Powered Vehicles, Revised July 2008, (``SAE J2343''), IBR approved for  
Sec.  1037.103(e).  
    (8) SAE J2452, Stepwise Coastdown Methodology for Measuring Tire  
Rolling Resistance, Revised June 1999, (``SAE J2452''), IBR approved  
for Sec.  1037.528(h).  
    (9) SAE J2966, Guidelines for Aerodynamic Assessment of Medium and  
Heavy Commercial Ground Vehicles Using Computational Fluid Dynamics,  
Issued September 2013, (``SAE J2966''), IBR approved for Sec.   
1037.532(a).  
0 
176. Amend Sec.  1037.825 by revising paragraph (a) to read as follows:  
Sec.  1037.825  Reporting and recordkeeping requirements.  
    (a) This part includes various requirements to submit and record  
data or other information. Unless we specify otherwise, store required  
records in any format and on any media and keep them readily available  
for eight years after you send an associated application for  
certification, or eight years after you generate the data if they do  
not support an application for certification. We may review these  
records at any time. You must promptly give us organized, written  
records in English if we ask for them. We may require you to submit  
written records in an electronic format.  
* * * * *  
0 
177. Revise appendix III to part 1037 to read as follows:  
Appendix III to Part 1037--Emission Control Identifiers  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 163/268    This appendix identifies abbreviations for emission control  
information labels, as required under Sec.  1037.135.  
Vehicle Speed Limiters  
--VSL--Vehicle speed limiter  
--VSLS--``Soft-top'' vehicle speed limiter  
--VSLE--Expiring vehicle speed limiter  
--VSLD--Vehicle speed limiter with both ``soft-top'' and expiration  
[[Page 34497]]  
Idle Reduction Technology  
--IRT5--Engine shutoff after 5 minutes or less of idling  
--IRTE--Expiring engine shutoff  
Tires 
--LRRA--Low rolling resistance tires (all, including trailers)  
--LRRD--Low rolling resistance tires (drive)  
--LRRS--Low rolling resistance tires (steer)  
Aerodynamic Components  
--ATS--Aerodynamic side skirt and/or fuel tank fairing  
--ARF--Aerodynamic roof fairing  
--ARFR--Adjustable height aerodynamic roof fairing  
--TGR--Gap reducing tractor fairing (tractor to trailer gap)  
--TGRT--Gap reducing trailer fairing (tractor to trailer gap)  
--TATS--Trailer aerodynamic side skirt  
--TARF--Trailer aerodynamic rear fairing  
--TAUD--Trailer aerodynamic underbody device  
Other Components  
--ADVH--Vehicle includes advanced hybrid technology components  
--ADVO--Vehicle includes other advanced-technology components (i.e.,  
non-hybrid system)  
--INV--Vehicle includes innovative (off-cycle) technology components  
--ATI--Automatic tire inflation system  
--TPMS--Tire pressure monitoring system  
--WRTW--Weight-reducing trailer wheels  
--WRTC--Weight-reducing trailer upper coupler plate  
--WRTS--Weight-reducing trailer axle sub-frames  
--WBSW--Wide-base single trailer tires with steel wheel  
--WBAW--Wide-base single trailer tires with aluminum wheel  
--WBLW--Wide-base single trailer tires with light-weight aluminum  
alloy wheel  
--DWSW--Dual-wide trailer tires with high-strength steel wheel  
--DWAW--Dual-wide trailer tires with aluminum wheel  
--DWLW--Dual-wide trailer tires with light-weight aluminum alloy  
wheel 
0 
178. Revise appendix IV to part 1037 to read as follows:  
Appendix IV to Part 1037--Heavy-Duty Grade Profile for Phase 2 Steady-  
State Test Cycles  
    The following table identifies a grade profile for operating  
vehicles over the highway cruise cycles specified in subpart F of  
this part. Determine intermediate values by linear interpolation.  
BILLING CODE 6560-50-P  
[[Page 34498]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.161  
[[Page 34499]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.162  
BILLING CODE 6560-50-C  
PART 1039--CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD  
COMPRESSION-IGNITION ENGINES  
0 
179. The authority citation for part 1039 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
180. Amend Sec.  1039.1 by revising paragraphs (b)(3) and (c) to read  
as follows:  
Sec.  1039.1  Does this part apply for my engines?  
* * * * *  
    (b) * * *  
    (3) Engines originally meeting Tier 1, Tier 2, or Tier 3 standards  
as specified in appendix I of this part remain subject to the standards  
in subpart B of this part. This includes uncertified engines that meet  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 164/268standards under 40 CFR 1068.265. Affected engines remain subject to  
recall provisions as specified in 40 CFR part 1068, subpart F,  
throughout the useful life corresponding to the original certification.  
Also, tampering and defeat-device prohibitions continue to apply for  
those engines as specified in 40 CFR 1068.101.  
* * * * *  
    (c) The definition of nonroad engine in 40 CFR 1068.30 excludes  
certain engines used in stationary applications. These engines may be  
required by 40 CFR part 60, subpart IIII, to comply with some of the  
provisions of this part; otherwise, these engines are only required to  
comply with the requirements in Sec.  1039.20. In addition, the  
prohibitions in 40 CFR 1068.101 restrict the use of stationary engines  
for nonstationary purposes unless they are certified to the same  
standards that would apply to certain nonroad engines for the same  
model year.  
* * * * *  
0 
181. Amend Sec.  1039.20 by revising paragraphs (a) introductory text,  
(b)(2) and (4), and (c) to read as follows:  
Sec.  1039.20  What requirements from this part apply to excluded  
stationary engines?  
* * * * *  
    (a) You must add a permanent label or tag to each new engine you  
produce or import that is excluded under Sec.  1039.1(c) as a  
stationary engine and is not required by 40 CFR part 60, subpart IIII,  
to meet the requirements described in this part, or the requirements  
described in 40 CFR part 1042, that are equivalent to the requirements  
applicable to marine or land-based nonroad engines for the same model  
year. To meet labeling requirements, you must do the following things:  
* * * * *  
    (b) * * *  
    (2) Include your full corporate name and trademark.  
* * * * *  
    (4) State: ``THIS ENGINE IS EXEMPTED FROM NONROAD CERTIFICATION  
REQUIREMENTS AS A ``STATIONARY ENGINE.'' INSTALLING OR USING THIS  
ENGINE IN ANY OTHER APPLICATION MAY BE A VIOLATION OF FEDERAL LAW  
SUBJECT TO CIVIL PENALTY.''  
    (c) Stationary engines required by 40 CFR part 60, subpart IIII, to  
meet the requirements described in this part or 40 CFR part 1042, must  
meet the labeling requirements of 40 CFR 60.4210.  
0 
182. Amend Sec.  1039.101 by revising the introductory text and  
paragraph (b) to read as follows:  
Sec.  1039.101  What exhaust emission standards must my engines meet  
after the 2014 model year?  
    The exhaust emission standards of this section apply after the 2014  
model year. Certain standards in this section also apply for model year  
2014 and earlier. This section presents the full set of emission  
standards that apply after all the transition and phase-in provisions  
of Sec. Sec.  1039.102 and 1039.104 expire. Section 1039.105 specifies  
smoke standards.  
* * * * *  
    (b) Emission standards for steady-state testing. Steady-state  
exhaust emissions from your engines may not exceed the applicable  
emission standards in Table 1 of this section. Measure emissions using  
the applicable steady-state test procedures described in subpart F of  
this part.  
[[Page 34500]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.163  
* * * * *  
0 
183. Amend Sec.  1039.102 by:  
0 
a. Revising the introductory text and paragraph (a)(2);  
0 
b. Revising Tables 1, 3, and 6 in paragraph (b); and  
[[Page 34501]]  
0 
c. Revising paragraphs (d)(1), (e)(3), (g)(1)(iv), and (g)(2).  
    The revisions read as follows:
Sec.  1039.102  What exhaust emission standards and phase-in allowances  
apply for my engines in model year 2014 and earlier?  
    The exhaust emission standards of this section apply for 2014 and  
earlier model years. See Sec.  1039.101 for exhaust emission standards  
that apply to later model years.  
    (a) * * *  
    (2) The transient standards in this section for gaseous pollutants  
do not apply to phase-out engines that you certify to the same  
numerical standards (and FELs if the engines are certified using ABT)  
for gaseous pollutants as you certified under the Tier 3 requirements  
identified in appendix I of this part. However, except as specified by  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 165/268paragraph (a)(1) of this section, the transient PM emission standards  
apply to these engines.  
    (b) * * *  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.164  
     
* * * * *  
[GRAPHIC] [TIFF OMITTED] TR29JN21.165  
[[Page 34502]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.166  
* * * * *  
    (d) * * *  
    (1) For model years 2012 through 2014, you may use banked  
NOX + NMHC credits from any Tier 2 engine at or above 37 kW  
certified under the standards identified in appendix I of this part to  
meet the NO X phase-in standards or the NO X + NMHC  
phase-out standards under paragraphs (b) and (c) of this section,  
subject to the additional ABT provisions in Sec.  1039.740.  
* * * * *  
    (e) * * *  
    (3) You use NO X + NMHC emission credits to certify an  
engine family to the alternate NO X + NMHC standards in this  
paragraph (e)(3) instead of the otherwise applicable alternate  
NOX and NMHC standards. Calculate the alternate  
NOX + NMHC standard by adding 0.1 g/kW-hr to the numerical  
value of the applicable alternate NO X standard of paragraph  
(e)(1) or (2) of this section. Engines certified to the NO X  
+ NMHC standards of this paragraph (e)(3) may not generate emission  
credits. The FEL caps for engine families certified under this  
paragraph (e)(3) are the previously applicable NO X + NMHC  
standards identified in appendix I of this part (generally the Tier 3  
standards).  
* * * * *  
    (g) * * *  
    (1) * * *  
    (iv) Gaseous pollutants for phase-out engines that you certify to  
the same numerical standards and FELs for gaseous pollutants to which  
you certified under the Tier 3 requirements identified in appendix I of  
this part. However, the NTE standards for PM apply to these engines.  
    (2) Interim FEL caps. As described in Sec.  1039.101(d), you may  
participate in the ABT program in subpart H of this part by certifying  
engines to FELs for PM, NO X, or NOX + NMHC  
instead of the standards in Tables 1 through 7 of this section for the  
model years shown. The FEL caps listed in the following table apply  
instead of the FEL caps in Sec.  1039.101(d)(1), except as allowed by  
Sec.  1039.104(g):  
[[Page 34503]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.167  
[[Page 34504]]  
* * * * *  
0 
184. Amend Sec.  1039.104 by revising paragraphs (c)(1), (c)(2)(ii),  
(c)(4), and (g)(4) to read as follows:  
Sec.  1039.104  Are there interim provisions that apply only for a  
limited time?  
* * * * *  
    (c) * * *  
    (1) You may delay complying with certain otherwise applicable Tier  
4 emission standards and requirements as described in the following  
table: 
----------------------------------------------------------------------------------------------------------------  
                                                                      Until model  
 If your engine's maximum  power is .   You may delay meeting . . .    year . . .    Before that model year the  
                 . .                                                               engine must comply with . . .  
----------------------------------------------------------------------------------------------------------------  
(i) kW <19...........................  The standards and                     2011  The standards and  
                                        requirements of this part.                  requirements described in  
                                                                                    appendix I of this part.  
(ii) 19 <=kW <37.....................  The Tier 4 standards and              2016  The Tier 4 standards and  
                                        requirements of this part                   requirements that apply for  
                                        that would otherwise be                     model year 2008.  
                                        applicable in model year  
                                        2013.  
                                      --------------------------------------------------------------------------  
(iii) 37 <=kW <56....................    See paragraph (c)(2) of this section for special provisions that apply  
                                                           for engines in this power category.  
                                      --------------------------------------------------------------------------  
(iv) 56 <=kW <130....................  The standards and                     2015  The standards and  
                                        requirements of this part.                  requirements described in  
                                                                                    appendix I of this part.  
----------------------------------------------------------------------------------------------------------------  
    (2) * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 166/268    (ii) If you do not choose to comply with paragraph (c)(2)(i) of  
this section, you may continue to comply with the standards and  
requirements described in appendix I of this part for model years  
through 2012, but you must begin complying in 2013 with Tier 4  
standards and requirements specified in Table 3 of Sec.  1039.102 for  
model years 2013 and later.  
* * * * *  
    (4) For engines not in the 19-56 kW power category, if you delay  
compliance with any standards under this paragraph (c), you must do all  
the following things for the model years when you are delaying  
compliance with the otherwise applicable standards:  
    (i) Produce engines that meet all the emission standards identified  
in appendix I of this part and other requirements in this part  
applicable for that model year, except as noted in this paragraph (c).  
    (ii) Meet the labeling requirements in this part that apply for  
certified engines but use the following alternative compliance  
statement: ``THIS ENGINE COMPLIES WITH U.S. EPA REGULATIONS FOR  
[CURRENT MODEL YEAR] NONROAD COMPRESSION--IGNITION ENGINES UNDER 40 CFR  
1039.104(c).''.  
* * * * *  
    (g) * * *  
    (4) Do not apply TCAFs to gaseous emissions for phase-out engines  
that you certify to the same numerical standards (and FELs if the  
engines are certified using ABT) for gaseous pollutants as you  
certified under the Tier 3 requirements identified in appendix I of  
this part.  
                                 Table 2 of Sec.   1039.104--Alternate FEL Caps  
----------------------------------------------------------------------------------------------------------------  
                                                                                                    Model years  
                                                                    Model years   NOX FEL cap, g/     for the  
              Maximum engine power                PM FEL cap, g/      for the        kW-hr \a\     alternate NOX  
                                                       kW-hr       alternate PM                       FEL cap  
                                                                      FEL cap  
----------------------------------------------------------------------------------------------------------------  
19 <=kW <56.....................................            0.30   \b\ 2012-2015  ..............  ..............  
56 <=kW <130 \c\................................            0.30       2012-2015             3.8   \d\ 2012-2015  
130 <=kW <=560..................................            0.20       2011-2014             3.8   \e\ 2011-2014  
kW >560 \f\.....................................            0.10       2015-2018             3.5       2015-2018  
----------------------------------------------------------------------------------------------------------------  
\a\ The FEL cap for engines demonstrating compliance with a NOX + NMHC standard is equal to the previously  
  applicable NOX + NMHC standard specified in appendix I of this part (generally the Tier 3 standards).  
\b\ For manufacturers certifying engines under Option #1 of Table 3 of Sec.   1039.102, these alternate FEL caps  
  apply to all 19-56 kW engines for model years from 2013 through 2016 instead of the years indicated in this  
  table. For manufacturers certifying engines under Option #2 of Table 3 of Sec.   1039.102, these alternate FEL  
  caps do not apply to 19-37 kW engines except in model years 2013 to 2015.  
\c\ For engines below 75 kW, the FEL caps are 0.40 g/kW-hr for PM emissions and 4.4 g/kW-hr for NOX emissions.  
\d\ For manufacturers certifying engines in this power category using a percentage phase-in/phase-out approach  
  instead of the alternate NOX standards of Sec.   1039.102(e)(1), the alternate NOX FEL cap in the table  
  applies only in the 2014-2015 model years if certifying under Sec.   1039.102(d)(1), and only in the 2015  
  model year if certifying under Sec.   1039.102(d)(2).  
\e\ For manufacturers certifying engines in this power category using the percentage phase-in/phase-out approach  
  instead of the alternate NOX standard of Sec.   1039.102(e)(2), the alternate NOX FEL cap in the table applies  
  only for the 2014 model year.  
\f\ For engines above 560 kW, the provision for alternate NOX FEL caps is limited to generator-set engines.  
* * * * *  
0 
185. Amend Sec.  1039.135 by revising paragraph (e) introductory text  
to read as follows:  
Sec.  1039.135  How must I label and identify the engines I produce?  
* * * * *  
    (e) For model year 2019 and earlier, create a separate label with  
the statement: ``ULTRA LOW SULFUR FUEL ONLY''. Permanently attach this  
label to the equipment near the fuel inlet or, if you do not  
manufacture the equipment, take one of the following steps to ensure  
that the equipment will be properly labeled:  
* * * * *  
0 
186. Amend Sec.  1039.205 by adding paragraph (c) to read as follows:  
Sec.  1039.205  What must I include in my application?  
* * * * *  
    (c) If your engines are equipped with an engine diagnostic system  
as required under Sec.  1039.110, explain how it works, describing  
especially the engine conditions (with the corresponding diagnostic  
trouble codes) that cause the warning lamp to go on and the design  
features that minimize the potential for  
[[Page 34505]]  
operation without reductant. Also identify the communication protocol  
(SAE J1939, SAE J1979, etc.)  
* * * * *  
0 
187. Amend Sec.  1039.245 by revising paragraph (a) to read as follows:  
Sec.  1039.245  How do I determine deterioration factors from exhaust  
durability testing?  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 167/268* * * * *  
    (a) You may ask us to approve deterioration factors for an engine  
family with established technology based on engineering analysis  
instead of testing. Engines certified to a NO X + NMHC  
standard or FEL greater than the Tier 3 NO X + NMHC standard  
described in appendix I of this part are considered to rely on  
established technology for gaseous emission control, except that this  
does not include any engines that use exhaust-gas recirculation or  
aftertreatment. In most cases, technologies used to meet the Tier 1 and  
Tier 2 emission standards would be considered to be established  
technology.  
* * * * *  
0 
188. Revise Sec.  1039.255 to read as follows:  
Sec.  1039.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Act, we  
will issue a certificate of conformity for the engine family for that  
model year. We may make the approval subject to additional conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Act. Note that these are also violations of 40 CFR  
1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1039.820).  
0 
189. Amend Sec.  1039.601 by revising paragraph (b) to read as follows:  
Sec.  1039.601  What compliance provisions apply?  
* * * * *  
    (b) Subpart C of this part describes how to test and certify dual-  
fuel and flexible-fuel engines. Some multi-fuel engines may not fit  
either of those defined terms. For such engines, we will determine  
whether it is most appropriate to treat them as single-fuel engines,  
dual-fuel engines, or flexible-fuel engines based on the range of  
possible and expected fuel mixtures. For example, an engine might burn  
natural gas but initiate combustion with a pilot injection of diesel  
fuel. If the engine is designed to operate with a single fueling  
algorithm (i.e., fueling rates are fixed at a given engine speed and  
load condition), we would generally treat it as a single-fuel engine.  
In this context, the combination of diesel fuel and natural gas would  
be its own fuel type. If the engine is designed to also operate on  
diesel fuel alone, we would generally treat it as a dual-fuel engine.  
If the engine is designed to operate on varying mixtures of the two  
fuels, we would generally treat it as a flexible-fuel engine. To the  
extent that requirements vary for the different fuels or fuel mixtures,  
we may apply the more stringent requirements.  
0 
190. Amend Sec.  1039.620 by revising paragraph (b) to read as follows:  
Sec.  1039.620  What are the provisions for exempting engines used  
solely for competition?  
* * * * *  
    (b) The definition of nonroad engine in 40 CFR 1068.30 excludes  
engines used solely for competition. These engines are not required to  
comply with this part, but 40 CFR 1068.101 prohibits the use of  
competition engines for noncompetition purposes.  
* * * * *  
0 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 168/268191. Amend Sec.  1039.625 by revising the introductory text, paragraphs  
(d)(4) introductory text, (e)(1) and (3), (g)(1)(vi), (j) introductory  
text, and (j)(1) to read as follows:  
Sec.  1039.625  What requirements apply under the program for  
equipment-manufacturer flexibility?  
    The provisions of this section allow equipment manufacturers to  
produce equipment with engines that are subject to less stringent  
emission standards after the Tier 4 emission standards begin to apply.  
To be eligible to use the provisions of this section, you must follow  
all the instructions in this section. See Sec.  1039.626 for  
requirements that apply specifically to companies that manufacture  
equipment outside the United States and to companies that import such  
equipment without manufacturing it. Engines and equipment you produce  
under this section are exempt from the prohibitions in 40 CFR  
1068.101(a)(1), subject to the provisions of this section.  
* * * * *  
    (d) * * *  
    (4) You may start using the allowances under this section for  
engines that are not yet subject to Tier 4 standards, as long as the  
seven-year period for using allowances under the Tier 2 or Tier 3  
program has expired. Table 3 of this section shows the years for which  
this paragraph (d)(4) applies. To use these early allowances, you must  
use engines that meet the emission standards described in paragraph (e)  
of this section. You must also count these units or calculate these  
percentages as described in paragraph (c) of this section and apply  
them toward the total number or percentage of equipment with exempted  
engines we allow for the Tier 4 standards as described in paragraph (b)  
of this section. The maximum number of cumulative early allowances  
under this paragraph (d)(4) is 10 percent under the percent-of-  
production allowance or 100 units under the small-volume allowance. For  
example, if you produce 5 percent of your equipment with engines  
between 130 and 560 kW that use allowances under this paragraph (d)(4)  
in 2009, you may use up to an additional 5 percent of your allowances  
in 2010. If you use allowances for 5 percent of your  
[[Page 34506]]  
equipment in both 2009 and 2010, your 80 percent allowance for 2011-  
2017 in the 130-560 kW power category decreases to 70 percent.  
Manufacturers using allowances under this paragraph (d)(4) must comply  
with the notification and reporting requirements specified in paragraph  
(g) of this section.  
* * * * *  
    (e) * * *  
    (1) If you are using the provisions of paragraph (d)(4) of this  
section, engines must meet the applicable Tier 1 or Tier 2 emission  
standards described in appendix I of this part.  
* * * * *  
    (3) In all other cases, engines at or above 56 kW and at or below  
560 kW must meet the appropriate Tier 3 standards described in appendix  
I of this part. Engines below 56 kW and engines above 560 kW must meet  
the appropriate Tier 2 standards described in appendix I of this part.  
* * * * *  
    (g) * * *  
    (1) * * *  
    (vi) The number of units in each power category you have sold in  
years for which the Tier 2 and Tier 3 standards apply.  
* * * * *  
    (j) Provisions for engine manufacturers. As an engine manufacturer,  
you may produce exempted engines as needed under this section. You do  
not have to request this exemption for your engines, but you must have  
written assurance from equipment manufacturers that they need a certain  
number of exempted engines under this section. Send us an annual report  
of the engines you produce under this section, as described in Sec.   
1039.250(a). Exempt engines must meet the emission standards in  
paragraph (e) of this section and you must meet all the requirements of  
40 CFR 1068.265, except that engines produced under the provisions of  
paragraph (a)(2) of this section must be identical in all material  
respects to engines previously certified under this part 1039. If you  
show under 40 CFR 1068.265(c) that the engines are identical in all  
material respects to engines that you have previously certified to one  
or more FELs above the standards specified in paragraph (e) of this  
section, you must supply sufficient credits for these engines.  
Calculate these credits under subpart H of this part using the  
previously certified FELs and the alternate standards. You must meet  
the labeling requirements in Sec.  1039.135, as applicable, with the  
following exceptions:  
    (1) Add the following statement instead of the compliance statement  
in Sec.  1039.135(c)(12):  
    THIS ENGINE MEETS U.S. EPA EMISSION STANDARDS UNDER 40 CFR  
1039.625. SELLING OR INSTALLING THIS ENGINE FOR ANY PURPOSE OTHER THAN  
FOR THE EQUIPMENT FLEXIBILITY PROVISIONS OF 40 CFR 1039.625 MAY BE A  
VIOLATION OF FEDERAL LAW SUBJECT TO CIVIL PENALTY.  
* * * * *  
0 
192. Amend Sec.  1039.626 by revising paragraph (b)(1)(iv) to read as  
follows:  
Sec.  1039.626  What special provisions apply to equipment imported  
under the equipment-manufacturer flexibility program?  
* * * * *  
    (b) * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 169/268    (1) * * *  
    (iv) The number of units in each power category you have imported  
in years for which the Tier 2 and Tier 3 standards apply.  
* * * * *  
0 
193. Amend Sec.  1039.655 by revising paragraphs (a)(2) and (b) to read  
as follows:  
Sec.  1039.655  What special provisions apply to engines sold in Guam,  
American Samoa, or the Commonwealth of the Northern Mariana Islands?  
    (a) * * *  
    (2) The engine meets the latest applicable emission standards in  
appendix I of this part.  
* * * * *  
    (b) If you introduce an engine into commerce in the United States  
under this section, you must meet the labeling requirements in Sec.   
1039.135, but add the following statement instead of the compliance  
statement in Sec.  1039.135(c)(12):  
    THIS ENGINE DOES NOT COMPLY WITH U.S. EPA TIER 4 EMISSION  
REQUIREMENTS. IMPORTING THIS ENGINE INTO THE UNITED STATES OR ANY  
TERRITORY OF THE UNITED STATES EXCEPT GUAM, AMERICAN SAMOA, OR THE  
COMMONWEALTH OF THE NORTHERN MARIANA ISLANDS MAY BE A VIOLATION OF  
FEDERAL LAW SUBJECT TO CIVIL PENALTY.  
* * * * *  
0 
194. Amend Sec.  1039.740 by revising paragraph (b) to read as follows:  
Sec.  1039.740  What restrictions apply for using emission credits?  
* * * * *  
    (b) Emission credits from earlier tiers of standards. (1) For  
purposes of ABT under this subpart, you may not use emission credits  
generated from engines subject to emission standards identified in  
appendix I of this part, except as specified in Sec.  1039.102(d)(1) or  
as follows:  
------------------------------------------------------------------------  
                                      And it was  
                                   certified to the    Then you may use  
   If the maximum power of the         following         those banked  
 credit-generating engine is * *       standards        credits for the  
                *                    identified in     following Tier 4  
                                  appendix I of this     engines * * *  
                                      part * * *  
------------------------------------------------------------------------  
(i) kW < 19.....................  Tier 2............  kW < 19.  
(ii) 19 <= kW < 37..............  Tier 2............  kW >= 19.  
(iii) 37 <= kW <= 560...........  Tier 3............  kW >= 19.  
(iv) kW > 560...................  Tier 2............  kW >= 19.  
------------------------------------------------------------------------  
    (2) Emission credits generated from marine engines certified to the  
standards identified in appendix I of this part for land-based engines  
may not be used under this part.  
* * * * *  
0 
195. Amend Sec.  1039.801 by:  
0 
a. Revising the definition for ``Low-hour'';  
0 
b. Revising paragraph (5)(ii) for the definition of ``Model year''; and  
0 
c. Revising the definitions for ``Small-volume engine manufacturer'',  
``Tier 1'', ``Tier 2'', and ``Tier 3''.  
    The revisions read as follows:
Sec.  1039.801  What definitions apply to this part?  
* * * * *  
    Low-hour means relating to an engine with stabilized emissions and  
represents the undeteriorated emission level. This would generally  
involve less than 300 hours of operation for engines with  
NOX aftertreatment and 125 hours of operation for other  
engines.  
* * * * *  
    Model year * * *  
    (5) * * *  
    (ii) For imported engines described in paragraph (5)(ii) of the  
definition of ``new nonroad engine'' in this section,  
[[Page 34507]]  
model year means the calendar year in which the engine is modified.  
* * * * *  
    Small-volume engine manufacturer means an engine manufacturer with  
1,000 or fewer employees that has had annual U.S.-directed production  
volume of no more than 2,500 units. For manufacturers owned by a parent  
company, these limits apply to the total number of employees and  
production volume from the parent company and all its subsidiaries.  
* * * * *  
    Tier 1 means relating to the Tier 1 emission standards identified  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 170/268in appendix I of this part.  
    Tier 2 means relating to the Tier 2 emission standards identified  
in appendix I of this part.  
    Tier 3 means relating to the Tier 3 emission standards identified  
in appendix I of this part.  
* * * * *  
0 
196. Add appendix I to part 1039 to read as follows:  
Appendix I to Part 1039--Summary of Previous Emission Standards  
    The following standards, which EPA originally adopted under 40  
CFR part 89, apply to nonroad compression-ignition engines produced  
before the model years specified in Sec.  1039.1:  
    (a) Tier 1 standards apply as summarized in the following table:  
                                                    Table 1 to Appendix I--Tier 1 Emission Standards  
                                                                        [g/kW-hr]  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                                                          Starting model  
                    Rated power (kW)                           year             NOX             HC           NOX+NMHC           CO              PM  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
kW < 8..................................................            2000  ..............  ..............            10.5             8.0             1.0  
8 <= kW < 19............................................            2000  ..............  ..............             9.5             6.6            0.80  
19 <= kW < 37...........................................            1999  ..............  ..............             9.5             5.5            0.80  
37 <= kW < 75...........................................            1998             9.2  
75 <= kW < 130..........................................            1997  
130 <= kW <= 560........................................            1996             9.2             1.3                            11.4            0.54  
kW > 560................................................            2000  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
    (b) Tier 2 standards apply as summarized in the following table:  
                                Table 2 to Appendix I--Tier 2 Emission Standards  
                                                    [g/kW-hr]  
----------------------------------------------------------------------------------------------------------------  
                                                  Starting model  
                Rated power (kW)                       year          NOX+NMHC           CO              PM  
----------------------------------------------------------------------------------------------------------------  
kW < 8..........................................            2005             7.5             8.0            0.80  
8 <= kW < 19....................................            2005             7.5             6.6            0.80  
19 <= kW < 37...................................            2004             7.5             5.5            0.60  
37 <= kW < 75...................................            2004             7.5             5.0            0.40  
75 <= kW < 130..................................            2003             6.6             5.0            0.30  
130 <= kW < 225.................................            2003             6.6             3.5            0.20  
225 <= kW < 450.................................            2001             6.4             3.5            0.20  
450 <= kW <= 560................................            2002  
kW > 560........................................            2006  
----------------------------------------------------------------------------------------------------------------  
    (c) Tier 3 standards apply as summarized in the following table:  
                                Table 3 to Appendix I--Tier 3 Emission Standards  
                                                    [g/kW-hr]  
----------------------------------------------------------------------------------------------------------------  
                                                  Starting model  
                Rated power (kW)                       year          NOX+NMHC           CO              PM  
----------------------------------------------------------------------------------------------------------------  
37 <= kW < 75...................................            2008             4.7             5.0            0.40  
75 <= kW < 130..................................            2007             4.0             5.0            0.30  
130 <= kW <= 560................................            2006             4.0             3.5            0.20  
----------------------------------------------------------------------------------------------------------------  
    (d) Tier 1 through Tier 3 standards applied only for discrete-  
mode steady-state testing. There were no not-to-exceed standards or  
transient testing.  
PART 1042--CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE  
COMPRESSION-IGNITION ENGINES AND VESSELS  
0 
197. The authority citation for part 1042 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
198. Amend Sec.  1042.1 by:  
0 
a. Revising paragraphs (b) and (c); and  
0 
b. Removing and reserving paragraph (d).  
    The revisions read as follows:
[[Page 34508]]  
Sec.  1042.1  Applicability.  
* * * * *  
    (b) New engines with maximum engine power below 37 kW and  
originally manufactured and certified before the model years identified  
in Table 1 to this section are subject to emission standards as  
specified in appendix I of this part. The provisions of this part do  
not apply for such engines, except as follows beginning June 29, 2010:  
    (1) The allowances of this part apply.  
    (2) The definitions of ``new marine engine'' and ``model year''  
apply. 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 171/268    (c) Marine engines originally meeting Tier 1 or Tier 2 standards as  
specified in appendix I of this part remain subject to those standards.  
This includes uncertified engines that meet standards under 40 CFR  
1068.265. Those engines remain subject to recall provisions as  
specified in 40 CFR part 1068, subpart F, throughout the useful life  
corresponding to the original certification. Also, tampering and  
defeat-device prohibitions continue to apply for those engines as  
specified in 40 CFR 1068.101. The remanufacturing provisions in subpart  
I of this part may apply for remanufactured engines originally  
manufactured in model years before the model years identified in Table  
1 to this section.  
* * * * *  
0 
199. Amend Sec.  1042.101 by revising paragraphs (a)(6), (c)(2), and  
(e)(2) to read as follows:  
Sec.  1042.101  Exhaust emission standards for Category 1 and Category  
2 engines.  
    (a) * * *  
    (6) Interim Tier 4 PM standards apply for 2014 and 2015 model year  
engines between 2000 and 3700 kW as specified in this paragraph (a)(6).  
These engines are considered Tier 4 engines.  
    (i) For Category 1 engines, the Tier 3 PM standards from Table 1 to  
this section continue to apply. PM FELs for these engines may not be  
higher than the applicable Tier 2 PM standards specified in appendix I  
of this part.  
    (ii) For Category 2 engines with per-cylinder displacement below  
15.0 liters, the Tier 3 PM standards from Table 2 to this section  
continue to apply. PM FELs for these engines may not be higher than  
0.27 g/kW-hr.  
    (iii) For Category 2 engines with per-cylinder displacement at or  
above 15.0 liters, the PM standard is 0.34 g/kW-hr for engines at or  
above 2000 kW and below 3300 kW, and 0.27 g/kW-hr for engines at or  
above 3300 kW and below 3700 kW. PM FELs for these engines may not be  
higher than 0.50 g/kW-hr.  
* * * * *  
    (c) * * *  
    (2) Determine the applicable NTE zone and subzones as described in  
Sec.  1042.515. Determine NTE multipliers for specific zones and  
subzones and pollutants as follows:  
    (i) For marine engines certified using the duty cycle specified in  
Sec.  1042.505(b)(1), except for variable-speed propulsion marine  
engines used with controllable-pitch propellers or with electrically  
coupled propellers, apply the following NTE multipliers:  
    (A) Subzone 1: 1.2 for Tier 3 NO X+HC standards.  
    (B) Subzone 1: 1.5 for Tier 4 standards and Tier 3 PM and CO  
standards.  
    (C) Subzone 2: 1.5 for Tier 4 NO X and HC standards and  
for Tier 3 NO X+HC standards.  
    (D) Subzone 2: 1.9 for PM and CO standards.  
    (ii) For recreational marine engines certified using the duty cycle  
specified in Sec.  1042.505(b)(2), except for variable-speed marine  
engines used with controllable-pitch propellers or with electrically  
coupled propellers, apply the following NTE multipliers:  
    (A) Subzone 1: 1.2 for Tier 3 NO X+HC standards.  
    (B) Subzone 1: 1.5 for Tier 3 PM and CO standards.  
    (C) Subzones 2 and 3: 1.5 for Tier 3 NO X+HC standards.  
    (D) Subzones 2 and 3: 1.9 for PM and CO standards.  
    (iii) For variable-speed marine engines used with controllable-  
pitch propellers or with electrically coupled propellers that are  
certified using the duty cycle specified in Sec.  1042.505(b)(1), (2),  
or (3), apply the following NTE multipliers:  
    (A) Subzone 1: 1.2 for Tier 3 NO X+HC standards.  
    (B) Subzone 1: 1.5 for Tier 4 standards and Tier 3 PM and CO  
standards.  
    (C) Subzone 2: 1.5 for Tier 4 NO X and HC standards and  
for Tier 3 NO X+HC standards.  
    (D) Subzone 2: 1.9 for PM and CO standards. However, there is no  
NTE standard in Subzone 2b for PM emissions if the engine family's  
applicable standard for PM is at or above 0.07 g/kW-hr.  
    (iv) For constant-speed engines certified using a duty cycle  
specified in Sec.  1042.505(b)(3) or (4), apply the following NTE  
multipliers:  
    (A) Subzone 1: 1.2 for Tier 3 NO X+HC standards.  
    (B) Subzone 1: 1.5 for Tier 4 standards and Tier 3 PM and CO  
standards.  
    (C) Subzone 2: 1.5 for Tier 4 NO X and HC standards and  
for Tier 3 NO X+HC standards.  
    (D) Subzone 2: 1.9 for PM and CO standards. However, there is no  
NTE standard for PM emissions if the engine family's applicable  
standard for PM is at or above 0.07 g/kW-hr.  
    (v) For variable-speed auxiliary marine engines certified using the  
duty cycle specified in Sec.  1042.505(b)(5)(ii) or (iii):  
    (A) Subzone 1: 1.2 for Tier 3 NO X+HC standards.  
    (B) Subzone 1: 1.5 for Tier 4 standards and Tier 3 PM and CO  
standards.  
    (C) Subzone 2: 1.2 for Tier 3 NO X+HC standards.  
    (D) Subzone 2: 1.5 for Tier 4 standards and Tier 3 PM and CO  
standards. However, there is no NTE standard for PM emissions if the  
engine family's applicable standard for PM is at or above 0.07 g/kW-hr.  
* * * * *  
    (e) * * *  
    (2) Specify a longer useful life in hours for an engine family  
under either of two conditions:  
    (i) If you design your engine to operate longer than the minimum  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 172/268useful life. Indicators of design life include your recommended  
overhaul interval and may also include your advertising and marketing  
materials.  
    (ii) If your basic mechanical warranty is longer than the minimum  
useful life.  
* * * * *  
0 
200. Amend Sec.  1042.104 by revising paragraphs (a)(2) and (c) to read  
as follows:  
Sec.  1042.104  Exhaust emission standards for Category 3 engines.  
    (a) * * *  
    (2) NO X standards apply based on the engine's model year  
and maximum in-use engine speed as shown in the following table:  
[[Page 34509]]  
                    Table 1 to Sec.   1042.104--NOX Emission Standards for Category 3 Engines  
                                                    [g/kW-hr]  
----------------------------------------------------------------------------------------------------------------  
                                                                            Maximum in-use engine speed  
                                                                 -----------------------------------------------  
               Emission standards                   Model year     Less than 130   130-2000 RPM
                                                                        RPM             \a\        Over 2000 RPM  
----------------------------------------------------------------------------------------------------------------  
Tier 1..........................................       2004-2010            17.0  45.0[middot]n(-            9.8  
                                                                                           0.20)  
Tier 2..........................................       2011-2015            14.4  44.0[middot]n(-            7.7  
                                                                                           0.23)  
Tier 3 \b\......................................  2016 and later             3.4  9.0[middot]n(-             2.0  
                                                                                           0.20)  
----------------------------------------------------------------------------------------------------------------  
\a\ Applicable standards are calculated from n (maximum in-use engine speed, in RPM, as specified in Sec.  
  1042.140). Round the standards to one decimal place.  
\b\ For engines designed with on-off controls as specified in Sec.   1042.115(g), the Tier 2 standards continue  
  to apply any time the engine has disabled its Tier 3 NOX emission controls.  
* * * * *  
    (c) Mode caps. Measured NO X emissions from Tier 3  
engines may not exceed the cap specified in this paragraph (c) for any  
applicable duty-cycle test modes with power greater than 10 percent  
maximum engine power. Calculate the mode cap by multiplying the  
applicable Tier 3 NO X standard by 1.5 and rounding to the  
nearest 0.1 g/kW-hr. Note that mode caps do not apply for pollutants  
other than NO X and do not apply for any modes of operation  
outside of the applicable duty cycles in Sec.  1042.505. Category 3  
engines are not subject to not-to-exceed standards.  
* * * * *  
0 
201. Amend Sec.  1042.115 by revising paragraph (g) to read as follows:  
Sec.  1042.115  Other requirements.  
* * * * *  
    (g) On-off controls for engines on Category 3 vessels.  
Manufacturers may equip Category 3 propulsion engines with features  
that disable Tier 3 NO X emission controls subject to the  
provisions of this paragraph (g). For auxiliary engines allowed to use  
on-off controls as specified in Sec.  1042.650(d), read ``Tier 2'' to  
mean ``IMO Tier II'' and read ``Tier 3'' to mean ``IMO Tier III''.  
    (1) Features that disable Tier 3 NO X emission controls  
are considered to be AECDs whether or not they meet the definition of  
an AECD. For example, manually operated on-off features are AECDs under  
this paragraph (g). The features must be identified in your application  
for certification as AECDs. For purposes of this paragraph (g), the  
term ``features that disable Tier 3 emission controls'' includes (but  
is not limited to) any combination of the following that cause the  
engine's emissions to exceed any Tier 3 emission standard:  
    (i) Bypassing of exhaust aftertreatment.  
    (ii) Reducing or eliminating flow of reductant to an SCR system.  
    (iii) Modulating engine calibration in a manner that increases  
engine-out emissions of a regulated pollutant.  
    (2) You must demonstrate that the AECD will not disable  
NOX emission controls while operating shoreward of the  
boundaries of the North American ECA and the U.S. Caribbean Sea ECA.  
You must demonstrate that the AECD will not disable emission control  
while operating in these waters. (Note: See the regulations in 40 CFR  
part 1043 for requirements related to operation in ECAs, including  
foreign ECAs.) Compliance with this paragraph (g)(2) will generally  
require that the AECD operation be based on Global Positioning System  
(GPS) inputs. We may consider any relevant information to determine  
whether your AECD conforms to this paragraph (g).  
    (3) The onboard computer log must record in nonvolatile computer  
memory all incidents of engine operation with the Tier 3 NO X  
emission controls disabled.  
    (4) The engine must comply with the Tier 2 NO X standard  
when the Tier 3 NO X emission controls are disabled.  
0 
202. Amend Sec.  1042.125 by revising paragraph (e) to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 173/268Sec.  1042.125  Maintenance instructions.  
* * * * *  
    (e) Maintenance that is not emission-related. For maintenance  
unrelated to emission controls, you may schedule any amount of  
inspection or maintenance. You may also take these inspection or  
maintenance steps during service accumulation on your emission-data  
engines, as long as they are reasonable and technologically necessary.  
This might include adding engine oil, changing air, fuel, or oil  
filters, servicing engine-cooling systems or fuel-water separator  
cartridges or elements, and adjusting idle speed, governor, engine bolt  
torque, valve lash, or injector lash. You may not perform this  
nonemission-related maintenance on emission-data engines more often  
than the least frequent intervals that you recommend to the ultimate  
purchaser.  
* * * * *  
0 
203. Amend Sec.  1042.135 by revising paragraph (c)(13) to read as  
follows:  
Sec.  1042.135  Labeling.  
* * * * *  
    (c) * * *  
    (13) For engines above 130 kW that are intended for installation on  
domestic or public vessels, include the following statement: ``THIS  
ENGINE DOES NOT COMPLY WITH INTERNATIONAL MARINE REGULATIONS UNLESS IT  
IS ALSO COVERED BY AN EIAPP CERTIFICATE.''  
* * * * *  
0 
204. Amend Sec.  1042.145 by removing and reserving paragraphs (b),  
(c), (e), (h), and (i) and revising paragraph (j) to read as follows:  
Sec.  1042.145  Interim provisions.  
* * * * *  
    (j) Installing land-based engines in marine vessels. Vessel  
manufacturers and marine equipment manufacturers may apply the  
provisions of Sec. Sec.  1042.605 and 1042.610 to land-based engines  
with maximum engine power at or above 37 kW and at or below 560 kW if  
they meet the Tier 3 emission standards in appendix I of 40 CFR part  
1039 as specified in 40 CFR 1068.265. All the provisions of Sec.   
1042.605 or Sec.  1042.610 apply as if those engines were certified to  
emission standards under 40 CFR part 1039. Similarly, engine  
manufacturers, vessel manufacturers, and marine equipment manufacturers  
must comply with all the provisions of 40 CFR part 1039 as if those  
engines were installed in land-based equipment. The following  
provisions apply for engine manufacturers shipping engines to vessel  
manufacturers or marine equipment manufacturers under this paragraph  
(j): 
    (1) You must label the engine as described in 40 CFR 1039.135, but  
[[Page 34510]]  
identify the engine family name as it was last certified under 40 CFR  
part 1039 and include the following alternate compliance statement:  
``THIS ENGINE MEETS THE TIER 3 STANDARDS FOR LAND-BASED NONROAD DIESEL  
ENGINES UNDER 40 CFR PART 1039. THIS ENGINE MAY BE USED ONLY IN A  
MARINE VESSEL UNDER THE DRESSING PROVISIONS OF 40 CFR 1042.605 OR 40  
CFR 1042.610.''  
    (2) You must use the provisions of 40 CFR 1068.262 for shipping  
uncertified engines under this section to secondary engine  
manufacturers.  
* * * * *  
0 
205. Amend Sec.  1042.235 by revising paragraph (d)(3) to read as  
follows:  
Sec.  1042.235  Emission testing related to certification.  
* * * * *  
    (d) * * *  
    (3) The data show that the emission-data engine would meet all the  
requirements of this part that apply to the engine family covered by  
the application for certification. For engines originally tested to  
demonstrate compliance with Tier 1 or Tier 2 standards, you may  
consider those test procedures to be equivalent to the procedures we  
specify in subpart F of this part.
* * * * *  
0 
206. Revise Sec.  1042.255 to read as follows:  
Sec.  1042.255  EPA decisions.  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Clean Air  
Act, we will issue a certificate of conformity for the engine family  
for that model year. We may make the approval subject to additional  
conditions.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 174/268    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Clean Air Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Clean Air Act. Note that these are also violations of 40  
CFR 1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1042.920).  
0 
207. Amend Sec.  1042.302 by revising paragraph (a) to read as follows:  
Sec.  1042.302  Applicability of this subpart for Category 3 engines.  
* * * * *  
    (a) You must test each Category 3 engine at the sea trial of the  
vessel in which it is installed or within the first 300 hours of  
operation, whichever occurs first. This may involve testing a fully  
assembled production engine before it is installed in the vessel. For  
engines with on-off controls, you may omit testing to demonstrate  
compliance with Tier 2 standards if the engine does not rely on  
aftertreatment when Tier 3 emission controls are disabled. Since you  
must test each engine, the provisions of Sec. Sec.  1042.310 and  
1042.315(b) do not apply for Category 3 engines. If we determine that  
an engine failure under this subpart is caused by defective components  
or design deficiencies, we may revoke or suspend your certificate for  
the engine family as described in Sec.  1042.340. If we determine that  
an engine failure under this subpart is caused only by incorrect  
assembly, we may suspend your certificate for the engine family as  
described in Sec.  1042.325. If the engine fails, you may continue  
operating only to complete the sea trial and return to port. It is a  
violation of 40 CFR 1068.101(b)(1) to operate the vessel further until  
you remedy the cause of failure. Each two-hour period of such operation  
constitutes a separate offense. A violation lasting less than two hours  
constitutes a single offense.  
* * * * *  
0 
208. Amend Sec.  1042.605 by revising paragraphs (a), (b), (c),  
(d)(1)(ii), (d)(2), (d)(3)(ii), (f), and (h) to read as follows:  
Sec.  1042.605  Dressing engines already certified to other standards  
for nonroad or heavy-duty highway engines for marine use.  
    (a) General provisions. If you are an engine manufacturer  
(including someone who marinizes a land-based engine), this section  
allows you to introduce new marine engines into U.S. commerce if they  
are already certified to the requirements that apply to compression-  
ignition engines under 40 CFR parts 85 and 86 or 40 CFR part 1033 or  
1039 for the appropriate model year. If you comply with all the  
provisions of this section, we consider the certificate issued under 40  
CFR part 86, 1033, or 1039 for each engine to also be a valid  
certificate of conformity under this part for its model year, without a  
separate application for certification under the requirements of this  
part. This section does not apply for Category 3 engines.  
    (b) Vessel-manufacturer provisions. If you are not an engine  
manufacturer, you may install an engine certified for the appropriate  
model year under 40 CFR part 86, 1033, or 1039 in a marine vessel as  
long as you do not make any of the changes described in paragraph  
(d)(3) of this section and you meet the requirements of paragraph (e)  
of this section. If you modify the non-marine engine in any of the ways  
described in paragraph (d)(3) of this section, we will consider you a  
manufacturer of a new marine engine. Such engine modifications prevent  
you from using the provisions of this section.  
    (c) Liability. Engines for which you meet the requirements of this  
section are exempt from all the requirements and prohibitions of this  
part, except for those specified in this section. Engines exempted  
under this section must meet all the applicable requirements from 40  
CFR parts 85 and 86 or 40 CFR part 1033 or 1039. This paragraph (c)  
applies to engine manufacturers, vessel manufacturers that use such an  
engine, and all other persons as if the engine were used in its  
originally intended application. The prohibited acts of 40 CFR  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 175/2681068.101(a)(1) apply to these new engines and vessels; however, we  
consider the certificate issued under 40 CFR part 86, 1033, or 1039 for  
each engine to also be a valid certificate of conformity under this  
part for its model  
[[Page 34511]]  
year. If we make a determination that these engines do not conform to  
the regulations in this chapter during their useful life, we may  
require you to recall them under 40 CFR part 85 or 1068.  
    (d) * * *  
    (1) * * *  
    (ii) Land-based compression-ignition nonroad engines (40 CFR part  
1039). 
* * * * *  
    (2) The engine must have the label required under 40 CFR part 86,  
1033, or 1039.  
    (3) * * *  
    (ii) Replacing an original turbocharger, except that small-volume  
engine manufacturers may replace an original turbocharger on a  
recreational engine with one that matches the performance of the  
original turbocharger.  
* * * * *  
    (f) Failure to comply. If your engines do not meet the criteria  
listed in paragraph (d) of this section, they will be subject to the  
standards, requirements, and prohibitions of this part and the  
certificate issued under 40 CFR part 86, 1033, or 1039 will not be  
deemed to also be a certificate issued under this part. Introducing  
these engines into U.S. commerce as marine engines without a valid  
exemption or certificate of conformity under this part violates the  
prohibitions in 40 CFR 1068.101(a)(1).  
* * * * *  
    (h) Participation in averaging, banking and trading. Engines  
adapted for marine use under this section may not generate or use  
emission credits under this part. These engines may generate credits  
under the ABT provisions in 40 CFR part 86, 1033, or 1039, as  
applicable. These engines must use emission credits under 40 CFR part  
86, 1033, or 1039 as applicable if they are certified to an FEL that  
exceeds an emission standard.  
* * * * *  
0 
209. Amend Sec.  1042.610 by revising paragraphs (a), (c), (d)(1), (f),  
and (g) to read as follows:  
Sec.  1042.610  Certifying auxiliary marine engines to land-based  
standards.  
* * * * *  
    (a) General provisions. If you are an engine manufacturer, this  
section allows you to introduce new marine engines into U.S. commerce  
if they are already certified to the requirements that apply to  
compression-ignition engines under 40 CFR part 1039 for the appropriate  
model year. If you comply with all the provisions of this section, we  
consider the certificate issued under 40 CFR part 1039 for each engine  
to also be a valid certificate of conformity under this part for its  
model year, without a separate application for certification under the  
requirements of this part.  
* * * * *  
    (c) Liability. Engines for which you meet the requirements of this  
section are exempt from all the requirements and prohibitions of this  
part, except for those specified in this section. Engines exempted  
under this section must meet all the applicable requirements from 40  
CFR part 1039. This paragraph (c) applies to engine manufacturers,  
vessel manufacturers that use such an engine, and all other persons as  
if the engine were used in its originally intended application. The  
prohibited acts of 40 CFR 1068.101(a)(1) apply to these new engines and  
vessels; however, we consider the certificate issued under 40 CFR part  
1039 for each engine to also be a valid certificate of conformity under  
this part for its model year. If we make a determination that these  
engines do not conform to the regulations in this chapter during their  
useful life, we may require you to recall them under 40 CFR part 1068.  
    (d) * * *  
    (1) The marine engine must be identical in all material respects to  
a land-based engine covered by a valid certificate of conformity for  
the appropriate model year showing that it meets emission standards for  
engines of that power rating under 40 CFR part 1039.  
* * * * *  
    (f) Failure to comply. If your engines do not meet the criteria  
listed in paragraph (d) of this section, they will be subject to the  
standards, requirements, and prohibitions of this part and the  
certificate issued under 40 CFR part 1039 will not be deemed to also be  
a certificate issued under this part. Introducing these engines into  
U.S. commerce as marine engines without a valid exemption or  
certificate of conformity under this part violates the prohibitions in  
40 CFR 1068.101(a)(1).  
    (g) Participation in averaging, banking, and trading. Engines using  
the exemption in this section may not generate or use emission credits  
under this part. These engines may generate credits under the ABT  
provisions in 40 CFR part 1039, as applicable. These engines must use  
emission credits under 40 CFR part 1039 as applicable if they are  
certified to an FEL that exceeds an emission standard.  
* * * * *  
0 
210. Amend Sec.  1042.615 by revising paragraphs (a) introductory text  
and (a)(1) and (3) and adding paragraphs (f) and (g) to read as  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 176/268follows:  
Sec.  1042.615  Replacement engine exemption.  
* * * * *  
    (a) This paragraph (a) applies instead of the provisions of 40 CFR  
1068.240(b)(2) for installing new marine engines in vessels that are  
not ``new vessels''. The prohibitions in 40 CFR 1068.101(a)(1) do not  
apply to a new replacement engine if all the following conditions are  
met: 
    (1) You use good engineering judgment to determine that no engine  
certified to the current requirements of this part is produced by any  
manufacturer with the appropriate physical or performance  
characteristics to repower the vessel. We have determined that Tier 4  
engines with aftertreatment technology do not have the appropriate  
physical or performance characteristics to replace uncertified engines  
or engines certified to emission standards that are less stringent than  
the Tier 4 standards.  
* * * * *  
    (3) Send us a report by September 30 of each year describing your  
engine shipments under this section from the preceding calendar year.  
Your report must include all the following things and be signed by an  
authorized representative of your company:  
    (i) Identify the number of Category 1 and Category 2 exempt  
replacement engines that meet Tier 1, Tier 2, or Tier 3 standards, or  
that meet no EPA standards. Count engines separately for each tier of  
standards. Identify the number of those engines that have been shipped  
(directly or indirectly) to a vessel owner. This includes engines  
shipped to anyone intending to install engines on behalf of a specific  
engine owner. Also include commercial Tier 3 engines with maximum  
engine power at or above 600 kW even if they have not been shipped to  
or designated for a specific vessel owner in the specified time frame.  
    (ii) Describe how you made the determinations described in  
paragraph (a)(1) of this section for each Category 1 and Category 2  
exempt replacement engine for each vessel during the preceding year.  
For Tier 3 replacement engines at or above 600 kW, describe why any  
engines certified to Tier 4 standards without aftertreatment are not  
suitable.  
    (iii) Identify the number of Category 3 exempt replacement engines.  
We may require you to describe how you made the determinations  
described in paragraph (a)(1) of this section for each engine.  
    (iv) Include the following statement:  
    I certify that the statements and information in the enclosed  
document  
[[Page 34512]]  
are true, accurate, and complete to the best of my knowledge. I am  
aware that there are significant civil and criminal penalties for  
submitting false statements and information, or omitting required  
statements and information.  
* * * * *  
    (f) The provisions of 40 CFR 1068.240(c) allow you to ship a  
limited number of exempt replacement engines to vessel owners or  
distributors without making the determinations described in paragraph  
(a) of this section. Note that such engines do not count toward the  
production limits of 40 CFR 1068.240(c) if you meet all the  
requirements of this section by the due date for the annual report. You  
may count Tier 3 commercial marine replacement engines at or above 600  
kW as tracked engines under 40 CFR 1068.240(b) even if they have not  
been shipped to or designated for a specific vessel owner in the  
specified time frame.  
    (g) In unusual circumstances, you may ask us to allow you to apply  
the replacement engine exemption of this section for repowering a  
vessel that becomes a ``new vessel'' under Sec.  1042.901 as a result  
of modifications, as follows:  
    (1) You must demonstrate that no manufacturer produces an engine  
certified to Tier 4 standards with the appropriate physical or  
performance characteristics to repower the vessel. We will consider  
concerns about the size of the replacement engine and its compatibility  
with vessel components relative to the overall scope of the project.  
    (2) Exempt replacement engines under this paragraph (g) must meet  
the Tier 3 standards specified in Sec.  1042.101 (or the Tier 2  
standards if there are no Tier 3 standards).  
    (3) We will not approve a request for an exemption from the Tier 3  
standards for any engines.  
    (4) You may not use the exemption provisions for untracked  
replacement engines under 40 CFR 1068.240(c) for repowering a vessel  
that becomes a ``new vessel'' under Sec.  1042.901 as a result of  
modifications.  
0 
211. Amend Sec.  1042.650 by revising the introductory text and  
paragraph (b)(4) to read as follows:  
Sec.  1042.650  Exemptions for migratory vessels and auxiliary engines  
on Category 3 vessels.  
    The provisions of paragraphs (a) through (c) of this section apply  
for Category 1 and Category 2 engines, including auxiliary engines  
installed on vessels with Category 3 propulsion engines. Paragraphs (a)  
through (c) do not apply for any Category 3 engines. All engines  
exempted under this section must comply with the applicable  
requirements of 40 CFR part 1043.  
* * * * *  
    (b) * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 177/268    (4) Operating a vessel containing an engine exempted under this  
paragraph (b) violates the prohibitions in 40 CFR 1068.101(a)(1) if the  
vessel is not in full compliance with applicable requirements for  
international safety specified in paragraph (b)(1)(i) of this section.  
* * * * *  
0 
212. Amend Sec.  1042.655 by revising the paragraph (b) to read as  
follows:  
Sec.  1042.655  Special certification provisions for Category 3 engines  
with aftertreatment.  
* * * * *  
    (b) Required testing. The emission-data engine must be tested as  
specified in subpart F of this part. Testing engine-out emissions to  
simulate operation with disabled Tier 3 emission controls must simulate  
backpressure and other parameters as needed to represent in-use  
operation with an SCR catalyst. The catalyst material or other  
aftertreatment device must be tested under conditions that accurately  
represent actual engine conditions for the test points. This catalyst  
or aftertreatment testing may be performed on a bench scale.  
* * * * *  
Sec.  1042.701  [Amended]  
0 
213. Amend Sec.  1042.701 by removing and reserving paragraph (j).  
0 
214. Amend Sec.  1042.801 by revising paragraph (f)(1) to read as  
follows:  
Sec.  1042.801  General provisions.  
* * * * *  
    (f) * * *  
    (1) Only fuel additives registered under 40 CFR part 79 may be used  
under this paragraph (f).  
* * * * *  
0 
215. Amend Sec.  1042.836 by revising the introductory text and  
paragraph (c) to read as follows:  
Sec.  1042.836  Marine certification of locomotive remanufacturing  
systems.  
    If you certify a Tier 0, Tier 1, or Tier 2 remanufacturing system  
for locomotives under 40 CFR part 1033, you may also certify the system  
under this part, according to the provisions of this section.  
* * * * *  
    (c) Systems that were certified to the standards of 40 CFR part 92  
are subject to the following restrictions:  
    (1) Tier 0 locomotive systems may not be used for any Category 1  
engines or Tier 1 or later Category 2 engines.  
    (2) Where systems certified to the standards of 40 CFR part 1033  
are also available for an engine, you may not use a system certified to  
the standards of 40 CFR part 92.  
0 
216. Amend Sec.  1042.901 by revising the definition for ``Low-hour''  
and paragraph (3) of the definition for ``Model year'' to read as  
follows:  
Sec.  1042.901  Definitions.  
* * * * *  
    Low-hour means relating to an engine that has stabilized emissions  
and represents the undeteriorated emission level. This would generally  
involve less than 300 hours of operation for engines with  
NOX aftertreatment and 125 hours of operation for other  
engines.  
* * * * *  
    Model year * * *  
    (3) For an uncertified marine engine excluded under Sec.  1042.5  
that is later subject to this part as a result of being installed in a  
different vessel, model year means the calendar year in which the  
engine was installed in the non-excluded vessel. For a marine engine  
excluded under Sec.  1042.5 that is later subject to this part as a  
result of reflagging the vessel, model year means the calendar year in  
which the engine was originally manufactured. For a marine engine that  
becomes new under paragraph (7) of the definition of ``new marine  
engine,'' model year means the calendar year in which the engine was  
originally manufactured. (See definition of ``new marine engine,''  
paragraphs (3) and (7).)  
* * * * *  
0 
217. Revise Sec.  1042.910 to read as follows:  
Sec.  1042.910  Incorporation by reference.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 178/268    (a) Certain material is incorporated by reference into this part  
with the approval of the Director of the Federal Register under 5  
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that  
specified in this section, the Environmental Protection Agency must  
publish a document in the Federal Register and the material must be  
available to the public. All approved material is available for  
inspection at EPA Docket Center, WJC West Building, Room 3334, 1301  
Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets ,  
(202) 202-1744, and is available from the sources listed in this  
section. It is also available for inspection at the National Archives  
and Records Administration (NARA). For information on the availability  
of this material at NARA, email fedreg.legal@nara.gov  or go to: http://  
www.archives.gov/federal_register/
[[Page 34513]]  
code_of_federal_regulations/ibr_locations.html.  
    (b) The International Maritime Organization, 4 Albert Embankment,  
London SE1 7SR, United Kingdom, or www.imo.org , or 44-(0)20-7735-7611.  
    (1) MARPOL Annex VI, Regulations for the Prevention of Air  
Pollution from Ships, Fourth Edition, 2017, and NO X  
Technical Code 2008.  
    (i) Revised MARPOL Annex VI, Regulations for the Prevention of  
Pollution from Ships, Fourth Edition, 2017 (``2008 Annex VI''); IBR  
approved for Sec.  1042.901.  
    (ii) NO X Technical Code 2008, Technical Code on Control  
of Emission of Nitrogen Oxides from Marine Diesel Engines, 2017  
Edition, (``NO X Technical Code''); IBR approved for  
Sec. Sec.  1042.104(g), 1042.230(d), 1042.302(c) and (e), 1042.501(g),  
and 1042.901.  
    (2) [Reserved]  
0 
218. Amend appendix I to part 1042 by revising paragraphs (a)  
introductory text, (b) introductory text, and (b)(3) to read as  
follows:  
Appendix I to Part 1042--Summary of Previous Emission Standards  
* * * * *  
    (a) Engines below 37 kW. Tier 1 and Tier 2 standards for engines  
below 37 kW originally adopted under 40 CFR part 89 apply as  
follows:  
* * * * *  
    (b) Engines at or above 37 kW. Tier 1 and Tier 2 standards for  
engines at or above 37 kW originally adopted under 40 CFR part 94  
apply as follows:  
* * * * *  
    (3) Tier 2 supplemental standards. The following not-to-exceed  
emission standards apply for all engines subject to the Tier 2  
standards described in paragraph (b)(2) of this appendix.  
    (i) Commercial marine engines. (A) 1.20 times the applicable  
standards (or FELs) when tested in accordance with the supplemental  
test procedures specified in Sec.  1042.515 at loads greater than or  
equal to 45 percent of the maximum power at rated speed or 1.50  
times the applicable standards (or FELs) at loads less than 45  
percent of the maximum power at rated speed.  
    (B) As an option, the manufacturer may instead choose to comply  
with limits of 1.25 times the applicable standards (or FELs) when  
tested over the whole power range in accordance with the  
supplemental test procedures specified in Sec.  1042.515.  
    (ii) Recreational marine engines. (A) 1.20 times the applicable  
standards (or FELs) when tested in accordance with the supplemental  
test procedures specified in Sec.  1042.515 at loads greater than or  
equal to 45 percent of the maximum power at rated speed and speeds  
less than 95 percent of maximum test speed, or 1.50 times the  
applicable standards (or FELs) at loads less than 45 percent of the  
maximum power at rated speed, or 1.50 times the applicable standards  
(or FELs) at any loads for speeds greater than or equal to 95  
percent of the maximum test speed.
    (B) As an option, the manufacturer may instead choose to comply  
with limits of 1.25 times the applicable standards (or FELs) when  
tested over the whole power range in accordance with the  
supplemental test procedures specified in Sec.  1042.515.  
PART 1043--CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE  
ENGINES AND VESSELS SUBJECT TO THE MARPOL PROTOCOL  
0 
219. The authority citation for part 1043 continues to read as follows:  
    Authority:  33 U.S.C. 1901-1912.  
0 
220. Amend Sec.  1043.41 by revising paragraph (a) to read as follows:  
Sec.  1043.41  EIAPP certification process.  
* * * * *  
    (a) You must send the Designated Certification Officer a separate  
application for an EIAPP certificate for each engine family. An EIAPP  
certificate is valid starting with the indicated effective date and is  
valid for any production until such time as the design of the engine  
family changes or more stringent emission standards become applicable,  
whichever comes first. Note that an EIAPP certificate demonstrating  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 179/268compliance with Tier I or Tier II standards (but not the Tier III  
standard) is only a limited authorization to install engines on  
vessels. For example, you may produce such Tier I or Tier II engines,  
but those engines may not be installed in vessels that are subject to  
Tier III standards. You may obtain preliminary approval of portions of  
the application under 40 CFR 1042.210.  
* * * * *  
0 
221. Revise Sec.  1043.100 to read as follows:  
Sec.  1043.100  Incorporation by reference.  
    (a) Certain material is incorporated by reference into this part  
with the approval of the Director of the Federal Register under 5  
U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that  
specified in this section, the Environmental Protection Agency must  
publish a document in the Federal Register and the material must be  
available to the public. All approved material is available for  
inspection at EPA Docket Center, WJC West Building, Room 3334, 1301  
Constitution Avenue NW, Washington, DC 20004, www.epa.gov/dockets ,  
(202) 202-1744, and is available from the sources listed in this  
section. It is also available for inspection at the National Archives  
and Records Administration (NARA). For information on the availability  
of this material at NARA, email fedreg.legal@nara.gov , or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html . 
    (b) The International Maritime Organization, 4 Albert Embankment,  
London SE1 7SR, United Kingdom, or www.imo.org , or 44-(0)20-7735-7611.  
    (1) MARPOL Annex VI, Regulations for the Prevention of Air  
Pollution from Ships, Fourth Edition, 2017, and NO X  
Technical Code 2008.  
    (i) Revised MARPOL Annex VI, Regulations for the Prevention of  
Pollution from Ships, Fourth Edition, 2017 (``2008 Annex VI''); IBR  
approved for Sec. Sec.  1043.1 introductory text, 1043.20, 1043.30(f),  
1043.60(c), and 1043.70(a).  
    (ii) NO X Technical Code 2008, Technical Code on Control  
of Emission of Nitrogen Oxides from Marine Diesel Engines, 2017  
Edition, (``NO X Technical Code''); IBR approved for  
Sec. Sec.  1043.20, 1043.41(b) and (h), and 1043.70(a).  
    (2) [Reserved]  
PART 1045--CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION  
MARINE ENGINES AND VESSELS  
0 
222. The authority citation for part 1045 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
223. Amend Sec.  1045.1 by revising paragraph (c) to read as follows:  
Sec.  1045.1  Does this part apply for my products?  
* * * * *  
    (c) Outboard and personal watercraft engines originally meeting the  
standards specified in appendix I of this part remain subject to those  
standards. Those engines remain subject to recall provisions as  
specified in 40 CFR part 1068, subpart F, throughout the useful life  
corresponding to the original certification. Also, tampering and  
defeat-device prohibitions continue to apply for those engines as  
specified in 40 CFR 1068.101.  
* * * * *  
0 
224. Amend Sec.  1045.145 by removing and reserving paragraphs (a)  
through (g), (i) through (k), and (m) and revising paragraph (n) to  
read as follows:  
Sec.  1045.145  Are there interim provisions that apply only for a  
limited time?  
* * * * *  
    (n) Continued use of 40 CFR part 91 test data. You may continue to  
use test data based on the test procedures that applied for engines  
built before the requirements of this part started to apply if we allow  
you to use carryover emission data under Sec.  1045.235(d) for your  
engine family. You may also use  
[[Page 34514]]  
those test procedures for production-line testing with any engine  
family whose certification is based on testing with those procedures.  
For any EPA testing, we will rely on the procedures described in  
subpart F of this part, even if you used carryover data based on older  
test procedures as allowed under this paragraph (n).  
* * * * *  
0 
225. Amend Sec.  1045.235 by revising paragraph (d)(3) to read as  
follows:  
Sec.  1045.235  What emission testing must I perform for my application  
for a certificate of conformity?  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 180/268* * * * *  
    (d) * * *  
    (3) The data show that the emission-data engine would meet all the  
requirements of this part that apply to the engine family covered by  
the application for certification.
* * * * *  
0 
226. Revise Sec.  1045.255 to read as follows:  
Sec.  1045.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Clean Air  
Act, we will issue a certificate of conformity for the engine family  
for that model year. We may make the approval subject to additional  
conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Clean Air Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Clean Air Act. Note that these are also violations of 40  
CFR 1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1045.820).  
0 
227. Amend Sec.  1045.310 by revising paragraphs (a)(1) introductory  
text and (a)(1)(iv) to read as follows:  
Sec.  1045.310  How must I select engines for production-line testing?  
    (a) * * *  
    (1) For engine families with projected U.S.-directed production  
volume of at least 1,600, the test periods are defined as follows:  
* * * * *  
    (iv) If your annual production period is 301 days or longer, divide  
the annual production period evenly into four test periods. For  
example, if your annual production period is 392 days (56 weeks),  
divide the annual production period into four test periods of 98 days  
(14 weeks).  
* * * * *  
0 
228. Amend Sec.  1045.501 by revising paragraph (c) to read as follows:  
Sec.  1045.501  How do I run a valid emission test?  
* * * * *  
    (c) Fuels. Use the fuels and lubricants specified in 40 CFR part  
1065, subpart H, for all the testing we require in this part, except as  
specified in Sec.  1045.515.  
    (1) Use gasoline meeting the specifications described in 40 CFR  
1065.710(c) for general testing. For service accumulation, use the test  
fuel or any commercially available fuel that is representative of the  
fuel that in-use engines will use.
    (2) You may alternatively use ethanol-blended fuel meeting the  
specifications described in 40 CFR 1065.710(b) for general testing  
without our advance approval. If you use the ethanol-blended fuel for  
certifying a given engine family, you may also use it for production-  
line testing or any other testing you perform for that engine family  
under this part. If you use the ethanol-blended fuel for certifying a  
given engine family, we may use the ethanol-blended fuel or the  
specified neat gasoline test fuel with that engine family.  
* * * * *  
0 
229. Revise appendix 1 to part 1045 to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 181/268Appendix I to Part 1045--Summary of Previous Emission Standards  
    (a) The following standards, which EPA originally adopted under  
40 CFR part 91, apply to outboard and personal watercraft engines  
produced from model year 2006 through 2009:  
    (1) For engines at or below 4.3 kW, the HC+NO X  
standard is 81.00 g/kW-hr.  
    (2) For engines above 4.3 kW, the following HC+NO X  
standard applies:  
HC+NOX standard = (151 + 557/P0.9) [sdot] 0.250 + 6.00  
Where: 
STD = The HC+NO X emission standard, in g/kW-hr.  
P = The average power of an engine family, in kW.  
    (b) Table 1 of this appendix describes the phase-in standards  
for outboard and personal watercraft engines for model years 1998  
through 2005. For engines with maximum engine power above 4.3 kW,  
the standard is expressed by the following formula, in g/kW-hr, with  
constants for each year identified in Table 1 of this appendix:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.168  
[[Page 34515]]  
          Table 1 of Appendix I--HC+NOX Phase-In Standards for Outboard and Personal Watercraft Engines  
----------------------------------------------------------------------------------------------------------------  
                                                                                 Maximum engine power >4.3 kW  
                        Model year                           Maximum  engine -----------------------------------  
                                                             power  <4.3 kW           A                 B  
----------------------------------------------------------------------------------------------------------------  
1998......................................................            278.00             0.917              2.44  
1999......................................................            253.00             0.833              2.89  
2000......................................................            228.00             0.750              3.33  
2001......................................................            204.00             0.667              3.78  
2002......................................................            179.00             0.583              4.22  
2003......................................................            155.00             0.500              4.67  
2004......................................................            130.00             0.417              5.11  
2005......................................................            105.00             0.333              5.56  
----------------------------------------------------------------------------------------------------------------  
PART 1048--CONTROL OF EMISSIONS FROM NEW, LARGE NONROAD SPARK-  
IGNITION ENGINES  
0 
230. The authority citation for part 1048 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
231. Revise Sec.  1048.145 to read as follows:  
Sec.  1048.145  Are there interim provisions that apply only for a  
limited time?  
    The interim provisions in this section apply instead of other  
provisions in this part. This section describes when these interim  
provisions expire.  
    (a)-(f) [Reserved]  
    (g) Small-volume provisions. If you qualify for the hardship  
provisions in Sec.  1068.250 of this chapter, we may approve extensions  
of up to four years total.  
0 
232. Revise Sec.  1048.255 to read as follows:  
Sec.  1048.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Act, we  
will issue a certificate of conformity for the engine family for that  
model year. We may make the approval subject to additional conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 182/268include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Act. Note that these are also violations of 40 CFR  
1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1048.820).  
0 
233. Amend Sec.  1048.501 by revising paragraph (c) to read as follows:  
Sec.  1048.501  How do I run a valid emission test?  
* * * * *  
    (c) Use the fuels and lubricants specified in 40 CFR part 1065,  
subpart H, to perform valid tests for all the testing we require in  
this part, except as noted in Sec.  1048.515.  
    (1) Use gasoline meeting the specifications described in 40 CFR  
1065.710(c) for general testing. For service accumulation, use the test  
fuel or any commercially available fuel that is representative of the  
fuel that in-use engines will use.
    (2) You may alternatively use ethanol-blended fuel meeting the  
specifications described in 40 CFR 1065.710(b) for general testing  
without our advance approval. If you use the ethanol-blended fuel for  
certifying a given engine family, you may also use it for production-  
line testing or any other testing you perform for that engine family  
under this part. If you use the ethanol-blended fuel for certifying a  
given engine family, we may use the ethanol-blended fuel or the  
specified neat gasoline test fuel with that engine family.  
* * * * *  
PART 1051--CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND  
VEHICLES  
0 
234. The authority citation for part 1051 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
Sec.  1051.145  [Removed and Reserved]  
0 
235. Remove and reserve Sec.  1051.145.  
0 
236. Revise Sec.  1051.255 to read as follows:  
Sec.  1051.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
engine family meets all the requirements of this part and the Act, we  
will issue a certificate of conformity for the engine family for that  
model year. We may make the approval subject to additional conditions.  
    (b) We may deny an application for certification if we determine  
that an engine family fails to comply with emission standards or other  
requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
[[Page 34516]]  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines for importation into the United States at a  
location where local law prohibits us from carrying out authorized  
activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Clean Air Act. Note that these are also violations of 40  
CFR 1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete after submission.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate, you may ask for a hearing (see Sec.  1051.820).  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 183/2680 
237. Amend Sec.  1051.310 by revising paragraphs (a)(1) introductory  
text and (a)(1)(iv) to read as follows:  
Sec.  1051.310  How must I select vehicles or engines for production-  
line testing?  
    (a) * * *  
    (1) For engine families with projected U.S.-directed production  
volume of at least 1,600, the test periods are defined as follows:  
* * * * *  
    (iv) If your annual production period is 301 days or longer, divide  
the annual production period evenly into four test periods. For  
example, if your annual production period is 392 days (56 weeks),  
divide the annual production period into four test periods of 98 days  
(14 weeks).  
* * * * *  
0 
238. Amend Sec.  1051.501 by revising paragraph (d) to read as follows:  
Sec.  1051.501  What procedures must I use to test my vehicles or  
engines?  
* * * * *  
    (d) Fuels. Use the fuels meeting the following specifications:  
    (1) Exhaust. Use the fuels and lubricants specified in 40 CFR part  
1065, subpart H, for all the exhaust testing we require in this part.  
For service accumulation, use the test fuel or any commercially  
available fuel that is representative of the fuel that in-use engines  
will use. The following provisions apply for using specific fuel types:  
    (i) For gasoline-fueled engines, use the grade of gasoline  
specified in 40 CFR 1065.710(c) for general testing. You may  
alternatively use ethanol-blended fuel meeting the specifications  
described in 40 CFR 1065.710(b) for general testing without our advance  
approval. If you use the ethanol-blended fuel for certifying a given  
engine family, you may also use it for production-line testing or any  
other testing you perform for that engine family under this part. If  
you use the ethanol-blended fuel for certifying a given engine family,  
we may use the ethanol-blended fuel or the specified neat gasoline test  
fuel with that engine family.  
    (ii) For diesel-fueled engines, use either low-sulfur diesel fuel  
or ultra low-sulfur diesel fuel meeting the specifications in 40 CFR  
1065.703. If you use sulfur-sensitive technology as defined in 40 CFR  
1039.801 and you measure emissions using ultra low-sulfur diesel fuel,  
you must add a permanent label near the fuel inlet with the following  
statement: ``ULTRA LOW SULFUR FUEL ONLY''.  
    (2) Fuel tank permeation. (i) For the preconditioning soak  
described in Sec.  1051.515(a)(1) and fuel slosh durability test  
described in Sec.  1051.515(d)(3), use the fuel specified in 40 CFR  
1065.710(b), or the fuel specified in 40 CFR 1065.710(c) blended with  
10 percent ethanol by volume. As an alternative, you may use Fuel CE10,  
which is Fuel C as specified in ASTM D 471-98 (see 40 CFR 1060.810)  
blended with 10 percent ethanol by volume.  
    (ii) For the permeation measurement test in Sec.  1051.515(b), use  
the fuel specified in 40 CFR 1065.710(c). As an alternative, you may  
use any of the fuels specified in paragraph (d)(2)(i) of this section.  
    (3) Fuel hose permeation. Use the fuel specified in 40 CFR  
1065.710(b), or the fuel specified in 40 CFR 1065.710(c) blended with  
10 percent ethanol by volume for permeation testing of fuel lines. As  
an alternative, you may use Fuel CE10, which is Fuel C as specified in  
ASTM D 471-98 (see 40 CFR 1060.810) blended with 10 percent ethanol by  
volume. 
* * * * *  
PART 1054--CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-  
IGNITION ENGINES AND EQUIPMENT  
0 
239. The authority citation for part 1054 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
240. Amend Sec.  1054.1 by revising paragraphs (a)(1) and (5), (c), and  
(d) to read as follows:  
Sec.  1054.1  Does this part apply for my engines and equipment?  
    (a) * * *  
    (1) The requirements of this part related to exhaust emissions  
apply to new, nonroad spark-ignition engines with maximum engine power  
at or below 19 kW. This includes auxiliary marine spark-ignition  
engines.  
* * * * *  
    (5) We specify provisions in Sec. Sec.  1054.145(f) and 1054.740  
that allow for meeting the requirements of this part before the dates  
shown in Table 1 to this section. Engines, fuel-system components, or  
equipment certified to the standards in Sec. Sec.  1054.145(f) and  
1054.740 are subject to all the requirements of this part as if these  
optional standards were mandatory.
* * * * *  
    (c) Engines originally meeting Phase 1 or Phase 2 standards as  
specified in appendix I of this part remain subject to those standards.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 184/268Those engines remain subject to recall provisions as specified in 40  
CFR part 1068, subpart F, throughout the useful life corresponding to  
the original certification. Also, tampering and defeat-device  
prohibitions continue to apply for those engines as specified in 40 CFR  
1068.101.  
    (d) The regulations in this part optionally apply to engines with  
maximum engine power at or below 30 kW and with displacement at or  
below 1,000 cubic centimeters that would otherwise be covered by 40 CFR  
part 1048. See 40 CFR 1048.615 for provisions related to this  
allowance.  
* * * * *  
0 
241. Revise Sec.  1054.2 to read as follows:  
Sec.  1054.2  Who is responsible for compliance?  
    (a) The requirements and prohibitions of this part apply to  
manufacturers of engines and equipment, as described in Sec.  1054.1.  
The requirements of this part are generally addressed to manufacturers  
subject to this part's requirements. The term ``you'' generally means  
the certifying manufacturer. For provisions related to exhaust  
emissions,  
[[Page 34517]]  
this generally means the engine manufacturer, especially for issues  
related to certification (including production-line testing, reporting,  
etc.). For provisions related to certification with respect to  
evaporative emissions, this generally means the equipment manufacturer.  
Note that for engines that become new after being placed into service  
(such as engines converted from highway or stationary use), the  
requirements that normally apply for manufacturers of freshly  
manufactured engines apply to the importer or any other entity we allow  
to obtain a certificate of conformity.  
    (b) Equipment manufacturers must meet applicable requirements as  
described in Sec.  1054.20. Engine manufacturers that assemble an  
engine's complete fuel system are considered to be the equipment  
manufacturer with respect to evaporative emissions (see 40 CFR 1060.5).  
Note that certification requirements for component manufacturers are  
described in 40 CFR part 1060.  
0 
242. Revise Sec.  1054.30 to read as follows:  
Sec.  1054.30  Submission of information.  
    Unless we specify otherwise, send all reports and requests for  
approval to the Designated Compliance Officer (see Sec.  1054.801). See  
Sec.  1054.825 for additional reporting and recordkeeping provisions.  
0 
243. Amend Sec.  1054.103 by revising paragraph (c) introductory text  
to read as follows:  
Sec.  1054.103  What exhaust emission standards must my handheld  
engines meet?  
* * * * *  
    (c) Fuel types. The exhaust emission standards in this section  
apply for engines using the fuel type on which the engines in the  
emission family are designed to operate. You must meet the numerical  
emission standards for hydrocarbon in this section based on the  
following types of hydrocarbon emissions for engines powered by the  
following fuels:  
* * * * *  
0 
244. Amend Sec.  1054.105 by revising paragraph (c) introductory text  
to read as follows:  
Sec.  1054.105  What exhaust emission standards must my nonhandheld  
engines meet?  
* * * * *  
    (c) Fuel types. The exhaust emission standards in this section  
apply for engines using the fuel type on which the engines in the  
emission family are designed to operate. You must meet the numerical  
emission standards for hydrocarbon in this section based on the  
following types of hydrocarbon emissions for engines powered by the  
following fuels:  
* * * * *  
0 
245. Amend Sec.  1054.110 by revising paragraph (b) to read as follows:  
Sec.  1054.110  What evaporative emission standards must my handheld  
equipment meet?  
* * * * *  
    (b) Tank permeation. Fuel tanks must meet the permeation  
requirements specified in 40 CFR 1060.103. The requirements in 40 CFR  
1060.103 apply for handheld equipment starting in the 2010 model year,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 185/268except that they apply starting in the 2011 model year for structurally  
integrated nylon fuel tanks, in the 2012 model year for handheld  
equipment using nonhandheld engines, and in the 2013 model year for all  
small-volume emission families. For nonhandheld equipment using engines  
at or below 80 cc, the requirements of this paragraph (b) apply  
starting in the 2012 model year. You may generate or use emission  
credits to show compliance with the requirements of this paragraph (b)  
under the averaging, banking, and trading program as described in  
subpart H of this part. FEL caps apply as specified in Sec.   
1054.112(b)(1) through (3) starting in the 2015 model year.  
* * * * *  
0 
246. Amend Sec.  1054.120 by revising paragraph (c) to read as follows:  
Sec.  1054.120  What emission-related warranty requirements apply to  
me? 
* * * * *  
    (c) Components covered. The emission-related warranty covers all  
components whose failure would increase an engine's emissions of any  
regulated pollutant, including components listed in 40 CFR part 1068,  
appendix I, and components from any other system you develop to control  
emissions. The emission-related warranty covers these components even  
if another company produces the component. Your emission-related  
warranty does not need to cover components whose failure would not  
increase an engine's emissions of any regulated pollutant.  
* * * * *  
0 
247. Amend Sec.  1054.125 by revising the introductory text and  
paragraphs (c) and (e) to read as follows:  
Sec.  1054.125  What maintenance instructions must I give to buyers?  
    Give the ultimate purchaser of each new engine written instructions  
for properly maintaining and using the engine, including the emission  
control system as described in this section. The maintenance  
instructions also apply to service accumulation on your emission-data  
engines as described in Sec.  1054.245 and in 40 CFR part 1065.  
* * * * *  
    (c) Special maintenance. You may specify more frequent maintenance  
to address problems related to special situations, such as atypical  
engine operation. You must clearly state that this additional  
maintenance is associated with the special situation you are  
addressing. You may also address maintenance of low-use engines (such  
as recreational or stand-by engines) by specifying the maintenance  
interval in terms of calendar months or years in addition to your  
specifications in terms of engine operating hours. All special  
maintenance instructions must be consistent with good engineering  
judgment. We may disapprove your maintenance instructions if we  
determine that you have specified special maintenance steps to address  
engine operation that is not atypical, or that the maintenance is  
unlikely to occur in use. For example, this paragraph (c) does not  
allow you to design engines that require special maintenance for a  
certain type of expected operation. If we determine that certain  
maintenance items do not qualify as special maintenance under this  
paragraph (c), you may identify this as recommended additional  
maintenance under paragraph (b) of this section.  
* * * * *  
    (e) Maintenance that is not emission-related. For maintenance  
unrelated to emission controls, you may schedule any amount of  
inspection or maintenance. You may also take these inspection or  
maintenance steps during service accumulation on your emission-data  
engines, as long as they are reasonable and technologically necessary.  
This might include adding engine oil, changing fuel or oil filters,  
servicing engine-cooling systems, and adjusting idle speed, governor,  
engine bolt torque, valve lash, or injector lash. You may not perform  
this nonemission-related maintenance on emission-data engines more  
often than the least frequent intervals that you recommend to the  
ultimate purchaser.  
* * * * *  
0 
248. Amend Sec.  1054.130 by revising paragraphs (b)(2) and (5) to read  
as follows:  
[[Page 34518]]  
Sec.  1054.130  What installation instructions must I give to equipment  
manufacturers?  
* * * * *  
    (b) * * *  
    (2) State: ``Failing to follow these instructions when installing a  
certified engine in a piece of equipment violates federal law (40 CFR  
1068.105(b)), subject to fines or other penalties as described in the  
Clean Air Act.''  
* * * * *  
    (5) Describe how your certification is limited for any type of  
application. For example, if you certify engines only for rated-speed  
applications, tell equipment manufacturers that the engine must not be  
installed in equipment involving intermediate-speed operation. Also, if  
your wintertime engines are not certified to the otherwise applicable  
HC+NOX standards in this subpart, tell equipment  
manufacturers that the engines must be installed in equipment that is  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 186/268used only in wintertime.  
* * * * *  
0 
249. Amend Sec.  1054.135 by revising paragraphs (c)(2) and (e)(1) to  
read as follows:  
Sec.  1054.135  How must I label and identify the engines I produce?  
* * * * *  
    (c) * * *  
    (2) Include your full corporate name and trademark. You may  
identify another company and use its trademark instead of yours if you  
comply with the branding provisions of 40 CFR 1068.45.  
* * * * *  
    (e) * * *  
    (1) You may identify other emission standards that the engine meets  
or does not meet (such as California standards), as long as this does  
not cause you to omit any of the information described in paragraph (c)  
of this section. You may include this information by adding it to the  
statement we specify or by including a separate statement.  
* * * * *  
0 
250. Revise Sec.  1054.145 to read as follows:  
Sec.  1054.145  Are there interim provisions that apply only for a  
limited time?  
    The interim provisions in this section apply instead of other  
provisions in this part. This section describes how and when these  
interim provisions apply.  
    (a)-(b) [Reserved]  
    (c) Special provisions for handheld engines. Handheld engines  
subject to Phase 3 emission standards must meet the standards at or  
above barometric pressures of 96.0 kPa in the standard configuration  
and are not required to meet emission standards at lower barometric  
pressures. This is intended to allow testing under most weather  
conditions at all altitudes up to 1,100 feet above sea level. In your  
application for certification, identify the altitude above which you  
rely on an altitude kit and describe your plan for making information  
and parts available such that you would reasonably expect that altitude  
kits would be widely used at all such altitudes.  
    (d) Alignment of model years for exhaust and evaporative standards.  
Evaporative emission standards generally apply based on the model year  
of the equipment, which is determined by the equipment's date of final  
assembly. However, in the first year of new emission standards,  
equipment manufacturers may apply evaporative emission standards based  
on the model year of the engine as shown on the engine's emission  
control information label. For example, for the fuel line permeation  
standards starting in 2012, equipment manufacturers may order a batch  
of 2011 model year engines for installation in 2012 model year  
equipment, subject to the anti-stockpiling provisions of 40 CFR  
1068.105(a). The equipment with the 2011 model year engines would not  
need to meet fuel line permeation standards, as long as the equipment  
is fully assembled by December 31, 2012.  
    (e) [Reserved]  
    (f) Early banking for evaporative emission standards--handheld  
equipment manufacturers. You may earn emission credits for handheld  
equipment you produce before the evaporative emission standards of  
Sec.  1054.110 apply. To do this, your equipment must use fuel tanks  
with a family emission limit below 1.5 g/m2/day (or 2.5 g/m2/day for  
testing at 40 [deg]C). Calculate your credits as described in Sec.   
1054.706 based on the difference between the family emission limit and  
1.5 g/m2/day (or 2.5 g/m2/day for testing at 40 [deg]C).  
    (g) through (i) [Reserved]  
    (j) Continued use of 40 CFR part 90 test data. You may continue to  
use data based on the test procedures that apply for engines built  
before the requirements of this part start to apply if we allow you to  
use carryover emission data under Sec.  1054.235(d) for your emission  
family. You may also use those test procedures for measuring exhaust  
emissions for production-line testing with any engine family whose  
certification is based on testing with those procedures. For any EPA  
testing, we will rely on the procedures described in subpart F of this  
part, even if you used carryover data based on older test procedures as  
allowed under this paragraph (j).  
    (k)-(m) [Reserved]  
    (n) California test fuel. You may perform testing with a fuel  
meeting the requirements for certifying the engine in California  
instead of the fuel specified in Sec.  1054.501(b)(2), as follows:  
    (1) You may certify individual engine families using data from  
testing conducted with California Phase 2 test fuel through model year  
2019. Any EPA testing with such an engine family may use either  
California Phase 2 test fuel or the test fuel specified in Sec.   
1054.501.  
    (2) Starting in model year 2013, you may certify individual engine  
families using data from testing conducted with California Phase 3 test  
fuel. Any EPA testing with such an engine family may use either  
California Phase 3 test fuel or the test fuel specified in Sec.   
1054.501, unless you certify to the more stringent CO standards  
specified in this paragraph (n)(2). If you meet these alternate CO  
standards, we will also use California Phase 3 test fuel for any  
testing we perform with engines from that engine family. The following  
alternate CO standards apply instead of the CO standards specified in  
Sec.  1054.103 or Sec.  1054.105:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 187/268   Table 1 to Sec.   1054.145--Alternate CO Standards for Testing With  
                      California Phase 3 Test Fuel  
                                [g/kW-hr]  
------------------------------------------------------------------------  
                                                           Alternate  CO  
                       Engine type                           standard  
------------------------------------------------------------------------  
Class I.................................................             549  
Class II................................................             549  
Class III...............................................             536  
Class IV................................................             536  
Class V.................................................             536  
Marine generators.......................................             4.5  
------------------------------------------------------------------------  
0 
251. Amend Sec.  1054.205 by revising paragraphs (o)(1), (p)(1), (v),  
and (x) to read as follows:  
Sec.  1054.205  What must I include in my application?  
* * * * *  
    (o) * * *  
    (1) Present emission data for hydrocarbon (such as THC, THCE, or  
NMHC, as applicable), NO X, and CO on an emission-data engine  
to show your engines meet the applicable exhaust emission standards as  
specified in Sec.  1054.101. Show emission figures before and after  
applying deterioration factors for each engine. Include test data from  
each applicable duty cycle specified in Sec.  1054.505(b). If we  
specify more than one grade of any fuel type (for example, low-  
temperature and all-season gasoline), you need to submit test data only  
for one grade, unless the  
[[Page 34519]]  
regulations of this part specify otherwise for your engine.  
* * * * *  
    (p) * * *  
    (1) Report all valid test results involving measurement of  
pollutants for which emission standards apply. Also indicate whether  
there are test results from invalid tests or from any other tests of  
the emission-data engine, whether or not they were conducted according  
to the test procedures of subpart F of this part. We may require you to  
report these additional test results. We may ask you to send other  
information to confirm that your tests were valid under the  
requirements of this part and 40 CFR parts 1060 and 1065.  
* * * * *  
    (v) Provide the following information about your plans for  
producing and selling engines:  
    (1) Identify the estimated initial and final dates for producing  
engines from the engine family for the model year.  
    (2) Identify the estimated date for initially introducing certified  
engines into U.S. commerce under this certificate.  
    (3) Include good-faith estimates of U.S.-directed production  
volumes. Include a justification for the estimated production volumes  
if they are substantially different than actual production volumes in  
earlier years for similar models. Also indicate whether you expect the  
engine family to contain only nonroad engines, only stationary engines,  
or both.  
* * * * *  
    (x) Include the information required by other subparts of this  
part. For example, include the information required by Sec.  1054.725  
if you participate in the ABT program and include the information  
required by Sec.  1054.690 if you need to post a bond under that  
section.  
* * * * *  
0 
252. Amend Sec.  1054.220 by revising the section heading to read as  
follows:  
Sec.  1054.220  How do I amend my maintenance instructions?  
* * * * *  
0 
253. Amend Sec.  1054.225 by:  
0 
a. Revising the section heading and paragraphs (b) and (f) introductory  
text; and  
0 
b. Adding paragraph (g).  
    The revisions and addition read as follows:  
Sec.  1054.225  How do I amend my application for certification?  
* * * * *  
    (b) To amend your application for certification, send the following  
relevant information to the Designated Compliance Officer.  
    (1) Describe in detail the addition or change in the model or  
configuration you intend to make.  
    (2) Include engineering evaluations or data showing that the  
amended emission family complies with all applicable requirements in  
this part. You may do this by showing that the original emission-data  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 188/268engine or emission-data equipment is still appropriate for showing that  
the amended family complies with all applicable requirements in this  
part. 
    (3) If the original emission-data engine for the engine family is  
not appropriate to show compliance for the new or modified engine  
configuration, include new test data showing that the new or modified  
engine configuration meets the requirements of this part.  
    (4) Include any other information needed to make your application  
correct and complete.  
* * * * *  
    (f) You may ask us to approve a change to your FEL with respect to  
exhaust emissions in certain cases after the start of production. The  
changed FEL may not apply to engines you have already introduced into  
U.S. commerce, except as described in this paragraph (f). If we approve  
a changed FEL after the start of production, you must identify the  
month and year for applying the new FEL. You may ask us to approve a  
change to your FEL in the following cases:  
* * * * *  
    (g) You may produce engines as described in your amended  
application for certification and consider those engines to be in a  
certified configuration if we approve a new or modified engine  
configuration during the model year under paragraph (d) of this  
section. Similarly, you may modify in-use engines as described in your  
amended application for certification and consider those engines to be  
in a certified configuration if we approve a new or modified engine  
configuration at any time under paragraph (d) of this section.  
Modifying a new or in-use engine to be in a certified configuration  
does not violate the tampering prohibition of 40 CFR 1068.101(b)(1), as  
long as this does not involve changing to a certified configuration  
with a higher family emission limit.  
0 
254. Amend Sec.  1054.235 by revising the section heading and  
paragraphs (a), (b), (c), and (d) to read as follows:  
Sec.  1054.235  What testing requirements apply for certification?  
* * * * *  
    (a) Select an emission-data engine from each engine family for  
testing as described in 40 CFR 1065.401. Select a configuration and set  
adjustable parameters in a way that is most likely to exceed the  
HC+NOX standard in subpart B of this part, using good  
engineering judgment. Configurations must be tested as they will be  
produced, including installed governors, if applicable.  
    (b) Test your emission-data engines using the procedures and  
equipment specified in subpart F of this part. In the case of dual-fuel  
engines, measure emissions when operating with each type of fuel for  
which you intend to certify the engine. In the case of flexible-fuel  
engines, measure emissions when operating with the fuel mixture that is  
most likely to cause the engine to exceed the applicable  
HC+NOX emission standard, though you may ask us to instead  
perform tests with both fuels separately if you can show that  
intermediate mixtures are not likely to occur in use.  
    (c) We may perform confirmatory testing by measuring emissions from  
any of your emission-data engines or other engines from the emission  
family, as follows:  
    (1) We may decide to do the testing at your plant or any other  
facility. If we do this, you must deliver the engine to a test facility  
we designate. The engine you provide must include appropriate  
manifolds, aftertreatment devices, electronic control units, and other  
emission-related components not normally attached directly to the  
engine block. If we do the testing at your plant, you must schedule it  
as soon as possible and make available the instruments, personnel, and  
equipment we need.  
    (2) If we measure emissions on one of your engines, the results of  
that testing become the official emission results for the engine.  
    (3) We may set the adjustable parameters of your engine to any  
point within the physically adjustable ranges (see Sec.  1054.115(b)).  
    (4) Before we test one of your engines, we may calibrate it within  
normal production tolerances for anything we do not consider an  
adjustable parameter. For example, we may calibrate it within normal  
production tolerances for a parameter that is subject to production  
variability because it is adjustable during production, but is not  
considered an adjustable parameter (as defined in Sec.  1054.801)  
because it is permanently sealed.  
    (d) You may ask to use carryover emission data from a previous  
model year instead of doing new tests, but only if all the following  
are true:  
[[Page 34520]]  
    (1) The emission family from the previous model year differs from  
the current emission family only with respect to model year, items  
identified in Sec.  1054.225(a), or other characteristics unrelated to  
emissions. We may waive this paragraph (d)(1) for differences we  
determine not to be relevant.  
    (2) The emission-data engine from the previous model year remains  
the appropriate emission-data engine under paragraph (b) of this  
section.  
    (3) The data show that the emission-data engine would meet all the  
requirements of this part that apply to the emission family covered by  
the application for certification.
* * * * *  
0 
255. Amend Sec.  1054.240 by revising paragraphs (a), (b), (c), and (d)  
to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 189/268Sec.  1054.240  How do I demonstrate that my emission family complies  
with exhaust emission standards?  
    (a) For purposes of certification, your emission family is  
considered in compliance with the emission standards in Sec.   
1054.101(a) if all emission-data engines representing that family have  
test results showing official emission results and deteriorated  
emission levels at or below these standards. This paragraph (a) also  
applies for all test points for emission-data engines within the family  
used to establish deterioration factors. Note that your FELs are  
considered to be the applicable emission standards with which you must  
comply if you participate in the ABT program in subpart H of this part.  
    (b) Your engine family is deemed not to comply if any emission-data  
engine representing that family has test results showing an official  
emission result or a deteriorated emission level for any pollutant that  
is above an applicable emission standard in subpart B of this part.  
This paragraph (b) also applies for all test points for emission-data  
engines within the family used to establish deterioration factors.  
    (c) Determine a deterioration factor to compare emission levels  
from the emission-data engine with the applicable emission standards in  
subpart B of this part. Section 1054.245 specifies how to test engines  
to develop deterioration factors that represent the expected  
deterioration in emissions over your engines' full useful life.  
Calculate a multiplicative deterioration factor as described in Sec.   
1054.245(b). If the deterioration factor is less than one, use one.  
Specify the deterioration factor to one more significant figure than  
the emission standard. In the case of dual-fuel and flexible-fuel  
engines, apply deterioration factors separately for each fuel type. You  
may use assigned deterioration factors that we establish for up to  
10,000 nonhandheld engines from small-volume emission families in each  
model year, except that small-volume engine manufacturers may use  
assigned deterioration factors for any or all of their engine families.  
    (d) Determine the official emission result for each pollutant to at  
least one more decimal place than the applicable standard in subpart B  
of this part. Apply the deterioration factor to the official emission  
result, as described in Sec.  1054.245(b), then round the adjusted  
figure to the same number of decimal places as the emission standard.  
Compare the rounded emission levels to the emission standard for each  
emission-data engine. In the case of HC+NO X standards, add  
the official emission results and apply the deterioration factor to the  
sum of the pollutants before rounding. However, if your deterioration  
factors are based on emission measurements that do not cover the  
engine's full useful life, apply deterioration factors to each  
pollutant and then add the results before rounding.  
* * * * *  
0 
256. Amend Sec.  1054.245 by:  
0 
a. Revising paragraphs (a), (b)(1), (2), (3), and (5), and (c); and  
0 
b. Adding paragraph (d).  
    The revisions and addition read as follows:  
Sec.  1054.245  How do I determine deterioration factors from exhaust  
durability testing?  
* * * * *  
    (a) You may ask us to approve deterioration factors for an emission  
family based on emission measurements from similar engines if you have  
already given us these data for certifying other engines in the same or  
earlier model years. Use good engineering judgment to decide whether  
the two engines are similar. We will approve your request if you show  
us that the emission measurements from other engines reasonably  
represent in-use deterioration for the engine family for which you have  
not yet determined deterioration factors.  
    (b) * * *  
    (1) Measure emissions from the emission-data engine at a low-hour  
test point, at the midpoint of the useful life, and at the end of the  
useful life, except as specifically allowed by this paragraph (b). You  
may test at additional evenly spaced intermediate points. Collect  
emission data using measurements to at least one more decimal place  
than the emission standard in subpart B of this part.  
    (2) Operate the engine over a duty cycle that is representative of  
in-use operation for a period at least as long as the useful life (in  
hours). You may operate the engine continuously. You may also use an  
engine installed in nonroad equipment to accumulate service hours  
instead of running the engine only in the laboratory.  
    (3) In the case of dual-fuel or flexible-fuel engines, you may  
accumulate service hours on a single emission-data engine using the  
type or mixture of fuel expected to have the highest combustion and  
exhaust temperatures; you may ask us to approve a different fuel  
mixture for flexible-fuel engines if you demonstrate that a different  
criterion is more appropriate. For dual-fuel engines, you must measure  
emissions on each fuel type at each test point, either with separate  
engines dedicated to a given fuel, or with different configurations of  
a single engine.  
* * * * *  
    (5) Calculate your deterioration factor using a linear least-  
squares fit of your test data but treat the low-hour test point as  
occurring at hour zero. Your deterioration factor is the ratio of the  
calculated emission level at the point representing the full useful  
life to the calculated emission level at zero hours, expressed to one  
more significant figure than the emission standard in subpart B of this  
part. 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 190/268* * * * *  
    (c) If you qualify for using assigned deterioration factors under  
Sec.  1054.240, determine the deterioration factors as follows:  
    (1) For two-stroke engines without aftertreatment, use a  
deterioration factor of 1.1 for HC, NO X, and CO. For four-  
stroke engines without aftertreatment, use deterioration factors of 1.4  
for HC, 1.0 for NO X, and 1.1 for CO for Class 2 engines, and  
use 1.5 for HC and NO X, and 1.1 for CO for all other  
engines.  
    (2) For Class 2 engines with aftertreatment, use a deterioration  
factor of 1.0 for NO X. For all other cases involving engines  
with aftertreatment, calculate separate deterioration factors for HC,  
NOX, and CO using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.169  
Where: 
NE = engine-out emission levels (pre-catalyst) from the low-hour  
test result for a given pollutant, in g/kW-hr.  
EDF = the deterioration factor specified in paragraph (c)(1) of this  
section for the type of engine for a given pollutant.  
CC = the catalyst conversion from the low-hour test, in g/kW-hr.  
This is the  
[[Page 34521]]  
difference between the official emission result and NE.  
F = 1.0 for NO X and 0.8 for HC and CO.  
    (3) Combine separate deterioration factors for HC and  
NOX from paragraph (c)(2) of this section into a combined  
deterioration factor for HC+NO X using the following  
equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.170  
    (d) Include the following information in your application for  
certification:  
    (1) If you determine your deterioration factors based on test data  
from a different emission family, explain why this is appropriate and  
include all the emission measurements on which you base the  
deterioration factor.  
    (2) If you do testing to determine deterioration factors, describe  
the form and extent of service accumulation, including the method you  
use to accumulate hours.  
    (3) If you calculate deterioration factors under paragraph (c) of  
this section, identify the parameters and variables you used for the  
calculation.  
0 
257. Amend Sec.  1054.250 by:  
0 
a. Removing and reserving paragraph (a)(3); and  
0 
b. Revising paragraphs (b)(3)(iv) and (c).  
    The revisions read as follows:
Sec.  1054.250  What records must I keep and what reports must I send  
to EPA? 
* * * * *  
    (b) * * *  
    (3) * * *  
    (iv) All your emission tests (valid and invalid), including the  
date and purpose of each test and documentation of test parameters as  
specified in part 40 CFR part 1065.  
* * * * *  
    (c) Keep required data from emission tests and all other  
information specified in this section for eight years after we issue  
your certificate. If you use the same emission data or other  
information for a later model year, the eight-year period restarts with  
each year that you continue to rely on the information.  
* * * * *  
0 
258. Revise Sec.  1054.255 to read as follows:  
Sec.  1054.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
emission family meets all the requirements of this part and the Clean  
Air Act, we will issue a certificate of conformity for the emission  
family for that model year. We may make the approval subject to  
additional conditions.  
    (b) We may deny an application for certification if we determine  
that an emission family fails to comply with emission standards or  
other requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing, reporting, or bonding  
requirements in this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 191/268    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce engines or equipment for importation into the United  
States at a location where local law prohibits us from carrying out  
authorized activities.  
    (6) Fail to supply requested information or amend an application to  
include all engines or equipment being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Clean Air Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Clean Air Act. Note that these are also violations of 40  
CFR 1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting your application that causes the  
submitted information to be false or incomplete.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate of conformity, you may ask for a hearing (see Sec.   
1054.820).  
0 
259. Amend Sec.  1054.301 by revising paragraph (a)(2) to read as  
follows:  
Sec.  1054.301  When must I test my production-line engines?  
    (a) * * *  
    (2) We may exempt small-volume emission families from routine  
testing under this subpart. Submit your request for approval as  
described in Sec.  1054.210. In your request, describe your basis for  
projecting a production volume below 5,000 units. We will approve your  
request if we agree that you have made good-faith estimates of your  
production volumes. You must promptly notify us if your actual  
production exceeds 5,000 units during the model year. If you exceed the  
production limit or if there is evidence of a nonconformity, we may  
require you to test production-line engines under this subpart, or  
under 40 CFR part 1068, subpart E, even if we have approved an  
exemption under this paragraph (a)(2).  
* * * * *  
0 
260. Amend Sec.  1054.310 by revising paragraphs (a)(1) introductory  
text, (a)(1)(iv), and (c)(2) introductory text to read as follows:  
Sec.  1054.310  How must I select engines for production-line testing?  
    (a) * * *  
    (1) For engine families with projected U.S.-directed production  
volume of at least 1,600, the test periods are defined as follows:  
* * * * *  
    (iv) If your annual production period is 301 days or longer, divide  
the annual production period evenly into four test periods. For  
example, if your annual production period is 392 days (56 weeks),  
divide the annual production period into four test periods of 98 days  
(14 weeks).  
* * * * *  
    (c) * * *  
    (2) Calculate the standard deviation, [sigma], for the test sample  
using the following formula:  
* * * * *  
0 
261. Amend Sec.  1054.315 by revising paragraph (a)(1) to read as  
follows:  
Sec.  1054.315  How do I know when my engine family fails the  
production-line testing requirements?  
* * * * *  
    (a) * * *  
    (1) Initial and final test results. Calculate and round the test  
results for each engine. If you do multiple tests on an engine in a  
given configuration  
[[Page 34522]]  
(without modifying the engine), calculate the initial results for each  
test, then add all the test results together and divide by the number  
of tests. Round this final calculated value for the final test results  
on that engine.  
* * * * *  
0 
262. Amend Sec.  1054.320 by adding paragraph (c) to read as follows:  
Sec.  1054.320  What happens if one of my production-line engines fails  
to meet emission standards?  
* * * * *  
    (c) Use test data from a failing engine for the compliance  
demonstration under Sec.  1054.315 as follows:  
    (1) Use the original, failing test results as described in Sec.   6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 192/2681054.315, whether or not you modify the engine or destroy it.  
    (2) Do not use test results from a modified engine as final test  
results under Sec.  1054.315, unless you change your production process  
for all engines to match the adjustments you made to the failing  
engine. If this occurs, count the modified engine as the next engine in  
the sequence, rather than averaging the results with the testing that  
occurred before modifying the engine.  
0 
263. Amend Sec.  1054.501 by revising paragraphs (b)(1) and (2) and  
(b)(4) introductory text to read as follows:  
Sec.  1054.501  How do I run a valid emission test?  
* * * * *  
    (b) * * *  
    (1) Measure the emissions of all exhaust constituents subject to  
emission standards as specified in Sec.  1054.505 and 40 CFR part 1065.  
Measure CO 2, N2O, and CH 4 as described  
in Sec.  1054.235. See Sec.  1054.650 for special provisions that apply  
for variable-speed engines (including engines shipped without  
governors).  
    (2) Use the appropriate fuels and lubricants specified in 40 CFR  
part 1065, subpart H, for all the testing we require in this part.  
Gasoline test fuel must meet the specifications in 40 CFR 1065.710(c),  
except as specified in Sec.  1054.145(n) and 40 CFR 1065.10 and  
1065.701. Use gasoline specified for general testing except as  
specified in paragraph (d) of this section. For service accumulation,  
use the test fuel or any commercially available fuel that is  
representative of the fuel that in-use engines will use. Note that  
Sec.  1054.145(n) allows for testing with gasoline test fuels specified  
by the California Air Resources Board for any individual engine family.  
* * * * *  
    (4) The provisions of 40 CFR 1065.405 describe how to prepare an  
engine for testing. However, you may consider emission levels stable  
without measurement after 12 hours of engine operation, except for the  
following special provisions that apply for engine families with a  
useful life of 300 hours or less:  
* * * * *  
0 
264. Amend Sec.  1054.505 by revising paragraph (b)(2) to read as  
follows:  
Sec.  1054.505  How do I test engines?  
* * * * *  
    (b) * * *  
    (2) For nonhandheld engines, use the six-mode duty cycle or the  
corresponding ramped-modal cycle described in paragraph (b) of appendix  
II of this part. Control engine speeds and torques during idle mode as  
specified in paragraph (c) of this section. Control engine speed during  
the full-load operating mode as specified in paragraph (d) of this  
section. For all other modes, control engine speed to within 5 percent  
of the nominal speed specified in paragraph (d) of this section or let  
the installed governor (in the production configuration) control engine  
speed. For all modes except idle, control torque as needed to meet the  
cycle-validation criteria in paragraph (a)(1) of this section. The  
governor may be adjusted before emission sampling to target the nominal  
speed identified in paragraph (d) of this section, but the installed  
governor must control engine speed throughout the emission-sampling  
period whether the governor is adjusted or not. Note that ramped-modal  
testing involves continuous sampling, so governor adjustments may not  
occur during such a test. Note also that our testing may involve  
running the engine with the governor in the standard configuration even  
if you adjust the governor as described in this paragraph (b)(2) for  
certification or production-line testing.  
* * * * *  
0 
265. Amend Sec.  1054.601 by adding paragraph (d) to read as follows:  
Sec.  1054.601  What compliance provisions apply?  
* * * * *  
    (d) Subpart C of this part describes how to test and certify dual-  
fuel and flexible-fuel engines. Some multi-fuel engines may not fit the  
definitions in this part of either dual-fuel or flexible-fuel. For such  
engines, we will determine whether it is most appropriate to treat them  
as single-fuel engines, dual-fuel engines, or flexible-fuel engines  
based on the range of possible and expected fuel mixtures.  
0 
266. Amend Sec.  1054.612 by revising the introductory text to read as  
follows:  
Sec.  1054.612  What special provisions apply for equipment  
manufacturers modifying certified nonhandheld engines?  
    The provisions of this section are limited to small-volume emission  
families.  
* * * * *  
0 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 193/268267. Amend Sec.  1054.620 by revising paragraph (c)(2) to read as  
follows:  
Sec.  1054.620  What are the provisions for exempting engines used  
solely for competition?  
* * * * *  
    (c) * * *  
    (2) Sale of the equipment in which the engine is installed must be  
limited to professional competition teams, professional competitors, or  
other qualified competitors. Engine manufacturers may sell loose  
engines to these same qualified competitors, and to equipment  
manufacturers supplying competition models for qualified competitors.  
* * * * *  
Sec.  Sec.  1054.625 and 1054.626  [Removed]  
0 
268. Remove Sec. Sec.  1054.625 and 1054.626.  
Sec.  1054.635  [Amended]  
0 
269. Amend Sec.  1054.635 by removing and reserving paragraph (c)(6).  
Sec.  1054.640  [Removed]  
0 
270. Remove Sec.  1054.640.  
0 
271. Revise Sec.  1054.655 to read as follows:  
Sec.  1054.655  What special provisions apply for installing and  
removing altitude kits?  
    An action for the purpose of installing or modifying altitude kits  
and performing other changes to compensate for changing altitude is not  
considered a prohibited act under 40 CFR 1068.101(b) if it is done  
consistent with the manufacturer's instructions.  
0 
272. Amend Sec.  1054.690 by revising paragraphs (f) and (i) to read as  
follows:  
Sec.  1054.690  What bond requirements apply for certified engines?  
* * * * *  
    (f) If you are required to post a bond under this section, you must  
get the bond from a third-party surety that is cited in the U.S.  
Department of Treasury Circular 570, ``Companies Holding Certificates  
of Authority as Acceptable Sureties on Federal Bonds and as Acceptable  
Reinsuring Companies'' ( https://www.fiscal.treasury.gov/surety-bonds/circular-570.html ). You must maintain this bond for every year in which  
you sell certified engines. The surety agent remains responsible for  
obligations under the bond for two years  
[[Page 34523]]  
after the bond is cancelled or expires without being replaced.  
* * * * *  
    (i) If you are required to post a bond under this section, you must  
note that in your application for certification as described in Sec.   
1054.205. Your certification is conditioned on your compliance with  
this section. Your certificate is automatically suspended if you fail  
to comply with the requirements of this section. This suspension  
applies with respect to all engines in your possession as well as all  
engines being imported or otherwise introduced into U.S. commerce. For  
example, if you maintain a bond sufficient to cover 500 engines, you  
may introduce into U.S. commerce only 500 engines under your  
certificate; your certificate would be automatically suspended for any  
additional engines. Introducing such additional engines into U.S.  
commerce would violate 40 CFR 1068.101(a)(1). For importation, U.S.  
Customs may deny entry of engines lacking the necessary bond, whether  
there is no bond or the value of the bond is not sufficient for the  
appropriate production volumes. We may also revoke your certificate.  
* * * * *  
0 
273. Amend Sec.  1054.701 by revising paragraphs (c)(2), (i)  
introductory text, and (i)(1) to read as follows:  
Sec.  1054.701  General provisions.  
* * * * *  
    (c) * * *  
    (2) Handheld engines and nonhandheld engines are in separate  
averaging sets with respect to exhaust emissions except as specified in  
Sec.  1054.740(e). You may use emission credits generated with Phase 2  
engines for Phase 3 handheld engines only if you can demonstrate that  
those credits were generated by handheld engines, except as specified  
in Sec.  1054.740(e). Similarly, you may use emission credits generated  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 194/268with Phase 2 engines for Phase 3 nonhandheld engines only if you can  
demonstrate that those credits were generated by nonhandheld engines,  
subject to the provisions of Sec.  1054.740.  
* * * * *  
    (i) As described in Sec.  1054.730, compliance with the  
requirements of this subpart is determined at the end of the model year  
based on actual U.S.-directed production volumes. Do not include any of  
the following engines or equipment to calculate emission credits:  
    (1) Engines or equipment with a permanent exemption under subpart G  
of this part or under 40 CFR part 1068.  
* * * * *  
0 
274. Amend Sec.  1054.710 by revising paragraph (c) to read as follows:  
Sec.  1054.710  How do I average emission credits?  
* * * * *  
    (c) If you certify a family to an FEL that exceeds the otherwise  
applicable standard, you must obtain enough emission credits to offset  
the family's deficit by the due date for the final report required in  
Sec.  1054.730. The emission credits used to address the deficit may  
come from your other families that generate emission credits in the  
same model year, from emission credits you have banked from previous  
model years, or from emission credits generated in the same or previous  
model years that you obtained through trading.  
0 
275. Amend Sec.  1054.715 by revising paragraph (b) to read as follows:  
Sec.  1054.715  How do I bank emission credits?  
* * * * *  
    (b) You may designate any emission credits you plan to bank in the  
reports you submit under Sec.  1054.730 as reserved credits. During the  
model year and before the due date for the final report, you may  
designate your reserved emission credits for averaging or trading.  
* * * * *  
0 
276. Amend Sec.  1054.725 by revising paragraph (b)(2) to read as  
follows:  
Sec.  1054.725  What must I include in my application for  
certification?  
* * * * *  
    (b) * * *  
    (2) Detailed calculations of projected emission credits (positive  
or negative) based on projected production volumes. We may require you  
to include similar calculations from your other engine families to  
demonstrate that you will be able to avoid negative credit balances for  
the model year. If you project negative emission credits for a family,  
state the source of positive emission credits you expect to use to  
offset the negative emission credits.  
0 
277. Amend Sec.  1054.730 by revising paragraphs (b)(1), (3), and (4),  
(d)(1)(iii), and (d)(2)(iii) to read as follows:  
Sec.  1054.730  What ABT reports must I send to EPA?  
* * * * *  
    (b) * * *  
    (1) Family designation and averaging set.  
* * * * *  
    (3) The FEL for each pollutant. If you change the FEL after the  
start of production, identify the date that you started using the new  
FEL and/or give the engine identification number for the first engine  
covered by the new FEL. In this case, identify each applicable FEL and  
calculate the positive or negative emission credits as specified in  
Sec.  1054.225.  
    (4) The projected and actual U.S.-directed production volumes for  
the model year as described in Sec.  1054.701(i). For fuel tanks, state  
the production volume in terms of surface area and production volume  
for each fuel tank configuration and state the total surface area for  
the emission family. If you changed an FEL during the model year,  
identify the actual U.S.-directed production volume associated with  
each FEL.  
* * * * *  
    (d) * * *  
    (1) * * *  
    (iii) The averaging set corresponding to the families that  
generated emission credits for the trade, including the number of  
emission credits from each averaging set.  
    (2) * * *  
    (iii) How you intend to use the emission credits, including the  
number of emission credits you intend to apply for each averaging set.  
* * * * *  
0 
278. Amend Sec.  1054.735 by revising paragraphs (a) and (b) to read as  
follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 195/268Sec.  1054.735  What records must I keep?  
    (a) You must organize and maintain your records as described in  
this section.  
    (b) Keep the records required by this section for at least eight  
years after the due date for the end-of-year report. You may not use  
emission credits for any engines or equipment if you do not keep all  
the records required under this section. You must therefore keep these  
records to continue to bank valid credits.  
* * * * *  
0 
279. Amend Sec.  1054.740 by revising paragraph (c) and removing and  
reserving paragraph (d) to read as follows:  
Sec.  1054.740  What special provisions apply for generating and using  
emission credits?  
* * * * *  
    (c) You may not use emission credits generated by nonhandheld  
engines certified to Phase 2 emission standards to demonstrate  
compliance with the Phase 3 exhaust emission standards in 2014 and  
later model years.  
* * * * *  
0 
280. Amend Sec.  1054.801 by:  
0 
a. Revising the definition for ``Designated Compliance Officer''.  
0 
b. Removing the definition for ``Dual-fuel engine''.  
[[Page 34524]]  
0 
c. Adding a definition for ``Dual-fuel'' in alphabetical order.  
0 
d. Revising the definitions for ``Engine configuration'' and  
``Equipment manufacturer''.  
0 
e. Removing the definition for ``Flexible-fuel engine''.  
0 
f. Adding a definition for ``Flexible-fuel'' in alphabetical order.  
0 
g. Revising the definitions for ``Fuel type'', ``Handheld'', ``New  
nonroad engine'', ``New nonroad equipment'', ``Nonmethane  
hydrocarbon'', ``Nonroad engine'', ``Phase 1'', ``Phase 2'', and  
``Placed into service''.  
0 
h. Removing the definition for ``Pressurized oil system''.  
0 
i. Revising the definitions for ``Small-volume emission family'',  
``Small-volume equipment manufacturer'', ``Total hydrocarbon'', and  
``Total hydrocarbon equivalent''.  
    The revisions and additions read as follows:  
Sec.  1054.801  What definitions apply to this part?  
* * * * *  
    Designated Compliance Officer means the Director, Gasoline Engine  
Compliance Center, U.S. Environmental Protection Agency, 2000  
Traverwood Drive, Ann Arbor, MI 48105; complianceinfo@epa.gov . 
* * * * *  
    Dual-fuel means relating to an engine designed for operation on two  
different fuels but not on a continuous mixture of those fuels (see  
Sec.  1054.601(d)). For purposes of this part, such an engine remains a  
dual-fuel engine even if it is designed for operation on three or more  
different fuels.  
* * * * *  
    Engine configuration means a unique combination of engine hardware  
and calibration within an emission family. Engines within a single  
engine configuration differ only with respect to normal production  
variability or factors unrelated to emissions.  
* * * * *  
    Equipment manufacturer means a manufacturer of nonroad equipment.  
All nonroad equipment manufacturing entities under the control of the  
same person are considered to be a single nonroad equipment  
manufacturer.  
* * * * *  
    Flexible-fuel means relating to an engine designed for operation on  
any mixture of two or more different fuels (see Sec.  1054.601(d)).  
* * * * *  
    Fuel type means a general category of fuels such as gasoline or  
natural gas. There can be multiple grades within a single fuel type,  
such as premium gasoline, regular gasoline, or low-level ethanol-  
gasoline blends.  
* * * * *  
    Handheld means relating to equipment that meets any of the  
following criteria:  
    (1) It is carried by the operator throughout the performance of its  
intended function.  
    (2) It is designed to operate multi-positionally, such as upside  
down or sideways, to complete its intended function.  
    (3) It has a combined engine and equipment dry weight under 16.0  
kilograms, has no more than two wheels, and at least one of the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 196/268following attributes is also present:  
    (i) The operator provides support or carries the equipment  
throughout the performance of its intended function. Carry means to  
completely bear the weight of the equipment, including the engine.  
Support means to hold a piece of equipment in position to prevent it  
from falling, slipping, or sinking, without carrying it.  
    (ii) The operator provides support or attitudinal control for the  
equipment throughout the performance of its intended function.  
Attitudinal control involves regulating the horizontal or vertical  
position of the equipment.  
    (4) It is an auger with a combined engine and equipment dry weight  
under 22.0 kilograms.  
    (5) It is used in a recreational application with a combined total  
vehicle dry weight under 20.0 kilograms.  
    (6) It is a hand-supported jackhammer or rammer/compactor. This  
does not include equipment that can remain upright without operator  
support, such as a plate compactor.  
* * * * *  
    New nonroad engine means any of the following things:  
    (1) A freshly manufactured nonroad engine for which the ultimate  
purchaser has never received the equitable or legal title. This kind of  
engine might commonly be thought of as ``brand new.'' In the case of  
this paragraph (1), the engine is new from the time it is produced  
until the ultimate purchaser receives the title or the product is  
placed into service, whichever comes first.  
    (2) An engine originally manufactured as a motor vehicle engine or  
a stationary engine that is later used or intended to be used in a  
piece of nonroad equipment. In this case, the engine is no longer a  
motor vehicle or stationary engine and becomes a ``new nonroad  
engine.'' The engine is no longer new when it is placed into nonroad  
service. This paragraph (2) applies if a motor vehicle engine or a  
stationary engine is installed in nonroad equipment, or if a motor  
vehicle or a piece of stationary equipment is modified (or moved) to  
become nonroad equipment.  
    (3) A nonroad engine that has been previously placed into service  
in an application we exclude under Sec.  1054.5, when that engine is  
installed in a piece of equipment that is covered by this part. The  
engine is no longer new when it is placed into nonroad service covered  
by this part. For example, this paragraph (3) would apply to a marine-  
propulsion engine that is no longer used in a marine vessel but is  
instead installed in a piece of nonroad equipment subject to the  
provisions of this part.  
    (4) An engine not covered by paragraphs (1) through (3) of this  
definition that is intended to be installed in new nonroad equipment.  
This generally includes installation of used engines in new equipment.  
The engine is no longer new when the ultimate purchaser receives a  
title for the equipment or the product is placed into service,  
whichever comes first.  
    (5) An imported nonroad engine, subject to the following  
provisions:  
    (i) An imported nonroad engine covered by a certificate of  
conformity issued under this part that meets the criteria of one or  
more of paragraphs (1) through (4) of this definition, where the  
original engine manufacturer holds the certificate, is new as defined  
by paragraphs (1) through (4).  
    (ii) An imported engine that will be covered by a certificate of  
conformity issued under this part, where someone other than the  
original engine manufacturer holds the certificate (such as when the  
engine is modified after its initial assembly), is a new nonroad engine  
when it is imported. It is no longer new when the ultimate purchaser  
receives a title for the engine or it is placed into service, whichever  
comes first.  
    (iii) An imported nonroad engine that is not covered by a  
certificate of conformity issued under this part at the time of  
importation is new. This paragraph (5)(iii) addresses uncertified  
engines and equipment initially placed into service that someone seeks  
to import into the United States. Importation of this kind of engine  
(or equipment containing such an engine) is generally prohibited by 40  
CFR part 1068. However, the importation of such an engine is not  
prohibited if the engine has a date of manufacture before January 1,  
1997, since it is not subject to standards.  
    New nonroad equipment means either of the following things:  
[[Page 34525]]  
    (1) A nonroad piece of equipment for which the ultimate purchaser  
has never received the equitable or legal title. The product is no  
longer new when the ultimate purchaser receives this title or the  
product is placed into service, whichever comes first.  
    (2) A nonroad piece of equipment with an engine that becomes new  
while installed in the equipment. For example, a complete piece of  
equipment that was imported without being covered by a certificate of  
conformity would be new nonroad equipment because the engine would be  
considered new at the time of importation.  
* * * * *  
    Nonmethane hydrocarbon has the meaning given in 40 CFR 1065.1001.  
This generally means the difference between the emitted mass of total  
hydrocarbon and the emitted mass of methane.  
* * * * *  
    Nonroad engine has the meaning given in 40 CFR 1068.30. In general,  
this means all internal-combustion engines except motor vehicle  
engines, stationary engines, engines used solely for competition, or  
engines used in aircraft.  
* * * * *  
    Phase 1 means relating to the Phase 1 emission standards described  
in appendix I of this part.  
    Phase 2 means relating to the Phase 2 emission standards described  
in appendix I of this part.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 197/268* * * * *  
    Placed into service means put into initial use for its intended  
purpose. Engines and equipment do not qualify as being ``placed into  
service'' based on incidental use by a manufacturer or dealer.  
* * * * *  
    Small-volume emission family means one of the following:  
    (1) For requirements related to exhaust emissions for nonhandheld  
engines and to exhaust and evaporative emissions for handheld engines,  
small-volume emission family means any emission family whose U.S.-  
directed production volume in a given model year is projected at the  
time of certification to be no more than 5,000 engines or pieces of  
equipment.  
    (2) For requirements related to evaporative emissions for  
nonhandheld equipment, small-volume emission family means any equipment  
manufacturer's U.S.-directed production volume for identical fuel tank  
is projected at the time of certification to be no more than 5,000  
units. Tanks are generally considered identical if they are produced  
under a single part number to conform to a single design or blueprint.  
Tanks should be considered identical if they differ only with respect  
to production variability, post-production changes (such as different  
fittings or grommets), supplier, color, or other extraneous design  
variables.  
* * * * *  
    Small-volume equipment manufacturer means one of the following:  
    (1) For handheld equipment, an equipment manufacturer that had a  
U.S.-directed production volume of no more than 25,000 pieces of  
handheld equipment in any calendar year. For manufacturers owned by a  
parent company, this production limit applies to the production of the  
parent company and all its subsidiaries.  
    (2) For nonhandheld equipment, an equipment manufacturer with  
annual U.S.-directed production volumes of no more than 5,000 pieces of  
nonhandheld equipment in any calendar year. For manufacturers owned by  
a parent company, this production limit applies to the production of  
the parent company and all its subsidiaries.  
    (3) An equipment manufacturer that we designate to be a small-  
volume equipment manufacturer under Sec.  1054.635.  
* * * * *  
    Total hydrocarbon has the meaning given in 40 CFR 1065.1001. This  
generally means the combined mass of organic compounds measured by the  
specified procedure for measuring total hydrocarbon, expressed as an  
atomic hydrocarbon with an atomic hydrogen-to-carbon ratio of 1.85:1.  
    Total hydrocarbon equivalent has the meaning given in 40 CFR  
1065.1001. This generally means the sum of the carbon mass  
contributions of non-oxygenated hydrocarbon, alcohols and aldehydes, or  
other organic compounds that are measured separately as contained in a  
gas sample, expressed as exhaust hydrocarbon from petroleum-fueled  
engines. The atomic hydrogen-to-carbon ratio of the equivalent  
hydrocarbon is 1.85:1.  
* * * * *  
0 
281. Revise Sec.  1054.815 to read as follows:  
Sec.  1054.815  What provisions apply to confidential information?  
    The provisions of 40 CFR 1068.10 apply for information you consider  
confidential.  
0 
282. Revise Sec.  1054.825 to read as follows:  
Sec.  1054.825  What reporting and recordkeeping requirements apply  
under this part?  
    (a) This part includes various requirements to submit and record  
data or other information. Unless we specify otherwise, store required  
records in any format and on any media and keep them readily available  
for eight years after you send an associated application for  
certification, or eight years after you generate the data if they do  
not support an application for certification. We may request these  
records at any time. You must promptly give us organized, written  
records in English if we ask for them. This requirement to give us  
records applies whether or not you rely on someone else to keep records  
on your behalf. We may require you to submit written records in an  
electronic format.  
    (b) The regulations in Sec.  1054.255 and 40 CFR 1068.25 and  
1068.101 describe your obligation to report truthful and complete  
information. This includes information not related to certification.  
Failing to properly report information and keep the records we specify  
violates 40 CFR 1068.101(a)(2), which may involve civil or criminal  
penalties.  
    (c) Send all reports and requests for approval to the Designated  
Compliance Officer (see Sec.  1054.801).  
    (d) Any written information we require you to send to or receive  
from another company is deemed to be a required record under this  
section. Such records are also deemed to be submissions to EPA. We may  
require you to send us these records.  
    (e) Under the Paperwork Reduction Act (44 U.S.C. 3501 et seq.,),  
the Office of Management and Budget approves the reporting and  
recordkeeping specified in the applicable regulations in this chapter.  
The following items illustrate the kind of reporting and recordkeeping  
we require for engines and equipment regulated under this part:  
    (1) We specify the following requirements related to engine and  
equipment certification in this part:  
    (i) In Sec.  1054.20 we require equipment manufacturers to label  
their equipment if they are relying on component certification.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 198/268    (ii) In Sec.  1054.135 we require engine manufacturers to keep  
certain records related to duplicate labels sent to equipment  
manufacturers.  
    (iii) In Sec.  1054.145 we include various reporting and  
recordkeeping requirements related to interim provisions.  
    (iv) In subpart C of this part we identify a wide range of  
information required to certify engines.  
[[Page 34526]]  
    (v) In Sec. Sec.  1054.345 and 1054.350 we specify certain records  
related to production-line testing.  
    (vi) [Reserved]  
    (vii) In subpart G of this part we identify several reporting and  
recordkeeping items for making demonstrations and getting approval  
related to various special compliance provisions.  
    (viii) In Sec. Sec.  1054.725, 1054.730, and 1054.735 we specify  
certain records related to averaging, banking, and trading.  
    (2) We specify the following requirements related to component and  
equipment certification in 40 CFR part 1060:  
    (i) In 40 CFR 1060.20 we give an overview of principles for  
reporting information.  
    (ii) In 40 CFR part 1060, subpart C, we identify a wide range of  
information required to certify products.  
    (iii) In 40 CFR 1060.301 we require manufacturers to keep records  
related to evaluation of production samples for verifying that the  
products are as specified in the certificate of conformity.  
    (iv) In 40 CFR 1060.310 we require manufacturers to make  
components, engines, or equipment available for our testing if we make  
such a request.  
    (v) In 40 CFR 1060.505 we specify information needs for  
establishing various changes to published test procedures.  
    (3) We specify the following requirements related to testing in 40  
CFR part 1065:  
    (i) In 40 CFR 1065.2 we give an overview of principles for  
reporting information.  
    (ii) In 40 CFR 1065.10 and 1065.12 we specify information needs for  
establishing various changes to published test procedures.  
    (iii) In 40 CFR 1065.25 we establish basic guidelines for storing  
test information.  
    (iv) In 40 CFR 1065.695 we identify the specific information and  
data items to record when measuring emissions.  
    (4) We specify the following requirements related to the general  
compliance provisions in 40 CFR part 1068:  
    (i) In 40 CFR 1068.5 we establish a process for evaluating good  
engineering judgment related to testing and certification.  
    (ii) In 40 CFR 1068.25 we describe general provisions related to  
sending and keeping information.  
    (iii) In 40 CFR 1068.27 we require manufacturers to make engines  
available for our testing or inspection if we make such a request.  
    (iv) In 40 CFR 1068.105 we require equipment manufacturers to keep  
certain records related to duplicate labels from engine manufacturers.  
    (v) In 40 CFR 1068.120 we specify recordkeeping related to  
rebuilding engines.  
    (vi) In 40 CFR part 1068, subpart C, we identify several reporting  
and recordkeeping items for making demonstrations and getting approval  
related to various exemptions.  
    (vii) In 40 CFR part 1068, subpart D, we identify several reporting  
and recordkeeping items for making demonstrations and getting approval  
related to importing engines.  
    (viii) In 40 CFR 1068.450 and 1068.455 we specify certain records  
related to testing production-line engines in a selective enforcement  
audit. 
    (ix) In 40 CFR 1068.501 we specify certain records related to  
investigating and reporting emission-related defects.  
    (x) In 40 CFR 1068.525 and 1068.530 we specify certain records  
related to recalling nonconforming engines.  
    (xi) In 40 CFR part 1068, subpart G, we specify certain records for  
requesting a hearing.  
0 
283. Revise appendix I to part 1054 to read as follows:  
Appendix I to Part 1054--Summary of Previous Emission Standards  
    The following standards, which EPA originally adopted under 40  
CFR part 90, apply to nonroad spark-ignition engines produced before  
the model years specified in Sec.  1054.1:  
    (a) Handheld engines. (1) Phase 1 standards apply for handheld  
engines as summarized in the following table starting with model  
year 1997:  
                     Table 1 to Appendix I--Phase 1 Emission Standards for Handheld Engines  
                                                  [g/kW-hr] \a\  
----------------------------------------------------------------------------------------------------------------  
                    Engine displacement class                           HC              NOX             CO  
----------------------------------------------------------------------------------------------------------------  
Class III.......................................................             295            5.36             805  
Class IV........................................................             241            5.36             805  
Class V.........................................................             161            5.36             603  
----------------------------------------------------------------------------------------------------------------  
\a\ Phase 1 standards are based on testing with new engines only.  
    (2) Phase 2 standards apply for handheld engines as summarized  
in the following table starting with model year 2002 for Class III  
and Class IV, and starting in model year 2004 for Class V:  
 Table 2 to Appendix I--Phase 2 Emission Standards for Handheld Engines  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 199/268                                [g/kW-hr]  
------------------------------------------------------------------------  
        Engine displacement class            HC + NOX           CO  
------------------------------------------------------------------------  
Class III...............................          \a\ 50             805  
Class IV................................          \b\ 50             805  
Class V.................................          \c\ 72             603  
------------------------------------------------------------------------  
\a\ Class III engines had alternate HC+NOX standards of 238, 175, and  
  113 for model years 2002, 2003, and 2004, respectively.  
\b\ Class IV engines had alternate HC+NOX standards of 196, 148, and 99  
  for model years 2002, 2003, and 2004, respectively.  
\c\ Class V engines had alternate HC+NOX standards of 143, 119, and 96  
  for model years 2004, 2005, and 2006, respectively.  
    (b) Nonhandheld engines. (1) Phase 1 standards apply for  
nonhandheld engines as summarized in the following table starting  
with model year 1997:  
[[Page 34527]]  
    Table 3 to Appendix I--Phase 1 Emission Standards for Nonhandheld  
                                 Engines  
                              [g/kW-hr] \a\  
------------------------------------------------------------------------  
        Engine displacement class            HC + NOX           CO  
------------------------------------------------------------------------  
Class I.................................            16.1             519  
Class II................................            13.4             519  
------------------------------------------------------------------------  
\a\ Phase 1 standards are based on testing with new engines only.  
    (2) Phase 2 standards apply for nonhandheld engines as  
summarized in the following table starting with model year 2001  
(except as noted for Class I engines):  
                    Table 4 to Appendix I--Phase 2 Emission Standards for Nonhandheld Engines  
                                                    [g/kW-hr]  
----------------------------------------------------------------------------------------------------------------  
                    Engine displacement class                        HC + NOX       NMHC + NOX          CO  
----------------------------------------------------------------------------------------------------------------  
Class I-A.......................................................              50  ..............             610  
Class I-B.......................................................              40              37             610  
Class I \a\.....................................................            16.1            14.8             610  
Class II \b\....................................................            12.1            11.3             610  
----------------------------------------------------------------------------------------------------------------  
\a\ The Phase 2 standards for Class I engines apply for new engines produced starting August 1, 2007, and for  
  any engines belonging to an engine model whose original production date was on or after August 1, 2003.  
\b\ Class II engines had alternate HC + NOX standards of 18.0, 16.6, 15.0, 13.6 and alternate NMHC + NOX  
  standards of 16.7, 15.3, 14.0, 12.7 for model years 2001 through 2004, respectively.  
    (3) Note that engines subject to Phase 1 standards were not  
subject to useful life provisions as specified in Sec.  1054.107. In  
addition, engines subject to Phase 1 standards and engines subject  
to Phase 2 standards were both not subject to the following  
provisions:  
    (i) Evaporative emission standards as specified in Sec. Sec.   
1054.110 and 1054.112.  
    (ii) Altitude adjustments as specified in Sec.  1054.115(c).  
    (iii) Warranty assurance provisions as specified in Sec.   
1054.120(f).  
    (iv) Emission-related installation instructions as specified in  
Sec.  1054.130.  
    (v) Bonding requirements as specified in Sec.  1054.690.  
0 
284. Amend appendix II to part 1054 by revising paragraph (b)(2) to  
read as follows:  
Appendix II to Part 1054--Duty Cycles for Laboratory Testing  
* * * * *  
    (b) * * *  
    (2) The following duty cycle applies for ramped-modal testing:  
                       Table 3 to Paragraph (b)(2)  
------------------------------------------------------------------------  
                                  Time in mode    Torque  (percent) b c  
          RMC mode \a\              (seconds)  
------------------------------------------------------------------------  
1a Steady-state................              41  0.  
1b Transition..................              20  Linear transition.  
2a Steady-state................             135  100.  
2b Transition..................              20  Linear transition.  
3a Steady-state................             112  10.  
3b Transition..................              20  Linear transition.  
4a Steady-state................             337  75.  
4b Transition..................              20  Linear transition.  
5a Steady-state................             518  25.  
5b Transition..................              20  Linear transition.  
6a Steady-state................             494  50.  
6b Transition..................              20  Linear transition.  
7 Steady-state.................              43  0.  
------------------------------------------------------------------------  
\a\ Control engine speed as described in Sec.   1054.505. Control engine  
  speed for Mode 6 as described in Sec.   1054.505(c) for idle  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 200/268  operation.  
\b\ Advance from one mode to the next within a 20-second transition  
  phase. During the transition phase, command a linear progression from  
  the torque setting of the current mode to the torque setting of the  
  next mode.  
\c\ The percent torque is relative to the value established for full-  
  load torque, as described in Sec.   1054.505.  
PART 1060--CONTROL OF EVAPORATIVE EMISSIONS FROM NEW AND IN-USE  
NONROAD AND STATIONARY EQUIPMENT  
0 
285. The authority citation for part 1060 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
286. Amend Sec.  1060.1 by revising paragraphs (a)(7), (c), and (d) to  
read as follows:  
Sec.  1060.1  Which products are subject to this part's requirements?  
    (a) * * *  
    (7) Portable nonroad fuel tanks are considered portable marine fuel  
tanks for purposes of this part. Portable nonroad fuel tanks and fuel  
lines associated with such fuel tanks must therefore meet evaporative  
emission standards specified in 40 CFR 1045.112, whether or not they  
are used with marine vessels.  
* * * * *  
[[Page 34528]]  
    (c) Fuel caps are subject to evaporative emission standards at the  
point of installation on a fuel tank. When a fuel cap is certified for  
use with Marine SI engines or Small SI engines under the optional  
standards of Sec.  1060.103, it becomes subject to all the requirements  
of this part as if these optional standards were mandatory.  
    (d) This part does not apply to any diesel-fueled engine or any  
other engine that does not use a volatile liquid fuel. In addition,  
this part does not apply to any engines or equipment in the following  
categories even if they use a volatile liquid fuel:  
    (1) Light-duty motor vehicles (see 40 CFR part 86).  
    (2) Heavy-duty motor vehicles and heavy-duty motor vehicle engines  
(see 40 CFR part 86). This part also does not apply to fuel systems for  
nonroad engines where such fuel systems are subject to part 86 because  
they are part of a heavy-duty motor vehicle.  
    (3) Aircraft engines (see 40 CFR part 87).  
    (4) Locomotives (see 40 CFR part 1033).  
* * * * *  
0 
287. Amend Sec.  1060.5 by revising paragraph (a)(1) to read as  
follows:  
Sec.  1060.5  Do the requirements of this part apply to me?  
* * * * *  
    (a) * * *  
    (1) Each person meeting the definition of manufacturer (see Sec.   
1060.801) for a product that is subject to the standards and other  
requirements of this part must comply with such requirements. However,  
if one person complies with a specific requirement for a given product,  
then all manufacturers are deemed to have complied with that specific  
requirement. For example, if a Small SI equipment manufacturer uses  
fuel lines manufactured and certified by another company, the equipment  
manufacturer is not required to obtain its own certificate with respect  
to the fuel line emission standards. Such an equipment manufacturer  
remains subject to the standards and other requirements of this part.  
However, where a provision in this part requires a specific  
manufacturer to comply with certain provisions, this paragraph (a) does  
not change or modify such a requirement. For example, this paragraph  
(a) does not allow you to rely on another company to certify instead of  
you if we specifically require you to certify.  
* * * * *  
0 
288. Revise Sec.  1060.30 to read as follows:  
Sec.  1060.30  Submission of information.  
    Unless we specify otherwise, send all reports and requests for  
approval to the Designated Compliance Officer (see Sec.  1060.801). See  
Sec.  1060.825 for additional reporting and recordkeeping provisions.  
0 
289. Amend Sec.  1060.104 by revising paragraph (b)(3) to read as  
follows:  
Sec.  1060.104  What running loss emission control requirements apply?  
* * * * *  
    (b) * * *  
    (3) Get an approved executive order or other written approval from  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 201/268the California Air Resources Board showing that your system meets  
applicable running loss standards in California.  
* * * * *  
0 
290. Amend Sec.  1060.105 by revising paragraphs (c)(1) and (e) to read  
as follows:  
Sec.  1060.105  What diurnal requirements apply for equipment?  
* * * * *  
    (c) * * *  
    (1) They must be self-sealing when detached from the engines. The  
tanks may not vent to the atmosphere when attached to an engine, except  
as allowed under paragraph (c)(2) of this section. An integrated or  
external manually activated device may be included in the fuel tank  
design to temporarily relieve pressure before refueling or connecting  
the fuel tank to the engine. However, the default setting for such a  
vent must be consistent with the requirement in paragraph (c)(2) of  
this section.  
* * * * *  
    (e) Manufacturers of nonhandheld Small SI equipment may optionally  
meet the diurnal emission standards adopted by the California Air  
Resources Board. To meet the requirement in this paragraph (e),  
equipment must be certified to the performance standards specified in  
Title 13 California Code of Regulations (CCR) 2754(a) based on the  
applicable requirements specified in CP-902 and TP-902, including the  
requirements related to fuel caps in Title 13 CCR 2756. Equipment  
certified under this paragraph (e) does not need to use fuel lines or  
fuel tanks that have been certified separately. Equipment certified  
under this paragraph (e) are subject to all the referenced requirements  
in this paragraph (e) as if these specifications were mandatory.  
* * * * *  
0 
291. Amend Sec.  1060.120 by revising paragraphs (b) and (c) to read as  
follows:  
Sec.  1060.120  What emission-related warranty requirements apply?  
* * * * *  
    (b) Warranty period. Your emission-related warranty must be valid  
for at least two years from the date the equipment is sold to the  
ultimate purchaser.  
    (c) Components covered. The emission-related warranty covers all  
components whose failure would increase the evaporative emissions,  
including those listed in 40 CFR part 1068, appendix I, and those from  
any other system you develop to control emissions. Your emission-  
related warranty does not need to cover components whose failure would  
not increase evaporative emissions.  
* * * * *  
0 
292. Amend Sec.  1060.130 by revising paragraph (b)(3) to read as  
follows:  
Sec.  1060.130  What installation instructions must I give to equipment  
manufacturers?  
* * * * *  
    (b) * * *  
    (3) Describe how your certification is limited for any type of  
application. For example:  
    (i) For fuel tanks sold without fuel caps, you must specify the  
requirements for the fuel cap, such as the allowable materials, thread  
pattern, how it must seal, etc. You must also include instructions to  
tether the fuel cap as described in Sec.  1060.101(f)(1) if you do not  
sell your fuel tanks with tethered fuel caps. The following  
instructions apply for specifying a certain level of emission control  
for fuel caps that will be installed on your fuel tanks:  
    (A) If your testing involves a default emission value for fuel cap  
permeation as specified in Sec.  1060.520(b)(5)(ii)(C), specify in your  
installation instructions that installed fuel caps must either be  
certified with a Family Emission Limit at or below 30 g/m2/day, or have  
gaskets made of certain materials meeting the definition of ``low-  
permeability material'' in Sec.  1060.801.  
    (B) If you certify your fuel tanks based on a fuel cap certified  
with a Family Emission Limit above 30 g/m2/day, specify in your  
installation instructions that installed fuel caps must either be  
certified with a Family Emission Limit at or below the level you used  
for certifying your fuel tanks, or have gaskets made of certain  
materials meeting the definition of ``low-permeability material'' in  
Sec.  1060.801.  
    (ii) If your fuel lines do not meet permeation standards specified  
in Sec.  1060.102 for EPA Low-Emission Fuel Lines, tell equipment  
manufacturers not to install the fuel lines with Large SI engines that  
operate on gasoline or another volatile liquid fuel.  
* * * * *  
[[Page 34529]]  
0 
293. Amend Sec.  1060.135 by revising the introductory text and  
paragraphs (a), (b) introductory text, and (b)(2), (3), and (4) to read  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 202/268as follows:  
Sec.  1060.135  How must I label and identify the engines and equipment  
I produce?  
    The labeling requirements of this section apply for all equipment  
manufacturers that are required to certify their equipment or use  
certified fuel-system components. Note that engine manufacturers are  
also considered equipment manufacturers if they install a complete fuel  
system on an engine. See Sec.  1060.137 for the labeling requirements  
that apply separately for fuel lines, fuel tanks, and other fuel-system  
components.  
    (a) At the time of manufacture, you must affix a permanent and  
legible label identifying each engine or piece of equipment. The label  
must be--  
    (1) Attached in one piece so it is not removable without being  
destroyed or defaced.  
    (2) Secured to a part of the engine or equipment needed for normal  
operation and not normally requiring replacement.  
    (3) Durable and readable for the equipment's entire life.  
    (4) Written in English.  
    (5) Readily visible in the final installation. It may be under a  
hinged door or other readily opened cover. It may not be hidden by any  
cover attached with screws or any similar designs. Labels on marine  
vessels (except personal watercraft) must be visible from the helm.  
    (b) If you hold a certificate under this part for your engine or  
equipment, the engine or equipment label specified in paragraph (a) of  
this section must--  
* * * * *  
    (2) Include your corporate name and trademark. You may identify  
another company and use its trademark instead of yours if you comply  
with the branding provisions of 40 CFR 1068.45.  
    (3) State the date of manufacture [MONTH and YEAR] of the  
equipment; however, you may omit this from the label if you stamp,  
engrave, or otherwise permanently identify it elsewhere on the  
equipment, in which case you must also describe in your application for  
certification where you will identify the date on the equipment.  
    (4) State: ``THIS [equipment, vehicle, boat, etc.] MEETS U.S. EPA  
EVAP STANDARDS.''  
* * * * *  
0 
294. Amend Sec.  1060.137 by revising paragraphs (a)(4) and (c)(1) to  
read as follows:  
Sec.  1060.137  How must I label and identify the fuel-system  
components I produce?  
* * * * *  
    (a) * * *  
    (4) Fuel caps, as described in this paragraph (a)(4). Fuel caps  
must be labeled if they are separately certified under Sec.  1060.103.  
If the equipment has a diurnal control system that requires the fuel  
tank to hold pressure, identify the part number on the fuel cap.  
* * * * *  
    (c) * * *  
    (1) Include your corporate name. You may identify another company  
instead of yours if you comply with the provisions of 40 CFR 1068.45.  
* * * * *  
0 
295. Amend Sec.  1060.205 by revising paragraphs (a) and (m) to read as  
follows:  
Sec.  1060.205  What must I include in my application?  
* * * * *  
    (a) Describe the emission family's specifications and other basic  
parameters of the emission controls. Describe how you meet the running  
loss emission control requirements in Sec.  1060.104, if applicable.  
Describe how you meet any applicable equipment-based requirements of  
Sec.  1060.101(e) and (f). State whether you are requesting  
certification for gasoline or some other fuel type. List each  
distinguishable configuration in the emission family. For equipment  
that relies on one or more certified components, identify the EPA-  
issued emission family name for all the certified components.  
* * * * *  
    (m) Report all valid test results. Also indicate whether there are  
test results from invalid tests or from any other tests of the  
emission-data unit, whether or not they were conducted according to the  
test procedures of subpart F of this part. We may require you to report  
these additional test results. We may ask you to send other information  
to confirm that your tests were valid under the requirements of this  
part. 
* * * * *  
0 
296. Amend Sec.  1060.225 by revising paragraphs (b) and (g) and adding  
paragraph (h) to read as follows:  
Sec.  1060.225  How do I amend my application for certification?  
* * * * *  
    (b) To amend your application for certification, send the following  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 203/268relevant information to the Designated Compliance Officer.  
    (1) Describe in detail the addition or change in the configuration  
you intend to make.  
    (2) Include engineering evaluations or data showing that the  
amended emission family complies with all applicable requirements in  
this part. You may do this by showing that the original emission data  
are still appropriate for showing that the amended family complies with  
all applicable requirements in this part.  
    (3) If the original emission data for the emission family are not  
appropriate to show compliance for the new or modified configuration,  
include new test data showing that the new or modified configuration  
meets the requirements of this part.  
    (4) Include any other information needed to make your application  
correct and complete.  
* * * * *  
    (g) You may produce equipment or components as described in your  
amended application for certification and consider those equipment or  
components to be in a certified configuration if we approve a new or  
modified configuration during the model year or production period under  
paragraph (d) of this section. Similarly, you may modify in-use  
products as described in your amended application for certification and  
consider those products to be in a certified configuration if we  
approve a new or modified configuration at any time under paragraph (d)  
of this section. Modifying a new or in-use product to be in a certified  
configuration does not violate the tampering prohibition of 40 CFR  
1068.101(b)(1), as long as this does not involve changing to a  
certified configuration with a higher family emission limit.  
    (h) Component manufacturers may not change an emission family's FEL  
under any circumstances. Changing the FEL would require submission of a  
new application for certification.
0 
297. Amend Sec.  1060.230 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1060.230  How do I select emission families?  
* * * * *  
    (d) * * *  
    (2) Type of material (such as type of charcoal used in a carbon  
canister). This paragraph (d)(2) does not apply for materials that are  
unrelated to emission control performance.  
* * * * *  
0 
298. Amend Sec.  1060.235 by:  
0 
a. Revising the section heading.  
0 
b. Redesignating paragraphs (a) and (b) as paragraphs (b) and (a),  
respectively.  
0 
c. Revising paragraphs (d) and (e)(1).  
    The revisions read as follows:
[[Page 34530]]  
Sec.  1060.235  What testing requirements apply for certification?  
* * * * *  
    (d) We may perform confirmatory testing by measuring emissions from  
any of your products from the emission family, as follows:  
    (1) You must supply your products to us if we choose to perform  
confirmatory testing. We may require you to deliver your test articles  
to a facility we designate for our testing.  
    (2) If we measure emissions on one of your products, the results of  
that testing become the official emission results for the emission  
family. Unless we later invalidate these data, we may decide not to  
consider your data in determining if your emission family meets  
applicable requirements in this part.  
    (e) * * *  
    (1) The emission family from the previous production period differs  
from the current emission family only with respect to production  
period, items identified in Sec.  1060.225(a), or other characteristics  
unrelated to emissions. We may waive the criterion in this paragraph  
(e)(1) for differences we determine not to be relevant.  
* * * * *  
0 
299. Amend Sec.  1060.240 by revising paragraph (e)(2)(i) to read as  
follows:  
Sec.  1060.240  How do I demonstrate that my emission family complies  
with evaporative emission standards?  
* * * * *  
    (e) * * *  
    (2) * * *  
    (i) You may use the measurement procedures specified by the  
California Air Resources Board in Attachment 1 to TP-902 to show that  
canister working capacity is least 3.6 grams of vapor storage capacity  
per gallon of nominal fuel tank capacity (or 1.4 grams of vapor storage  
capacity per gallon of nominal fuel tank capacity for fuel tanks used  
in nontrailerable boats).  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 204/2680 
300. Amend Sec.  1060.250 by revising paragraphs (a)(3)(ii) and (b) to  
read as follows:  
Sec.  1060.250  What records must I keep?  
    (a) * * *  
    (3) * * *  
    (ii) All your emission tests (valid and invalid), including the  
date and purpose of each test and documentation of test parameters  
described in subpart F of this part.  
* * * * *  
    (b) Keep required data from emission tests and all other  
information specified in this section for eight years after we issue  
your certificate. If you use the same emission data or other  
information for a later model year, the eight-year period restarts with  
each year that you continue to rely on the information.  
* * * * *  
0 
301. Revise Sec.  1060.255 to read as follows:  
Sec.  1060.255  What decisions may EPA make regarding a certificate of  
conformity?  
    (a) If we determine an application is complete and shows that the  
emission family meets all the requirements of this part and the Clean  
Air Act, we will issue a certificate of conformity for the emission  
family for that production period. We may make the approval subject to  
additional conditions.  
    (b) We may deny an application for certification if we determine  
that an emission family fails to comply with emission standards or  
other requirements of this part or the Clean Air Act. We will base our  
decision on all available information. If we deny an application, we  
will explain why in writing.  
    (c) In addition, we may deny your application or suspend or revoke  
a certificate of conformity if you do any of the following:  
    (1) Refuse to comply with any testing or reporting requirements in  
this part.  
    (2) Submit false or incomplete information. This includes doing  
anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (3) Cause any test data to become inaccurate.  
    (4) Deny us from completing authorized activities (see 40 CFR  
1068.20). This includes a failure to provide reasonable assistance.  
    (5) Produce equipment or components for importation into the United  
States at a location where local law prohibits us from carrying out  
authorized activities.  
    (6) Fail to supply requested information or amend an application to  
include all equipment or components being produced.  
    (7) Take any action that otherwise circumvents the intent of the  
Clean Air Act or this part.  
    (d) We may void a certificate of conformity if you fail to keep  
records, send reports, or give us information as required under this  
part or the Clean Air Act. Note that these are also violations of 40  
CFR 1068.101(a)(2).  
    (e) We may void a certificate of conformity if we find that you  
intentionally submitted false or incomplete information. This includes  
doing anything after submitting an application that causes submitted  
information to be false or incomplete.  
    (f) If we deny an application or suspend, revoke, or void a  
certificate of conformity, you may ask for a hearing (see Sec.   
1060.820).  
0 
302. Amend Sec.  1060.501 by revising paragraph (c) to read as follows:  
Sec.  1060.501  General testing provisions.  
* * * * *  
    (c) The specification for gasoline to be used for testing is given  
in 40 CFR 1065.710(b) or (c). Use the grade of gasoline specified for  
general testing. For testing specified in this part that requires  
blending gasoline and ethanol, blend this grade of neat gasoline with  
fuel-grade ethanol meeting the specifications of ASTM D4806  
(incorporated by reference in Sec.  1060.810). You do not need to  
measure the ethanol concentration of such blended fuels and may instead  
calculate the blended composition by assuming that the ethanol is pure  
and mixes perfectly with the base fuel. For example, if you mix 10.0  
liters of fuel-grade ethanol with 90.0 liters of gasoline, you may  
assume the resulting mixture is 10.0 percent ethanol. You may use more  
pure or less pure ethanol if you can demonstrate that it will not  
affect your ability to demonstrate compliance with the applicable  
emission standards in subpart B of this part. Note that unless we  
specify otherwise, any references to gasoline-ethanol mixtures  
containing a specified ethanol concentration means mixtures meeting the  
provisions of this paragraph (c). The following table summarizes test  
fuel requirements for the procedures specified in this subpart:  
      Table 1 to Sec.   1060.501--Summary of Test Fuel Requirements  
------------------------------------------------------------------------  
            Procedure                  Reference         Test Fuel \a\  
------------------------------------------------------------------------  
Low-Emission Fuel Lines.........  Sec.   1060.510     CE10.  
Nonroad Fuel Lines..............  Sec.   1060.515     CE10 \b\.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 205/268Cold-Weather Fuel Lines.........  Sec.   1060.515     Splash-blended  
                                                       E10.  
Fuel tank and fuel cap            Sec.   1060.520     Splash-blended  
 permeation.                                           E10;  
                                                       manufacturers may  
                                                       instead use CE10.  
[[Page 34531]]  
  
Diurnal.........................  Sec.   1060.525     E0.  
------------------------------------------------------------------------  
\a\ Pre-mixed gasoline blends are specified in 40 CFR 1065.710(b).  
  Splash-blended gasoline blends are a mix of neat gasoline specified in  
  40 CFR 1065.710(c) and fuel-grade ethanol.  
\b\ Different fuel specifications apply for fuel lines tested under 40  
  CFR part 1051 for recreational vehicles, as described in 40 CFR  
  1051.501.  
* * * * *  
0 
303. Amend Sec.  1060.505 by revising paragraph (c)(3) to read as  
follows:  
Sec.  1060.505  Other procedures.  
* * * * *  
    (c) * * *  
    (3) You may request to use alternate procedures that are equivalent  
to the specified procedures, or procedures that are more accurate or  
more precise than the specified procedures. We may perform tests with  
your equipment using either the approved alternate procedures or the  
specified procedures. See 40 CFR 1065.12 for a description of the  
information that is generally required for such alternate procedures.  
* * * * *  
0 
304. Amend Sec.  1060.515 by revising paragraph (a)(2) to read as  
follows:  
Sec.  1060.515  How do I test EPA Nonroad Fuel Lines and EPA Cold-  
Weather Fuel Lines for permeation emissions?  
* * * * *  
    (a) * * *  
    (2) For EPA Cold-Weather Fuel Lines, use gasoline blended with  
ethanol as described in Sec.  1060.501(c).  
* * * * *  
0 
305. Amend Sec.  1060.520 by revising paragraphs (a), (b)(1) and (4),  
(d)(3) and (6), (d)(8)(ii), (d)(9), and (e) to read as follows:  
Sec.  1060.520  How do I test fuel tanks for permeation emissions?  
* * * * *  
    (a) Preconditioning durability testing. Take the following steps  
before an emission test, in any order, if your emission control  
technology involves surface treatment or other post-processing  
treatments such as an epoxy coating:  
    (1) Pressure cycling. Perform a pressure test by sealing the fuel  
tank and cycling it between +13.8 and -3.4 kPa (+2.0 and -0.5 psig) for  
10,000 cycles at a rate of 60 seconds per cycle. The purpose of this  
test is to represent environmental wall stresses caused by pressure  
changes and other factors (such as vibration or thermal expansion). If  
your fuel tank cannot be tested using the pressure cycles specified by  
this paragraph (a)(1), you may ask to use special test procedures under  
Sec.  1060.505.  
    (2) UV exposure. Perform a sunlight-exposure test by exposing the  
fuel tank to an ultraviolet light of at least 24 W/m2 (0.40 W-hr/m2/  
min) on the fuel tank surface for at least 450 hours. Alternatively,  
the fuel tank may be exposed to direct natural sunlight for an  
equivalent period of time as long as you ensure that the fuel tank is  
exposed to at least 450 daylight hours.  
    (3) Slosh testing. Perform a slosh test by filling the fuel tank to  
40-50 percent of its capacity with the fuel specified in paragraph (e)  
of this section and rocking it at a rate of 15 cycles per minute until  
you reach one million total cycles. Use an angle deviation of +15[deg]  
to -15[deg] from level. Take steps to ensure that the fuel remains at  
40-50 percent of its capacity throughout the test run.  
    (4) Cap testing. Perform durability cycles on fuel caps intended  
for use with handheld equipment by putting the fuel cap on and taking  
it off 300 times. Tighten the fuel cap each time in a way that  
represents the typical in-use experience.  
    (b) * * *  
    (1) Fill the fuel tank to its nominal capacity with the fuel  
specified in paragraph (e) of this section, seal it, and allow it to  
soak at 28 5 [deg]C for at least 20 weeks. Alternatively,  
the fuel tank may be soaked for at least 10 weeks at 43 5 [deg]C. You  
may count the time of the preconditioning steps in paragraph (a) of  
this section as part of the preconditioning fuel soak as long as the  
ambient temperature remains within the specified temperature range and  
the fuel tank continues to be at least 40 percent full throughout the  
test; you may add or replace fuel as needed to conduct the specified  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 206/268durability procedures. Void the test if you determine that the fuel  
tank has any kind of leak.  
* * * * *  
    (4) Allow the fuel tank and its contents to equilibrate to the  
temperatures specified in paragraph (d)(7) of this section. Seal the  
fuel tank as described in paragraph (b)(5) of this section once the  
fuel temperatures are stabilized at the test temperature. You must seal  
the fuel tank no more than eight hours after refueling. Until the fuel  
tank is sealed, take steps to minimize the vapor losses from the fuel  
tank, such as keeping the fuel cap loose on the fuel inlet or routing  
vapors through a vent hose.  
* * * * *  
    (d) * * *  
    (3) Carefully place the test tank within a temperature-controlled  
room or enclosure. Do not spill or add any fuel.  
* * * * *  
    (6) Leave the test tank in the room or enclosure for the duration  
of the test run, except that you may remove the tank for up to 30  
minutes at a time to meet weighing requirements.  
* * * * *  
    (8) * * *  
    (ii) If after ten days of testing your r2 value is below  
0.95 and your measured value is more than 50 percent of the applicable  
standard in subpart B of this part, continue testing for a total of 20  
days or until r2 is at or above 0.95. If r2 is  
not at or above 0.95 within 20 days of testing, discontinue the test  
and precondition the test tank further until it has stabilized emission  
levels, then repeat the testing.  
    (9) Record the difference in mass between the reference tank and  
the test tank for each measurement. This value is M i, where  
``i'' is a counter representing the number of days elapsed. Subtract  
Mi from Mo and divide the difference by the  
internal surface area of the fuel tank. Divide this g/m2  
value by the number of test days (using at least two decimal places) to  
calculate the emission rate in g/m2/day. Example: If a fuel  
tank with an internal surface area of 0.720 m2 weighed 1.31  
grams less than the reference tank at the beginning of the test and  
weighed 9.86 grams less than the reference tank after soaking for 10.03  
days, the emission rate would be ((-1.31 g) - (-9.86 g))/0.720  
m2 /10.03 days = 1.1839 g/m\2\/day.  
* * * * *  
    (e) Fuel specifications. Use a low-level ethanol-gasoline blend as  
specified in Sec.  1060.501(c). As an alternative, you may use Fuel  
CE10, as described in Sec.  1060.515(a)(1).  
* * * * *  
0 
306. Amend Sec.  1060.525 by revising paragraph (a)(2) to read as  
follows:  
[[Page 34532]]  
Sec.  1060.525  How do I test fuel systems for diurnal emissions?  
* * * * *  
    (a) * * *  
    (2) Fill the fuel tank to 40 percent of nominal capacity with the  
gasoline specified in 40 CFR 1065.710(c) for general testing.  
* * * * *  
0 
307. Amend Sec.  1060.601 by revising paragraphs (a) and (b)(2) to read  
as follows:  
Sec.  1060.601  How do the prohibitions of 40 CFR 1068.101 apply with  
respect to the requirements of this part?  
    (a) As described in Sec.  1060.1, fuel tanks and fuel lines that  
are used with or intended to be used with new nonroad engines or  
equipment are subject to evaporative emission standards under this  
part. This includes portable marine fuel tanks and fuel lines and other  
fuel-system components associated with portable marine fuel tanks. Note  
that Sec.  1060.1 specifies an implementation schedule based on the  
date of manufacture of nonroad equipment, so new fuel tanks and fuel  
lines are not subject to standards under this part if they will be  
installed for use in equipment built before the specified dates for  
implementing the appropriate standards, subject to the limitations in  
paragraph (b) of this section. Except as specified in paragraph (f) of  
this section, fuel-system components that are subject to permeation or  
diurnal emission standards under this part must be covered by a valid  
certificate of conformity before being introduced into U.S. commerce to  
avoid violating the prohibition of 40 CFR 1068.101(a). To the extent we  
allow it under the exhaust standard-setting part, fuel-system  
components may be certified with a family emission limit higher than  
the specified emission standard.  
    (b) * * *  
    (2) Applicability of standards after January 1, 2020. Starting  
January 1, 2020, it is presumed that replacement components will be  
used with nonroad engines regulated under this part if they can  
reasonably be used with such engines. Manufacturers, distributors,  
retailers, and importers are therefore obligated to take reasonable  
steps to ensure that any uncertified components are not used to replace  
certified components. This would require labeling the components and  
may also require restricting the sales and requiring the ultimate  
purchaser to agree to not use the components inappropriately. This  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 207/268paragraph (b)(2) does not apply for components that are clearly not  
intended for use with fuels.  
* * * * *  
0 
308. Add Sec.  1060.610 to read as follows:  
Sec.  1060.610  Temporary exemptions for manufacturing and assembling  
equipment and fuel-system components.  
    (a) If you are a certificate holder, you may ship components or  
equipment requiring further assembly between two of your facilities,  
subject to the provisions of this paragraph (a). Unless we approve  
otherwise, you must maintain ownership and control of the products  
until they reach their destination. We may allow for shipment where you  
do not maintain actual ownership and control of the engines (such as  
hiring a shipping company to transport the products) but only if you  
demonstrate that the products will be transported only according to  
your specifications. Notify us of your intent to use the exemption in  
this paragraph (a) in your application for certification, if  
applicable. Your exemption is effective when we grant your certificate.  
You may alternatively request an exemption in a separate submission;  
for example, this would be necessary if you will not be the certificate  
holder for the products in question. We may require you to take  
specific steps to ensure that such products are in a certified  
configuration before reaching the ultimate purchaser. Note that since  
this is a temporary exemption, it does not allow you to sell or  
otherwise distribute equipment in an uncertified configuration to  
ultimate purchasers. Note also that the exempted equipment remains new  
and subject to emission standards until its title is transferred to the  
ultimate purchaser or it otherwise ceases to be new.  
    (b) If you certify equipment, you may ask us at the time of  
certification for an exemption to allow you to ship your equipment  
without a complete fuel system. We will generally approve an exemption  
under this paragraph (b) only if you can demonstrate that the exemption  
is necessary and that you will take steps to ensure that equipment  
assembly will be properly completed before reaching the ultimate  
purchaser. We may specify conditions that we determine are needed to  
ensure that shipping the equipment without such components will not  
result in the equipment operating with uncertified components or  
otherwise in an uncertified configuration. For example, we may require  
that you ship the equipment to manufacturers that are contractually  
obligated to install certain components. See 40 CFR 1068.261.  
Sec.  1060.640  [Removed]  
0 
309. Remove Sec.  1060.640.  
0 
310. Amend Sec.  1060.801 by revising the definitions for  
``Configuration'', ``Designated Compliance Officer'', ``Fuel type'',  
``Model year'', ``Placed into service'', ``Portable nonroad fuel  
tank'', and ``Small SI'' to read as follows:  
Sec.  1060.801  What definitions apply to this part?  
* * * * *  
    Configuration means a unique combination of hardware (material,  
geometry, and size) and calibration within an emission family. Units  
within a single configuration differ only with respect to normal  
production variability or factors unrelated to emissions.  
* * * * *  
    Designated Compliance Officer means the Director, Gasoline Engine  
Compliance Center, U.S. Environmental Protection Agency, 2000  
Traverwood Drive, Ann Arbor, MI 48105; complianceinfo@epa.gov . 
* * * * *  
    Fuel type means a general category of fuels such as gasoline or  
natural gas. There can be multiple grades within a single fuel type,  
such as premium gasoline, regular gasoline, or low-level ethanol-  
gasoline blends.  
* * * * *  
    Model year means one of the following things:  
    (1) For equipment defined as ``new nonroad equipment'' under  
paragraph (1) of the definition of ``new nonroad equipment'' model year  
means one of the following:  
    (i) Calendar year of production.  
    (ii) Your annual new model production period if it is different  
than the calendar year. This must include January 1 of the calendar  
year for which the model year is named. It may not begin before January  
2 of the previous calendar year and it must end by December 31 of the  
named calendar year.  
    (2) For other equipment defined as ``new nonroad equipment'' under  
paragraph (2) of the definition of ``new nonroad equipment'' model year  
has the meaning given in the exhaust standard-setting part.  
    (3) For other equipment defined as ``new nonroad equipment'' under  
paragraph (3) or (4) of the definition of ``new nonroad equipment''  
model year means the model year of the engine as defined in the exhaust  
standard-setting part.  
* * * * *  
    Placed into service means put into initial use for its intended  
purpose. Equipment does not qualify as being ``placed into service''  
based on  
[[Page 34533]]  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 208/268incidental use by a manufacturer or dealer.  
* * * * *  
    Portable nonroad fuel tank means a fuel tank that meets each of the  
following criteria:  
    (1) It has design features indicative of use in portable  
applications, such as a carrying handle and fuel line fitting that can  
be readily attached to and detached from a nonroad engine.  
    (2) It has a nominal fuel capacity of 12 gallons or less.  
    (3) It is designed to supply fuel to an engine while the engine is  
operating.  
    (4) It is not used or intended to be used to supply fuel to a  
marine engine. Note that portable tanks excluded from this definition  
of ``portable nonroad fuel tank'' under this paragraph (4) because of  
their use with marine engines are portable marine fuel tanks.  
* * * * *  
    Small SI means relating to engines that are subject to emission  
standards in 40 CFR part 1054.  
* * * * *  
0 
311. Amend Sec.  1060.810 by:  
0 
a. Removing and reserving paragraph (d); and  
0 
b. Revising paragraph (e) introductory text.  
    The revision reads as follows:
Sec.  1060.810  What materials does this part reference?  
* * * * *  
    (e) American Boat and Yacht Council Material. The following  
documents are available from the American Boat and Yacht Council, 613  
Third Street, Suite 10, Annapolis, MD 21403 or (410) 990-4460 or http://abycinc.org/ : 
* * * * *  
0 
312. Revise Sec.  1060.815 to read as follows:  
Sec.  1060.815  What provisions apply to confidential information?  
    The provisions of 40 CFR 1068.10 apply for information you consider  
confidential.  
0 
313. Revise Sec.  1060.825 to read as follows:  
Sec.  1060.825  What reporting and recordkeeping requirements apply  
under this part?  
    (a) This part includes various requirements to submit and record  
data or other information. Unless we specify otherwise, store required  
records in any format and on any media and keep them readily available  
for eight years after you send an associated application for  
certification, or eight years after you generate the data if they do  
not support an application for certification. We may request these  
records at any time. You must promptly give us organized, written  
records in English if we ask for them. This paragraph (a) applies  
whether or not you rely on someone else to keep records on your behalf.  
We may require you to submit written records in an electronic format.  
    (b) The regulations in Sec.  1060.255 and 40 CFR 1068.25 and  
1068.101 describe your obligation to report truthful and complete  
information. This includes information not related to certification.  
Failing to properly report information and keep the records we specify  
violates 40 CFR 1068.101(a)(2), which may involve civil or criminal  
penalties.  
    (c) Send all reports and requests for approval to the Designated  
Compliance Officer (see Sec.  1060.801).  
    (d) Any written information we require you to send to or receive  
from another company is deemed to be a required record under this  
section. Such records are also deemed to be submissions to EPA. We may  
require you to send us these records.  
    (e) Under the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the  
Office of Management and Budget approves the reporting and  
recordkeeping specified in the applicable regulations in this chapter.  
The following items illustrate the kind of reporting and recordkeeping  
we require for products regulated under this part:  
    (1) We specify the following requirements related to component and  
equipment certification in this part:  
    (i) In Sec.  1060.20 we give an overview of principles for  
reporting information.  
    (ii) In subpart C of this part we identify a wide range of  
information required to certify engines.  
    (iii) In Sec.  1060.301 we require manufacturers to make  
components, engines, or equipment available for our testing if we make  
such a request, and to keep records related to evaluation of production  
samples for verifying that the products are as specified in the  
certificate of conformity.  
    (iv) In Sec.  1060.505 we specify information needs for  
establishing various changes to published test procedures.  
    (2) We specify the following requirements related to the general  
compliance provisions in 40 CFR part 1068:  
    (i) In 40 CFR 1068.5 we establish a process for evaluating good  
engineering judgment related to testing and certification.  
    (ii) In 40 CFR 1068.25 we describe general provisions related to  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 209/268sending and keeping information.  
    (iii) In 40 CFR 1068.27 we require manufacturers to make equipment  
available for our testing or inspection if we make such a request.  
    (iv) In 40 CFR 1068.105 we require equipment manufacturers to keep  
certain records related to duplicate labels from engine manufacturers.  
    (v) [Reserved]  
    (vi) In 40 CFR part 1068, subpart C, we identify several reporting  
and recordkeeping items for making demonstrations and getting approval  
related to various exemptions.  
    (vii) In 40 CFR part 1068, subpart D, we identify several reporting  
and recordkeeping items for making demonstrations and getting approval  
related to importing equipment.  
    (viii) In 40 CFR 1068.450 and 1068.455 we specify certain records  
related to testing production-line products in a selective enforcement  
audit. 
    (ix) In 40 CFR 1068.501 we specify certain records related to  
investigating and reporting emission-related defects.  
    (x) In 40 CFR 1068.525 and 1068.530 we specify certain records  
related to recalling nonconforming equipment.  
    (xi) In 40 CFR part 1068, subpart G, we specify certain records for  
requesting a hearing.  
PART 1065--ENGINE-TESTING PROCEDURES  
0 
314. The authority citation for part 1065 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
315. Amend Sec.  1065.1 by revising paragraph (g) to read as follows:  
Sec.  1065.1  Applicability.  
* * * * *  
    (g) For additional information regarding the test procedures in  
this part, visit our website at www.epa.gov , and in particular https://www.epa.gov/vehicle-and-fuel-emissions-testing/engine-testing-regulations . 
* * * * *  
0 
316. Amend Sec.  1065.2 by revising paragraph (c) to read as follows:  
Sec.  1065.2  Submitting information to EPA under this part.  
* * * * *  
    (c) We may void any certificates or approvals associated with a  
submission of information if we find that you intentionally submitted  
false, incomplete, or misleading information. For example, if we find  
that you intentionally submitted incomplete information to mislead EPA  
when requesting approval to use alternate test procedures, we may void  
the certificates for all engine families certified based on emission  
data collected using the  
[[Page 34534]]  
alternate procedures. This paragraph (c) would also apply if you ignore  
data from incomplete tests or from repeat tests with higher emission  
results.  
* * * * *  
0 
317. Amend Sec.  1065.130 by revising paragraph (e) to read as follows:  
Sec.  1065.130  Engine exhaust.  
* * * * *  
    (e) Leaks. Minimize leaks sufficiently to ensure your ability to  
demonstrate compliance with the applicable standards in this chapter.  
We recommend performing carbon balance error verification as described  
in Sec.  1065.543 to verify exhaust system integrity.  
* * * * *  
0 
318. Amend Sec.  1065.140 by revising paragraphs (c)(6)(i) and (e)(2)  
to read as follows:  
Sec.  1065.140  Dilution for gaseous and PM constituents.  
* * * * *  
    (c) * * *  
    (6) * * *  
    (i) Preventing aqueous condensation. To prevent condensation, you  
must keep the temperature of internal surfaces, excluding any sample  
probes, above the dewpoint of the dilute exhaust passing through the  
CVS tunnel. Use good engineering judgment to monitor temperatures in  
the CVS. For the purposes of this paragraph (c)(6), assume that aqueous  
condensation is pure water condensate only, even though the definition  
of ``aqueous condensation'' in Sec.  1065.1001 includes condensation of  
any constituents that contain water. No specific verification check is  
required under this paragraph (c)(6)(i), but we may ask you to show how  
you comply with this requirement. You may use engineering analysis, CVS  
tunnel design, alarm systems, measurements of wall temperatures, and  
calculation of water dewpoint to demonstrate compliance with this  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 210/268requirement. For optional CVS heat exchangers, you may use the lowest  
water temperature at the inlet(s) and outlet(s) to determine the  
minimum internal surface temperature.  
* * * * *  
    (e) * * *  
    (2) For any PM dilution system (i.e., CVS or PFD), add dilution air  
to the raw exhaust such that the minimum overall ratio of diluted  
exhaust to raw exhaust is within the range of (5:1 to 7:1) and is at  
least 2:1 for any primary dilution stage. Base this minimum value on  
the maximum engine exhaust flow rate during a given duty cycle for  
discrete-mode testing and on the maximum engine exhaust flow rate  
during a given test interval for other testing. Either measure the  
maximum exhaust flow during a practice run of the test interval or  
estimate it based on good engineering judgment (for example, you might  
rely on manufacturer-published literature).  
* * * * *  
0 
319. Amend Sec.  1065.145 by revising paragraph (e)(3)(i) to read as  
follows:  
Sec.  1065.145  Gaseous and PM probes, transfer lines, and sampling  
system components.  
* * * * *  
    (e) * * *  
    (3) * * *  
    (i) If you use a NO X sample pump upstream of either an  
NO2-to-NO converter that meets Sec.  1065.378 or a chiller  
that meets Sec.  1065.376, design the sampling system to prevent  
aqueous condensation.  
* * * * *  
0 
320. Amend Sec.  1065.170 by revising the introductory text and  
paragraph (a)(1) to read as follows:  
Sec.  1065.170  Batch sampling for gaseous and PM constituents.  
    Batch sampling involves collecting and storing emissions for later  
analysis. Examples of batch sampling include collecting and storing  
gaseous emissions in a bag or collecting and storing PM on a filter.  
You may use batch sampling to store emissions that have been diluted at  
least once in some way, such as with CVS, PFD, or BMD. You may use  
batch sampling to store undiluted emissions. You may stop emission  
sampling anytime the engine is turned off, consistent with good  
engineering judgment. This is intended to allow for higher  
concentrations of dilute exhaust gases and more accurate measurements.  
Account for exhaust transport delay in the sampling system and  
integrate over the actual sampling duration when determining  
ndexh. Use good engineering judgment to add dilution air to  
fill bags up to minimum read volumes, as needed.  
    (a) * * *  
    (1) Verify proportional sampling after an emission test as  
described in Sec.  1065.545. You must exclude from the proportional  
sampling verification any portion of the test where you are not  
sampling emissions because the engine is turned off and the batch  
samplers are not sampling, accounting for exhaust transport delay in  
the sampling system. Use good engineering judgment to select storage  
media that will not significantly change measured emission levels  
(either up or down). For example, do not use sample bags for storing  
emissions if the bags are permeable with respect to emissions or if  
they off gas emissions to the extent that it affects your ability to  
demonstrate compliance with the applicable gaseous emission standards  
in this chapter. As another example, do not use PM filters that  
irreversibly absorb or adsorb gases to the extent that it affects your  
ability to demonstrate compliance with the applicable PM emission  
standard in this chapter.  
* * * * *  
0 
321. Revise Sec.  1065.205 to read as follows:  
Sec.  1065.205  Performance specifications for measurement instruments.  
    Your test system as a whole must meet all the calibrations,  
verifications, and test-validation criteria specified elsewhere in this  
part for laboratory testing or field testing, as applicable. We  
recommend that your instruments meet the specifications in this section  
for all ranges you use for testing. We also recommend that you keep any  
documentation you receive from instrument manufacturers showing that  
your instruments meet the specifications in the following table:  
BILLING CODE 6560-50-P  
[[Page 34535]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.171  
BILLING CODE 6560-50-C  
[[Page 34536]]  
0 
322. Amend Sec.  1065.220 by revising paragraph (a) introductory text  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 211/268to read as follows:  
Sec.  1065.220  Fuel flow meter.  
    (a) Application. You may use fuel flow meters in combination with a  
chemical balance of fuel, DEF, intake air, and raw exhaust to calculate  
raw exhaust flow as described in Sec.  1065.655(f). You may also use  
fuel flow meters to determine the mass flow rate of carbon-carrying  
fuel streams for performing carbon balance error verification in Sec.   
1065.543 and to calculate the mass of those fuel streams as described  
in Sec.  1065.643. The following provisions apply for using fuel flow  
meters: 
* * * * *  
0 
323. Amend Sec.  1065.225 by revising paragraph (a) introductory text  
to read as follows:  
Sec.  1065.225  Intake-air flow meter.  
    (a) Application. You may use intake-air flow meters in combination  
with a chemical balance of fuel, DEF, intake air, and raw exhaust to  
calculate raw exhaust flow as described in Sec.  1065.655(f) and (g).  
You may also use intake-air flow meters to determine the amount of  
intake air input for performing carbon balance error verification in  
Sec.  1065.543 and to calculate the measured amount of intake air,  
nint, as described in Sec.  1065.643. The following  
provisions apply for using intake air flow meters:  
* * * * *  
0 
324. Revise Sec.  1065.247 to read as follows:  
Sec.  1065.247  Diesel exhaust fluid flow rate.  
    (a) Application. Determine diesel exhaust fluid (DEF) flow rate  
over a test interval for batch or continuous emission sampling using  
one of the three methods described in this section.  
    (b) ECM. Use the ECM signal directly to determine DEF flow rate.  
You may combine this with a gravimetric scale if that improves  
measurement quality. Prior to testing, you may characterize the ECM  
signal using a laboratory measurement and adjust the ECM signal,  
consistent with good engineering judgment.  
    (c) Flow meter. Measure DEF flow rate with a flow meter. We  
recommend that the flow meter that meets the specifications in Table 1  
of Sec.  1065.205. Note that your overall system for measuring DEF flow  
must meet the linearity verification in Sec.  1065.307. Measure using  
the following procedure:  
    (1) Condition the flow of DEF as needed to prevent wakes, eddies,  
circulating flows, or flow pulsations from affecting the accuracy or  
repeatability of the meter. You may accomplish this by using a  
sufficient length of straight tubing (such as a length equal to at  
least 10 pipe diameters) or by using specially designed tubing bends,  
straightening fins, or pneumatic pulsation dampeners to establish a  
steady and predictable velocity profile upstream of the meter.  
Condition the flow as needed to prevent any gas bubbles in the fluid  
from affecting the flow meter.  
    (2) Account for any fluid that bypasses the DEF dosing unit or  
returns from the dosing unit to the fluid storage tank.  
    (d) Gravimetric scale. Use a gravimetric scale to determine the  
mass of DEF the engine uses over a discrete-mode test interval and  
divide by the time of the test interval.  
0 
325. Amend Sec.  1065.260 by revising paragraph (e) to read as follows:  
Sec.  1065.260  Flame-ionization detector.  
* * * * *  
    (e) NMHC and NMOG. For demonstrating compliance with NMHC  
standards, you may either measure THC and determine NMHC mass as  
described in Sec.  1065.660(b)(1), or you may measure THC and  
CH4 and determine NMHC as described in Sec.  1065.660(b)(2)  
or (3). You may also use the additive method in Sec.  1065.660(b)(4)  
for natural gas-fueled engines as described in Sec.  1065.266. See 40  
CFR 1066.635 for methods to demonstrate compliance with NMOG standards  
for vehicle testing.  
* * * * *  
0 
326. Amend Sec.  1065.266 by revising paragraphs (a) and (b) to read as  
follows:  
Sec.  1065.266  Fourier transform infrared analyzer.  
    (a) Application. For engines that run only on natural gas, you may  
use a Fourier transform infrared (FTIR) analyzer to measure nonmethane  
hydrocarbon (NMHC) and nonmethane-nonethane hydrocarbon (NMNEHC) for  
continuous sampling. You may use an FTIR analyzer with any gaseous-  
fueled engine, including dual-fuel and flexible-fuel engines, to  
measure CH 4 and C2H6, for either batch  
or continuous sampling (for subtraction from THC).  
    (b) Component requirements. We recommend that you use an FTIR  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 212/268analyzer that meets the specifications in Table 1 of Sec.  1065.205.  
Note that your FTIR-based system must meet the linearity verification  
in Sec.  1065.307. Use appropriate analytical procedures for  
interpretation of infrared spectra. For example, EPA Test Method 320  
(see https://www.epa.gov/emc/method-320-vapor-phase-organic-and-inorganic-emissions-extractive-ftir ) and ASTM D6348 (incorporated by  
reference in Sec.  1065.1010) are considered valid methods for spectral  
interpretation. You must use heated FTIR analyzers that maintain all  
surfaces that are exposed to emissions at a temperature of (110 to 202)  
[deg]C. 
* * * * *  
0 
327. Amend Sec.  1065.275 by revising paragraph (b)(2) to read as  
follows:  
Sec.  1065.275  N2O measurement devices.  
* * * * *  
    (b) * * *  
    (2) Fourier transform infrared (FTIR) analyzer. Use appropriate  
analytical procedures for interpretation of infrared spectra. For  
example, EPA Test Method 320 (see Sec.  1065.266(b)) and ASTM D6348  
(incorporated by reference in Sec.  1065.1010) are considered valid  
methods for spectral interpretation.  
* * * * *  
0 
328. Amend Sec.  1065.280 by revising paragraph (a) to read as follows:  
Sec.  1065.280  Paramagnetic and magnetopneumatic O2 detection  
analyzers.  
    (a) Application. You may use a paramagnetic detection (PMD) or  
magnetopneumatic detection (MPD) analyzer to measure O 2  
concentration in raw or diluted exhaust for batch or continuous  
sampling. You may use good engineering judgment to develop calculations  
that use O 2 measurements with a chemical balance of fuel,  
DEF, intake air, and exhaust to calculate exhaust flow rate.  
* * * * *  
0 
329. Revise Sec.  1065.303 to read as follows:  
Sec.  1065.303  Summary of required calibration and verifications.  
    The following table summarizes the required and recommended  
calibrations and verifications described in this subpart and indicates  
when these have to be performed:  
[[Page 34537]]  
     Table 1 of Sec.   1065.303--Summary of Required Calibration and  
                              Verifications  
------------------------------------------------------------------------  
      Type of calibration or  
           verification                      Minimum frequency a  
------------------------------------------------------------------------  
Sec.   1065.305: Accuracy,          Accuracy: Not required, but  
 repeatability and noise.            recommended for initial  
                                     installation. Repeatability: Not  
                                     required, but recommended for  
                                     initial installation.  
                                    Noise: Not required, but recommended  
                                     for initial installation.  
Sec.   1065.307: Linearity  
 verification.  
                                    Speed: Upon initial installation,  
                                     within 370 days before testing and  
                                     after major maintenance.  
                                    Torque: Upon initial installation,  
                                     within 370 days before testing and  
                                     after major maintenance.  
                                    Electrical power, current, and  
                                     voltage: Upon initial installation,  
                                     within 370 days before testing and  
                                     after major maintenance.b  
                                    Fuel mass flow rate: Upon initial  
                                     installation, within 370 days  
                                     before testing, and after major  
                                     maintenance.  
                                    Fuel mass scale: Upon initial  
                                     installation, within 370 days  
                                     before testing, and after major  
                                     maintenance.  
                                    DEF mass flow rate: Upon initial  
                                     installation, within 370 days  
                                     before testing, and after major  
                                     maintenance.c  
                                    DEF mass scale: Upon initial  
                                     installation, within 370 days  
                                     before testing, and after major  
                                     maintenance.  
                                    Intake-air, dilution air, diluted  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 213/268                                     exhaust, and batch sampler flow  
                                     rates: Upon initial installation,  
                                     within 370 days before testing and  
                                     after major maintenance.d  
                                    Raw exhaust flow rate: Upon initial  
                                     installation, within 185 days  
                                     before testing and after major  
                                     maintenance.d  
                                    Gas dividers: Upon initial  
                                     installation, within 370 days  
                                     before testing, and after major  
                                     maintenance.  
                                    Gas analyzers (unless otherwise  
                                     noted): Upon initial installation,  
                                     within 35 days before testing and  
                                     after major maintenance.  
                                    FTIR and photoacoustic analyzers:  
                                     Upon initial installation, within  
                                     370 days before testing and after  
                                     major maintenance.  
                                    GC-ECD: Upon initial installation  
                                     and after major maintenance.  
                                    PM balance: Upon initial  
                                     installation, within 370 days  
                                     before testing and after major  
                                     maintenance.  
                                    Pressure, temperature, and dewpoint:  
                                     Upon initial installation, within  
                                     370 days before testing and after  
                                     major maintenance.  
Sec.   1065.308: Continuous gas     Upon initial installation or after  
 analyzer system response and        system modification that would  
 updating-recording verification--   affect response.  
 for gas analyzers not  
 continuously compensated for  
 other gas species.  
Sec.   1065.309: Continuous gas     Upon initial installation or after  
 analyzer system-response and        system modification that would  
 updating-recording verification--   affect response.  
 for gas analyzers continuously  
 compensated for other gas species.  
Sec.   1065.310: Torque...........  Upon initial installation and after  
                                     major maintenance.  
Sec.   1065.315: Pressure,          Upon initial installation and after  
 temperature, dewpoint.              major maintenance.  
Sec.   1065.320: Fuel flow........  Upon initial installation and after  
                                     major maintenance.  
Sec.   1065.325: Intake flow......  Upon initial installation and after  
                                     major maintenance.  
Sec.   1065.330: Exhaust flow.....  Upon initial installation and after  
                                     major maintenance.  
Sec.   1065.340: Diluted exhaust    Upon initial installation and after  
 flow (CVS).                         major maintenance.  
Sec.   1065.341: CVS and PFD flow   Upon initial installation, within 35  
 verification (propane check).       days before testing, and after  
                                     major maintenance.e  
Sec.   1065.342 Sample dryer        For thermal chillers: Upon  
 verification.                       installation and after major  
                                     maintenance. For osmotic membranes;  
                                     upon installation, within 35 days  
                                     of testing, and after major  
                                     maintenance.  
Sec.   1065.345: Vacuum leak......  For laboratory testing: Upon initial  
                                     installation of the sampling  
                                     system, within 8 hours before the  
                                     start of the first test interval of  
                                     each duty-cycle sequence, and after  
                                     maintenance such as pre-filter  
                                     changes.  
                                    For field testing: After each  
                                     installation of the sampling system  
                                     on the vehicle, prior to the start  
                                     of the field test, and after  
                                     maintenance such as pre-filter  
                                     changes.  
Sec.   1065.350: CO2 NDIR H2O       Upon initial installation and after  
 interference.                       major maintenance.  
Sec.   1065.355: CO NDIR CO2 and    Upon initial installation and after  
 H2O interference.                   major maintenance.  
Sec.   1065.360: FID calibration    Calibrate all FID analyzers: upon  
 THC FID optimization, and THC FID   initial installation and after  
 verification.                       major maintenance.  
                                    Optimize and determine CH4 response  
                                     for THC FID analyzers: upon initial  
                                     installation and after major  
                                     maintenance.  
                                    Verify CH4 response for THC FID  
                                     analyzers: upon initial  
                                     installation, within 185 days  
                                     before testing, and after major  
                                     maintenance.  
                                    Verify C2H6 response for THC FID  
                                     analyzers if used for NMNEHC  
                                     determination: upon initial  
                                     installation, within 185 days  
                                     before testing, and after major  
                                     maintenance.  
Sec.   1065.362: Raw exhaust FID    For all FID analyzers: upon initial  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 214/268 O2 interference.                    installation, and after major  
                                     maintenance.  
                                    For THC FID analyzers: upon initial  
                                     installation, after major  
                                     maintenance, and after FID  
                                     optimization according to Sec.  
                                     1065.360.  
Sec.   1065.365: Nonmethane cutter  Upon initial installation, within  
 penetration.                        185 days before testing, and after  
                                     major maintenance.  
Sec.   1065.366: Interference       Upon initial installation and after  
 verification for FTIR analyzers.    major maintenance.  
[[Page 34538]]  
  
Sec.   1065.369: H2O, CO, and CO2   Upon initial installation and after  
 interference verification for       major maintenance.  
 ethanol photoacoustic analyzers.  
Sec.   1065.370: CLD CO2 and H2O    Upon initial installation and after  
 quench.                             major maintenance.  
Sec.   1065.372: NDUV HC and H2O    Upon initial installation and after  
 interference.                       major maintenance.  
Sec.   1065.375: N2O analyzer       Upon initial installation and after  
 interference.                       major maintenance.  
Sec.   1065.376: Chiller NO2        Upon initial installation and after  
 penetration.                        major maintenance.  
Sec.   1065.378: NO2-to-NO          Upon initial installation, within 35  
 converter conversion.               days before testing, and after  
                                     major maintenance.  
Sec.   1065.390: PM balance and     Independent verification: Upon  
 weighing.                           initial installation, within 370  
                                     days before testing, and after  
                                     major maintenance.  
                                    Zero, span, and reference sample  
                                     verifications: Within 12 hours of  
                                     weighing, and after major  
                                     maintenance.  
Sec.   1065.395: Inertial PM        Independent verification: Upon  
 balance and weighing.               initial installation, within 370  
                                     days before testing, and after  
                                     major maintenance.  
                                    Other verifications: Upon initial  
                                     installation and after major  
                                     maintenance.  
------------------------------------------------------------------------  
a Perform calibrations and verifications more frequently than we  
  specify, according to measurement system manufacturer instructions and  
  good engineering judgment.  
b Perform linearity verification either for electrical power or for  
  current and voltage.  
c Linearity verification is not required if DEF flow rate comes directly  
  from the ECM signal as described in Sec.   1065.247(b).  
d Linearity verification is not required if the flow signal's accuracy  
  is verified by carbon balance error verification as described in Sec.  
   1065.307(e)(5) or a propane check as described in Sec.   1065.341.  
e CVS and PFD flow verification (propane check) is not required for  
  measurement systems verified by linearity verification as described in  
  Sec.   1065.307 or carbon balance error verification as described in  
  Sec.   1065.341(h).  
0 
330. Amend Sec.  1065.307 by:  
0 
a. Revising paragraphs (c)(13), (d)(4), (d)(6)(i), (d)(7) and (9), and  
(e)(3) and (5).  
0 
b. Adding paragraphs (e)(7)(i)(F) and (G).  
0 
c. Designating table 1 to the section as paragraph (f) and revising  
newly designated paragraph (f).  
0 
d. Adding paragraph (g).  
    The revisions and additions read as follows:  
Sec.  1065.307  Linearity verification.  
* * * * *  
    (c) * * *  
    (13) Use the arithmetic means, Y i, and reference values,  
yrefi, to calculate least-squares linear regression  
parameters and statistical values to compare to the minimum performance  
criteria specified in Table 1 of this section. Use the calculations for  
a floating intercept described in Sec.  1065.602. Using good  
engineering judgment, you may weight the results of individual data  
pairs (i.e., (y refi, yi)), in the linear 
regression calculations.  
    (d) * * *  
    (4) Fuel and DEF mass flow rate. Use a gravimetric reference  
measurement (such as a scale, balance, or mass comparator) and a  
container. Use a stopwatch or timer to measure the time intervals over  
which reference masses of fluid pass through the mass flow rate meter.  
Use good engineering judgment to correct the reference mass flowing  
through the mass flow rate meter for buoyancy effects from any tubes,  
temperature probes, or objects submerged in the fluid in the container  
that are not attached to the container. If the container has any tubes  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 215/268or wires connected to the container, recalibrate the gravimetric  
reference measurement device with them connected and at normal  
operating pressure using calibration weights that meet the requirements  
in Sec.  1065.790. The corrected reference mass that flowed through the  
mass flow rate meter during a time interval divided by the duration of  
the time interval is the average reference mass flow rate. For meters  
that report a different quantity (such as actual volume, standard  
volume, or moles), convert the reported quantity to mass. For meters  
that report a cumulative quantity calculate the average measured mass  
flow rate as the difference in the reported cumulative mass during the  
time interval divided by the duration of the time interval. For  
measuring flow rate of gaseous fuel prevent condensation on the fuel  
container and any attached tubes, fittings, or regulators.  
* * * * *  
    (6) * * *  
    (i) At the outlet of the gas-division system, connect a gas  
analyzer that meets the linearity verification described in this  
section and has not been linearized with the gas divider being  
verified. For example, verify the linearity of an analyzer using a  
series of reference analytical gases directly from compressed gas  
cylinders that meet the specifications of Sec.  1065.750. We recommend  
using a FID analyzer or a PMD or MPD O 2 analyzer because of  
their inherent linearity. Operate this analyzer consistent with how you  
would operate it during an emission test. Connect a span gas containing  
only a single constituent of interest with balance of purified air or  
purified N 2 to the gas-divider inlet. Use the gas-division  
system to divide the span gas with purified air or nitrogen. Select gas  
divisions that you typically use. Use a selected gas division as the  
measured value. Use the analyzer response divided by the span gas  
concentration as the reference gas-division value. Because the  
instrument response is not absolutely constant, sample and record  
values of x refi for 30 seconds and use the arithmetic mean  
of the values, x ref, as the reference value. Refer to Sec.   
1065.602 for an example of calculating arithmetic mean.  
* * * * *  
    (7) Continuous constituent concentration. For reference values, use  
a series of gas cylinders of known gas concentration containing only a  
single constituent of interest with balance of purified air or purified  
N2 or use a gas-division system that is known to be linear  
with a span gas. Gas cylinders, gas-division systems, and span gases  
that you use for reference values must meet the specifications of Sec.   
1065.750.  
* * * * *  
    (9) Mass. For linearity verification for gravimetric PM balances,  
fuel mass scales, and DEF mass scales, use external calibration weights  
that meet the requirements in Sec.  1065.790. Perform the linearity  
verification for fuel mass scales and DEF mass scales with the in-use  
container, installing all objects that interface with the container.  
For example, this includes all tubes, temperature probes, and objects  
submerged in the fluid in the container; it also includes tubes,  
fittings, regulators, and wires, and any other  
[[Page 34539]]  
objects attached to the container. We recommend that you develop and  
apply appropriate buoyancy corrections for the configuration of your  
mass scale during normal testing, consistent with good engineering  
judgment. Account for the scale weighing a calibration weight instead  
of fluid if you calculate buoyancy corrections. You may also correct  
for the effect of natural convection currents from temperature  
differences between the container and ambient air. Prepare for  
linearity verification by taking the following steps for vented and  
unvented containers:  
    (i) If the container is vented to ambient, fill the container and  
tubes with fluid above the minimum level used to trigger a fill  
operation; drain the fluid down to the minimum level; tare the scale;  
and perform the linearity verification.  
    (ii) If the container is rigid and not vented, drain the fluid down  
to the minimum level; fill all tubes attached to the container to  
normal operating pressure; tare the scale; and perform the linearity  
verification.  
    (e) * * *  
    (3) The expression ``max'' generally refers to the absolute value  
of the reference value used during linearity verification that is  
furthest from zero. This is the value used to scale the first and third  
tolerances in Table 1 of this section using a 0 and SEE. For  
example, if the reference values chosen to validate a pressure  
transducer vary from -10 to -1 kPa, then p max is +10 kPa. If  
the reference values used to validate a temperature device vary from  
290 to 390 K, then T max is 390 K. For gas dividers where  
``max'' is expressed as, x max/xspan;  
xmax is the maximum gas concentration used during the  
verification, x span is the undivided, undiluted, span gas  
concentration, and the resulting ratio is the maximum divider point  
reference value used during the verification (typically 1). The  
following are special cases where ``max'' refers to a different value:  
    (i) For linearity verification of a PM balance, m max is  
the typical mass of a PM filter.  
    (ii) For linearity verification of a torque measurement system used  
with the engine's primary output shaft, T max is the  
manufacturer's specified peak torque of the lowest torque engine  
expected during testing.  
    (iii) For linearity verification of a fuel mass scale,  
mmax is determined based on the range of engines and test  
interval durations expected during testing. It is the minimum, over all  
engines expected during testing, of the fuel consumption expected over  
the minimum test interval duration at the engine's maximum fuel rate.  
If the minimum test interval duration used during testing does not  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 216/268change with engine power or if the minimum test interval duration used  
during testing increases with engine power, m max is given by  
Eq. 1065.307-1. Calculate m max using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.172  
Where: 
mmax,fuel  = the manufacturer's specified maximum fuel  
rate on the lowest-power engine expected during testing.  
tmin = the minimum test interval duration expected during  
testing. If the minimum test interval duration decreases with engine  
power, evaluate Eq. 1065.307-1 for the range of engines expected  
during testing and use the minimum calculated value of  
mmax,fuel scale . 
    (iv) For linearity verification of a DEF mass scale,  
mmax is 10% of the value determined for a fuel mass scale in  
paragraph (e)(3)(iii) of this section. You may determine  
mmax for a DEF mass scale by evaluating m max for  
a fuel mass scale based only on the DEF-using engines expected during  
testing.  
    (v) For linearity verification of a fuel flow rate meter,  
mmax is the manufacturer's specified maximum fuel rate of  
the lowest-power engine expected during testing.  
    (vi) For linearity verification of a DEF flow rate meter,  
mmax is 10% of the manufacturer's specified maximum fuel  
rate of the lowest-power DEF-using engine expected during testing.  
    (vii) For linearity verification of an intake-air flow rate meter,  
nmax is the manufacturer's specified maximum intake-air flow  
rate (converted to molar flow rate) of the lowest-power engine expected  
during testing.  
    (viii) For linearity verification of a raw exhaust flow rate meter,  
nmax is the manufacturer's specified maximum exhaust flow  
rate (converted to molar flow rate) of the lowest-power engine expected  
during testing.  
    (ix) For linearity verification of an electrical-power measurement  
system used to determine the engine's primary output shaft torque,  
Pmax is the manufacturer's specified maximum power of the  
lowest-power engine expected during testing.  
    (x) For linearity verification of an electrical-current measurement  
system used to determine the engine's primary output shaft torque,  
Imax is the maximum current expected on the lowest-power  
engine expected during testing.  
    (xi) For linearity verification of an electrical-voltage  
measurement system used to determine the engine's primary output shaft  
torque, V max is the minimum peak voltage expected on the  
range of engines expected during testing.  
* * * * *  
    (5) Table 2 of this section describes optional verification  
procedures you may perform instead of linearity verification for  
certain systems. The following provisions apply for the alternative  
verification procedures:  
    (i) Perform the propane check verification described in Sec.   
1065.341 at the frequency specified in Table 1 of Sec.  1065.303.  
    (ii) Perform the carbon balance error verification described in  
Sec.  1065.543 on all test sequences that use the corresponding system.  
It must also meet the restrictions listed in Table 2 of this section.  
You may evaluate the carbon balance error verification multiple ways  
with different inputs to validate multiple flow-measurement systems.  
* * * * *  
    (7) * * *  
    (i) * * *  
    (F) Transmission oil.  
    (G) Axle gear oil.  
* * * * *  
    (f) Performance criteria for measurement systems. Table 1 follows:  
BILLING CODE 6560-50-P  
[[Page 34540]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.173  
BILLING CODE 6560-50-C  
    (g) Alternative verification procedures. Table 2 follows:  
                   Table 2 of Sec.   1065.307--Optional Verification to Linearity Verification  
----------------------------------------------------------------------------------------------------------------  
                                                                                           Restrictions for Sec.  
         Measurement system               Sec.   1065.341            Sec.   1065.543               1065.543  
----------------------------------------------------------------------------------------------------------------  
Intake-air flow rate...............  Yes......................  Yes......................  Determine raw exhaust  
                                                                                            flow rate using the  
                                                                                            intake-air flow rate  
                                                                                            signal as an input  
                                                                                            into Eq. 1065.655-24  
                                                                                            and determine mass  
                                                                                            of CO2 over each  
                                                                                            test interval input  
                                                                                            into Eq. 1065.643-6  
                                                                                            using samples taken  
                                                                                            from the raw exhaust  
                                                                                            (continuous or bag,  
                                                                                            and with or without  
                                                                                            a PFD).  
Dilution air flow rate for CVS.....  Yes......................  No.......................  Not allowed.  
Diluted exhaust flow rate for CVS..  Yes......................  Yes......................  Determine mass of CO2  
                                                                                            over each test  
                                                                                            interval input into  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 217/268                                                                                            Eq. 1065.643-6 using  
                                                                                            samples taken from  
                                                                                            the CVS (continuous  
                                                                                            or bag, and with or  
                                                                                            without a PFD).  
Raw exhaust flow rate for exhaust    Yes......................  Yes......................  Determine mass of CO2  
 stack.                                                                                     over each test  
                                                                                            interval input into  
                                                                                            Eq. 1065.643-6 using  
                                                                                            samples taken from  
                                                                                            the raw exhaust  
                                                                                            (continuous or bag,  
                                                                                            and with or without  
                                                                                            a PFD).  
[[Page 34541]]  
  
Flow measurements in a PFD (usually  Yes......................  Yes......................  Determine mass of CO2  
 dilution air and diluted exhaust                                                           over each test  
 streams) used to determine the                                                             interval input into  
 dilution ratio in the PFD.                                                                 Eq. 1065.643-6 using  
                                                                                            samples taken from  
                                                                                            the PFD (continuous  
                                                                                            or bag).  
Batch sampler flow rates...........  Yes......................  No.......................  Not allowed.  
Fuel mass flow rate................  No.......................  Yes......................  Determine mass of a  
                                                                                            carbon-carrying  
                                                                                            fluid stream used as  
                                                                                            an input into Eq.  
                                                                                            1065.643-1 using the  
                                                                                            fuel mass flow rate  
                                                                                            meter.  
Fuel mass scale....................  No.......................  Yes......................  Determine mass of a  
                                                                                            carbon-carrying  
                                                                                            fluid stream used as  
                                                                                            an input into Eq.  
                                                                                            1065.643-1 using the  
                                                                                            fuel mass scale.  
----------------------------------------------------------------------------------------------------------------  
0 
331. Amend Sec.  1065.309 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1065.309  Continuous gas analyzer system-response and updating-  
recording verification--for gas analyzers continuously compensated for  
other gas species.  
* * * * *  
    (d) * * *  
    (2) Equipment setup. We recommend using minimal lengths of gas  
transfer lines between all connections and fast-acting three-way valves  
(2 inlets, 1 outlet) to control the flow of zero and blended span gases  
to the sample system's probe inlet or a tee near the outlet of the  
probe. If you inject the gas at a tee near the outlet of the probe, you  
may correct the transformation time, t 50, for an estimate of  
the transport time from the probe inlet to the tee. Normally the gas  
flow rate is higher than the sample flow rate and the excess is  
overflowed out the inlet of the probe. If the gas flow rate is lower  
than the sample flow rate, the gas concentrations must be adjusted to  
account for the dilution from ambient air drawn into the probe. We  
recommend you use the final, stabilized analyzer reading as the final  
gas concentration. Select span gases for the species being continuously  
combined, other than H 2O. Select concentrations of  
compensating species that will yield concentrations of these species at  
the analyzer inlet that covers the range of concentrations expected  
during testing. You may use binary or multi-gas span gases. You may use  
a gas blending or mixing device to blend span gases. A gas blending or  
mixing device is recommended when blending span gases diluted in  
N2 with span gases diluted in air. You may use a multi-gas  
span gas, such as NO-CO-CO 2-C3H8- 
CH4, to verify multiple analyzers at the same time. In  
designing your experimental setup, avoid pressure pulsations due to  
stopping the flow through the gas blending device. The change in gas  
concentration must be at least 20% of the analyzer's range. If  
H2O correction is applicable, then span gases must be  
humidified before entering the analyzer; however, you may not humidify  
NO2 span gas by passing it through a sealed humidification  
vessel that contains H 2O. You must humidify NO 2  
span gas with another moist gas stream. We recommend humidifying your  
NO-CO-CO 2-C3H8-CH4, balance  
N2, blended gas by bubbling the gas mixture that meets the  
specifications in Sec.  1065.750 through distilled H 2O in a  
sealed vessel and then mixing the gas with dry NO 2 gas,  
balance purified air, or by using a device that introduces distilled  
H2O as vapor into a controlled span gas flow. If the sample  
does not pass through a dryer during emission testing, humidify your  
span gas to an H 2O level at or above the maximum expected  
during emission testing. If the sample passes through a dryer during  
emission testing, it must pass the sample dryer verification check in  
Sec.  1065.342, and you must humidify your span gas to an  
H2O level at or above the level determined in Sec.   
1065.145(e)(2) for that dryer. If you are humidifying span gases  
without NO 2, use good engineering judgment to ensure that  
the wall temperatures in the transfer lines, fittings, and valves from  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 218/268the humidifying system to the probe are above the dewpoint required for  
the target H 2O content. If you are humidifying span gases  
with NO2, use good engineering judgment to ensure that there  
is no condensation in the transfer lines, fittings, or valves from the  
point where humidified gas is mixed with NO 2 span gas to the  
probe. We recommend that you design your setup so that the wall  
temperatures in the transfer lines, fittings, and valves from the  
humidifying system to the probe are at least 5 [deg]C above the local  
sample gas dewpoint. Operate the measurement and sample handling system  
as you do for emission testing. Make no modifications to the sample  
handling system to reduce the risk of condensation. Flow humidified gas  
through the sampling system before this check to allow stabilization of  
the measurement system's sampling handling system to occur, as it would  
for an emission test.  
* * * * *  
Sec.  1065.320  [Amended]  
0 
332. Amend Sec.  1065.320 by removing and reserving paragraph (b).  
0 
333. Revise Sec.  1065.341 to read as follows:  
Sec.  1065.341  CVS and PFD flow verification (propane check).  
    This section describes two optional methods, using propane as a  
tracer gas, to verify CVS and PFD flow streams. You may use good  
engineering judgment and safe practices to use other tracer gases, such  
as CO2 or CO. The first method, described in paragraphs (a)  
through (e) of this section, applies for the CVS diluted exhaust flow  
measurement system. The first method may also apply for other single-  
flow measurement systems as described in Table 2 of Sec.  1065.307.  
Paragraph (g) of this section describes a second method you may use to  
verify flow measurements in a PFD for determining the PFD dilution  
ratio. 
    (a) A propane check uses either a reference mass or a reference  
flow rate of C 3H8 as a tracer gas in a CVS. Note  
that if you use a reference flow rate, account for any non-ideal gas  
behavior of C 3H8 in the reference flow meter.  
Refer to Sec. Sec.  1065.640 and 1065.642, which describe how to  
calibrate and use certain flow meters. Do not use any ideal gas  
assumptions in Sec. Sec.  1065.640 and 1065.642. The propane check  
compares the calculated mass of injected C 3H8  
using HC measurements and CVS flow rate measurements with the reference  
value. 
    (b) Prepare for the propane check as follows:  
    (1) If you use a reference mass of C 3H8  
instead of a reference flow rate, obtain a cylinder charged with  
C3H8. Determine the reference cylinder's mass of  
C3H8 within 0.5% of the amount of  
C3H8 that you expect to use. You may substitute a  
C3H8 analytical gas mixture  
[[Page 34542]]  
(i.e., a prediluted tracer gas) for pure C 3H8.  
This would be most appropriate for lower flow rates. The analytical gas  
mixture must meet the specifications in Sec.  1065.750(a)(3).  
    (2) Select appropriate flow rates for the CVS and  
C3H8. 
    (3) Select a C 3H8 injection port in the CVS.  
Select the port location to be as close as practical to the location  
where you introduce engine exhaust into the CVS, or at some point in  
the laboratory exhaust tubing upstream of this location. Connect the  
C3H8 cylinder to the injection system.  
    (4) Operate and stabilize the CVS.  
    (5) Preheat or pre-cool any heat exchangers in the sampling system.  
    (6) Allow heated and cooled components such as sample lines,  
filters, chillers, and pumps to stabilize at operating temperature.  
    (7) You may purge the HC sampling system during stabilization.  
    (8) If applicable, perform a vacuum side leak verification of the  
HC sampling system as described in Sec.  1065.345.  
    (9) You may also conduct any other calibrations or verifications on  
equipment or analyzers.  
    (c) If you performed the vacuum-side leak verification of the HC  
sampling system as described in paragraph (b)(8) of this section, you  
may use the HC contamination procedure in Sec.  1065.520(f) to verify  
HC contamination. Otherwise, zero, span, and verify contamination of  
the HC sampling system, as follows:  
    (1) Select the lowest HC analyzer range that can measure the  
C3H8 concentration expected for the CVS and  
C3H8 flow rates.  
    (2) Zero the HC analyzer using zero air introduced at the analyzer  
port. 
    (3) Span the HC analyzer using C 3H8 span gas  
introduced at the analyzer port.  
    (4) Overflow zero air at the HC probe inlet or into a tee near the  
outlet of the probe.  
    (5) Measure the stable HC concentration of the HC sampling system  
as overflow zero air flows. For batch HC measurement, fill the batch  
container (such as a bag) and measure the HC overflow concentration.  
    (6) If the overflow HC concentration exceeds 2 [mu]mol/mol, do not  
proceed until contamination is eliminated. Determine the source of the  
contamination and take corrective action, such as cleaning the system  
or replacing contaminated portions.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 219/268    (7) When the overflow HC concentration does not exceed 2 [mu]mol/  
mol, record this value as x THCinit and use it to correct for  
HC contamination as described in Sec.  1065.660.  
    (d) Perform the propane check as follows:  
    (1) For batch HC sampling, connect clean storage media, such as  
evacuated bags.  
    (2) Operate HC measurement instruments according to the instrument  
manufacturer's instructions.  
    (3) If you will correct for dilution air background concentrations  
of HC, measure and record background HC in the dilution air.  
    (4) Zero any integrating devices.  
    (5) Begin sampling, and start any flow integrators.  
    (6) Release the contents of the C 3H8  
reference cylinder at the rate you selected. If you use a reference  
flow rate of C 3H8, start integrating this flow  
rate. 
    (7) Continue to release the cylinder's contents until at least  
enough C 3H8 has been released to ensure accurate  
quantification of the reference C 3H8 and the  
measured C 3H8. 
    (8) Shut off the C 3H8 reference cylinder and  
continue sampling until you have accounted for time delays due to  
sample transport and analyzer response.  
    (9) Stop sampling and stop any integrators.  
    (e) Perform post-test procedure as follows:  
    (1) If you used batch sampling, analyze batch samples as soon as  
practical.  
    (2) After analyzing HC, correct for contamination and background.  
    (3) Calculate total C 3H8 mass based on your  
CVS and HC data as described in Sec.  1065.650 (40 CFR 1066.605 for  
vehicle testing) and Sec.  1065.660, using the molar mass of  
C3H8, MC3H8, instead the effective  
molar mass of HC, M HC. 
    (4) If you use a reference mass, determine the cylinder's propane  
mass within 0.5% and determine the  
C3H8 reference mass by subtracting the empty  
cylinder propane mass from the full cylinder propane mass.  
    (5) Subtract the reference C 3H8 mass from the  
calculated mass. If this difference is within 2% of the  
reference mass, the CVS passes this verification. If not, take  
corrective action as described in paragraph (f) of this section.  
    (f) A failed propane check might indicate one or more problems  
requiring corrective action, as follows:  
  Table 1 of Sec.   1065.341--Troubleshooting Guide for Propane Checks  
------------------------------------------------------------------------  
           Problem                   Recommended corrective action  
------------------------------------------------------------------------  
Incorrect analyzer             Recalibrate, repair, or replace the FID  
 calibration.                   analyzer.  
Leaks........................  Inspect CVS tunnel, connections,  
                                fasteners, and HC sampling system.  
                                Repair or replace components.  
Poor mixing..................  Perform the verification as described in  
                                this section while traversing a sampling  
                                probe across the tunnel's diameter,  
                                vertically and horizontally. If the  
                                analyzer response indicates any  
                                deviation exceeding 2% of 
                                the mean measured concentration,  
                                consider operating the CVS at a higher  
                                flow rate or installing a mixing plate  
                                or orifice to improve mixing.  
Hydrocarbon contamination in   Perform the hydrocarbon-contamination  
 the sample system.             verification as described in Sec.  
                                1065.520.  
Change in CVS calibration....  Perform a calibration of the CVS flow  
                                meter as described in Sec.   1065.340.  
Flow meter entrance effects..  Inspect the CVS tunnel to determine  
                                whether the entrance effects from the  
                                piping configuration upstream of the  
                                flow meter adversely affect the flow  
                                measurement.  
Other problems with the CVS    Inspect the CVS system and related  
 or sampling verification       verification hardware, and software for  
 hardware or software.          discrepancies.  
------------------------------------------------------------------------  
    (g) You may verify flow measurements in a PFD (usually dilution air  
and diluted exhaust streams) for determining the dilution ratio in the  
PFD using the following method:  
    (1) Configure the HC sampling system to extract a sample from the  
PFD's diluted exhaust stream (such as near a PM filter). If the  
absolute pressure at this location is too low to extract an HC sample,  
you may sample HC from the PFD's pump exhaust. Use caution when  
sampling from pump exhaust because
[[Page 34543]]  
an otherwise acceptable pump leak downstream of a PFD diluted exhaust  
flow meter will cause a false failure of the propane check.  
    (2) Perform the propane check described in paragraphs (b), (c), and  
(d) of this section, but sample HC from the PFD's diluted exhaust  
stream. Inject the propane in the same exhaust stream that the PFD is  
sampling from (either CVS or raw exhaust stack).  
    (3) Calculate C 3H8 mass, taking into account  
the dilution from the PFD.  
    (4) Subtract the reference C 3H8 mass from the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 220/268calculated mass. If this difference is within 2% of the  
reference mass, all PFD flow measurements for determining PFD dilution  
ratio pass this verification. If not, take corrective action as  
described in paragraph (f) of this section. For PFDs sampling only for  
PM, the allowed difference is 5%. 
    (h) Table 2 of Sec.  1065.307 describes optional verification  
procedures you may perform instead of linearity verification for  
certain flow-measurement systems. Performing carbon balance error  
verification also replaces any required propane checks.  
0 
334. Amend Sec.  1065.342 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1065.342  Sample dryer verification.  
* * * * *  
    (d) * * *  
    (2) Humidify room air, purified N 2, or purified air by  
bubbling it through distilled H 2O in a sealed vessel or use  
a device that injects distilled H 2O as vapor into a  
controlled gas flow to humidify the gas to the highest sample  
H2O content that you estimate during emission sampling.  
* * * * *  
0 
335. Amend Sec.  1065.350 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1065.350  H2O interference verification for CO2O NDIR analyzers.  
* * * * *  
    (d) * * *  
    (2) Create a humidified test gas by bubbling zero gas that meets  
the specifications in Sec.  1065.750 through distilled H 2O  
in a sealed vessel or use a device that introduces distilled  
H2O as vapor into a controlled gas flow. If the sample does  
not pass through a dryer during emission testing, humidify your test  
gas to an H 2O level at or above the maximum expected during  
emission testing. If the sample passes through a dryer during emission  
testing, you must humidify your test gas to an H 2O level at  
or above the level determined in Sec.  1065.145(e)(2) for that dryer.  
* * * * *  
0 
336. Amend Sec.  1065.355 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1065.355  H2O and CO2O interference verification for CO NDIR  
analyzers.  
* * * * *  
    (d) * * *  
    (2) Create a humidified CO 2O test gas by bubbling a  
CO2O span gas that meets the specifications in Sec.   
1065.750 through distilled H 2O in a sealed vessel or use a  
device that introduces distilled H 2O as vapor into a  
controlled gas flow. If the sample does not pass through a dryer during  
emission testing, humidify your test gas to an H 2O level at  
or above the maximum expected during emission testing. If the sample  
passes through a dryer during emission testing, you must humidify your  
test gas to an H 2O at or above the level determined in Sec.   
1065.145(e)(2) for that dryer. Use a CO 2O span gas  
concentration at least as high as the maximum expected during testing.  
* * * * *  
0 
337. Amend Sec.  1065.360 by adding paragraphs (a)(4) and (d)(12) to  
read as follows:  
Sec.  1065.360  FID optimization and verification.  
    (a) * * *  
    (4) For any gaseous-fueled engine, including dual-fuel and  
flexible-fuel engines, you may determine the methane (CH 4)  
and ethane (C 2H6) response factors as a function  
of the molar water concentration in the raw or diluted exhaust. If you  
choose the option in this paragraph (a)(4), generate and verify the  
humidity level (or fraction) as described in Sec.  1065.365(d)(11).  
* * * * *  
    (d) * * *  
    (12) Determine the response factor as a function of molar water  
concentration and use this response factor to account for the  
CH4 response for NMHC determination described in Sec.   
1065.660(b)(2)(iii). Humidify the CH 4 span gas as described  
in Sec.  1065.365(d)(11) and repeat the steps in paragraphs (d)(7)  
through (9) of this section until measurements are complete for each  
setpoint in the selected range. Divide each mean measured  
CH4 concentration by the recorded span concentration of the  
CH4 calibration gas, adjusted for water content, to determine the FID  
analyzer's CH 4 response factor, RFCH4[THC FID]. Use the  
CH4 response factors at the different setpoints to create a  
functional relationship between response factor and molar water  
concentration, downstream of the last sample dryer if any sample dryers  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 221/268are present. Use this functional relationship to determine the response  
factor during an emission test.  
* * * * *  
0 
338. Amend Sec.  1065.365 by revising paragraphs (a), (d), and (f)(9)  
and (14) to read as follows:  
Sec.  1065.365  Nonmethane cutter penetration fractions.  
    (a) Scope and frequency. If you use a FID analyzer and a nonmethane  
cutter (NMC) to measure methane (CH 4), determine the  
nonmethane cutter's penetration fractions of methane, PF CH4,  
and ethane, PF C2H6. As detailed in this section, these  
penetration fractions may be determined as a combination of NMC  
penetration fractions and FID analyzer response factors, depending on  
your particular NMC and FID analyzer configuration. Perform this  
verification after installing the nonmethane cutter. Repeat this  
verification within 185 days of testing to verify that the catalytic  
activity of the cutter has not deteriorated. Note that because  
nonmethane cutters can deteriorate rapidly and without warning if they  
are operated outside of certain ranges of gas concentrations and  
outside of certain temperature ranges, good engineering judgment may  
dictate that you determine a nonmethane cutter's penetration fractions  
more frequently.  
* * * * *  
    (d) Procedure for a FID calibrated with the NMC. The method  
described in this paragraph (d) is recommended over the procedures  
specified in paragraphs (e) and (f) of this section and required for  
any gaseous-fueled engine, including dual-fuel and flexible-fuel  
engines. If your FID arrangement is such that a FID is always  
calibrated to measure CH 4 with the NMC, then span that FID  
with the NMC using a CH 4 span gas, set the product of that  
FID's CH 4 response factor and CH 4 penetration  
fraction, RFPF CH4[NMC-FID] , equal to 1.0 for all emission  
calculations, and determine its combined C 2H6  
response factor and C 2H6 penetration fraction,  
RFPFC2H6[NMC-FID] , as follows. For any gaseous-fueled  
engine, including dual-fuel and flexible-fuel engines, you must  
determine the CH 4 penetration fraction,  
PFCH4[NMC-FID] , and C2H6 response  
factor and C 2H6 penetration fraction,  
RFPFC2H6[NMC-FID] , as a function of the molar water  
concentration in the raw or diluted exhaust as described in paragraphs  
(d)(10) and (12) of this section. Generate and verify the humidity  
generation as described in paragraph (d)(11) of this section. When  
using the option in this paragraph (d), note that the FID's  
CH4 penetration fraction, PF CH4[NMC-FID] , is set  
equal to  
[[Page 34544]]  
1.0 only for 0% molar water concentration. You are not required to meet  
the recommended lower limit for PF CH4 of greater than 0.85  
for any of the penetration fractions generated as a function of molar  
water concentration.  
    (1) Select CH 4 and C2H6 analytical  
gas mixtures and ensure that both mixtures meet the specifications of  
Sec.  1065.750. Select a CH 4 concentration that you would  
use for spanning the FID during emission testing and select a  
C2H6 concentration that is typical of the peak  
NMHC concentration expected at the hydrocarbon standard or equal to the  
THC analyzer's span value. For CH 4 analyzers with multiple  
ranges, perform this procedure on the highest range used for emission  
testing.  
    (2) Start, operate, and optimize the nonmethane cutter according to  
the manufacturer's instructions, including any temperature  
optimization.  
    (3) Confirm that the FID analyzer meets all the specifications of  
Sec.  1065.360.  
    (4) Start and operate the FID analyzer according to the  
manufacturer's instructions.  
    (5) Zero and span the FID with the nonmethane cutter as you would  
during emission testing. Span the FID through the cutter by using  
CH4 span gas.  
    (6) Introduce the C 2H6 analytical gas mixture  
upstream of the nonmethane cutter. Use good engineering judgment to  
address the effect of hydrocarbon contamination if your point of  
introduction is vastly different from the point of zero/span gas  
introduction.  
    (7) Allow time for the analyzer response to stabilize.  
Stabilization time may include time to purge the nonmethane cutter and  
to account for the analyzer's response.  
    (8) While the analyzer measures a stable concentration, record 30  
seconds of sampled data. Calculate the arithmetic mean of these data  
points. 
    (9) Divide the mean C 2H6 concentration by the  
reference concentration of C 2H6, converted to a  
C1 basis. The result is the C 2H6  
combined response factor and penetration fraction,  
RFPFC2H6[NMC-FID] . Use the CH 4 response factors  
at the different setpoints to create a functional relatFID]. Use this  
combined C 2H6 response factor and  
C2H6 penetration fraction and the product of the  
CH4 response factor and CH 4 penetration fraction,  
RFPFCH4[NMC-FID] . Use the CH 4 response factors at  
the different setpoints to create a functional relatFID], set to 1.0 in  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 222/268emission calculations according to Sec.  1065.660(b)(2)(i) or (d)(1)(i)  
or Sec.  1065.665, as applicable.  
    (10) Determine the combined C 2H6 response  
factor and C 2H6 penetration fraction as a  
function of molar water concentration and use it to account for  
C2H6 response factor and  
C2H6 penetration fraction for NMHC determination  
as described in Sec.  1065.660(b)(2)(iii) and for CH 4  
determination in Sec.  1065.660(d)(1)(iii). Humidify the  
C2H6 analytical gas mixture as described in  
paragraph (d)(11) of this section. Repeat the steps in paragraphs  
(d)(6) through (8) of this section until measurements are complete for  
each setpoint in the selected range. Divide each mean measured  
C2H6 concentration by the reference concentration  
of C2H6, converted to a C 1-basis and  
adjusted for water content to determine the FID analyzer's combined  
C2H6 response factor and  
C2H6 penetration fraction,  
RFPFC2H6[NMC-FID] . Use the CH 4 response factors  
at the different setpoints to create a functional relatFID]. Use  
RFPFC2H6[NMC-FID] . Use the CH 4 response factors  
at the different setpoints to create a functional relatFID] at the  
different setpoints to create a functional relationship between the  
combined response factor and penetration fraction and molar water  
concentration, downstream of the last sample dryer if any sample dryers  
are present. Use this functional relationship to determine the combined  
response factor and penetration fraction during the emission test.  
    (11) Create a humidified test gas by bubbling the analytical gas  
mixture that meets the specifications in Sec.  1065.750 through  
distilled H 2O in a sealed vessel or use a device that  
introduces distilled H 2O as vapor into a controlled gas  
flow. If the sample does not pass through a dryer during emission  
testing, generate at least five different H 2O concentrations  
that cover the range from less than the minimum expected to greater  
than the maximum expected water concentration during testing. Use good  
engineering judgment to determine the target concentrations. For  
analyzers where the sample passes through a dryer during emission  
testing, humidify your test gas to an H 2O level at or above  
the level determined in Sec.  1065.145(e)(2) for that dryer and  
determine a single wet analyzer response to the dehumidified sample.  
Heat all transfer lines from the water generation system to a  
temperature at least 5 [deg]C higher than the highest dewpoint  
generated. Determine H 2O concentration as an average value  
over intervals of at least 30 seconds. Monitor the humidified sample  
stream with a dewpoint analyzer, relative humidity sensor, FTIR, NDIR,  
or other water analyzer during each test or, if the humidity generator  
achieves humidity levels with controlled flow rates, validate the  
instrument within 370 days before testing and after major maintenance  
using one of the following methods:  
    (i) Determine the linearity of each flow metering device. Use one  
or more reference flow meters to measure the humidity generator's flow  
rates and verify the H 2O level value based on the humidity  
generator manufacturer's recommendations and good engineering judgment.  
We recommend that you utilize at least 10 flow rates for each flow-  
metering device.  
    (ii) Perform validation testing based on monitoring the humidified  
stream with a dewpoint analyzer, relative humidity sensor, FTIR, NDIR,  
or other water analyzer as described in this paragraph (d)(11). Compare  
the measured humidity to the humidity generator's value. Verify overall  
linearity performance for the generated humidity as described in Sec.   
1065.307 using the criteria for other dewpoint measurements or confirm  
all measured values are within 2% of the target mole  
fraction. In the case of dry gas, the measured value may not exceed  
0.002 mole fraction.  
    (iii) Follow the performance requirements in Sec.  1065.307(b) if  
the humidity generator does not meet validation criteria.  
    (12) Determine the CH 4 penetration fraction as a  
function of molar water concentration and use this penetration fraction  
for NMHC determination in Sec.  1065.660(b)(2)(iii) and for  
CH4 determination in Sec.  1065.660(d)(1)(iii). Repeat the  
steps in paragraphs (d)(6) through (11) of this section, but with the  
CH4 analytical gas mixture instead of  
C2H6. Use this functional relationship to  
determine the penetration fraction during the emission test.  
* * * * *  
    (f) * * *  
    (9) Divide the mean C 2H6 concentration by the  
reference concentration of C 2H6, converted to a  
C1 basis. The result is the combined  
C2H6 response factor and  
C2H6 penetration fraction,  
RFPFC2H6[NMC-FID] . Use this combined  
C2H6 response factor and  
C2H6 penetration fraction according to Sec.   
1065.660(b)(2)(iii) or (d)(1)(iii) or Sec.  1065.665, as applicable.  
* * * * *  
    (14) Divide the mean CH 4 concentration measured through  
the nonmethane cutter by the mean CH 4 concentration measured  
after bypassing the nonmethane cutter. The result is the CH 4  
penetration fraction, PF CH4[NMC-FID] . 
[[Page 34545]]  
Use this CH 4 penetration fraction according to Sec.   
1065.660(b)(2)(iii) or (d)(1)(iii) or Sec.  1065.665, as applicable.  
0 
339. Amend Sec.  1065.370 by revising paragraph (e)(5) to read as  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 223/268follows:  
Sec.  1065.370  CLD CO2 and H2O quench verification.  
* * * * *  
    (e) * * *  
    (5) Create a humidified NO span gas by bubbling a NO gas that meets  
the specifications in Sec.  1065.750 through distilled H 2O  
in a sealed vessel or use a device that introduces distilled  
H2O as vapor into a controlled gas flow. If the sample does  
not pass through a dryer during emission testing, humidify your test  
gas to an H 2O level approximately equal to the maximum mole  
fraction of H 2O expected during emission testing. If the  
humidified NO span gas sample does not pass through a sample dryer, the  
quench verification calculations in Sec.  1065.675 scale the measured  
H2O quench to the highest mole fraction of H 2O  
expected during emission testing. If the sample passes through a dryer  
during emission testing, you must humidify your test gas to an  
H2O level at or above the level determined in Sec.   
1065.145(e)(2) for that dryer. For this case, the quench verification  
calculations in Sec.  1065.675 do not scale the measured H 2O  
quench. 
* * * * *  
0 
340. Amend Sec.  1065.375 by revising paragraph (d)(2) to read as  
follows:  
Sec.  1065.375  Interference verification for N2O analyzers.  
* * * * *  
    (d) * * *  
    (2) Create a humidified test gas by bubbling a multi component span  
gas that incorporates the target interference species and meets the  
specifications in Sec.  1065.750 through distilled H 2O in a  
sealed vessel or use a device that introduces distilled H 2O  
as vapor into a controlled gas flow. If the sample does not pass  
through a dryer during emission testing, humidify your test gas to an  
H2O level at or above the maximum expected during emission  
testing. If the sample passes through a dryer during emission testing,  
you must humidify your test gas to an H 2O level at or above  
the level determined in Sec.  1065.145(e)(2) for that dryer. Use  
interference span gas concentrations that are at least as high as the  
maximum expected during testing.  
* * * * *  
0 
341. Amend Sec.  1065.410 by revising paragraphs (c) and (d) to read as  
follows:  
Sec.  1065.410  Maintenance limits for stabilized test engines.  
* * * * *  
    (c) If you inspect an engine, keep a record of the inspection and  
update your application for certification to document any changes that  
result. You may use any kind of equipment, instrument, or tool that is  
available at dealerships and other service outlets to identify  
malfunctioning components or perform maintenance.  
    (d) You may repair defective parts from a test engine if they are  
unrelated to emission control. You must ask us to approve repairs that  
might affect the engine's emission controls. If we determine that a  
part failure, system malfunction, or associated repair makes the  
engine's emission controls unrepresentative of production engines, you  
may not use it as an emission-data engine. Also, if your test engine  
has a major mechanical failure that requires you to take it apart, you  
may no longer use it as an emission-data engine.  
0 
342. Amend Sec.  1065.510 by:  
0 
a. Revising paragraphs (a) introductory text and (b)(5)(i).  
0 
b. Adding paragraph (c)(5).  
0 
c. Revising paragraph (f)(4)(i)  
    The revisions and addition read as follows:  
Sec.  1065.510  Engine mapping.  
    (a) Applicability, scope, and frequency. An engine map is a data  
set that consists of a series of paired data points that represent the  
maximum brake torque versus engine speed, measured at the engine's  
primary output shaft. Map your engine if the standard-setting part  
requires engine mapping to generate a duty cycle for your engine  
configuration. Map your engine while it is connected to a dynamometer  
or other device that can absorb work output from the engine's primary  
output shaft according to Sec.  1065.110. Configure any auxiliary work  
inputs and outputs such as hybrid, turbo-compounding, or thermoelectric  
systems to represent their in-use configurations, and use the same  
configuration for emission testing. See Figure 1 of Sec.  1065.210.  
This may involve configuring initial states of charge and rates and  
times of auxiliary-work inputs and outputs. We recommend that you  
contact the Designated Compliance Officer before testing to determine  
how you should configure any auxiliary-work inputs and outputs. Use the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 224/268most recent engine map to transform a normalized duty cycle from the  
standard-setting part to a reference duty cycle specific to your  
engine. Normalized duty cycles are specified in the standard-setting  
part. You may update an engine map at any time by repeating the engine-  
mapping procedure. You must map or re-map an engine before a test if  
any of the following apply:  
* * * * *  
    (b) * * *  
    (5) * * *  
    (i) For any engine subject only to steady-state duty cycles, you  
may perform an engine map by using discrete speeds. Select at least 20  
evenly spaced setpoints from 95% of warm idle speed to the highest  
speed above maximum power at which 50% of maximum power occurs. We  
refer to this 50% speed as the check point speed as described in  
paragraph (b)(5)(iii) of this section. At each setpoint, stabilize  
speed and allow torque to stabilize. We recommend that you stabilize an  
engine for at least 15 seconds at each setpoint and record the mean  
feedback speed and torque of the last (4 to 6) seconds. Record the mean  
speed and torque at each setpoint. Use linear interpolation to  
determine intermediate speeds and torques. Use this series of speeds  
and torques to generate the power map as described in paragraph (e) of  
this section.  
* * * * *  
    (c) * * *  
    (5) For engines with an electric hybrid system, map the negative  
torque required to motor the engine by repeating paragraph (b) of this  
section with minimum operator demand and a fully charged RESS or with  
the hybrid system disabled, such that it doesn't affect the motoring  
torque. You may start the negative torque map at either the minimum or  
maximum speed from paragraph (b) of this section.  
* * * * *  
    (f) * * *  
    (4) * * *  
    (i) For variable-speed engines, declare a warm idle torque that is  
representative of in-use operation. For example, if your engine is  
typically connected to an automatic transmission or a hydrostatic  
transmission, declare the torque that occurs at the idle speed at which  
your engine operates when the transmission is engaged. Use this value  
for cycle generation. You may use multiple warm idle torques and  
associated idle speeds in cycle generation for representative testing.  
For example, for cycles that start the engine and begin with idle, you  
may start a cycle in idle with the transmission in neutral with zero  
torque and later switch to a different idle with the transmission in  
drive with the Curb-Idle Transmission Torque (CITT). For variable-speed  
engines intended primarily for propulsion of a vehicle with an  
automatic transmission where  
[[Page 34546]]  
that engine is subject to a transient duty cycle with idle operation,  
you must declare a CITT. We recommend that you specify CITT as a  
function of idle speed for engines with adjustable warm idle or  
enhanced-idle. You may specify a CITT based on typical applications at  
the mean of the range of idle speeds you specify at stabilized  
temperature conditions.  
* * * * *  
0 
343. Amend Sec.  1065.512 by revising paragraphs (b)(1) and (2) to read  
as follows:  
Sec.  1065.512  Duty cycle generation.  
* * * * *  
    (b) * * *  
    (1) Engine speed for variable-speed engines. For variable-speed  
engines, normalized speed may be expressed as a percentage between warm  
idle speed, f nidle, and maximum test speed,  
fntest, or speed may be expressed by referring to a defined  
speed by name, such as ``warm idle,'' ``intermediate speed,'' or ``A,''  
``B,'' or ``C'' speed. Section 1065.610 describes how to transform  
these normalized values into a sequence of reference speeds,  
fnref. Running duty cycles with negative or small normalized  
speed values near warm idle speed may cause low-speed idle governors to  
activate and the engine torque to exceed the reference torque even  
though the operator demand is at a minimum. In such cases, we recommend  
controlling the dynamometer so it gives priority to follow the  
reference torque instead of the reference speed and let the engine  
govern the speed. Note that the cycle-validation criteria in Sec.   
1065.514 allow an engine to govern itself. This allowance permits you  
to test engines with enhanced-idle devices and to simulate the effects  
of transmissions such as automatic transmissions. For example, an  
enhanced-idle device might be an idle speed value that is normally  
commanded only under cold-start conditions to quickly warm up the  
engine and aftertreatment devices. In this case, negative and very low  
normalized speeds will generate reference speeds below this higher  
enhanced-idle speed. You may do either of the following with when using  
enhanced-idle devices:  
    (i) Control the dynamometer so it gives priority to follow the  
reference torque, controlling the operator demand so it gives priority  
to follow reference speed and let the engine govern the speed when the  
operator demand is at minimum.  
    (ii) While running an engine where the electronic control module  
broadcasts an enhanced-idle speed that is above the denormalized speed,  
use the broadcast speed as the reference speed. Use these new reference  
points for duty-cycle validation. This does not affect how you  
determine denormalized reference torque in paragraph (b)(2) of this  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 225/268section.  
    (2) Engine torque for variable-speed engines. For variable-speed  
engines, normalized torque is expressed as a percentage of the mapped  
torque at the corresponding reference speed. Section 1065.610 describes  
how to transform normalized torques into a sequence of reference  
torques, T ref. Section 1065.610 also describes special  
requirements for modifying transient duty cycles for variable-speed  
engines intended primarily for propulsion of a vehicle with an  
automatic transmission. Section 1065.610 also describes under what  
conditions you may command Tref greater than the reference torque you  
calculated from a normalized duty cycle, which permits you to command  
Tref values that are limited by a declared minimum torque.  
For any negative torque commands, command minimum operator demand and  
use the dynamometer to control engine speed to the reference speed, but  
if reference speed is so low that the idle governor activates, we  
recommend using the dynamometer to control torque to zero, CITT, or a  
declared minimum torque as appropriate. Note that you may omit power  
and torque points during motoring from the cycle-validation criteria in  
Sec.  1065.514. Also, use the maximum mapped torque at the minimum  
mapped speed as the maximum torque for any reference speed at or below  
the minimum mapped speed.  
* * * * *  
0 
344. Amend Sec.  1065.514 by revising paragraphs (e) introductory text,  
(e)(3), and (f)(3) to read as follows:  
Sec.  1065.514  Cycle-validation criteria for operation over specified  
duty cycles.  
* * * * *  
    (e) Statistical parameters. Use the remaining points to calculate  
regression statistics for a floating intercept as described in Sec.   
1065.602. Round calculated regression statistics to the same number of  
significant digits as the criteria to which they are compared. Refer to  
Table 2 of this section for the default criteria and refer to the  
standard-setting part to determine if there are other criteria for your  
engine. Calculate the following regression statistics:  
* * * * *  
    (3) Standard error of the estimate for feedback speed, SEEfn,  
feedback torque, SEET, and feedback power SEEP.  
* * * * *  
    (f) * * *  
    (3) For discrete-mode steady-state testing, apply cycle-validation  
criteria by treating the sampling periods from the series of test modes  
as a continuous sampling period, analogous to ramped-modal testing and  
apply statistical criteria as described in paragraph (f)(1) or (2) of  
this section. Note that if the gaseous and particulate test intervals  
are different periods of time, separate validations are required for  
the gaseous and particulate test intervals. Table 2 follows:  
               Table 2 of Sec.   1065.514--Default Statistical Criteria for Validating Duty Cycles  
----------------------------------------------------------------------------------------------------------------  
            Parameter                        Speed                     Torque                     Power  
----------------------------------------------------------------------------------------------------------------  
Slope, a1........................  0.950 <= a1 <= 1.030.....  0.830 <= a1 <= 1.030....  0.830 <= a1 <= 1.030.  
Absolute value of intercept,       <= 10% of warm idle......  <= 2% of maximum mapped   <= 2% of maximum mapped  
 [verbarlm]a0[verbarlm].                                       torque.                   power.
Standard error of the estimate,    <= 5% of maximum test      <= 10% of maximum mapped  <= 10% of maximum mapped  
 SEE.                               speed.                     torque.                   power.
Coefficient of determination, r2.  >= 0.970.................  >= 0.850................  >= 0.910.  
----------------------------------------------------------------------------------------------------------------  
0 
345. Amend Sec.  1065.530 by revising paragraph (a)(2)(iii) and adding  
paragraph (g)(5) to read as follows:  
Sec.  1065.530  Emission test sequence.  
    (a) * * *  
    (2) * * *  
    (iii) For testing that involves hot-stabilized emission  
measurements, bring the engine either to warm idle or the first  
operating point of the duty cycle. Start the test within 10 min of  
achieving temperature stability. Determine temperature stability as the  
point at  
[[Page 34547]]  
which the engine thermostat controls engine temperature or as the point  
at which measured operating temperature has stayed within 2% of the mean value for at least 2 min based on the following  
parameters:  
    (A) Engine coolant or block or head absolute temperatures for  
water-cooled engines.  
    (B) Oil sump absolute temperature for air-cooled engines with an  
oil sump.  
    (C) Cylinder head absolute temperature or exhaust gas temperature  
for air-cooled engines with no oil sump.  
* * * * *  
    (g) * * *  
    (5) If you perform carbon balance error verification, verify carbon  
balance error as specified in the standard-setting part and Sec.   
1065.543. Calculate and report the three carbon balance error  
quantities for each test interval; carbon mass absolute error for a  
test interval ([epsi] aC), carbon mass rate absolute error  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 226/268for a test interval ([epsi] aCrate), and carbon mass relative  
error for a test interval ([epsi] rC). For duty cycles with  
multiple test intervals, you may calculate and report the composite  
carbon mass relative error, [epsi] rCcomp, for the whole duty  
cycle. If you report [epsi] rCcomp, you must still calculate  
and report [epsi] aC, [epsi] aCrate, and  
[epsi]rC for each test interval.  
* * * * *  
0 
346. Add Sec.  1065.543 to read as follows:  
Sec.  1065.543  Carbon balance error verification.  
    (a) Carbon balance error verification compares independently  
calculated quantities of carbon flowing into and out of an engine  
system. The engine system includes aftertreatment devices as  
applicable. Calculating carbon intake considers carbon-carrying streams  
flowing into the system, including intake air, fuel, and optionally DEF  
or other fluids. Carbon flow out of the system comes from exhaust  
emission calculations. Note that this verification is not valid if you  
calculate exhaust molar flow rate using fuel rate and chemical balance  
as described in Sec.  1065.655(f)(3) because carbon flows into and out  
of the system are not independent. Use good engineering judgment to  
ensure that carbon mass in and carbon mass out data signals align.  
    (b) Perform the carbon balance error verification after emission  
sampling is complete for a test interval or duty cycle as described in  
Sec.  1065.530(g). Testing must include measured values as needed to  
determine intake air, fuel flow, and carbon-related gaseous exhaust  
emissions. You may optionally account for the flow of carbon-carrying  
fluids other than intake air and fuel into the system. Perform carbon  
balance error verification as follows:  
    (1) Calculate carbon balance error quantities as described in Sec.   
1065.643. The three quantities for individual test intervals are carbon  
mass absolute error, [epsi] aC, carbon mass rate absolute  
error, [epsi] aCrate, and carbon mass relative error,  
[epsi]rC. Determine [epsi] aC,  
[epsi]aCrate, and [epsi] rC for all test  
intervals. You may determine composite carbon mass relative error,  
[epsi]rCcomp, as a fourth quantity that optionally applies for duty  
cycles with multiple test intervals.  
    (2) You meet verification criteria for an individual test interval  
if the absolute values of carbon balance error quantities are at or  
below the following limit values:  
    (i) Calculate the carbon mass absolute error limit,  
L[epsi]aC , in grams to three decimal places for comparision  
to the absolute value of [epsi] ;aC, using the following  
equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.174  
Where: 
c = power-specific carbon mass absolute error coefficient = 0.007 g/  
kW. 
Pmax = maximum power from the engine map generated  
according to Sec.  1065.510. If measured  
Pmax is not available, use a manufacturer-declared value  
for Pmax. 
Example:  
c = 0.007 g/kW  
Pmax = 230.0 kW  
LoaC = 0.007 [middot] 230.0 = 1.610 g  
    (ii) Calculate the carbon mass rate absolute error limit,  
L[epsi]aCrate, in grams per hour to three decimal places for  
comparison to the absolute value of [epsi] aCrate, using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.175  
Where: 
d = power-specific carbon mass rate absolute error coefficient =  
0.31 g/(kW [middot] hr).  
Pmax = maximum power from the engine map generated  
according to Sec.  1065.510. If measured  
Pmax is not available, use a manufacturer-declared value  
for Pmax. 
Example:  
d = 0.31 g/(kW[middot]hr)  
Pmax = 230.0 kW  
L[egr]aCrate  = 71.300 g/hr  
    (iii) The carbon mass relative error limit,  
    L[egr]rC, is 0.020 for comparision to the absolute value  
of [epsi]rC , and optionally the absolute value of  
[epsi]rCcomp . 
    (c) A failed carbon balance error verification might indicate one  
or more problems requiring corrective action, as follows:  
             Table 1 of Sec.   1065.543--Troubleshooting Guide for Carbon Balance Error Verification  
----------------------------------------------------------------------------------------------------------------  
          Area of concern                      Problem                     Recommended corrective action  
----------------------------------------------------------------------------------------------------------------  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 227/268Gas analyzer system................  Incorrect analyzer           Calibrate NDIR and THC analyzers.  
                                      calibration.  
                                     Incorrect time alignment     Determine transformation time, t50, for  
                                      between flow and             continuous gas analyzers and time-align flow  
                                      concentration data.          and concentration data as described in Sec.  
                                                                   1065.650(c)(2)(i).  
                                     Problems with the sample     Inspect sample system components such as  
                                      system.                      sample lines, filters, chillers, and pumps  
                                                                   for leaks, operating temperature, and  
                                                                   contamination.  
Fuel flow measurement..............  Zero shift of fuel flow      Perform an in-situ zero adjustment.  
                                      rate meter.  
                                     Change in fuel flow meter    Calibrate the fuel flow meter as described in  
                                      calibration.                 Sec.   1065.320.  
                                     Incorrect time alignment of  Verify alignment of carbon mass in and carbon  
                                      fuel flow data.              mass out data streams.  
                                     Short sampling periods.....  For test intervals with varying duration, such  
                                                                   as discrete-mode steady-state duty cycles,  
                                                                   make the test intervals longer to improve  
                                                                   accuracy when measuring low fuel flow rates.  
[[Page 34548]]  
  
                                     Fluctuations in the fuel     Improve stability of the fuel temperature and  
                                      conditioning system.         pressure conditioning system to improve  
                                                                   accuracy when measuring low fuel flow rates.  
Dilute testing using a CVS system..  Leaks......................  Inspect exhaust system and CVS tunnel,  
                                                                   connections, and fasteners. Repair or replace  
                                                                   components as needed. A leak in the exhaust  
                                                                   transfer tube to the CVS may result in  
                                                                   negative values for carbon balance error.  
                                     Poor mixing................  Perform the verification related to mixing in  
                                                                   Sec.   1065.341(f).  
                                     Change in CVS calibration..  Calibrate the CVS flow meter as described in  
                                                                   Sec.   1065.340.  
                                     Flow meter entrance effects  Inspect the CVS tunnel to determine whether  
                                                                   entrance effects from the piping  
                                                                   configuration upstream of the flow meter  
                                                                   adversely affect flow measurement.  
                                     Other problems with the CVS  Inspect hardware and software for the CVS  
                                      or sampling verification     system and CVS verification system for  
                                      hardware or software.        discrepancies.  
Raw testing using intake air flow    Leaks......................  Inspect intake air and exhaust systems,  
 measurement or direct exhaust flow                                connections, fasteners. Repair or replace  
 measurement.                                                      components as needed.  
                                     Zero shift of intake air     Perform an in-situ zero adjustment.  
                                      flow rate meter.  
                                     Change in intake air flow    Calibrate the intake air flow meter as  
                                      meter calibration.           described in Sec.   1065.325.  
                                     Zero shift of exhaust flow   Perform an in-situ zero adjustment.  
                                      rate meter.  
                                     Change in exhaust flow       Calibrate the exhaust flow meter as described  
                                      meter calibration.           in Sec.   1065.330.  
                                     Flow meter entrance effects  Inspect intake air and exhaust systems to  
                                                                   determine whether entrance effects from the  
                                                                   piping configuration upstream and downstream  
                                                                   of the intake air flow meter or the exhaust  
                                                                   flow meter adversely affect flow measurement.  
                                     Other problems with the      Look for discrepancies in the hardware and  
                                      intake air flow and          software for measuring intake air flow and  
                                      exhaust flow measurement     exhaust flow.  
                                      hardware or software.  
                                     Poor mixing................  Ensure that all streams are well mixed.  
Accuracy of fluid properties.......  Inaccurate fluid properties  If defaults are used, use measured values. If  
                                                                   measured values are used, verify fluid  
                                                                   property determination.  
----------------------------------------------------------------------------------------------------------------  
0 
347. Amend Sec.  1065.545 by revising paragraphs (a) and (b)  
introductory text to read as follows:  
Sec.  1065.545  Verification of proportional flow control for batch  
sampling.  
* * * * *  
    (a) For any pair of flow rates, use recorded sample and total flow  
rates. Total flow rate means the raw exhaust flow rate for raw exhaust  
sampling and the dilute exhaust flow rate for CVS sampling, or their 1  
Hz means with the statistical calculations in Sec.  1065.602 forcing  
the intercept through zero. Determine the standard error of the  
estimate, SEE, of the sample flow rate versus the total flow rate. For  
each test interval, demonstrate that SEE was less than or equal to 3.5%  
of the mean sample flow rate.  
    (b) For any pair of flow rates, use recorded sample and total flow  
rates. Total flow rate means the raw exhaust flow rate for raw exhaust  
sampling and the dilute exhaust flow rate for CVS sampling, or their 1  
Hz means to demonstrate that each flow rate was constant within 2.5% of its respective mean or target flow rate. You may use the  
following options instead of recording the respective flow rate of each  
type of meter:  
* * * * *  
0 
348. Revise Sec.  1065.602 to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 228/268Sec.  1065.602  Statistics.  
    (a) Overview. This section contains equations and example  
calculations for statistics that are specified in this part. In this  
section we use the letter ``y'' to denote a generic measured quantity,  
the superscript over-bar ``-'' to denote an arithmetic mean,  
and the subscript `` ref'' to denote the reference quantity  
being measured.  
    (b) Arithmetic mean. Calculate an arithmetic mean, y, as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.176  
     
Example:  
N = 3 
y1 = 10.60  
y2 = 11.91  
yN = y3 = 11.09  
[GRAPHIC] [TIFF OMITTED] TR29JN21.177  
y = 11.20  
    (c) Standard deviation. Calculate the standard deviation for a non-  
biased (e.g., N-1) sample, [sigma], as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.178  
Example:  
N = 3 
y1 = 10.60  
y2 = 11.91  
yN = y3 = 11.09  
y = 11.20  
[[Page 34549]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.179  
[sigma]y = 0.6619  
    (d) Root mean square. Calculate a root mean square,  
rmsy, as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.180  
Example:  
N = 3 
y1 = 10.60  
y2 = 11.91  
yN = y3 = 11.09  
[GRAPHIC] [TIFF OMITTED] TR29JN21.181  
rmsy = 11.21  
    (e) Accuracy. Determine accuracy as described in this paragraph  
(e). Make multiple measurements of a standard quantity to create a set  
of observed values, yi, and compare each observed value to the known  
value of the standard quantity. The standard quantity may have a single  
known value, such as a gas standard, or a set of known values of  
negligible range, such as a known applied pressure produced by a  
calibration device during repeated applications. The known value of the  
standard quantity is represented by y refi. If you use a  
standard quantity with a single value, y refi would be  
constant. Calculate an accuracy value as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.182  
Example:  
yref = 1800.0  
N = 3 
y1 = 1806.4  
y2 = 1803.1  
y3 = 1798.9  
[GRAPHIC] [TIFF OMITTED] TR29JN21.183  
accuracy = 2.8  
    (f) t-test. Determine if your data passes a t-test by using the  
following equations and tables: (1) For an unpaired t-test, calculate  
the t statistic and its number of degrees of freedom, v, as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.184  
[GRAPHIC] [TIFF OMITTED] TR29JN21.185  
Example:  
Yref = 1205.3  
Y = 1123.8  
[sigma]ref = 9.399  
[sigma]y = 10.583  
Nref = 11 
N = 7 
[GRAPHIC] [TIFF OMITTED] TR29JN21.186  
t = 16.63  
[sigma]ref = 9.399  
[sigma]y = 10.583  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 229/268Nref = 11 
N = 7 
[GRAPHIC] [TIFF OMITTED] TR29JN21.187  
v = 11.76  
    (2) For a paired t-test, calculate the t statistic and its number  
of degrees of freedom, v, as follows, noting that the [epsi]i are the  
errors (e.g., differences) between each pair of y refi and  
yi: 
[GRAPHIC] [TIFF OMITTED] TR29JN21.188  
Example 1:  
[egr] = -0.12580  
N = 16 
[sigma][egr] = 0.04837  
[GRAPHIC] [TIFF OMITTED] TR29JN21.189  
t = 10.403  
v = N-1 
Example 2:  
N = 16 
v = 16-1  
v = 15 
    (3) Use Table 1 of this section to compare t to the  
tcrit values tabulated versus the number of degrees of  
freedom. If t is less than t crit, then t passes the t-test.  
The Microsoft Excel software has a TINV function that returns results  
equivalent results and may be used in place of Table 1, which follows:  
 Table 1 of Sec.   1065.602--Critical t Values Versus Number of Degrees  
                             of Freedom, v a  
------------------------------------------------------------------------  
                                                    Confidence  
                    v                    -------------------------------  
                                                90%             95%  
------------------------------------------------------------------------  
1.......................................           6.314          12.706  
2.......................................           2.920           4.303  
[[Page 34550]]  
  
3.......................................           2.353           3.182  
4.......................................           2.132           2.776  
5.......................................           2.015           2.571  
6.......................................           1.943           2.447  
7.......................................           1.895           2.365  
8.......................................           1.860           2.306  
9.......................................           1.833           2.262  
10......................................           1.812           2.228  
11......................................           1.796           2.201  
12......................................           1.782           2.179  
13......................................           1.771           2.160  
14......................................           1.761           2.145  
15......................................           1.753           2.131  
16......................................           1.746           2.120  
18......................................           1.734           2.101  
20......................................           1.725           2.086  
22......................................           1.717           2.074  
24......................................           1.711           2.064  
26......................................           1.706           2.056  
28......................................           1.701           2.048  
30......................................           1.697           2.042  
35......................................           1.690           2.030  
40......................................           1.684           2.021  
50......................................           1.676           2.009  
70......................................           1.667           1.994  
100.....................................           1.660           1.984  
1000+...................................           1.645           1.960  
------------------------------------------------------------------------  
a Use linear interpolation to establish values not shown here.  
    (g) F-test. Calculate the F statistic as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.190  
     
Example:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.191  
F = 1.268  
    (1) For a 90% confidence F-test, use the following table to compare  
F to the F crit90 values tabulated versus (N-1) and  
(Nref-1). If F is less than F crit90, then F  
passes the F-test at 90% confidence.  
BILLING CODE 6560-50-P  
[[Page 34551]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.192  
    (2) For a 95% confidence F-test, use the following table to compare  
F to the F crit90 values tabulated versus (N-1) and  
(Nref-1). If F is less than F crit95, then F  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 230/268passes the F-test at 95% confidence.  
[[Page 34552]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.193  
BILLING CODE 6560-50-C  
[[Page 34553]]  
    (h) Slope. Calculate a least-squares regression slope,  
a1y, using one of the following two methods:  
    (1) If the intercept floats, i.e., is not forced through zero:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.194  
     
Example:  
N = 6000  
y1 = 2045.8  
y = 1050.1  
yref1 = 2045.0  
yref = 1055.3  
[GRAPHIC] [TIFF OMITTED] TR29JN21.195  
a1y = 1.0110  
    (2) If the intercept is forced through zero, such as for verifying  
proportional sampling:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.196  
Example:  
N = 6000  
y1 = 2045.8  
yref1 = 2045.0  
[GRAPHIC] [TIFF OMITTED] TR29JN21.197  
a1y = 1.0110  
    (i) Intercept. For a floating intercept, calculate a least-squares  
regression intercept, a 0y, as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.198  
Example:  
y = 1050.1  
a1y = 1.0110  
yref = 1055.3  
a0y = 1050.1 - (1.0110 [middot] 1055.3)  
a0y = -16.8083  
    (j) Standard error of the estimate. Calculate a standard error of  
the estimate, SEE, using one of the following two methods:  
    (1) For a floating intercept:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.199  
     
Example:  
N = 6000  
y1 = 2045.8  
a0y = -16.8083  
a1y = 1.0110  
yref1 = 2045.0  
[GRAPHIC] [TIFF OMITTED] TR29JN21.200  
SEEy = 5.348  
    (2) If the intercept is forced through zero, such as for verifying  
proportional sampling:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.201  
Example:  
N = 6000  
y1 = 2045.8  
a1y = 1.0110  
yref1 = 2045.0  
[GRAPHIC] [TIFF OMITTED] TR29JN21.202  
[[Page 34554]]  
SEEy = 5.347  
    (k) Coefficient of determination. Calculate a coefficient of  
determination, r y2, as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.203  
Example:  
N = 6000  
y1 = 2045.8  
a0y = -16.8083  
a1y = 1.0110  
yref1 = 2045.0  
y = 1480.5  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 231/268[GRAPHIC] [TIFF OMITTED] TR29JN21.204  
    (l) Flow-weighted mean concentration. In some sections of this  
part, you may need to calculate a flow-weighted mean concentration to  
determine the applicability of certain provisions. A flow-weighted mean  
is the mean of a quantity after it is weighted proportional to a  
corresponding flow rate. For example, if a gas concentration is  
measured continuously from the raw exhaust of an engine, its flow-  
weighted mean concentration is the sum of the products of each recorded  
concentration times its respective exhaust molar flow rate, divided by  
the sum of the recorded flow rate values. As another example, the bag  
concentration from a CVS system is the same as the flow-weighted mean  
concentration because the CVS system itself flow-weights the bag  
concentration. You might already expect a certain flow-weighted mean  
concentration of an emission at its standard based on previous testing  
with similar engines or testing with similar equipment and instruments.  
If you need to estimate your expected flow-weighted mean concentration  
of an emission at its standard, we recommend using the following  
examples as a guide for how to estimate the flow-weighted mean  
concentration expected at the standard. Note that these examples are  
not exact and that they contain assumptions that are not always valid.  
Use good engineering judgment to determine if you can use similar  
assumptions.  
    (1) To estimate the flow-weighted mean raw exhaust NO X  
concentration from a turbocharged heavy-duty compression-ignition  
engine at a NO X standard of 2.5 g/(kW[middot]hr), you may do  
the following:  
    (i) Based on your engine design, approximate a map of maximum  
torque versus speed and use it with the applicable normalized duty  
cycle in the standard-setting part to generate a reference duty cycle  
as described in Sec.  1065.610. Calculate the total reference work,  
Wref, as described in Sec.  1065.650. Divide the reference  
work by the duty cycle's time interval, [Delta]t dutycycle ,  
to determine mean reference power, p ref. 
    (ii) Based on your engine design, estimate maximum power,  
Pmax, the design speed at maximum power,  
[fnof]nmax, the design maximum intake manifold boost  
pressure, P inmax, and temperature, T inmax. Also,  
estimate a mean fraction of power that is lost due to friction and  
pumping, P. Use this information along with the engine displacement  
volume, V disp, an approximate volumetric efficiency,  
[eta]V, and the number of engine strokes per power stroke  
(two-stroke or four-stroke), N stroke, to estimate the  
maximum raw exhaust molar flow rate, n exhmax. 
    (iii) Use your estimated values as described in the following  
example calculation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.205  
Example:  
eNOX = 2.5 g/(kW[middot]hr)  
Wref = 11.883 kW[middot]hr  
MNOX = 46.0055 g/mol = 46.0055[middot]10-\6\ g/[mu]mol  
[Delta]t dutycycle  = 20 min = 1200 s  
Pref = 35.65 kW  
Pfrict = 15% 
Pmax = 125 kW  
[[Page 34555]]  
pmax = 300 kPa = 300000 Pa  
Vdisp = 3.0 l = 0.0030 m\3\/r  
fnmax = 2800 r/min = 46.67 r/s  
Nstroke = 4 
[eta]V = 0.9 
R = 8.314472 J/(mol[middot]K)  
Tmax = 348.15 K  
[GRAPHIC] [TIFF OMITTED] TR29JN21.206  
    (2) To estimate the flow-weighted mean NMHC concentration in a CVS  
from a naturally aspirated nonroad spark-ignition engine at an NMHC  
standard of 0.5 g/(kW[middot]hr), you may do the following:  
    (i) Based on your engine design, approximate a map of maximum  
torque versus speed and use it with the applicable normalized duty  
cycle in the standard-setting part to generate a reference duty cycle  
as described in Sec.  1065.610. Calculate the total reference work,  
Wref, as described in Sec.  1065.650.  
    (ii) Multiply your CVS total molar flow rate by the time interval  
of the duty cycle, [Delta]t dutycycle . The result is the  
total diluted exhaust flow of the n dexh. 
    (iii) Use your estimated values as described in the following  
example calculation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.207  
Example:  
eNMHC = 1.5 g/(kW[middot]hr)  
Wref = 5.389 kW[middot]hr  
MNMHC = 13.875389 g/mol = 13.875389[middot]10-\6\ g/[mu]mol  
ndexh = 6.021 mol/s  
[Delta]t dutycycle  = 30 min = 1800 s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.208  
XNMHC = 53.8 [micro]mol/mol  
0 
349. Amend Sec.  1065.610 by revising paragraphs (a)(1)(iv), (a)(2)  
introductory text, and (d)(3) introductory text to read as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 232/268Sec.  1065.610  Duty cycle generation.  
* * * * *  
    (a) * * *  
    (1) * * *  
    (iv) Transform the map into a normalized power-versus-speed map by  
dividing power terms by P max and dividing speed terms by  
fnPmax. Use the following equation to calculate a quantity  
representing the sum of squares from the normalized map:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.209  
Where: 
i = an indexing variable that represents one recorded value of an  
engine map.  
fnnormi = an engine speed normalized by dividing it by  
fnPmax. 
Pnormi = an engine power normalized by dividing it by  
Pmax. 
* * * * *  
    (2) For engines with a high-speed governor that will be subject to  
a reference duty cycle that specifies normalized speeds greater than  
100%, calculate an alternate maximum test speed, f ntest,alt ,  
as specified in this paragraph (a)(2). If f ntest,alt  is less  
than the measured maximum test speed, f ntest, determined in  
paragraph (a)(1) of this section, replace f ntest with  
fntest,alt . In this case, f ntest,alt  becomes the  
``maximum test speed'' for that engine for all duty cycles. Note that  
Sec.  1065.510 allows you to apply an optional declared maximum test  
speed to the final measured maximum test speed determined as an outcome  
of the comparison between f ntest, and fntest,alt   
in this paragraph (a)(2). Determine f ntest,alt  as follows:  
* * * * *  
    (d) * * *  
    (3) Required deviations. We require the following deviations for  
variable-speed engines intended primarily for propulsion of a vehicle  
with an automatic transmission where that engine is subject to a  
transient duty cycle with idle operation. These deviations are intended  
to produce a more representative transient duty cycle for these  
applications. For steady-state duty cycles or transient duty cycles  
with no idle operation, the requirements in this paragraph (d)(3) do  
not apply. Idle points for steady-state duty cycles of such engines are  
to be run at conditions simulating neutral or park on the transmission.  
You may develop  
[[Page 34556]]  
different procedures for adjusting CITT as a function of speed,  
consistent with good engineering judgment.  
* * * * *  
0 
350. Amend Sec.  1065.640 by revising paragraph (a), (b)(3), and (d)(1)  
and (3) to read as follows:  
Sec.  1065.640  Flow meter calibration calculations.  
* * * * *  
    (a) Reference meter conversions. The calibration equations in this  
section use molar flow rate, n ref, as a reference quantity.  
If your reference meter outputs a flow rate in a different quantity,  
such as standard volume rate,V stdref, actual volume  
rate,Vactref, or mass rate, m ref, convert your  
reference meter output to a molar flow rate using the following  
equations, noting that while values for volume rate, mass rate,  
pressure, temperature, and molar mass may change during an emission  
test, you should ensure that they are as constant as practical for each  
individual set point during a flow meter calibration:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.210  
Where: 
nref = reference molar flow rate.  
Vstdref = reference volume flow rate corrected to a  
standard pressure and a standard temperature.  
Vactref = reference volume flow rate at the actual  
pressure and temperature of the flow rate.  
mref = reference mass flow.  
pstd = standard pressure.  
pact = actual pressure of the flow rate.  
Tstd = standard temperature.  
Tact = actual temperature of the flow rate.  
R = molar gas constant.  
Mmix = molar mass of the flow rate.  
Example 1:  
Vstdref = 1000.00 ft\3/min\ = 0.471948 m\3/s\  
pstd = 29.9213 in Hg @ 32 [deg]F = 101.325 kPa = 101325 Pa =  
101325 kg/(m[middot]s\2\)  
Tstd = 68.0 [deg]F = 293.15 K  
R = 8.314472 J/(mol[middot]K) = 8.314472 (m\2\[middot]kg)/  
(s\2\[middot]mol[middot]K)  
[GRAPHIC] [TIFF OMITTED] TR29JN21.211  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 233/268nref = 19.619 mol/s  
Example 2:  
mref = 17.2683 kg/min = 287.805 g/s  
Mmix = 28.7805 g/mol  
[GRAPHIC] [TIFF OMITTED] TR29JN21.212  
nref = 10.0000 mol/s  
    (b) * *  
    (3) Perform a least-squares regression of V rev, versus  
Ks, by calculating slope, a 1, and intercept,  
a0, as described for a floating intercept in Sec.  1065.602.  
* * * * *  
    (d) * * *  
    (1) Calculate the Reynolds number, Re#, for each  
reference molar flow rate, n ref, using the throat diameter  
of the venturi, d t. Because the dynamic viscosity, [micro],  
is needed to compute Re#, you may use your own fluid  
viscosity model to determine [micro] for your calibration gas (usually  
air), using good engineering judgment. Alternatively, you may use the  
Sutherland three-coefficient viscosity model to approximate [micro], as  
shown in the following sample calculation for Re#: 
[GRAPHIC] [TIFF OMITTED] TR29JN21.213  
    Where, using the Sutherland three-coefficient viscosity model as  
captured in Table 4 of this section:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.214  
Where: 
[micro]0 = Sutherland reference viscosity.  
T0 = Sutherland reference temperature.  
S = Sutherland constant.  
               Table 4 of Sec.   1065.640--Sutherland Three-Coefficient Viscosity Model Parameters  
----------------------------------------------------------------------------------------------------------------  
                                           [micro] 0         T0           S         Temperature   Pressure limit  
                                       ------------------------------------------  range within         \b\  
                                                                                  2% ---------------  
                Gas \a\                      (kg/                                    error \b\  
                                         (m[middot]s))      (K)          (K)     ----------------      (kPa)  
                                                                                        (K)  
----------------------------------------------------------------------------------------------------------------  
Air...................................  1.716[middot]1          273          111     170 to 1900          <=1800  
                                                   0-5  
CO2...................................  1.370[middot]1          273          222     190 to 1700          <=3600  
                                                   0-5  
H2O...................................  1.12[middot]10-         350         1064     360 to 1500         <=10000  
                                                     5  
O2....................................  1.919[middot]1          273          139     190 to 2000          <=2500  
                                                   0-5  
N2....................................  1.663[middot]1          273          107     100 to 1500          <=1600  
                                                   0-5  
----------------------------------------------------------------------------------------------------------------  
\a\ Use tabulated parameters only for the pure gases, as listed. Do not combine parameters in calculations to  
  calculate viscosities of gas mixtures.  
\b\ The model results are valid only for ambient conditions in the specified ranges.  
Example:  
[micro]0 = 1.716[middot]10-5 kg/(m[middot]s)  
T0 = 273 K  
S = 111 K  
[[Page 34557]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.215  
[micro] = 1.838[middot]10-5 kg/(m[middot]s)  
Mmix = 28.7805 g/mol = 0.0287805 kg/mol  
nref = 57.625 mol/s  
dt = 152.4 mm = 0.1524 m  
Tin = 298.15 K  
[GRAPHIC] [TIFF OMITTED] TR29JN21.216  
Re# = 7.538[middot]105 
* * * * *  
    (3) Perform a least-squares regression analysis to determine the  
best-fit coefficients for the equation and calculate SEE as described  
in Sec.  1065.602. When using Eq. 1065.640-12, treat C d as y  
and the radical term as y ref and use Eq. 1065.602-12 to  
calculate SEE. When using another mathematical expression, use the same  
approach to substitute that expression into the numerator of Eq.  
1065.602-12 and replace the 2 in the denominator with the number of  
coefficients in the mathematical expression.  
* * * * *  
0 
351. Amend Sec.  1065.642 by revising paragraphs (b) and (c)(1) to read  
as follows:  
Sec.  1065.642  PDP, SSV, and CFV molar flow rate calculations.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 234/268* * * * *  
    (b) SSV molar flow rate. Calculate SSV molar flow rate, n, as  
follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.217  
Where: 
Cd = discharge coefficient, as determined based on the  
Cd versus Re# equation in Sec.   
1065.640(d)(2).  
Cf = flow coefficient, as determined in Sec.   
1065.640(c)(3)(ii).  
At = venturi throat cross-sectional area.  
pin = static absolute pressure at the venturi inlet.  
Z = compressibility factor.  
Mmix = molar mass of gas mixture.  
R = molar gas constant.  
Tin = absolute temperature at the venturi inlet.  
Example:  
At = 0.01824 m\2\  
pin = 99.132 kPa = 99132 Pa = 99132 kg/(m[middot]s\2\)  
Z = 1 
Mmix = 28.7805 g/mol = 0.0287805 kg/mol  
R = 8.314472 J/(mol[middot]K) = 8.314472 (m\2\[middot]kg)/  
(s\2\[middot]mol[middot]K)  
Tin = 298.15 K  
Re# = 7.232[middot]10\5\  
[gamma] = 1.399  
[beta] = 0.8  
[Delta]p = 2.312 kPa  
    Using Eq. 1065.640-7:  
rssv = 0.997  
    Using Eq. 1065.640-6:  
Cf = 0.274  
    Using Eq. 1065.640-5:  
Cd = 0.990  
[GRAPHIC] [TIFF OMITTED] TR29JN21.218  
n = 58.173 mol/s  
    (c) * * *  
    (1) To calculate n through one venturi or one combination of  
venturis, use its respective mean C d and other constants you  
determined according to Sec.  1065.640 and calculate n as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.219  
Where: 
Cf = flow coefficient, as determined in Sec.   
1065.640(c)(3).  
Example:  
Cd = 0.985  
Cf = 0.7219  
At = 0.00456 m2
pin = 98.836 kPa = 98836 Pa = 98836 kg/  
(m[middot]s2) 
Z = 1 
Mmix = 28.7805 g/mol = 0.0287805 kg/mol  
R = 8.314472 J/(mol[middot]K) = 8.314472 (m2[middot]kg)/  
(s2[middot]mol[middot]K)  
Tin = 378.15 K  
[GRAPHIC] [TIFF OMITTED] TR29JN21.220  
n = 33.690 mol/s  
* * * * *  
0 
352. Add Sec.  1065.643 to read as follows:  
Sec.  1065.643  Carbon balance error verification calculations.  
    This section describes how to calculate quantities used in the  
carbon balance error verification described in Sec.  1065.543.  
Paragraphs (a) through (c) of this section describe how to calculate  
the mass of carbon for a test interval from carbon-carrying fluid  
streams, intake air into the system, and exhaust emissions,  
respectively. Paragraph (d) of this section describes how to use these  
carbon masses to calculate four different quantities for evaluating  
carbon balance error. Use rectangular or trapezoidal integration  
methods to calculate masses and amounts over a test interval from  
continuously measured or calculated mass and molar flow rates.  
    (a) Fuel and other fluids. Determine the mass of fuel, DEF, and  
other carbon-carrying fluid streams, other than intake air, flowing  
into the system, m fluidj, for each test interval. Note that  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 235/268Sec.  1065.543 allows you to omit all flows other than fuel. You may  
determine the mass of DEF based on ECM signals for DEF flow rate. You  
may determine fuel mass during field testing based on ECM signals for  
fuel flow rate. Calculate the mass of carbon from the combined  
[[Page 34558]]  
carbon-carrying fluid streams flowing into the system as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.221  
Where: 
j = an indexing variable that represents one carbon-carrying fluid  
stream. 
N = total number of carbon-carrying fluid streams into the system  
over the test interval.  
wC = carbon mass fraction of the carbon-carrying fluid  
stream as determined in Sec.  1065.655(d).  
mfluid = the mass of the carbon-carrying fluid stream  
determined over the test interval.
Example:  
N = 2 
wCfuel = 0.869  
wCDEF = 0.065  
mfuel = 1119.6 g  
mDEF = 36.8 g  
mCfluid = 0.869[middot]1119.6 + 0.065[middot]36.8 = 975.3 g  
    (b) Intake air. Calculate the mass of carbon in the intake air,  
mCair, for each test interval using one of the methods in  
this paragraph (b). The methods are listed in order of preference. Use  
the first method where all the inputs are available for your test  
configuration. For methods that calculate m Cair based on the  
amount of CO 2 per mole of intake air, we recommend measuring  
intake air concentration, but you may calculate x CO2int  
using Eq. 1065.655-10 and letting x CO2intdry  = 375  
[micro]mol/mol.  
    (1) Calculate m Cair, using the following equation if you  
measure intake air flow:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.222  
Where: 
MC = molar mass of carbon.  
nint = measured amount of intake air over the test  
interval.  
xCO2int = amount of intake air CO 2 per mole of  
intake air.  
Example:  
MC = 12.0107 g/mol  
nint = 62862 mol  
xCO2int = 369 [micro]mol/mol = 0.000369 mol/mol  
mCair = 12.0107[middot]62862[middot]0.000369 = 278.6 g  
    (2) Calculate m Cair, using the following equation if you  
measure or calculate raw exhaust flow and you calculate chemical  
balance terms:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.223  
Where: 
MC = molar mass of carbon.  
nexh = calculated or measured amount of raw exhaust over  
the test interval.  
xH2Oexh = amount of H 2O in exhaust per mole of  
exhaust.  
xCO2int = amount of intake air CO 2 per mole of  
intake air.  
xdil/exhdry  = amount of excess air per mole of dry  
exhaust. Note that excess air and intake air have the same  
composition, so x CO2dil = xCO2int and  
xH2Odil = xH2Oint for the chemical balance  
calculation for raw exhaust.  
xint/exhdry  = amount of intake air required to produce  
actual combustion products per mole of dry exhaust.  
Example:  
MC = 12.0107 g/mol  
nexh = 62862 mol  
xH2Oexh = 0.034 mol/mol  
xCO2int = 369 [micro]mol/mol = 0.000369 mol/mol  
xdil/exhdry  = 0.570 mol/mol  
xint/exhdry  = 0.465 mol/mol  
mCair = 12.0107[middot]62862[middot](1 -  
0.034)[middot]0.000369[middot](0.570 + 0.465) = 278.6 g  
    (3) Calculate m Cair, using the following equation if you  
measure raw exhaust flow:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.224  
Where: 
MC = molar mass of carbon.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 236/268nexh = measured amount of raw exhaust over the test  
interval.  
xCO2int = amount of intake air CO 2 per mole of  
intake air.  
Example:  
MC = 12.0107 g/mol  
nexh = 62862 mol  
xCO2int = 369 [micro]mol/mol = 0.000369 mol/mol  
mCair = 12.0107[middot]62862[middot]0.000369 = 278.6 g  
    (4) Calculate m Cair, using the following equation if you  
measure diluted exhaust flow and dilution air flow:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.225  
Where: 
MC = molar mass of carbon.  
ndexh = measured amount of diluted exhaust over the test  
interval as determined in Sec.  1065.642.  
ndil = measured amount of dilution air over the test  
interval as determined in Sec.  1065.667(b).  
xCO2int = amount of intake air CO 2 per mole of  
intake air.  
Example:  
MC = 12.0107 g/mol  
ndexh = 942930 mol  
ndil = 880068 mol  
xCO2int = 369 [micro]mol/mol = 0.000369 mol/mol  
mCair = 12.0107[middot](942930 - 880068)[middot]0.000369 =  
278.6 g 
    (5) Determined m Cair based on ECM signals for intake air  
flow as described in paragraph (b)(1) of this section.  
    (6) If you measure diluted exhaust, determine m Cair as  
described in paragraph (b)(4) of this section using a calculated amount  
of dilution air over the test interval as determined in Sec.   
1065.667(d) instead of the measured amount of dilution air.  
    (c) Exhaust emissions. Calculate the mass of carbon in exhaust  
emissions, m Cexh, for each test interval as follows:  
[[Page 34559]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.226  
Where: 
MC = molar mass of carbon.  
mCO2 = mass of CO 2 over the test interval as  
determined in Sec.  1065.650(c).  
MCO2 = molar mass of carbon dioxide.  
mCO = mass of CO over the test interval as determined in  
Sec.  1065.650(c).  
MCO = molar mass of carbon monoxide.  
mTHC = mass of THC over the test interval as determined  
in Sec.  1065.650(c).  
MTHC = effective C 1 molar mass of total  
hydrocarbon as defined in Sec.  1065.1005(f)(2).  
Example:  
MC = 12.0107 g/mol  
mCO2 = 4567 g  
MCO2 = 44.0095 g/mol  
mCO = 0.803 g  
MCO = 28.0101 g/mol  
mTHC = 0.537 g  
MTHC = 13.875389 g/mol  
[GRAPHIC] [TIFF OMITTED] TR29JN21.227  
    (d) Carbon balance error quantities. Calculate carbon balance error  
quantities as follows:  
    (1) Calculate carbon mass absolute error, [epsi] aC, for  
a test interval as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.228  
Where: 
mCexh = mass of carbon in exhaust emissions over the test  
interval as determined in paragraph (d) of this section.  
mCfluid = mass of carbon in all the carbon-carrying fluid  
streams flowing into the system over the test interval as determined  
in paragraph (a) of this section.  
mCair = mass of carbon in the intake air flowing into the  
system over the test interval as determined in paragraph (b) of this  
section.  
Example:  
mCexh = 1247.2 g  
mCfluid = 975.3 g  
mCair = 278.6 g  
[Ograve] aC = 1247.2-975.3-278.6 = -6.7 g  
    (2) Calculate carbon mass rate absolute error,  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 237/268[isin]aCrate, for a test interval as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.229  
Where: 
t = duration of the test interval.
Example:  
[isin]aC = -6.7 g  
t = 1202.2 s = 0.3339 hr  
[GRAPHIC] [TIFF OMITTED] TR29JN21.230  
    (3) Calculate carbon mass relative error, [isin] rC, for  
a test interval as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.276  
Example:  
[isin]aC = -6.7 g  
mCfliud = 975.3 g  
mCair = 278.6 g  
[GRAPHIC] [TIFF OMITTED] TR29JN21.231  
    (4) Calculate composite carbon mass relative error,  
[isin]rCcomp, for a duty cycle with multiple test intervals  
as follows:  
    (i) Calculate [isin] rCcomp using the following equation:  
[[Page 34560]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.232  
Where: 
i = an indexing variable that represents one test interval.  
N = number of test intervals.  
WF = weighting factor for the test interval as defined in the  
standard-setting part.  
mCexh = mass of carbon in exhaust emissions over the test  
interval as determined in paragraph (c) of this section.  
mCfluid = mass of carbon in all the carbon-carrying fluid  
streams that flowed into the system over the test interval as  
determined in paragraph (a) of this section.  
mCair = mass of carbon in the intake air that flowed into  
the system over the test interval as determined in paragraph (b) of  
this section.  
t = duration of the test interval. For duty cycles with multiple  
test intervals of a prescribed duration, such as cold-start and hot-  
start transient cycles, set t = 1 for all test intervals. For  
discrete-mode steady-state duty cycles with multiple test intervals  
of varying duration, set t equal to the actual duration of each test  
interval.  
    (ii) The following example illustrates calculation of  
[isin]rCcomp, for cold-start and hot-start transient cycles:  
N = 2 
WF1 = 1/7 
WF2 = 6/7 
mCexh1 = 1255.3 g  
mCexh2 = 1247.2 g  
mCfluid1 = 977.8 g  
mCfluid2 = 975.3 g  
mCair1 = 280.2 g  
mCair2 = 278.6 g  
[GRAPHIC] [TIFF OMITTED] TR29JN21.233  
    (iii) The following example illustrates calculation of  
[isin]rCcomp for multiple test intervals with varying  
duration, such as discrete-mode steady-state duty cycles:  
N = 2 
WF1 = 0.85 
WF2 = 0.15 
mCexh1 = 2.873 g  
mCexh2 = 0.125 g  
mCfluid1 = 2.864 g  
mCfluid2 = 0.095 g  
mCair1 = 0.023 g  
mCair2 = 0.024 g  
t1 = 123 s  
t2 = 306 s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.234  
0 
353. Amend Sec.  1065.650 by revising paragraphs (b)(3) introductory  
text, (c)(1), (c)(2)(i) introductory text, (c)(3), (d) introductory  
text, (d)(7), (f)(2) introductory text, and (g) to read as follows:  
Sec.  1065.650  Emission calculations.  
* * * * *  
    (b) * * *  
    (3) For field testing, you may calculate the ratio of total mass to  
total work, where these individual values are determined as described  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 238/268in paragraph (f) of this section. You may also use this approach for  
laboratory testing, consistent with good engineering judgment. Good  
engineering judgment dictates that this method not be used if there are  
any work flow paths described in Sec.  1065.210 that cross the system  
boundary, other than the primary output shaft (crankshaft). This is a  
special case in which you use a signal linearly proportional to raw  
exhaust molar flow rate to determine a value proportional to total  
emissions. You then use the same linearly proportional signal to  
determine total work using a chemical balance of fuel, DEF, intake air,  
and exhaust as described in Sec.  1065.655, plus information about your  
engine's brake-specific fuel consumption. Under this method, flow  
meters need not meet accuracy specifications, but they must meet the  
applicable linearity and repeatability specifications in subpart D or J  
of this part. The result is a brake-specific emission value calculated  
as follows:  
* * * * *  
    (c) * * *  
    (1) Concentration corrections. Perform the following sequence of  
preliminary calculations on recorded concentrations:  
    (i) Use good engineering judgment to time-align flow and  
concentration data to match transformation time, t 50, to  
within 1 s. 
    (ii) Correct all gaseous emission analyzer concentration readings,  
including continuous readings, sample bag readings, and dilution air  
background readings, for drift as described in Sec.  1065.672. Note  
that you must omit this step where brake-specific emissions are  
calculated without the drift correction for performing the drift  
[[Page 34561]]  
validation according to Sec.  1065.550(b). When applying the initial  
THC and CH 4 contamination readings according to Sec.   
1065.520(f), use the same values for both sets of calculations. You may  
also use as-measured values in the initial set of calculations and  
corrected values in the drift-corrected set of calculations as  
described in Sec.  1065.520(f)(7).
    (iii) Correct all THC and CH 4 concentrations for initial  
contamination as described in Sec.  1065.660(a), including continuous  
readings, sample bags readings, and dilution air background readings.  
    (iv) Correct all concentrations measured on a ``dry'' basis to a  
``wet'' basis, including dilution air background concentrations, as  
described in Sec.  1065.659.  
    (v) Calculate all NMHC and CH 4 concentrations, including  
dilution air background concentrations, as described in Sec.  1065.660.  
    (vi) For emission testing with an oxygenated fuel, calculate any HC  
concentrations, including dilution air background concentrations, as  
described in Sec.  1065.665. See subpart I of this part for testing  
with oxygenated fuels.  
    (vii) Correct all the NO X concentrations, including  
dilution air background concentrations, for intake-air humidity as  
described in Sec.  1065.670.  
    (2) * * *  
    (i) Varying flow rate. If you continuously sample from a changing  
exhaust flow rate, time align and then multiply concentration  
measurements by the flow rate from which you extracted it. We consider  
the following to be examples of changing flows that require a  
continuous multiplication of concentration times molar flow rate: Raw  
exhaust, exhaust diluted with a constant flow rate of dilution air, and  
CVS dilution with a CVS flow meter that does not have an upstream heat  
exchanger or electronic flow control. This multiplication results in  
the flow rate of the emission itself. Integrate the emission flow rate  
over a test interval to determine the total emission. If the total  
emission is a molar quantity, convert this quantity to a mass by  
multiplying it by its molar mass, M. The result is the mass of the  
emission, m. Calculate m for continuous sampling with variable flow  
using the following equations:  
* * * * *  
    (3) Batch sampling. For batch sampling, the concentration is a  
single value from a proportionally extracted batch sample (such as a  
bag, filter, impinger, or cartridge). In this case, multiply the mean  
concentration of the batch sample by the total flow from which the  
sample was extracted. You may calculate total flow by integrating a  
changing flow rate or by determining the mean of a constant flow rate,  
as follows:  
    (i) Varying flow rate. If you collect a batch sample from a  
changing exhaust flow rate, extract a sample proportional to the  
changing exhaust flow rate. We consider the following to be examples of  
changing flows that require proportional sampling: Raw exhaust, exhaust  
diluted with a constant flow rate of dilution air, and CVS dilution  
with a CVS flow meter that does not have an upstream heat exchanger or  
electronic flow control. Integrate the flow rate over a test interval  
to determine the total flow from which you extracted the proportional  
sample. Multiply the mean concentration of the batch sample by the  
total flow from which the sample was extracted. If the total emission  
is a molar quantity, convert this quantity to a mass by multiplying it  
by its molar mass, M. The result is the mass of the emission, m. In the  
case of PM emissions, where the mean PM concentration is already in  
units of mass per mole of sample, M PM, simply multiply it by  
the total flow. The result is the total mass of PM, m PM.  
Calculate m for batch sampling with variable flow using the following  
equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.235  
Example:  
MNOX = 46.0055 g/mol  
N = 9000  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 239/268XNOX= 85.6 [mu]mol/mol = 85.6[middot]10-6 mol/mol  
ndexh1= 25.534 mol/s  
ndexh2= 26.950 mol/s  
[fnof]record = 5 Hz 
    Using Eq. 1065.650-5:  
[Delta]t = 1/5 = 0.2  
mNOX = 46.0055[middot]85.6[middot]10-6[middot](25.534 +  
26.950 +...+ n exh9000)[middot]0.2  
mNOX = 4.201 g  
    (ii) Constant flow rate. If you batch sample from a constant  
exhaust flow rate, extract a sample at a proportional or constant flow  
rate. We consider the following to be examples of constant exhaust  
flows: CVS diluted exhaust with a CVS flow meter that has either an  
upstream heat exchanger, electronic flow control, or both. Determine  
the mean molar flow rate from which you extracted the constant flow  
rate sample. Multiply the mean concentration of the batch sample by the  
mean molar flow rate of the exhaust from which the sample was  
extracted, and multiply the result by the time of the test interval. If  
the total emission is a molar quantity, convert this quantity to a mass  
by multiplying it by its molar mass, M. The result is the mass of the  
emission, m. In the case of PM emissions, where the mean PM  
concentration is already in units of mass per mole of sample,  
MPM, simply multiply it by the total flow, and the result is  
the total mass of PM, m PM. 
    (A) Calculate m for sampling with constant flow using the following  
equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.236  
    (B) Calculate M for PM or any other analysis of a batch sample that  
yields a mass per mole of sample using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.237  
    (C) The following example illustrates a calculation of  
mPM: 
MPM = 144.0 [mu]g/mol = 144.0[middot]10-6 g/mol 
n&dexh= 57.692 mol/s  
[Delta]t = 1200 s  
mPM = 144.0[middot]10-6[middot]57.692[middot]1200  
mPM = 9.9692 g  
* * * * *  
    (d) Total work over a test interval. To calculate the total work  
from the engine over a test interval, add the total work from all the  
work paths described in Sec.  1065.210 that cross the system boundary  
including electrical energy/work, mechanical shaft work, and fluid  
pumping work. For all work paths, except the engine's primary output  
shaft (crankshaft), the total work for the path over the test interval  
is the integration of the net work flow rate (power) out of the system  
boundary. When energy/work flows into the system boundary, this work  
flow rate signal becomes negative; in this case, include these negative  
work rate values in the integration to calculate total work from that  
work path. Some work paths may result in a negative total work. Include  
negative total work values from any work path in the calculated total  
work from the engine rather than setting the values to zero. The rest  
of this paragraph (d) describes how to calculate total work from the  
engine's primary output shaft over a test interval. Before integrating  
power on the engine's primary output shaft, adjust the speed and torque  
data for the time alignment used in Sec.  1065.514(c). Any advance or  
delay used on the feedback signals for cycle validation must also be  
used for  
[[Page 34562]]  
calculating work. Account for work of accessories according to Sec.   
1065.110. Exclude any work during cranking and starting. Exclude work  
during actual motoring operation (negative feedback torques), unless  
the engine was connected to one or more energy storage devices.  
Examples of such energy storage devices include hybrid powertrain  
batteries and hydraulic accumulators, like the ones illustrated in  
Figure 1 of Sec.  1065.210. Exclude any work during reference zero-load  
idle periods (0% speed or idle speed with 0 N[middot]m reference  
torque). Note, that there must be two consecutive reference zero load  
idle points to establish a period where the zero-load exclusion  
applies. Include work during idle points with simulated minimum torque  
such as Curb Idle Transmissions Torque (CITT) for automatic  
transmissions in ``drive''. The work calculation method described in  
paragraphs (d)(1) though (7) of this section meets the requirements of  
this paragraph (d) using rectangular integration. You may use other  
logic that gives equivalent results. For example, you may use a  
trapezoidal integration method as described in paragraph (d)(8) of this  
section.  
* * * * *  
    (7) Integrate the resulting values for power over the test  
interval. Calculate total work as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.238  
Where: 
W = total work from the primary output shaft.  
Pi = instantaneous power from the primary output shaft  
over an interval i.  
[GRAPHIC] [TIFF OMITTED] TR29JN21.239  
Example:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 240/268N = 9000  
[fnof]n1 = 1800.2 r/min  
[fnof]n2 = 1805.8 r/min  
T1 = 177.23 N[middot]m  
T2 = 175.00 N[middot]m  
Crev = 2[middot][pi] rad/r  
Ct1 = 60 s/min  
Cp = 1000 (N[middot]m[middot]rad/s)/kW  
[fnof]record = 5 Hz 
Ct2 = 3600 s/hr  
[GRAPHIC] [TIFF OMITTED] TR29JN21.240  
P1 = 33.41 kW  
P2 = 33.09 kW  
    Using Eq. 1065.650-5:  
[Delta]t = 1/5 = 0.2 s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.241  
W = 16.875 kW[middot]hr  
* * * * *  
    (f) * * *  
    (2) Total work. To calculate a value proportional to total work  
over a test interval, integrate a value that is proportional to power.  
Use information about the brake-specific fuel consumption of your  
engine, e fuel, to convert a signal proportional to fuel flow  
rate to a signal proportional to power. To determine a signal  
proportional to fuel flow rate, divide a signal that is proportional to  
the mass rate of carbon products by the fraction of carbon in your  
fuel, wC. You may use a measured w C or you may  
use default values for a given fuel as described in Sec.  1065.655(e).  
Calculate the mass rate of carbon from the amount of carbon and water  
in the exhaust, which you determine with a chemical balance of fuel,  
DEF, intake air, and exhaust as described in Sec.  1065.655. In the  
chemical balance, you must use concentrations from the flow that  
generated the signal proportional to molar flow rate, nj, in paragraph  
(e)(1) of this section. Calculate a value proportional to total work as  
follows:  
* * * * *  
    (g) Brake-specific emissions over a duty cycle with multiple test  
intervals. The standard-setting part may specify a duty cycle with  
multiple test intervals, such as with discrete-mode steady-state  
testing. Unless we specify otherwise, calculate composite brake-  
specific emissions over the duty cycle as described in this paragraph  
(g). If a measured mass (or mass rate) is negative, set it to zero for  
calculating composite brake-specific emissions, but leave it unchanged  
for drift validation. In the case of calculating composite brake-  
specific emissions relative to a combined emission standard (such as a  
NOX + NMHC standard), change any negative mass (or mass  
rate) values to zero for a particular pollutant before combining the  
values for the different pollutants.  
    (1) Use the following equation to calculate composite brake-  
specific emissions for duty cycles with multiple test intervals all  
with prescribed durations, such as cold-start and hot-start transient  
cycles: 
[GRAPHIC] [TIFF OMITTED] TR29JN21.242  
Where: 
i = test interval number.  
N[middot] = number of test intervals.  
WF = weighting factor for the test interval as defined in the  
standard-setting part.  
m = mass of emissions over the test interval as determined in  
paragraph (c) of this section.  
W = total work from the engine over the test interval as determined  
in paragraph (d) of this section.  
Example:  
N = 2 
WF1 = 0.1428  
WF2 = 0.8572  
m1 = 70.125 g  
m2 = 64.975 g  
W1 = 25.783 kW[middot]hr  
W2 = 25.783 kW[middot]hr  
[GRAPHIC] [TIFF OMITTED] TR29JN21.243  
eNOXcomp = 2.548 g/kW[middot]hr  
    (2) Calculate composite brake-specific emissions for duty cycles  
with multiple test intervals that allow use of varying duration, such  
as discrete-mode steady-state duty cycles, as follows:  
    (i) Use the following equation if you calculate brake-specific  
emissions over test intervals based on total mass and total work as  
described in paragraph (b)(1) of this section:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.244  
Where: 
i = test interval number.  
N = number of test intervals.  
WF = weighting factor for the test interval as defined in the  
standard-setting part.  
m = mass of emissions over the test interval as determined in  
paragraph (c) of this section.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 241/268W = total work from the engine over the test interval as determined  
in paragraph (d) of this section.  
t = duration of the test interval.
Example:  
N = 2 
WF1 = 0.85 
WF2 = 0.15 
m1 = 1.3753 g  
[[Page 34563]]  
m2 = 0.4135 g  
t1 = 120 s  
t2 = 200 s  
W1 = 2.8375 kW[middot]hr  
W2 = 0.0 kW[middot]hr  
[GRAPHIC] [TIFF OMITTED] TR29JN21.245  
eNOxcomp = 0.5001 g/kW[middot]hr  
    (ii) Use the following equation if you calculate brake-specific  
emissions over test intervals based on the ratio of mass rate to power  
as described in paragraph (b)(2) of this section:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.246  
Where: 
i = test interval number.  
N = number of test intervals.  
WF = weighting factor for the test interval as defined in the  
standard-setting part.  
mi = mean steady-state mass rate of emissions over the test interval  
as determined in paragraph (e) of this section.  
P = mean steady-state power over the test interval as described in  
paragraph (e) of this section.  
Example:  
N = 2 
WF1 = 0.85 
WF2 = 0.15 
mi1 = 2.25842 g/hr  
mi2 = 0.063443 g/hr  
P1 = 4.5383 kW  
P2 = 0.0 kW  
[GRAPHIC] [TIFF OMITTED] TR29JN21.247  
eNOxcomp = 0.5001 g/kW[middot]hr  
* * * * *  
0 
354. Amend Sec.  1065.655 by revising the section heading and  
paragraphs (a), (c) introductory text, (c)(3), (d) introductory text,  
(e), and (f)(3) to read as follows:  
Sec.  1065.655  Chemical balances of fuel, DEF, intake air, and  
exhaust.  
    (a) General. Chemical balances of fuel, intake air, and exhaust may  
be used to calculate flows, the amount of water in their flows, and the  
wet concentration of constituents in their flows. With one flow rate of  
either fuel, intake air, or exhaust, you may use chemical balances to  
determine the flows of the other two. For example, you may use chemical  
balances along with either intake air or fuel flow to determine raw  
exhaust flow. Note that chemical balance calculations allow measured  
values for the flow rate of diesel exhaust fluid for engines with urea-  
based selective catalytic reduction.  
* * * * *  
    (c) Chemical balance procedure. The calculations for a chemical  
balance involve a system of equations that require iteration. We  
recommend using a computer to solve this system of equations. You must  
guess the initial values of up to three quantities: The amount of water  
in the measured flow, x H2Oexh, fraction of dilution air in  
diluted exhaust, x dil/exh, and the amount of products on a  
C1 basis per dry mole of dry measured flow,  
xCcombdry . You may use time-weighted mean values of  
combustion air humidity and dilution air humidity in the chemical  
balance; as long as your combustion air and dilution air humidities  
remain within tolerances of 0.0025 mol/mol of their  
respective mean values over the test interval. For each emission  
concentration, x, and amount of water, x H2Oexh, you must  
determine their completely dry concentrations, x dry and  
xH2Oexhdry . You must also use your fuel mixture's atomic  
hydrogen-to-carbon ratio, [alpha], oxygen-to-carbon ratio, [beta],  
sulfur-to-carbon ratio, [gamma], and nitrogen-to-carbon ratio, [delta];  
you may optionally account for diesel exhaust fluid (or other fluids  
injected into the exhaust), if applicable. You may calculate [alpha],  
[beta], [gamma], and [delta] based on measured fuel composition or  
based on measured fuel and diesel exhaust fluid (or other fluids  
injected into the exhaust) composition together, as described in  
paragraph (e) of this section. You may alternatively use any  
combination of default values and measured values as described in  
paragraph (e) of this section. Use the following steps to complete a  
chemical balance:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 242/268* * * * *  
    (3) Use the following symbols and subscripts in the equations for  
performing the chemical balance calculations in this paragraph (c):  
 Table 1 of Sec.   1065.655--Symbols and Subscripts for Chemical Balance  
                                Equations  
------------------------------------------------------------------------  
                                Amount of dilution gas or excess air per  
              x                             mole of exhaust  
------------------------------------------------------------------------  
xH2Oexh......................  amount of H2O in exhaust per mole of  
                                exhaust  
xCcombdry....................  amount of carbon from fuel and any  
                                injected fluids in the exhaust per mole  
                                of dry exhaust  
xH2dry.......................  amount of H2 in exhaust per amount of dry  
                                exhaust  
KH2Ogas......................  water-gas reaction equilibrium  
                                coefficient; you may use 3.5 or  
                                calculate your own value using good  
                                engineering judgment  
xH2Oexhdry...................  amount of H2O in exhaust per dry mole of  
                                dry exhaust  
xprod/intdry.................  amount of dry stoichiometric products per  
                                dry mole of intake air  
xdil/exhdry..................  amount of dilution gas and/or excess air  
                                per mole of dry exhaust  
xint/exhdry..................  amount of intake air required to produce  
                                actual combustion products per mole of  
                                dry (raw or diluted) exhaust  
xraw/exhdry..................  amount of undiluted exhaust, without  
                                excess air, per mole of dry (raw or  
                                diluted) exhaust  
xO2int.......................  amount of intake air O2 per mole of  
                                intake air  
xCO2intdry...................  amount of intake air CO2 per mole of dry  
                                intake air; you may use xCO2intdry = 375  
                                [micro]mol/mol, but we recommend  
                                measuring the actual concentration in  
                                the intake air  
xH2Ointdry...................  amount of intake air H2O per mole of dry  
                                intake air  
xCO2int......................  amount of intake air CO2 per mole of  
                                intake air  
xCO2dil......................  amount of dilution gas CO2 per mole of  
                                dilution gas  
xCO2dildry...................  amount of dilution gas CO2 per mole of  
                                dry dilution gas; if you use air as  
                                diluent, you may use xCO2dildry = 375  
                                [micro]mol/mol, but we recommend  
                                measuring the actual concentration in  
                                the intake air  
xH2Odildry...................  amount of dilution gas H2O per mole of  
                                dry dilution gas  
xH2Odil......................  amount of dilution gas H2O per mole of  
                                dilution gas  
x[emission]meas..............  amount of measured emission in the sample  
                                at the respective gas analyzer  
x[emission]dry...............  amount of emission per dry mole of dry  
                                sample  
xH2O[emission]meas...........  amount of H2O in sample at emission-  
                                detection location; measure or estimate  
                                these values according to Sec.  
                                1065.145(e)(2)  
xH2Oint......................  amount of H2O in the intake air, based on  
                                a humidity measurement of intake air  
[alpha]......................  atomic hydrogen-to-carbon ratio of the  
                                fuel (or mixture of test fuels) and any  
                                injected fluids  
[[Page 34564]]  
  
[beta].......................  atomic oxygen-to-carbon ratio of the fuel  
                                (or mixture of test fuels) and any  
                                injected fluids  
[gamma]......................  atomic sulfur-to-carbon ratio of the fuel  
                                (or mixture of test fuels) and any  
                                injected fluids  
[delta]......................  atomic nitrogen-to-carbon ratio of the  
                                fuel (or mixture of test fuels) and any  
                                injected fluids  
------------------------------------------------------------------------  
* * * * *  
    (d) Carbon mass fraction of fuel. Determine carbon mass fraction of  
fuel, wC, based on the fuel properties as determined in  
paragraph (e) of this section, optionally accounting for diesel exhaust  
fluid's contribution to [alpha], [beta], [gamma], and [delta], or other  
fluids injected into the exhaust, if applicable (for example, the  
engine is equipped with an emission control system that utilizes DEF).  
Calculate w C using the following equation:  
* * * * *  
    (e) Fuel and diesel exhaust fluid composition. Determine fuel and  
diesel exhaust fluid composition represented by [alpha], [beta],  
[gamma], and [delta] as described in this paragraph (e). When using  
measured fuel or diesel exhaust fluid properties, you must determine  
values for [alpha] and [beta] in all cases. If you determine  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 243/268compositions based on measured values and the default value listed in  
Table 2 of this section is zero, you may set [gamma] and [delta] to  
zero; otherwise determine [gamma] and [delta] (along with [alpha] and  
[beta]) based on measured values. Determine elemental mass fractions  
and values for [alpha], [beta], [gamma], and [delta] as follows:  
    (1) For liquid fuels, use the default values for [alpha], [beta],  
[gamma], and [delta] in Table 2 of this section or determine mass  
fractions of liquid fuels for calculation of [alpha], [beta], [gamma],  
and [delta] as follows:  
    (i) Determine the carbon and hydrogen mass fractions according to  
ASTM D5291 (incorporated by reference in Sec.  1065.1010). When using  
ASTM D5291 to determine carbon and hydrogen mass fractions of gasoline  
(with or without blended ethanol), use good engineering judgment to  
adapt the method as appropriate. This may include consulting with the  
instrument manufacturer on how to test high-volatility fuels. Allow the  
weight of volatile fuel samples to stabilize for 20 minutes before  
starting the analysis; if the weight still drifts after 20 minutes,  
prepare a new sample). Retest the sample if the carbon, hydrogen,  
oxygen, sulfur, and nitrogen mass fractions do not add up to a total  
mass of 100  0.5%; if you do not measure oxygen, you may  
assume it has a zero concentration for this specification. You may also  
assume that sulfur and nitrogen have a zero concentration for all fuels  
except residual fuel blends.  
    (ii) Determine oxygen mass fraction of gasoline (with or without  
blended ethanol) according to ASTM D5599 (incorporated by reference in  
Sec.  1065.1010). For all other liquid fuels, determine the oxygen mass  
fraction using good engineering judgment.  
    (iii) Determine the nitrogen mass fraction according to ASTM D4629  
or ASTM D5762 (incorporated by reference in Sec.  1065.1010) for all  
liquid fuels. Select the correct method based on the expected nitrogen  
content.  
    (iv) Determine the sulfur mass fraction according to subpart H of  
this part.  
    (2) For gaseous fuels and diesel exhaust fluid, use the default  
values for [alpha], [beta], [gamma], and [delta] in Table 2 of this  
section, or use good engineering judgment to determine those values  
based on measurement.  
    (3) For nonconstant fuel mixtures, you must account for the varying  
proportions of the different fuels. This paragraph (e)(3) generally  
applies for dual-fuel and flexible-fuel engines, but it also applies if  
diesel exhaust fluid is injected in a way that is not strictly  
proportional to fuel flow. Account for these varying concentrations  
either with a batch measurement that provides averaged values to  
represent the test interval, or by analyzing data from continuous mass  
rate measurements. Application of average values from a batch  
measurement generally applies to situations where one fluid is a minor  
component of the total fuel mixture, for example dual-fuel and  
flexible-fuel engines with diesel pilot injection, where the diesel  
pilot fuel mass is less than 5% of the total fuel mass and diesel  
exhaust fluid injection; consistent with good engineering judgment.  
    (4) Calculate [alpha], [beta], [gamma], and [delta] using the  
following equations:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.248  
[GRAPHIC] [TIFF OMITTED] TR29JN21.249  
Where: 
N = total number of fuels and injected fluids over the duty cycle.  
j = an indexing variable that represents one fuel or injected fluid,  
starting with j = 1.  
mj = the mass flow rate of the fuel or any injected fluid j. For  
applications using a single fuel and no DEF fluid, set this value to  
1. For batch measurements, divide the total mass of fuel over the  
test interval duration to determine a mass rate.  
wHj = hydrogen mass fraction of fuel or any injected  
fluid j.  
wCj = carbon mass fraction of fuel or any injected fluid  
j. 
wOj = oxygen mass fraction of fuel or any injected fluid  
j. 
wSj = sulfur mass fraction of fuel or any injected fluid  
j. 
wNj = nitrogen mass fraction of fuel or any injected  
fluid j.  
Example:  
N = 1 
j = 1 
m1= 1 
wH1 = 0.1239  
wC1 = 0.8206  
wO1 = 0.0547  
wS1 = 0.00066  
wN1 = 0.000095  
MC = 12.0107  
[[Page 34565]]  
MH = 1.00794  
MO = 15.9994  
MS = 32.065  
MN = 14.0067  
[GRAPHIC] [TIFF OMITTED] TR29JN21.250  
[alpha] = 1.799  
[beta] = 0.05004  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 244/268[gamma] = 0.0003012  
[delta] = 0.0001003  
    (5) Table 2 follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.251  
     
    (f) * * *  
    (3) Fluid mass flow rate calculation. This calculation may be used  
only for steady-state laboratory testing. You may not use this  
calculation if the standard-setting part requires carbon balance error  
verification as described in Sec.  1065.543. See Sec.   
1065.915(d)(5)(iv) for application to field testing. Calculate  
nexh based on mj using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.252  
Where: 
nexh = raw exhaust molar flow rate from which you  
measured emissions.  
j = an indexing variable that represents one fuel or injected fluid,  
starting with j = 1.  
N = total number of fuels and injected fluids over the duty cycle.  
mj = the mass flow rate of the fuel or any injected fluid j.  
wCj = carbon mass fraction of the fuel and any injected  
fluid j.  
Example:  
N = 1 
j = 1 
m1= 7.559 g/s  
wC1 = 0.869 g/g  
MC = 12.0107 g/mol  
[chi]Ccombdry1  = 99.87 mmol/mol = 0.09987 mol/mol  
[chi]H20exhdry1  = 107.64 mmol/mol = 0.10764 mol/mol  
[[Page 34566]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.253  
nexh = 6.066 mol/s  
* * * * *  
0 
355. Amend Sec.  1065.659 by revising paragraph (c)(2) and (3) to read  
as follows:  
Sec.  1065.659  Removed water correction.  
* * * * *  
    (c) * * *  
    (2) If the measurement comes from raw exhaust, you may determine  
the amount of water based on intake-air humidity, plus a chemical  
balance of fuel, DEF, intake air, and exhaust as described in Sec.   
1065.655.  
    (3) If the measurement comes from diluted exhaust, you may  
determine the amount of water based on intake-air humidity, dilution  
air humidity, and a chemical balance of fuel, DEF, intake air, and  
exhaust as described in Sec.  1065.655.  
* * * * *  
0 
356. Amend Sec.  1065.660 by adding paragraphs (a)(5) and (6) and  
revising paragraphs (b)(2) introductory text, (b)(2)(ii) introductory  
text, (b)(2)(iii) introductory text, (b)(3) introductory text, (b)(4),  
(c)(2), (d) introductory text, (d)(1) introductory text, (d)(1)(ii)  
introductory text, (d)(1)(iii) introductory text, (d)(2), and (e) to  
read as follows:  
Sec.  1065.660  THC, NMHC, NMNEHC, CH4, and C2H6 determination.  
    (a) * * *  
    (5) You may calculate THC as the sum of NMHC and CH 4 if  
you determine CH 4 with an FTIR as described in paragraph  
(d)(2) of this section and NMHC with an FTIR using the additive method  
from paragraph (b)(4) of this section.  
    (6) You may calculate THC as the sum of NMNEHC,  
C2H6, and CH 4 if you determine  
CH4 with an FTIR as described in paragraph (d)(2) of this  
section, C 2H6 with an FTIR as described in  
paragraph (e) of this section, and NMNEHC with an FTIR using the  
additive method from paragraph (c)(3) of this section.  
    (b) * * *  
    (2) For nonmethane cutters, calculate [chi] NMHC using  
the nonmethane cutter's methane penetration fraction,  
PFCH4[NMC-FID] , and the ethane response factor penetration  
fraction, RFPF C2H6[NMC-FID] , from Sec.  1065.365, the THC  
FID's methane response factor, RF CH4[THC-FID] , from Sec.   
1065.360, the initial THC contamination and dry-to-wet corrected THC  
concentration, [chi] THC[THC-FID]cor , as determined in  
paragraph (a) of this section, and the dry-to-wet corrected methane  
concentration, [chi] THC[NMC-FID]cor , optionally corrected  
for initial THC contamination as determined in paragraph (a) of this  
section.  
* * * * *  
    (ii) Use the following equation for penetration fractions  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 245/268determined using an NMC configuration as outlined in Sec.  1065.365(e):  
* * * * *  
    (iii) Use the following equation for penetration fractions  
determined using an NMC configuration as outlined in Sec.  1065.365(f)  
or for penetration fractions determined as a function of molar water  
concentration using an NMC configuration as outlined in Sec.   
1065.365(d):  
* * * * *  
    (3) For a GC-FID or FTIR, calculate [chi] NMHC using the  
THC analyzer's methane response factor, RF CH4[THC-FID] , from  
Sec.  1065.360, and the initial THC contamination and dry-to-wet  
corrected THC concentration, [chi] THC[THC-FID]cor , as  
determined in paragraph (a) of this section as follows:  
* * * * *  
    (4) For an FTIR, calculate [chi] NMHC by summing the  
hydrocarbon species listed in Sec.  1065.266(c) as follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.254  
Where: 
[chi]NMHC = concentration of NMHC.  
[chi]HCi = the C 1-equivalent concentration of  
hydrocarbon species i as measured by the FTIR, not corrected for  
initial contamination.  
[chi]HCi-init  = the C 1-equivalent  
concentration of the initial system contamination (optional) of  
hydrocarbon species i, dry-to-wet corrected, as measured by the  
FTIR. 
Example:  
[chi]C2H6 = 4.9 [mu]mol/mol  
[chi]C2H4 = 0.9 [mu]mol/mol  
[chi]C2H2 = 0.8 [mu]mol/mol  
[chi]C3H8 = 0.4 [mu]mol/mol  
[chi]C3H6 = 0.5 [mu]mol/mol  
[chi]C4H10 = 0.3 [mu]mol/mol  
[chi]CH2O = 0.8 [mu]mol/mol  
[chi]C2H4O = 0.3 [mu]mol/mol  
[chi]CH2O2 = 0.1 [mu]mol/mol  
[chi]CH4O = 0.1 [mu]mol/mol  
[chi]NMHC = 4.9 + 0.9 + 0.8 + 0.4 + 0.5 + 0.3 + 0.8 + 0.3 +  
0.1 + 0.1  
[chi]NMHC = 9.1 [mu]mol/mol  
    (c) * * *  
    (2) For a GC-FID, NMC FID, or FTIR, calculate  
[chi]NMNEHC using the THC analyzer's methane response  
factor, RF CH4[THC-FID] , and ethane response factor,  
RFC2H6[THC-FID] , from Sec.  1065.360, the initial  
contamination and dry-to-wet corrected THC concentration,  
[chi]THC[THC-FID]cor , as determined in paragraph (a) of this  
section, the dry-to-wet corrected methane concentration,  
[chi]CH4, as determined in paragraph (d) of this section,  
and the dry-to-wet corrected ethane concentration,  
[chi]C2H6, as determined in paragraph (e) of this section as  
follows:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.255  
Where: 
[chi]NMNEHC = concentration of NMNEHC.  
[chi]THC[THC-FID]cor  = concentration of THC, initial THC  
contamination and dry-to-wet corrected, as measured by the THC FID.  
RFCH4[THC-FID]  = response factor of THC-FID to  
CH4. 
[chi]CH4 = concentration of CH 4, dry-to-wet  
corrected, as measured by the GC-FID, NMC FID, or FTIR.  
RFC2H6[THC-FID]  = response factor of THC-FID to  
C2H6. 
[chi]C2H6 = the C 1-equivalent concentration of  
C2H6, dry-to-wet corrected, as measured by the  
GC-FID or FTIR.  
Example:  
[chi]THC[THC-FID]cor  = 145.6 [mu]mol/mol  
RFCH4[THC-FID]  = 0.970  
[chi]CH4 = 18.9 [mu]mol/mol  
RFC2H6[THC-FID]  = 1.02 
[chi]C2H6 = 10.6 [mu]mol/mol  
[chi]NMNEHC = 145.6-0.970 [middot] 18.9-1.02 [middot] 10.6  
[chi]NMNEHC = 116.5 [mu]mol/mol  
* * * * *  
    (d) CH4 determination. Use one of the following methods to  
determine methane concentration, [chi] CH4: 
    (1) For nonmethane cutters, calculate [chi] CH4 using the  
nonmethane cutter's methane penetration fraction,  
PFCH4[NMC-FID] , and the ethane response  
[[Page 34567]]  
factor penetration fraction, RFPF C2H6[NMC-FID , from Sec.   
1065.365, the THC FID's methane response factor,  
RFCH4[THC-FID] , from Sec.  1065.360, the initial THC  
contamination and dry-to-wet corrected THC concentration,  
[chi]THC[THC-FID]cor , as determined in paragraph (a) of this  
section, and the dry-to-wet corrected methane concentration,  
[chi]THC[NMC-FID]cor , optionally corrected for initial THC  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 246/268contamination as determined in paragraph (a) of this section.  
* * * * *  
    (ii) Use the following equation for penetration fractions  
determined using an NMC configuration as outlined in Sec.  1065.365(e):  
* * * * *  
    (iii) Use the following equation for penetration fractions  
determined using an NMC configuration as outlined in Sec.  1065.365(f)  
or for penetration fractions determined as a function of molar water  
concentration using an NMC configuration as outlined in Sec.   
1065.365(d):  
* * * * *  
    (2) For a GC-FID or FTIR, [chi] CH4 is the actual dry-to-  
wet corrected methane concentration as measured by the analyzer.  
    (e) C2H6 determination. For a GC-FID or FTIR, [chi] C2H6  
is the C 1-equivalent, dry-to-wet corrected ethane  
concentration as measured by the analyzer.  
0 
357. Amend Sec.  1065.665 by revising paragraph (a) to read as follows:  
Sec.  1065.665  THCE and NMHCE determination.  
    (a) If you measured an oxygenated hydrocarbon's mass concentration,  
first calculate its molar concentration in the exhaust sample stream  
from which the sample was taken (raw or diluted exhaust), and convert  
this into a C 1-equivalent molar concentration. Add these  
C1-equivalent molar concentrations to the molar  
concentration of non-oxygenated total hydrocarbon (NOTHC). The result  
is the molar concentration of total hydrocarbon equivalent (THCE).  
Calculate THCE concentration using the following equations, noting that  
Eq. 1065.665-3 is required only if you need to convert your oxygenated  
hydrocarbon (OHC) concentration from mass to moles:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.256  
[GRAPHIC] [TIFF OMITTED] TR29JN21.257  
[GRAPHIC] [TIFF OMITTED] TR29JN21.258  
Where: 
[chi]THCE = the sum of the C 1-equivalent  
concentrations of non-oxygenated hydrocarbon, alcohols, and  
aldehydes.  
[chi]NOTHC = the sum of the C 1-equivalent  
concentrations of NOTHC.  
[chi]OHCi = the C 1-equivalent concentration of oxygenated  
species i in diluted exhaust, not corrected for initial  
contamination.  
[chi]OHCi-init  = the C 1-equivalent  
concentration of the initial system contamination (optional) of  
oxygenated species i, dry-to-wet corrected.  
[chi]THC[THC-FID]cor  = the C 1-equivalent  
response to NOTHC and all OHC in diluted exhaust, HC contamination  
and dry-to-wet corrected, as measured by the THC-FID.  
RFOHCi[THC-FID]  = the response factor of the FID to  
species i relative to propane on a C 1-equivalent basis.  
Mdexh = the molar mass of diluted exhaust as determine in  
Sec.  1065.340.  
mdexhOHCi  = the mass of oxygenated species i in dilute  
exhaust.  
MOHCi = the C 1-equivalent molecular weight of  
oxygenated species i.  
mdexh = the mass of diluted exhaust.  
ndexhOHCi  = the number of moles of oxygenated species i  
in total diluted exhaust flow.  
ndexh = the total diluted exhaust flow.  
* * * * *  
0 
358. Amend Sec.  1065.667 by revising paragraph (d) to read as follows:  
Sec.  1065.667  Dilution air background emission correction.  
* * * * *  
    (d) You may determine the total flow of dilution air from the  
measured dilute exhaust flow and a chemical balance of the fuel, DEF,  
intake air, and dilute exhaust as described in Sec.  1065.655. For this  
paragraph (d), the molar flow of dilution air is calculated by  
multiplying the dilute exhaust flow by the mole fraction of dilution  
gas to dilute exhaust, [chi] dil/ex, from the dilute chemical  
balance. This may be done by totaling continuous calculations or by  
using batch results. For example, to use batch results, the total flow  
of dilution air is calculated by multiplying the total flow of diluted  
exhaust, n dexh, by the flow-weighted mean mole fraction of  
dilution air in diluted exhaust, [chi] dil/exh. Calculate  
[chi]dil/exh using flow-weighted mean concentrations of  
emissions in the chemical balance, as described in Sec.  1065.655. The  
chemical balance in Sec.  1065.655 assumes that your engine operates  
stoichiometrically, even if it is a lean-burn engine, such as a  
compression-ignition engine. Note that for lean-burn engines this  
assumption could result in an error in emission calculations. This  
error could occur because the chemical balance in Sec.  1065.655 treats  
excess air passing through a lean-burn engine as if it was dilution  
air. If an emission concentration expected at the standard is about 100  
times its dilution air background concentration, this error is  
negligible. However, if an emission concentration expected at the  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 247/268standard is similar to its background concentration, this error could  
be significant. If this error might affect your ability to show that  
your engines comply with applicable standards in this chapter, we  
recommend that you either determine the total flow of  
[[Page 34568]]  
dilution air using one of the more accurate methods in paragraph (b) or  
(c) of this section, or remove background emissions from dilution air  
by HEPA filtration, chemical adsorption, or catalytic scrubbing. You  
might also consider using a partial-flow dilution technique such as a  
bag mini-diluter, which uses purified air as the dilution air.  
* * * * *  
0 
359. Amend Sec.  1065.675 by revising paragraph (d) to read as follows:  
Sec.  1065.675  CLD quench verification calculations.  
* * * * *  
    (d) Calculate quench as follows:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.259  
     
Where: 
quench = amount of CLD quench.  
[chi]NOdry = concentration of NO upstream of a humidity  
generator, according to Sec.  1065.370(e)(4).  
[chi]NOwet = measured concentration of NO downstream of a  
humidity generator, according to Sec.  1065.370(e)(9).  
[chi]H2Oexp = maximum expected mole fraction of water  
during emission testing, according to paragraph (b) of this section.  
[chi]H2Omeas = measured mole fraction of water during the  
quench verification, according to Sec.  1065.370(e)(7).  
[chi]NOmeas = measured concentration of NO when NO span  
gas is blended with CO 2 span gas, according to Sec.   
1065.370(d)(10).  
[chi]NOact = actual concentration of NO when NO span gas  
is blended with CO 2 span gas, according to Sec.   
1065.370(d)(11) and calculated according to Eq. 1065.675-2.  
[chi]CO2exp = maximum expected concentration of  
CO2 during emission testing, according to paragraph (c)  
of this section.  
[chi]CO2act = actual concentration of CO 2 when  
NO span gas is blended with CO 2 span gas, according to  
Sec.  1065.370(d)(9).  
[GRAPHIC] [TIFF OMITTED] TR29JN21.260  
Where: 
[chi]NOspan = the NO span gas concentration input to the  
gas divider, according to Sec.  1065.370(d)(5).  
[chi]CO2span = the CO 2 span gas concentration  
input to the gas divider, according to Sec.  1065.370(d)(4).  
Example:  
[chi]NOdry = 1800.0 [mu]mol/mol  
[chi]NOwet = 1739.6 [mu]mol/mol  
[chi]H2Oexp = 0.030 mol/mol  
[chi]H2Omeas = 0.030 mol/mol  
[chi]NOmeas = 1515.2 [mu]mol/mol  
[chi]NOspan = 3001.6 [mu]mol/mol  
[chi]CO2exp = 3.2% 
[chi]CO2span = 6.1% 
[chi]CO2act = 2.98%  
[GRAPHIC] [TIFF OMITTED] TR29JN21.261  
quench = (-0.0036655-0.014020171) [middot] 100% = -1.7685671%  
0 
360. Amend Sec.  1065.695 by adding paragraph (c)(8)(v) to read as  
follows:  
Sec.  1065.695  Data requirements.
* * * * *  
    (c) * * *  
    (8) * * *  
    (v) Carbon balance error verification, if performed.  
* * * * *  
0 
361. Amend Sec.  1065.701 by revising paragarphs (b) and (f) to read as  
follows:  
Sec.  1065.701  General requirements for test fuels.  
* * * * *  
    (b) Fuels meeting alternate specifications. We may allow you to use  
a different test fuel (such as California LEV III gasoline) if it does  
not affect your ability to show that your engines would comply with all  
applicable emission standards in this chapter using the test fuel  
specified in this subpart.  
* * * * *  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 248/268    (f) Service accumulation and field testing fuels. If we do not  
specify a service-accumulation or field-testing fuel in the standard-  
setting part, use an appropriate commercially available fuel such as  
those meeting minimum specifications from the following table:  
 Table 1 of Sec.   1065.701--Examples of Service-Accumulation and Field-  
                              Testing Fuels  
------------------------------------------------------------------------  
                                                            Reference  
         Fuel category                Subcategory         procedure \a\  
------------------------------------------------------------------------  
Diesel........................  Light distillate and    ASTM D975.  
                                 light blends with  
                                 residual.  
[[Page 34569]]  
  
                                Middle distillate.....  ASTM D6985.  
                                Biodiesel (B100)......  ASTM D6751.  
Intermediate and residual fuel  All...................  See Sec.  
                                                         1065.705.  
Gasoline......................  Automotive gasoline...  ASTM D4814.  
                                Automotive gasoline     ASTM D4814.  
                                 with ethanol  
                                 concentration up to  
                                 10 volume %.  
Alcohol.......................  Ethanol (E51-83)......  ASTM D5798.  
                                Methanol (M70-M85)....  ASTM D5797.  
Aviation fuel.................  Aviation gasoline.....  ASTM D910.  
                                Gas turbine...........  ASTM D1655.  
                                Jet B wide cut........  ASTM D6615.  
Gas turbine fuel..............  General...............  ASTM D2880.  
------------------------------------------------------------------------  
\a\ Incorporated by reference; see Sec.   1065.1010.  
0 
362. Amend Sec.  1065.703 by revising paragraph (b) to read as follows:  
Sec.  1065.703  Distillate diesel fuel.  
* * * * *  
    (b) There are three grades of #2 diesel fuel specified for use as a  
test fuel. See the standard-setting part to determine which grade to  
use. If the standard-setting part does not specify which grade to use,  
use good engineering judgment to select the grade that represents the  
fuel on which the engines will operate in use. The three grades are  
specified in Table 1 of this section.  
                                     Table 1 of Sec.   1065.703--Test Fuel Specifications for Distillate Diesel Fuel  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                                                                               Ultra low  
                 Property                                Unit                   sulfur        Low sulfur      High sulfur       Reference procedure a  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
Cetane Number............................  ...............................           40-50           40-50           40-50  ASTM D613.  
Distillation range:  
    Initial boiling point................  [deg]C.........................         171-204         171-204         171-204  ASTM D86.  
    10 pct. point........................  ...............................         204-238         204-238         204-238  
    50 pct. point........................  ...............................         243-282         243-282         243-282  
    90 pct. point........................  ...............................         293-332         293-332         293-332  
    Endpoint.............................  ...............................         321-366         321-366         321-366  
Gravity..................................  [deg]API.......................           32-37           32-37           32-37  ASTM D4052.  
Total sulfur.............................  mg/kg..........................            7-15         300-500        800-2500  ASTM D2622, ASTM D5453, or  
                                                                                                                             ASTM D7039.  
Aromatics, min. (Remainder shall be        g/kg...........................             100             100             100  ASTM D5186.  
 paraffins, naphthenes, and olefins).  
Flashpoint, min..........................  [deg]C.........................              54              54              54  ASTM D93.  
Kinematic Viscosity......................  mm\2\/s........................         2.0-3.2         2.0-3.2         2.0-3.2  ASTM D445.  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
\a\ Incorporated by reference, see Sec.   1065.1010. See Sec.   1065.701(d) for other allowed procedures.  
* * * * *  
0 
363. Amend Sec.  1065.705 by revising paragraph (c) to read as follows:  
Sec.  1065.705  Residual and intermediate residual fuel.  
* * * * *  
    (c) The fuel must meet the specifications for one of the categories  
in the following table:  
BILLING CODE 6560-50-P  
[[Page 34570]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.262  
[[Page 34571]]  
0 
364. Amend Sec.  1065.710 by revising paragraphs (b)(2) and (c) to read  
as follows:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 249/268Sec.  1065.710  Gasoline.  
* * * * *  
    (b) * * *  
    (2) Table 1 of this section identifies limit values consistent with  
the units in the reference procedure for each fuel property. These  
values are generally specified in international units. Values presented  
in parentheses are for information only. Table 1 follows:  
[[Page 34572]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.263  
BILLING CODE 6560-50-C  
* * * * *  
    (c) The specifications of this paragraph (c) apply for testing with  
neat gasoline. This is sometimes called indolene or E0 test fuel.  
Gasoline for  
[[Page 34573]]  
testing must have octane values that represent commercially available  
fuels for the appropriate application. Test fuel specifications apply  
as follows:  
                   Table 2 of Sec.   1065.710--Test Fuel Specifications for Neat (E0) Gasoline  
----------------------------------------------------------------------------------------------------------------  
                                                                 Specification  
                                                     ------------------------------------- Reference procedure a  
           Property                     Unit                              Low-temperature  
                                                       General testing        testing  
----------------------------------------------------------------------------------------------------------------  
Distillation Range:  
    Evaporated initial boiling  [deg]C..............  24-35 \b\........  24-36...........  ASTM D86.  
     point.  
    10% evaporated............  [deg]C..............  49-57............  37-48...........  
    50% evaporated............  [deg]C..............  93-110...........  82-101..........  
    90% evaporated............  [deg]C..............  149-163..........  158-174.........  
    Evaporated final boiling    [deg]C..............  Maximum, 213.....  Maximum, 212....  
     point.  
Total Aromatic Hydrocarbons...  volume %............  Maximum, 35......  Maximum, 30.4...  ASTM D1319 or ASTM  
                                                                                            D5769.  
Olefins \c\...................  volume %............  Maximum, 10......  Maximum, 17.5...  ASTM D1319 or ASTM  
                                                                                            D6550.  
Lead..........................  g/liter.............  Maximum, 0.013...  Maximum, 0.013..  ASTM D3237.  
Phosphorous...................  g/liter.............  Maximum, 0.0013..  Maximum, 0.005..  ASTM D3231.  
Total sulfur..................  mg/kg...............  Maximum, 80......  Maximum, 80.....  ASTM D2622.  
Dry vapor pressure equivalent   kPa.................  60.0-63.4 b e....  77.2-81.4.......  ASTM D5191.  
 \d\. 
----------------------------------------------------------------------------------------------------------------  
\a\ Incorporated by reference; see Sec.   1065.1010. See Sec.   1065.701(d) for other allowed procedures.  
\b\ For testing at altitudes above 1219 m, the specified initial boiling point range is (23.9 to 40.6) [deg]C  
  and the specified volatility range is (52.0 to 55.2) kPa.  
\c\ ASTM D6550 prescribes measurement of olefin concentration in mass %. Multiply this result by 0.857 and round  
  to the first decimal place to determine the olefin concentration in volume %.  
\d\ Calculate dry vapor pressure equivalent, DVPE, based on the measured total vapor pressure, pT, in kPa using  
  the following equation: DVPE(kPa) = 0.956[middot]pT - 2.39 or DVPE(psi) = 0.956[middot]pT - 0.347. DVPE is  
  intended to be equivalent to Reid Vapor Pressure using a different test method.  
\e\ For testing unrelated to evaporative emissions, the specified range is (55.2 to 63.4) kPa.  
* * * * *  
0 
365. Amend Sec.  1065.715 by revising paragraph (a) to read as follows:  
Sec.  1065.715  Natural gas.  
    (a) Except as specified in paragraph (b) of this section, natural  
gas for testing must meet the specifications in the following table:  
  Table 1 of Sec.   1065.715--Test Fuel Specifications for Natural Gas  
------------------------------------------------------------------------  
            Property                             Value a  
------------------------------------------------------------------------  
Methane, CH4...................  Minimum, 0.87 mol/mol.  
Ethane, C2H6...................  Maximum, 0.055 mol/mol.  
Propane, C3H8..................  Maximum, 0.012 mol/mol.  
Butane, C4H10..................  Maximum, 0.0035 mol/mol.  
Pentane, C5H12.................  Maximum, 0.0013 mol/mol.  
C6 and higher..................  Maximum, 0.001 mol/mol.  
Oxygen.........................  Maximum, 0.001 mol/mol.  
Inert gases (sum of CO2 and N2)  Maximum, 0.051 mol/mol.  
------------------------------------------------------------------------  
\a\ Demonstrate compliance with fuel specifications based on the  
  reference procedures in ASTM D1945 (incorporated by reference in Sec.  
   1065.1010), or on other measurement procedures using good engineering  
  judgment. See Sec.   1065.701(d) for other allowed procedures.  
* * * * *  
0 
366. Amend Sec.  1065.720 by revising paragraph (a) to read as follows:  
Sec.  1065.720  Liquefied petroleum gas.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 250/268    (a) Except as specified in paragraph (b) of this section, liquefied  
petroleum gas for testing must meet the specifications in the following  
table: 
               Table 1 of Sec.   1065.720(a)--Test Fuel Specifications for Liquefied Petroleum Gas  
----------------------------------------------------------------------------------------------------------------  
               Property                           Value                        Reference procedure a  
----------------------------------------------------------------------------------------------------------------  
Propane, C3H8.........................  Minimum, 0.85 m\3\/m\3\..  ASTM D2163.  
Vapor pressure at 38 [deg]C...........  Maximum, 1400 kPa........  ASTM D1267 or  
                                                                   \b\ ASTM D2598.  
Volatility residue (evaporated          Maximum, -38 [deg]C......  ASTM D1837.  
 temperature, 35 [deg]C).  
Butanes...............................  Maximum, 0.05 m\3\/m\3\..  ASTM D2163.  
Butenes...............................  Maximum, 0.02 m\3\/m\3\..  ASTM D2163.  
Pentenes and heavier..................  Maximum, 0.005 m\3\/m\3\.  ASTM D2163.  
Propene...............................  Maximum, 0.1 m\3\/m\3\...  ASTM D2163.  
Residual matter (residue on             Maximum, 0.05 ml pass \c\  ASTM D2158.  
 evaporation of 100 ml oil stain  
 observation).  
Corrosion, copper strip...............  Maximum, No. 1...........  ASTM D1838.  
Sulfur................................  Maximum, 80 mg/kg........  ASTM D6667.  
[[Page 34574]]  
  
Moisture content......................  pass.....................  ASTM D2713.  
----------------------------------------------------------------------------------------------------------------  
\a\ Incorporated by reference; see Sec.   1065.1010. See Sec.   1065.701(d) for other allowed procedures.  
\b\ If these two test methods yield different results, use the results from ASTM D1267.  
\c\ The test fuel must not yield a persistent oil ring when you add 0.3 ml of solvent residue mixture to a  
  filter paper in 0.1 ml increments and examine it in daylight after two minutes.  
* * * * *  
0 
367. Amend Sec.  1065.750 by revising paragraph (a)(1)(ii) to read as  
follows:  
Sec.  1065.750  Analytical gases.  
* * * * *  
    (a) * * *  
    (1) * * *  
    (ii) Contamination as specified in the following table:  
 Table 1 of Sec.   1065.750--General Specifications for Purified Gases a  
------------------------------------------------------------------------  
          Constituent                Purified air          Purified N2  
------------------------------------------------------------------------  
THC (C1-equivalent)...........  <=0.05 [mu]mol/mol....  <=0.05 [mu]mol/  
                                                         mol.  
CO............................  <=1 [mu]mol/mol.......  <=1 [mu]mol/mol.  
CO2...........................  <=10 [mu]mol/mol......  <=10 [mu]mol/  
                                                         mol.  
O2............................  0.205 to 0.215 mol/mol  <=2 [mu]mol/mol.  
NOX...........................  <=0.02 [mu]mol/mol....  <=0.02 [mu]mol/  
                                                         mol.  
N2O b.........................  <=0.02 [mu]mol/mol....  <=0.02 [mu]mol/  
                                                         mol.  
------------------------------------------------------------------------  
a We do not require these levels of purity to be NIST-traceable.  
b The N2O limit applies only if the standard-setting part requires you  
  to report N2O or certify to an N2O standard.  
* * * * *  
0 
368. Amend Sec.  1065.790 by revising paragraph (b) to read as follows:  
Sec.  1065.790  Mass standards.  
* * * * *  
    (b) Dynamometer, fuel mass scale, and DEF mass scale calibration  
weights. Use dynamometer and mass scale calibration weights that are  
certified as NIST-traceable within 0.1% uncertainty. Calibration  
weights may be certified by any calibration lab that maintains NIST-  
traceability.  
0 
369. Amend Sec.  1065.905 by revising paragraph (f) to read as follows:  
Sec.  1065.905  General provisions.  
* * * * *  
    (f) Summary. The following table summarizes the requirements of  
paragraphs (d) and (e) of this section:  
          Table 1 of Sec.   1065.905--Summary of Testing Requirements Specified Outside of This Subpart  
----------------------------------------------------------------------------------------------------------------  
                                                                     Applicability for       Applicability for  
                                                                  laboratory  or similar  laboratory  or similar  
              Subpart                  Applicability for field      testing with  PEMS      testing with  PEMS  
                                              testing a            without restriction a    with restrictions a  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 251/268  
----------------------------------------------------------------------------------------------------------------  
A: Applicability and general         Use all....................  Use all...............  Use all.  
 provisions.  
B: Equipment for testing...........  Use Sec.  Sec.   1065.101    Use all...............  Use all. Section  
                                      and 1065.140 through the                             1065.910 specifies  
                                      end of subpart B of this                             equipment specific to  
                                      part, except Sec.  Sec.                              laboratory testing  
                                      1065.140(e)(1) and (4),                              with PEMS.  
                                      1065.170(c)(1)(vi), and  
                                      1065.195(c). Section  
                                      1065.910 specifies  
                                      equipment specific to  
                                      field testing.  
C: Measurement instruments.........  Use all Section 1065.915     Use all except Sec.     Use all except Sec.  
                                      allows deviations..          1065.295(c).            1065.295(c).  
                                                                                          Section1065.915 allows  
                                                                                           deviations.  
D: Calibrations and verifications..  Use all except Sec.  Sec.    Use all...............  Use all. Section  
                                      1065.308 and 1065.309.                               1065.920 allows  
                                      Section 1065.920 allows                              deviations, but also  
                                      deviations, but also has                             has additional  
                                      additional specifications.                           specifications.  
E: Test engine selection,            Do not use Use standard-     Use all...............  Use all.  
 maintenance, and durability.         setting part..  
F: Running an emission test in the   Use Sec.  Sec.   1065.590    Use all...............  Use all.  
 laboratory.                          and 1065.595 for PM. Sec.  
                                      Sec.   1065.930 and  
                                      1065.935 to start and run  
                                      a field test.  
G: Calculations and data             Use all Section 1065.940     Use all...............  Use all. Section  
 requirements.                        has additional calculation                           1065.940 has  
                                      instructions.                                        additional  
                                                                                           calculation  
                                                                                           instructions  
H: Fuels, engine fluids, analytical  Use all....................  Use all...............  Use all.  
 gases, and other calibration  
 materials.  
I: Testing with oxygenated fuels...  Use all....................  Use all...............  Use all.  
[[Page 34575]]  
  
K: Definitions and reference         Use all....................  Use all...............  Use all.  
 materials.  
----------------------------------------------------------------------------------------------------------------  
a Refer to paragraphs (d) and (e) of this section for complete specifications.  
0 
370. Amend Sec.  1065.910 by revising paragraph (a)(2) to read as  
follows:  
Sec.  1065.910  PEMS auxiliary equipment for field testing.  
* * * * *  
    (a) * * *  
    (2) Tubing. We recommend using rigid 300 series stainless steel  
tubing to connect between flexible connectors. Tubing may be straight  
or bent to accommodate vehicle geometry. You may use ``T'' or ``Y''  
fittings to join multiple connections, or you may cap or plug redundant  
flow paths if the engine manufacturer recommends it.  
* * * * *  
0 
371. Amend Sec.  1065.915 by revising paragraph (a) to read as follows:  
Sec.  1065.915  PEMS instruments.  
    (a) Instrument specifications. We recommend that you use PEMS that  
meet the specifications of subpart C of this part. For unrestricted use  
of PEMS in a laboratory or similar environment, use a PEMS that meets  
the same specifications as each lab instrument it replaces. For field  
testing or for testing with PEMS in a laboratory or similar  
environment, under the provisions of Sec.  1065.905(b), the  
specifications in the following table apply instead of the  
specifications in Table 1 of Sec.  1065.205:  
                                 Table 1 of Sec.   1065.915--Recommended Minimum PEMS Measurement Instrument Performance  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
                                                     Rise time,  t10-90,  
                                 Measured quantity   and Fall time,  t90-  Recording  update                      Repeatability a  
          Measurement                  symbol                 10               frequency          Accuracy a                              Noise a  
  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
Engine speed transducer.......  fn.................  1 s................  1 Hz means.........  5% of pt. or 1%   2% of pt. or 1%   0.5% of max.  
                                                                                                of max.           of max.  
Engine torque estimator, BSFC   T or BSFC..........  1 s................  1 Hz means.........  8% of pt. or 5%   2% of pt. or 1%   1% of max.  
 (This is a signal from an                                                                      of max.           of max.  
 engine's ECM).  
General pressure transducer     p..................  5 s................  1 Hz...............  5% of pt. or 5%   2% of pt. or      1% of max.  
 (not a part of another                                                                         of max.           0.5% of max.  
 instrument).  
Atmospheric pressure meter....  patmos.............  50 s...............  0.1 Hz.............  250 Pa..........  200 Pa..........  100 Pa.  
General temperature sensor      T..................  5 s................  1 Hz...............  1% of pt. K or 5  0.5% of pt. K or  0.5% of max 0.5 K.  
 (not a part of another                                                                         K.                2 K.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 252/268 instrument).  
General dewpoint sensor.......  Tdew...............  50 s...............  0.1 Hz.............  3 K.............  1 K.............  1 K.  
Exhaust flow meter............  n ......  1 s................  1 Hz means.........  5% of pt. or 3%   2% of pt........  2% of max.  
                                                                                                of max.  
Dilution air, inlet air,        n ......  1 s................  1 Hz means.........  2.5% of pt. or    1.25% of pt. or   1% of max.  
 exhaust, and sample flow                                                                       1.5% of max.      0.75% of max.  
 meters.  
Continuous gas analyzer.......  x..................  5 s................  1 Hz...............  4% of pt. or 4%   2% of pt. or 2%   1% of max.  
                                                                                                of meas.          of meas.  
Gravimetric PM balance........  mPM................  ...................  ...................  See Sec.          0.5 [mu]g.......  
                                                                                                1065.790.  
Inertial PM balance...........  mPM................  ...................  ...................  4% of pt. or 4%   2% of pt. or 2%   1% of max.  
                                                                                                of meas.          of meas.  
--------------------------------------------------------------------------------------------------------------------------------------------------------  
a Accuracy, repeatability, and noise are all determined with the same collected data, as described in Sec.   1065.305, and based on absolute values.  
  ``pt.'' refers to the overall flow-weighted mean value expected at the standard; ``max.'' refers to the peak value expected at the standard over any  
  test interval, not the maximum of the instrument's range; ``meas'' refers to the actual flow-weighted mean measured over any test interval.  
* * * * *  
0 
372. Amend Sec.  1065.1001 by adding a definition for ``Enhanced-idle''  
in alphabetical order and revising the definition for ``Test interval''  
to read as follows:  
Sec.  1065.1001  Definitions.  
* * * * *  
    Enhanced-idle means a mode of engine idle operation where idle  
speed is elevated above warm idle speed as determined by the electronic  
control module, for example during engine warm-up or to increase  
exhaust temperature.  
* * * * *  
    Test interval means a duration of time over which you determine  
mass of emissions. For example, the standard-setting part may specify a  
complete laboratory duty cycle as a cold-start test interval, plus a  
hot-start test interval. As another example, a standard-setting part  
may specify a field-test interval, such as a ``not-to-exceed'' (NTE)  
event, as a duration of time over which an engine operates within a  
certain range of speed and torque. In cases where multiple test  
intervals occur over a duty cycle, the standard-setting part may  
specify additional calculations that weight and combine results to  
arrive at composite values for comparison against the applicable  
standards in this chapter.  
* * * * *  
0 
373. Amend Sec.  1065.1005 by revising paragraphs (a), (c), (d), (e),  
(f)(2), and (g) to read as follows:  
Sec.  1065.1005  Symbols, abbreviations, acronyms, and units of  
measure.  
* * * * *  
    (a) Symbols for quantities. This part uses the following symbols  
and units of measure for various quantities:  
[[Page 34576]]  
                               Table 1 of Sec.   1065.1005--Symbols for Quantities  
----------------------------------------------------------------------------------------------------------------  
                                                                                           Units in terms of SI  
         Symbol                 Quantity               Unit             Unit symbol             base units  
----------------------------------------------------------------------------------------------------------------  
a.......................  atomic hydrogen-to-  mole per mole......  mol/mol............  1.  
                           carbon ratio.  
A.......................  area...............  square meter.......  m2.................  m2.  
a0......................  intercept of least  
                           squares regression.  
a1......................  slope of least  
                           squares regression.  
ag......................  acceleration of      meter per square     m/s2...............  m[middot] s-2.  
                           Earth's gravity.     second.  
[beta]..................  ratio of diameters.  meter per meter....  m/m................  1.  
[beta]..................  atomic oxygen-to-    mole per mole......  mol/mol............  1.  
                           carbon ratio.  
C......................  number of carbon  
                           atoms in a  
                           molecule.  
c.......................  power-specific       gram per kilowatt-   g/(kW[middot]hr)...  3.6-1 [middot] 10-9  
                           carbon mass error    hour.                                     [middot] m-2 [middot]  
                           coefficient.                                                   s2.  
Cd......................  discharge  
                           coefficient.  
Cf......................  flow coefficient...  
[delta].................  atomic nitrogen-to-  mole per mole......  mol/mol............  1.  
                           carbon ratio.  
d.......................  diameter...........  meter..............  m..................  m.  
d.......................  power-specific       gram per kilowatt-   g/(kW[middot]hr)...  3.6-1 [middot] 10-9  
                           carbon mass rate     hour.                                     [middot] m-2 [middot]  
                           absolute error                                                 s2.  
                           coefficent.  
DR......................  dilution ratio.....  mole per mole......  mol/mol............  1.  
[egr]...................  error between a  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 253/268                           quantity and its  
                           reference.  
[isin]..................  difference or error  
                           quantity.  
e.......................  brake-specific       gram per kilowatt    g/(kW[middot]hr)...  3.6-1 [middot] 10-9  
                           emission or fuel     hour.                                     [middot] m-2 [middot]  
                           consumption.                                                   s2.  
F.......................  F-test statistic...  
[fnof]..................  frequency..........  hertz..............  Hz.................  s-1.  
[fnof]n.................  angular speed        revolutions per      r/min..............  [pi] [middot] 30-1  
                           (shaft).             minute.                                   [middot] s-1.  
[gamma].................  ratio of specific    (joule per kilogram  (J/(kg[middot]K))/   1.  
                           heats.               kelvin) per (joule   (J/(kg[middot]K)).  
                                                per kilogram  
                                                kelvin).  
[gamma].................  atomic sulfur-to-    mole per mole......  mol/mol............  1.  
                           carbon ratio.  
K.......................  correction factor..  ...................  ...................  1.  
Kv......................  calibration          ...................  m4 [middot] s        m4 [middot] kg-1  
                           coefficient.                              [middot] K0.5/kg.    [middot] s [middot]  
                                                                                          K0.5.
l.......................  length.............  meter..............  m..................  m.  
L.......................  limit..............  
[mu]....................  viscosity, dynamic.  pascal second......  Pa[middot]s........  m-1 [middot] kg  
                                                                                          [middot] s-1.  
M.......................  molar mass 1.......  gram per mole......  g/mol..............  10-3 [middot] kg  
                                                                                          [middot] mol-1.  
m.......................  mass...............  kilogram...........  kg.................  kg.  
m.......................  mass rate..........  kilogram per second  kg/s...............  kg [middot] s-1.  
v.......................  viscosity,           meter squared per    m2/s...............  m2 [middot] s-1.  
                           kinematic.           second.  
N.......................  total number in  
                           series.
n.......................  amount of substance  mole...............  mol................  mol.  
n.......................  amount of substance  mole per second....  mol/s..............  mol [middot] s-1.  
                           rate.  
P.......................  power..............  kilowatt...........  kW.................  103 [middot] m2  
                                                                                          [middot] kg [middot] s-  
                                                                                          3.  
PF......................  penetration  
                           fraction.  
p.......................  pressure...........  pascal.............  Pa.................  m-1 [middot] kg  
                                                                                          [middot] s-2.  
[rho]...................  mass density.......  kilogram per cubic   kg/m3..............  m-3 [middot] kg.  
                                                meter.  
[Delta]p................  differential static  pascal.............  Pa.................  m-1 [middot] kg  
                           pressure.                                                      [middot] s-2.  
r.......................  ratio of pressures.  pascal per pascal..  Pa/Pa..............  1.  
r.......................  coefficient of  
                           determination.  
Ra......................  average surface      micrometer.........  [mu]m..............  10-6 [middot] m.  
                           roughness.  
Re.....................  Reynolds number....  
RF......................  response factor....  
RH......................  relative humidity..  
[sigma].................  non-biased standard  
                           deviation.  
S.......................  Sutherland constant  kelvin.............  K..................  K.  
[[Page 34577]]  
  
SEE.....................  standard error of  
                           the estimate.  
T.......................  absolute             kelvin.............  K..................  K.  
                           temperature.  
T.......................  Celsius temperature  degree Celsius.....  [deg]C.............  K-273.15.  
T.......................  torque (moment of    newton meter.......  N[middot]m.........  m2 [middot] kg [middot]  
                           force).                                                        s-2.  
[theta].................  plane angle........  degrees............  [deg]..............  rad.  
t.......................  time...............  second.............  s..................  s.  
[Delta]t................  time interval,       second.............  s..................  s.  
                           period, 1/  
                           frequency.  
V.......................  volume.............  cubic meter........  m3.................  m3.  
V.......................  volume rate........  cubic meter per      m3/s...............  m3 [middot] s-1.  
                                                second.  
W.......................  work...............  kilowatt-hour......  kW[middot]hr.......  3.6 [middot] 106  
                                                                                          [middot] m2 [middot]  
                                                                                          kg [middot] s-2.  
wC......................  carbon mass          gram per gram......  g/g................  1.  
                           fraction.  
x.......................  amount of substance  mole per mole......  mol/mol............  1.  
                           mole fraction.2  
X.......................  flow-weighted mean   mole per mole......  mol/mol............  1.  
                           concentration.  
y.......................  generic variable...  
Z.......................  compressibility  
                           factor.
----------------------------------------------------------------------------------------------------------------  
1 See paragraph (f)(2) of this section for the values to use for molar masses. Note that in the cases of NOX and  
  HC, the regulations specify effective molar masses based on assumed speciation rather than actual speciation.  
2 Note that mole fractions for THC, THCE, NMHC, NMHCE, and NOTHC are expressed on a C1-equivalent basis.  
* * * * *  
    (c) Prefixes. This part uses the following prefixes for units and  
unit symbols:  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 254/268                  Table 3 of Sec.   1065.1005--Prefixes  
------------------------------------------------------------------------  
              Symbol                     Prefix name          Factor  
------------------------------------------------------------------------  
[mu]..............................  micro...............            10-6  
m.................................  milli...............            10-3  
c.................................  centi...............            10-2  
k.................................  kilo................             103  
M.................................  mega................             106  
------------------------------------------------------------------------  
    (d) Superscripts. This part uses the following superscripts for  
modifying quantity symbols:  
                Table 4 of Sec.   1065.1005--Superscripts  
------------------------------------------------------------------------  
                Superscript                            Meaning  
------------------------------------------------------------------------  
overbar (such as y).......................  arithmetic mean.  
overdot (such as y).......................  quantity per unit time.  
------------------------------------------------------------------------  
    (e) Subscripts. This part uses the following subscripts for  
modifying quantity symbols:  
                 Table 5 of Sec.   1065.1005--Subscripts  
------------------------------------------------------------------------  
          Subscript                             Meaning  
------------------------------------------------------------------------  
a............................  absolute (e.g., absolute difference or  
                                error).  
abs..........................  absolute quantity.  
act..........................  actual condition.  
air..........................  air, dry.  
amb..........................  ambient.  
atmos........................  atmospheric.  
bkgnd........................  background.  
C............................  carbon mass.  
cal..........................  calibration quantity.  
CFV..........................  critical flow venturi.  
comb.........................  combined.  
comp.........................  composite value.  
cor..........................  corrected quantity.  
dil..........................  dilution air.  
dew..........................  dewpoint.  
dexh.........................  diluted exhaust.  
dry..........................  dry condition.  
dutycycle....................  duty cycle.  
[isin].......................  related to a difference or error  
                                quantity.  
exh..........................  raw exhaust.  
exp..........................  expected quantity.  
fluid........................  fluid stream.  
fn...........................  feedback speed.  
frict........................  friction.  
fuel.........................  fuel consumption.  
hi,idle......................  condition at high-idle.  
i............................  an individual of a series.  
idle.........................  condition at idle.  
in...........................  quantity in.  
[[Page 34578]]  
  
init.........................  initial quantity, typically before an  
                                emission test.  
int..........................  intake air.  
j............................  an individual of a series.  
mapped.......................  conditions over which an engine can  
                                operate.  
max..........................  the maximum (i.e., peak) value expected  
                                at the standard over a test interval;  
                                not the maximum of an instrument range.  
meas.........................  measured quantity.  
media........................  PM sample media.  
mix..........................  mixture of diluted exhaust and air.  
norm.........................  normalized.  
out..........................  quantity out.  
P............................  power.  
part.........................  partial quantity.  
PDP..........................  positive-displacement pump.  
post.........................  after the test interval.  
pre..........................  before the test interval.  
prod.........................  stoichiometric product.  
r............................  relative (e.g., relative difference or  
                                error).  
rate.........................  rate (divided by time).  
record.......................  record rate.  
ref..........................  reference quantity.  
rev..........................  revolution.  
sat..........................  saturated condition.  
s............................  slip.  
span.........................  span quantity.  
SSV..........................  subsonic venturi.  
std..........................  standard condition.  
stroke.......................  engine strokes per power stroke.  
T............................  torque.  
test.........................  test quantity.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 255/268test,alt.....................  alternate test quantity.  
uncor........................  uncorrected quantity.  
vac..........................  vacuum side of the sampling system.  
weight.......................  calibration weight.  
zero.........................  zero quantity  
------------------------------------------------------------------------  
    (f) * * *  
    (2) This part uses the following molar masses or effective molar  
masses of chemical species:  
                                    Table 7 of Sec.   1065.1005--Molar Masses  
----------------------------------------------------------------------------------------------------------------  
                                                                            g/mol (10-3[middot]kg[middot]mol-1)  
              Symbol                              Quantity  
----------------------------------------------------------------------------------------------------------------  
Mair.............................  molar mass of dry air 1...............                    28.96559  
MAr..............................  molar mass of argon...................                      39.948  
MC...............................  molar mass of carbon..................                     12.0107  
MCH3OH...........................  molar mass of methanol................                    32.04186  
MC2H5OH..........................  molar mass of ethanol.................                    46.06844  
MC2H4O...........................  molar mass of acetaldehyde............                    44.05256  
MCH4N2O..........................  molar mass of urea....................                    60.05526  
MC2H6............................  molar mass of ethane..................                    30.06904  
MC3H8............................  molar mass of propane.................                    44.09562  
MC3H7OH..........................  molar mass of propanol................                    60.09502  
MCO..............................  molar mass of carbon monoxide.........                     28.0101  
MCH4.............................  molar mass of methane.................                     16.0425  
MCO2.............................  molar mass of carbon dioxide..........                     44.0095  
MH...............................  molar mass of atomic hydrogen.........                     1.00794  
MH2..............................  molar mass of molecular hydrogen......                     2.01588  
MH2O.............................  molar mass of water...................                    18.01528  
MCH2O............................  molar mass of formaldehyde............                    30.02598  
MHe..............................  molar mass of helium..................                    4.002602  
MN...............................  molar mass of atomic nitrogen.........                     14.0067  
MN2..............................  molar mass of molecular nitrogen......                     28.0134  
MNH3.............................  molar mass of ammonia.................                    17.03052  
MNMHC............................  effective C1 molar mass of nonmethane                    13.875389  
                                    hydrocarbon 2.  
MNMHCE...........................  effective C1 molar mass of nonmethane                    13.875389  
                                    hydrocarbon equivalent 2.  
MNMNEHC..........................  effective C1 molar mass of nonmethane-                   13.875389  
                                    nonethane hydrocarbon 2.  
MNOx.............................  effective molar mass of oxides of                          46.0055  
                                    nitrogen 3.  
[[Page 34579]]  
  
MN2O.............................  molar mass of nitrous oxide...........                     44.0128  
MO...............................  molar mass of atomic oxygen...........                     15.9994  
MO2..............................  molar mass of molecular oxygen........                     31.9988  
MS...............................  molar mass of sulfur..................                      32.065  
MTHC.............................  effective C1 molar mass of total                         13.875389  
                                    hydrocarbon 2.  
MTHCE............................  effective C1 molar mass of total                         13.875389  
                                    hydrocarbon equivalent 2.  
----------------------------------------------------------------------------------------------------------------  
1 See paragraph (f)(1) of this section for the composition of dry air.  
2 The effective molar masses of THC, THCE, NMHC, NMHCE, and NMNEHC are defined on a C1 basis and are based on an  
  atomic hydrogen-to-carbon ratio, [alpha], of 1.85 (with [beta], [gamma], and [delta] equal to zero).  
3 The effective molar mass of NOX is defined by the molar mass of nitrogen dioxide, NO2.  
* * * * *  
    (g) Other acronyms and abbreviations. This part uses the following  
additional abbreviations and acronyms:  
     Table 10 of Sec.   1065.1005--Other Acronyms and Abbreviations  
------------------------------------------------------------------------  
                Acronym                              Meaning  
------------------------------------------------------------------------  
ABS....................................  acrylonitrile-butadiene-  
                                          styrene.  
ASTM...................................  ASTM International.  
BMD....................................  bag mini-diluter.  
BSFC...................................  brake-specific fuel  
                                          consumption.  
CARB...................................  California Air Resources Board.  
CFR....................................  Code of Federal Regulations.  
CFV....................................  critical-flow venturi.  
CI.....................................  compression-ignition.  
CITT...................................  Curb Idle Transmission Torque.  
CLD....................................  chemiluminescent detector.  
CVS....................................  constant-volume sampler.  
DEF....................................  diesel exhaust fluid.  
DF.....................................  deterioration factor.  
ECM....................................  electronic control module.  
EFC....................................  electronic flow control.  
e.g....................................  exempli gratia, for example.  
EGR....................................  exhaust gas recirculation.  
EPA....................................  Environmental Protection  
                                          Agency.  
FEL....................................  Family Emission Limit.  
FID....................................  flame-ionization detector.  
FTIR...................................  Fourier transform infrared.  
GC.....................................  gas chromatograph.  
GC-ECD.................................  gas chromatograph with an  
                                          electron-capture detector.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 256/268GC-FID.................................  gas chromatograph with a flame  
                                          ionization detector.  
HEPA...................................  high-efficiency particulate  
                                          air.  
IBP....................................  initial boiling point.  
IBR....................................  incorporated by reference.  
i.e....................................  id est, in other words.  
ISO....................................  International Organization for  
                                          Standardization.  
LPG....................................  liquefied petroleum gas.  
MPD....................................  magnetopneumatic detection.  
NDIR...................................  nondispersive infrared.  
NDUV...................................  nondispersive ultraviolet.  
NIST...................................  National Institute for  
                                          Standards and Technology.  
NMC....................................  nonmethane cutter.  
PDP....................................  positive-displacement pump.  
PEMS...................................  portable emission measurement  
                                          system.  
PFD....................................  partial-flow dilution.  
PLOT...................................  porous layer open tubular.  
PMD....................................  paramagnetic detection.  
PMP....................................  Polymethylpentene.  
pt.....................................  a single point at the mean  
                                          value expected at the  
                                          standard.  
psi....................................  pounds per square inch.  
PTFE...................................  polytetrafluoroethylene  
                                          (commonly known as TeflonTM).  
RE.....................................  rounding error.  
RESS...................................  rechargeable energy storage  
                                          system.  
RFPF...................................  response factor penetration  
                                          fraction.  
RMC....................................  ramped-modal cycle.  
rms....................................  root-mean square.  
RTD....................................  resistive temperature detector.  
SAW....................................  surface acoustic wave.  
SEE....................................  standard error of the estimate.  
SSV....................................  subsonic venturi.  
SI.....................................  spark-ignition.  
THC-FID................................  total hydrocarbon flame  
                                          ionization detector.  
TINV...................................  inverse student t-test function  
                                          in Microsoft Excel.  
UCL....................................  upper confidence limit.  
UFM....................................  ultrasonic flow meter.  
U.S.C..................................  United States Code  
------------------------------------------------------------------------  
0 
374. Amend Sec.  1065.1010 by revising paragraph (b) to read as  
follows:  
Sec.  1065.1010  Incorporation by reference.  
* * * * *  
    (b) ASTM material. The following standards are available from ASTM  
International, 100 Barr Harbor Dr., P.O. Box C700, West Conshohocken,  
PA 19428-2959, (877) 909-ASTM, or http://www.astm.org : 
    (1) ASTM D86-12, Standard Test Method for Distillation of Petroleum  
Products at Atmospheric Pressure, approved December 1, 2012 (``ASTM  
D86''), IBR approved for Sec. Sec.  1065.703(b) and 1065.710(b) and  
(c). 
    (2) ASTM D93-13, Standard Test Methods for Flash Point by Pensky-  
Martens Closed Cup Tester, approved July 15, 2013 (``ASTM D93''), IBR  
approved for Sec.  1065.703(b).  
    (3) ASTM D130-12, Standard Test Method for Corrosiveness to Copper  
from Petroleum Products by Copper Strip Test, approved November 1, 2012  
(``ASTM D130''), IBR approved for Sec.  1065.710(b).  
    (4) ASTM D381-12, Standard Test Method for Gum Content in Fuels by  
Jet Evaporation, approved April 15, 2012 (``ASTM D381''), IBR approved  
for Sec.  1065.710(b).  
    (5) ASTM D445-12, Standard Test Method for Kinematic Viscosity of  
Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity),  
approved April 15, 2012 (``ASTM D445''), IBR approved for Sec.   
1065.703(b).  
    (6) ASTM D525-12a, Standard Test Method for Oxidation Stability of  
Gasoline (Induction Period Method), approved September 1, 2012 (``ASTM  
D525''), IBR approved for Sec.  1065.710(b).  
    (7) ASTM D613-13, Standard Test Method for Cetane Number of Diesel  
Fuel Oil, approved December 1, 2013 (``ASTM D613''), IBR approved for  
Sec.  1065.703(b).  
    (8) ASTM D910-13a, Standard Specification for Aviation Gasolines,  
approved December 1, 2013 (``ASTM D910''), IBR approved for Sec.   
1065.701(f).  
    (9) ASTM D975-13a, Standard Specification for Diesel Fuel Oils,  
approved December 1, 2013 (``ASTM D975''), IBR approved for Sec.   
1065.701(f).  
    (10) ASTM D1267-12, Standard Test Method for Gage Vapor Pressure of  
Liquefied Petroleum (LP) Gases (LP-Gas Method), approved November 1,  
2012 (``ASTM D1267''), IBR approved for Sec.  1065.720(a).  
    (11) ASTM D1319-13, Standard Test Method for Hydrocarbon Types in  
Liquid Petroleum Products by Fluorescent Indicator Adsorption, approved  
May 1, 2013 (``ASTM D1319''), IBR approved for Sec.  1065.710(c).  
    (12) ASTM D1655-13a, Standard Specification for Aviation Turbine  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 257/268Fuels, approved December 1, 2013 (``ASTM D1655''), IBR approved for  
Sec.  1065.701(f).  
    (13) ASTM D1837-11, Standard Test Method for Volatility of  
Liquefied Petroleum (LP) Gases, approved October  
[[Page 34580]]  
1, 2011 (``ASTM D1837''), IBR approved for Sec.  1065.720(a).  
    (14) ASTM D1838-12a, Standard Test Method for Copper Strip  
Corrosion by Liquefied Petroleum (LP) Gases, approved December 1, 2012  
(``ASTM D1838''), IBR approved for Sec.  1065.720(a).  
    (15) ASTM D1945-03 (Reapproved 2010), Standard Test Method for  
Analysis of Natural Gas by Gas Chromatography, approved January 1, 2010  
(``ASTM D1945''), IBR approved for Sec.  1065.715(a).  
    (16) ASTM D2158-11, Standard Test Method for Residues in Liquefied  
Petroleum (LP) Gases, approved January 1, 2011 (``ASTM D2158''), IBR  
approved for Sec.  1065.720(a).  
    (17) ASTM D2163-07, Standard Test Method for Determination of  
Hydrocarbons in Liquefied Petroleum (LP) Gases and Propane/Propene  
Mixtures by Gas Chromatography, approved December 1, 2007 (``ASTM  
D2163''), IBR approved for Sec.  1065.720(a).  
    (18) ASTM D2598-12, Standard Practice for Calculation of Certain  
Physical Properties of Liquefied Petroleum (LP) Gases from  
Compositional Analysis, approved November 1, 2012 (``ASTM D2598''), IBR  
approved for Sec.  1065.720(a).  
    (19) ASTM D2622-16, Standard Test Method for Sulfur in Petroleum  
Products by Wavelength Dispersive X-ray Fluorescence Spectrometry,  
approved January 1, 2016 (``ASTM D2622''), IBR approved for Sec. Sec.   
1065.703(b) and 1065.710(b) and (c).  
    (20) ASTM D2699-13b, Standard Test Method for Research Octane  
Number of Spark-Ignition Engine Fuel, approved October 1, 2013 (``ASTM  
D2699''), IBR approved for Sec.  1065.710(b).  
    (21) ASTM D2700-13b, Standard Test Method for Motor Octane Number  
of Spark-Ignition Engine Fuel, approved October 1, 2013 (``ASTM  
D2700''), IBR approved for Sec.  1065.710(b).  
    (22) ASTM D2713-13, Standard Test Method for Dryness of Propane  
(Valve Freeze Method), approved October 1, 2013 (``ASTM D2713''), IBR  
approved for Sec.  1065.720(a).  
    (23) ASTM D2880-13b, Standard Specification for Gas Turbine Fuel  
Oils, approved November 15, 2013 (``ASTM D2880''), IBR approved for  
Sec.  1065.701(f).  
    (24) ASTM D2986-95a, Standard Practice for Evaluation of Air Assay  
Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test, approved  
September 10, 1995 (``ASTM D2986''), IBR approved for Sec.   
1065.170(c). (Note: This standard was withdrawn by ASTM.)  
    (25) ASTM D3231-13, Standard Test Method for Phosphorus in  
Gasoline, approved June 15, 2013 (``ASTM D3231''), IBR approved for  
Sec.  1065.710(b) and (c).  
    (26) ASTM D3237-12, Standard Test Method for Lead in Gasoline By  
Atomic Absorption Spectroscopy, approved June 1, 2012 (``ASTM D3237''),  
IBR approved for Sec.  1065.710(b) and (c).  
    (27) ASTM D4052-11, Standard Test Method for Density, Relative  
Density, and API Gravity of Liquids by Digital Density Meter, approved  
October 15, 2011 (``ASTM D4052''), IBR approved for Sec.  1065.703(b).  
    (28) ASTM D4629-12, Standard Test Method for Trace Nitrogen in  
Liquid Petroleum Hydrocarbons by Syringe/Inlet Oxidative Combustion and  
Chemiluminescence Detection, approved April 15, 2012 (``ASTM D4629''),  
IBR approved for Sec.  1065.655(e).  
    (29) ASTM D4814-13b, Standard Specification for Automotive Spark-  
Ignition Engine Fuel, approved December 1, 2013 (``ASTM D4814''), IBR  
approved for Sec.  1065.701(f).  
    (30) ASTM D4815-13, Standard Test Method for Determination of MTBE,  
ETBE, TAME, DIPE, tertiary-Amyl Alcohol and C1 to C4 Alcohols in  
Gasoline by Gas Chromatography, approved October 1, 2013 (``ASTM  
D4815''), IBR approved for Sec.  1065.710(b).  
    (31) ASTM D5186-03 (Reapproved 2009), Standard Test Method for  
Determination of the Aromatic Content and Polynuclear Aromatic Content  
of Diesel Fuels and Aviation Turbine Fuels By Supercritical Fluid  
Chromatography, approved April 15, 2009 (``ASTM D5186''), IBR approved  
for Sec.  1065.703(b).  
    (32) ASTM D5191-13, Standard Test Method for Vapor Pressure of  
Petroleum Products (Mini Method), approved December 1, 2013 (``ASTM  
D5191''), IBR approved for Sec.  1065.710(b) and (c).  
    (33) ASTM D5291-10, Standard Test Methods for Instrumental  
Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products  
and Lubricants, approved May 1, 2010 (``ASTM D5291''), IBR approved for  
Sec.  1065.655(e).  
    (34) ASTM D5453-19a, Standard Test Method for Determination of  
Total Sulfur in Light Hydrocarbons, Spark Ignition Engine Fuel, Diesel  
Engine Fuel, and Engine Oil by Ultraviolet Fluorescence, approved July  
1, 2019 (``ASTM D5453''), IBR approved for Sec. Sec.  1065.703(b) and  
1065.710(b).  
    (35) ASTM D5599-00 (Reapproved 2010), Standard Test Method for  
Determination of Oxygenates in Gasoline by Gas Chromatography and  
Oxygen Selective Flame Ionization Detection, approved October 1, 2010  
(``ASTM D5599''), IBR approved for Sec. Sec.  1065.655(e) and  
1065.710(b).  
    (36) ASTM D5762-12 Standard Test Method for Nitrogen in Petroleum  
and Petroleum Products by Boat-Inlet Chemiluminescence, approved April  
15, 2012 (``ASTM D5762''), IBR approved for Sec.  1065.655(e).  
    (37) ASTM D5769-10, Standard Test Method for Determination of  
Benzene, Toluene, and Total Aromatics in Finished Gasolines by Gas  
Chromatography/Mass Spectrometry, approved May 1, 2010 (``ASTM  
D5769''), IBR approved for Sec.  1065.710(b).  
    (38) ASTM D5797-13, Standard Specification for Fuel Methanol (M70-  
M85) for Automotive Spark-Ignition Engines, approved June 15, 2013  
(``ASTM D5797''), IBR approved for Sec.  1065.701(f).  
    (39) ASTM D5798-13a, Standard Specification for Ethanol Fuel Blends  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 258/268for Flexible Fuel Automotive Spark-Ignition Engines, approved June 15,  
2013 (``ASTM D5798''), IBR approved for Sec.  1065.701(f).  
    (40) ASTM D6348-12e1, Standard Test Method for Determination of  
Gaseous Compounds by Extractive Direct Interface Fourier Transform  
Infrared (FTIR) Spectroscopy, approved February 1, 2012 (``ASTM  
D6348''), IBR approved for Sec. Sec.  1065.266(b) and 1065.275(b).  
    (41) ASTM D6550-10, Standard Test Method for Determination of  
Olefin Content of Gasolines by Supercritical-Fluid Chromatography,  
approved October 1, 2010 (``ASTM D6550''), IBR approved for Sec.   
1065.710(b).  
    (42) ASTM D6615-11a, Standard Specification for Jet B Wide-Cut  
Aviation Turbine Fuel, approved October 1, 2011 (``ASTM D6615''), IBR  
approved for Sec.  1065.701(f).  
    (43) ASTM D6667-14 (Reapproved 2019), Standard Test Method for  
Determination of Total Volatile Sulfur in Gaseous Hydrocarbons and  
Liquefied Petroleum Gases by Ultraviolet Fluorescence, approved May 1,  
2019 (``ASTM D6667''), IBR approved for Sec.  1065.720(a).  
    (44) ASTM D6751-12, Standard Specification for Biodiesel Fuel Blend  
Stock (B100) for Middle Distillate Fuels, approved August 1, 2012  
(``ASTM D6751''), IBR approved for Sec.  1065.701(f).  
    (45) ASTM D6985-04a, Standard Specification for Middle Distillate  
Fuel Oil--Military Marine Applications, approved November 1, 2004  
(``ASTM D6985''), IBR approved for Sec.  1065.701(f). (Note: This  
standard was withdrawn by ASTM.)  
[[Page 34581]]  
    (46) ASTM D7039-15a (Reapproved 2020), Standard Test Method for  
Sulfur in Gasoline, Diesel Fuel, Jet Fuel, Kerosine, Biodiesel,  
Biodiesel Blends, and Gasoline-Ethanol Blends by Monochromatic  
Wavelength Dispersive X-ray Fluorescence Spectrometry, approved May 1,  
2020 (``ASTM D7039''), IBR approved for Sec. Sec.  1065.703(b) and  
1065.710(b).  
    (47) ASTM F1471-09, Standard Test Method for Air Cleaning  
Performance of a High- Efficiency Particulate Air Filter System,  
approved March 1, 2009 (``ASTM F1471''), IBR approved for Sec.   
1065.1001.  
* * * * *  
PART 1066--VEHICLE-TESTING PROCEDURES  
0 
375. The authority citation for part 1066 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
376. Amend Sec.  1066.1 by revising paragraph (g) to read as follows:  
Sec.  1066.1  Applicability.  
* * * * *  
    (g) For additional information regarding the test procedures in  
this part, visit our website at www.epa.gov , and in particular https://www.epa.gov/vehicle-and-fuel-emissions-testing/vehicle-testing-regulations . 
0 
377. Amend Sec.  1066.135 by revising paragraph (a)(1) to read as  
follows:  
Sec.  1066.135  Linearity verification.  
* * * * *  
    (a) * * *  
    (1) Use instrument manufacturer recommendations and good  
engineering judgment to select at least ten reference values,  
yrefi, that cover the range of values that you expect during  
testing (to prevent extrapolation beyond the verified range during  
emission testing). We recommend selecting zero as one of your reference  
values. For each range calibrated, if the deviation from a least-  
squares best-fit straight line is 2% or less of the value at each data  
point, concentration values may be calculated by use of a straight-line  
curve fit for that range. If the deviation exceeds 2% at any point, use  
the best-fit nonlinear equation that represents the data to within 2%  
of each test point to determine concentration. If you use a gas divider  
to blend calibration gases, you may verify that the calibration curve  
produced names a calibration gas within 2% of its certified  
concentration. Perform this verification between 10 and 60% of the  
full-scale analyzer range.  
* * * * *  
0 
378. Amend Sec.  1066.210 by revising paragraph (d)(3) to read as  
follows:  
Sec.  1066.210  Dynamometers.  
* * * * *  
    (d) * * *  
    (3) The load applied by the dynamometer simulates forces acting on  
the vehicle during normal driving according to the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.264  
Where: 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 259/268FR = total road-load force to be applied at the surface of the roll.  
The total force is the sum of the individual tractive forces applied  
at each roll surface.  
i = a counter to indicate a point in time over the driving schedule.  
For a dynamometer operating at 10-Hz intervals over a 600-second  
driving schedule, the maximum value of i should be 6,000.  
A = a vehicle-specific constant value representing the vehicle's  
frictional load in lbf or newtons. See subpart D of this part.  
Gi = instantaneous road grade, in percent. If your duty  
cycle is not subject to road grade, set this value to 0.  
B = a vehicle-specific coefficient representing load from drag and  
rolling resistance, which are a function of vehicle speed, in lbf/  
(mi/hr) or N[middot]s/m. See subpart D of this part.  
v = instantaneous linear speed at the roll surfaces as measured by  
the dynamometer, in mi/hr or m/s. Let v i-1 = 0 for i = 0.  
C = a vehicle-specific coefficient representing aerodynamic effects,  
which are a function of vehicle speed squared, in lbf/(mi/  
hr)2 or N[middot]s2/m2. See subpart  
D of this part.  
Me = the vehicle's effective mass in lbm or kg, including  
the effect of rotating axles as specified in Sec.  1066.310(b)(7).  
t = elapsed time in the driving schedule as measured by the  
dynamometer, in seconds. Let t i-1 = 0 for i = 0.  
M = the measured vehicle mass, in lbm or kg.  
ag = acceleration of Earth's gravity = 9.80665 m/  
s2. 
* * * * *  
0 
379. Amend Sec.  1066.255 by revising paragraph (c) to read as follows:  
Sec.  1066.255  Parasitic loss verification.  
* * * * *  
    (c) Procedure. Perform this verification by following the  
dynamometer manufacturer's specifications to establish a parasitic loss  
curve, taking data at fixed speed intervals to cover the range of  
vehicle speeds that will occur during testing. You may zero the load  
cell at a selected speed if that improves your ability to determine the  
parasitic loss. Parasitic loss forces may never be negative. Note that  
the torque transducers must be mathematically zeroed and spanned prior  
to performing this procedure.  
* * * * *  
0 
380. Amend Sec.  1066.260 by revising paragraph (c)(4) to read as  
follows:  
Sec.  1066.260  Parasitic friction compensation evaluation.  
* * * * *  
    (c) * * *  
    (4) Calculate the power equivalent of friction compensation error,  
FCerror, using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.265  
Where: 
I = dynamometer inertia setting.  
t = duration of the measurement interval, accurate to at least 0.01  
s. 
vinit = the roll speed corresponding to the start of the  
measurement interval, accurate to at least 0.05 mi/hr.  
vfinal = the roll speed corresponding to the end of the  
measurement interval, accurate to at least 0.05 mi/hr.  
Example:  
I = 2000 lbm = 62.16 lbf[middot]s2/ft 
t = 60.0 s  
vinit = 9.2 mi/hr = 13.5 ft/s  
vfinal = 10.0 mi/hr = 14.7 ft/s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.266  
FCerror = -17.5 ft[middot]lbf/s =-0.032 hp  
* * * * *  
0 
381. Amend Sec.  1066.265 by revising paragraph (d)(1) to read as  
follows:  
[[Page 34582]]  
Sec.  1066.265  Acceleration and deceleration verification.  
* * * * *  
    (d) * * *  
    (1) Calculate the force setting, F, using the following equation:  
    [GRAPHIC] [TIFF OMITTED] TR29JN21.267  
     
Where: 
Ib = the dynamometer manufacturer's stated base inertia,  
in lbf[middot]s2/ft. 
a = nominal acceleration rate, in ft/s2. 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 260/268Example:  
Ib = 2967 lbm = 92.217 lbf[middot]s2/ft 
a = 1 (mi/hr)/s = 1.4667 ft/s2 
F = 92.217[middot][verbarlm]1.4667[verbarlm]  
F = 135.25 lbf  
* * * * *  
0 
382. Amend Sec.  1066.270 by revising paragraphs (c)(4) and (d)(2) to  
read as follows:  
Sec.  1066.270  Unloaded coastdown verification.  
* * * * *  
    (c) * * *  
    (4) Determine the mean coastdown force, F, for each speed and  
inertia setting for each of the coastdowns performed using the  
following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.268  
Where: 
F = the mean force measured during the coastdown for each speed  
interval and inertia setting, expressed in lbf and rounded to four  
significant figures.  
I = the dynamometer's inertia setting, in lbf[middot]s2/ 
ft. 
vinit = the speed at the start of the coastdown interval,  
expressed in ft/s to at least four significant figures.  
vfinal = the speed at the end of the coastdown interval,  
expressed in ft/s to at least four significant figures.  
t = coastdown time for each speed interval and inertia setting,  
accurate to at least 0.01 s.  
Example:  
I = 2000 lbm = 62.16 lbf[middot]s2/ft 
vinit = 25 mi/hr = 36.66 ft/s  
vfinal = 15 mi/hr = 22.0 ft/s  
t = 5.00 s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.269  
F = 182.3 lbf  
* * * * *  
    (d) * * *  
    (2) For vehicles above 20,000 pounds GVWR, the maximum allowable  
error, F errormax , for all speed intervals and inertia  
settings is 1.0% or the value determined from Eq. 1066.270-3  
(substituting 8.8 lbf for 2.2 lbf in the numerator), whichever is  
greater.  
* * * * *  
0 
383. Amend Sec.  1066.275 by revising paragraphs (b) and (d) to read as  
follows:  
Sec.  1066.275  Daily dynamometer readiness verification.  
* * * * *  
    (b) Scope and frequency. Perform this verification upon initial  
installation, within 1 day before testing, and after major maintenance.  
You may run this within 7 days before testing if you accumulate data to  
support a less frequent verification interval.  
* * * * *  
    (d) Performance evaluation. The coastdown force error determined in  
paragraph (c) of this section may not exceed the following:  
    (1) For vehicles at or below 20,000 pounds GVWR, 1.0% or the value  
determined from Eq. 1066.270-3, whichever is greater.  
    (2) For vehicles above 20,000 pounds GVWR, 1.0% or the value  
determined from Eq. 1066.270-3 (substituting 8.8 lbf for 2.2 lbf),  
whichever is greater.  
* * * * *  
0 
384. Revise Sec.  1066.405 to read as follows:  
Sec.  1066.405  Vehicle preparation, preconditioning, and maintenance.  
    (a) Prepare the vehicle for testing (including measurement of  
evaporative and refueling emissions if appropriate), as described in  
the standard-setting part.  
    (b) If you inspect a vehicle, keep a record of the inspection and  
update your application for certification to document any changes that  
result. You may use any kind of equipment, instrument, or tool that is  
available at dealerships and other service outlets to identify  
malfunctioning components or perform maintenance.  
    (c) You may repair defective parts from a test vehicle if they are  
unrelated to emission control. You must ask us to approve repairs that  
might affect the vehicle's emission controls. If we determine that a  
part failure, system malfunction, or associated repair makes the  
vehicle's emission controls unrepresentative of production engines, you  
may not use it as an emission-data vehicle. Also, if the engine  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 261/268installed in the test vehicle has a major mechanical failure that  
requires you to take the vehicle apart, you may no longer use the  
vehicle as an emission-data vehicle for exhaust measurements.  
0 
385. Amend Sec.  1066.420 by revising paragraph (d) to read as follows:  
Sec.  1066.420  Test preparation.  
* * * * *  
    (d) Control test cell ambient air humidity as follows:  
    (1) For vehicles at or below 14,000 pounds GVWR, follow the  
humidity requirements in Table 1 of this section, unless the standard-  
setting part specifies otherwise. When complying with humidity  
requirements in Table 1, where no tolerance is specified, use good  
engineering judgment to maintain the humidity level near the specified  
value within the limitations of your test facility.  
    (2) For vehicles above 14,000 pounds GVWR, you may test vehicles at  
any humidity.  
    (3) Table 1 follows:  
       Table 1 of Sec.   1066.420--Test Cell Humidity Requirements  
------------------------------------------------------------------------  
                                       Humidity  
                                      requirement     Tolerance (grains  
            Test cycle                (grains H2O     H2O per pound dry  
                                     per pound dry          air)  
                                         air)  
------------------------------------------------------------------------  
AC17..............................              69  5 
                                                     average, 10 
                                                     instantaneous.  
FTP \a\ and LA-92.................              50  
HFET..............................              50  
SC03..............................             100  5 
                                                     average.  
US06..............................              50  
------------------------------------------------------------------------  
\a\ FTP humidity requirement does not apply for cold (-7[deg]C),  
  intermediate (10[deg]C), and hot (35[deg]C) temperature testing.  
[[Page 34583]]  
* * * * *  
0 
386. Amend Sec.  1066.605 by revising paragraphs (c)(4) and (h)(2)(i)  
to read as follows:  
Sec.  1066.605  Mass-based and molar-based exhaust emission  
calculations.  
* * * * *  
    (c) * * *  
    (4) For vehicles at or below 14,000 pounds GVWR, calculate HC  
concentrations, including dilution air background concentrations, as  
described in this section, and as described in Sec.  1066.635 for NMOG.  
For emission testing of vehicles above 14,000 pounds GVWR, with fuels  
that contain 25% or more oxygenated compounds by volume, calculate THCE  
and NMHCE concentrations, including dilution air background  
concentrations, as described in 40 CFR part 1065, subpart I.  
* * * * *  
    (h) * * *  
    (2) * * *  
    (i) Varying flow rate. If you continuously sample from a varying  
exhaust flow rate, calculate V [flow] using the following  
equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.270  
Where: 
[Delta]t = 1/[fnof] record 
    Eq. 1066.605-11  
Example:  
N = 505 
QCVS1= 0.276 m3/s 
QCVS2= 0.294 m3/s 
[fnof]record = 1 Hz 
    Using Eq. 1066.605-11:  
[Delta]t = 1/1 = 1 s  
VCVS = (0.276 + 0.294 + Q CVS505) [middot] 1  
VCVS = 170.721 m3 
* * * * *  
0 
387. Amend Sec.  1066.610 by revising paragraph (d) to read as follows:  
Sec.  1066.610  Dilution air background correction.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 262/268* * * * *  
    (d) Determine the time-weighted dilution factor, DF w,  
over the duty cycle using the following equation:  
[GRAPHIC] [TIFF OMITTED] TR29JN21.272  
Where: 
N = number of test intervals  
i = test interval number  
t = duration of the test interval  
DF = dilution factor over the test interval  
Example:  
N = 3 
DF1 = 14.40  
t1 = 505 s  
DF2 = 24.48  
t2 = 867 s  
DF3 = 17.28  
t3 = 505 s  
[GRAPHIC] [TIFF OMITTED] TR29JN21.273  
0 
388. Amend Sec.  1066.710 by revising paragraph (c) to read as follows:  
Sec.  1066.710  Cold temperature testing procedures for measuring CO  
and NMHC emissions and determining fuel economy.  
* * * * *  
    (c) During the test, operate the vehicle's interior climate control  
system with the heat on and air conditioning off. You may not use any  
supplemental auxiliary heat during this testing. You may set the heater  
to any temperature and fan setting during vehicle preconditioning.  
    (1) Manual and automatic temperature control. Unless you rely on  
full automatic control as specified in paragraph (c)(2) of this  
section, take the following steps to control heater settings:  
    (i) Set the climate control system as follows before the first  
acceleration (t = 20 s), or before starting the vehicle if the climate  
control system allows it:  
    (A) Temperature. Set controls to maximum heat. For automatic  
temperature control systems that allow the operator to select a  
specific temperature, set the heater control to 72[deg]F or higher.  
    (B) Fan speed. Set the fan speed to full off or the lowest  
available speed if a full off position is not available.  
    (C) Airflow direction. Direct airflow to the front window (window  
defrost mode).  
    (D) Air source. If independently controllable, set the system to  
draw in outside air.  
    (ii) At the second idle of the test cycle, which occurs 125 seconds  
after the start of the test, set the fan speed to maximum. Complete by  
130 seconds after the start of the test. Leave temperature and air  
source settings unchanged.  
    (iii) At the sixth idle of the test interval, which occurs at the  
deceleration to zero miles per hour 505 seconds after the start of the  
test, set the fan speed to the lowest setting that maintains air flow.  
Complete these changes by 510 seconds after the start of the test. You  
may use different vent and fan speed settings for the remainder of the  
test. Leave the temperature and air source settings unchanged.  
    (2) Full automatic control. Vehicles with full automatic control  
systems may instead operate as described in this paragraph (c)(2). Set  
the temperature to 72[deg]F in full automatic control for the whole  
test, allowing the vehicle to adjust the air temperature and direction  
of the airflow.  
    (3) Multiple-zone systems. For vehicles that have separate driver  
and passenger controls or separate front and rear controls, you must  
set all temperature and fan controls as described in paragraphs (c)(1)  
and (2) of this section, except that rear controls need not be set to  
defrost the front window.  
    (4) Alternative test procedures. We may approve the use of other  
settings under 40 CFR 86.1840 if a vehicle's climate control system is  
not compatible with the provisions of this section.  
* * * * *  
0 
389. Amend Sec.  1066.801 by revising paragraph (e) to read as follows:  
Sec.  1066.801  Applicability and general provisions.  
* * * * *  
    (e) The following figure illustrates the FTP test sequence for  
measuring exhaust and evaporative emissions:  
BILLING CODE 6560-50-P  
[[Page 34584]]  
[GRAPHIC] [TIFF OMITTED] TR29JN21.274  
BILLING CODE 6560-50-C  
[[Page 34585]]  
0 6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 263/268390. Amend Sec.  1066.835 by revising paragraphs (a) and (f)(2) to read  
as follows:  
Sec.  1066.835  Exhaust emission test procedure for SC03 emissions.  
* * * * *  
    (a) Drain and refill the vehicle's fuel tank(s) if testing starts  
more than 72 hours after the most recent FTP or HFET measurement (with  
or without evaporative emission measurements).  
* * * * *  
    (f) * * *  
    (2) Conditions before and after testing. Use good engineering  
judgment to demonstrate that you meet the specified temperature and  
humidity tolerances in paragraph (f)(1) of this section at all times  
before and between emission measurements.  
* * * * *  
0 
391. Revise Sec.  1066.930 to read as follows:  
Sec.  1066.930  Equipment for point-source measurement of running  
losses. 
    For point-source measurement of running loss emissions, use  
equipment meeting the specifications in 40 CFR 86.107-96(i).  
0 
392. Amend Sec.  1066.1005 by revising paragraphs (a), (c), (d), (e),  
and (f) to read as follows:  
Sec.  1066.1005  Symbols, abbreviations, acronyms, and units of  
measure.  
* * * * *  
    (a) Symbols for quantities. This part uses the following symbols  
and units of measure for various quantities:  
                               Table 1 of Sec.   1066.1005--Symbols for Quantities  
----------------------------------------------------------------------------------------------------------------  
                                                                                                Unit in terms of  
            Symbol                     Quantity                 Unit             Unit symbol      SI base units  
----------------------------------------------------------------------------------------------------------------  
[alpha].......................  atomic hydrogen to     mole per mole........  mol/mol.........  1.  
                                 carbon ratio.  
A.............................  area.................  square meter.........  m2..............  m2.  
A.............................  vehicle frictional     pound force or newton  lbf or N........  m[middot]kg[midd  
                                 load.                                                           ot]s-2.  
ag............................  acceleration of        meters per second      m/s2............  m[middot]s-2.  
                                 Earth's gravity.       squared.  
am............................  calculated vehicle     pound force or newton  lbf or N........  m[middot]kg[midd  
                                 frictional load.                                                ot]s-2.  
a0............................  intercept of least  
                                 squares regression.  
a1............................  slope of least  
                                 squares regression.  
a.............................  acceleration.........  feet per second        ft/s2 or m/s2...  m[middot]s 2. 
                                                        squared or meters  
                                                        per second squared.  
B.............................  vehicle load from      pound force per mile   lbf/(mi/hr) or    kg[middot]s 1. 
                                 drag and rolling       per hour or newton     N[middot]s/m.  
                                 resistance.            second per meter.  
[beta]........................  ratio of diameters...  meter per meter......  m/m.............  1.  
[beta]........................  atomic oxygen to       mole per mole........  mol/mol.........  1.  
                                 carbon ratio.  
c.............................  conversion factor.  
C.............................  vehicle-specific       pound force per mile   lbf/(mi/hr)2 or   m 1[middot]kg.  
                                 aerodynamic effects.   per hour squared or    N[middot]s2/m2.  
                                                        newton-second  
                                                        squared per meter  
                                                        squared.  
C............................  number of carbon       C...................  number of carbon  C.  
                                 atoms in a molecule.                          atoms in a  
                                                                               molecule.  
Cd............................  discharge  
                                 coefficient.  
CdA...........................  drag area............  meter squared........  m2..............  m2.  
Cf............................  flow coefficient.  
Cp............................  heat capacity at       joule per kelvin.....  J/K.............  m2[middot]kg[mid  
                                 constant pressure.                                              dot]s-2[middot]  
                                                                                                 K-1.  
Cv............................  heat capacity at       joule per kelvin.....  J/K.............  m2[middot]kg[mid  
                                 constant volume.                                                dot]s-2[middot]  
                                                                                                 K-1.  
d.............................  diameter.............  meters...............  m...............  m.  
D.............................  distance.............  miles or meters......  mi or m.........  m.  
D.............................  slope correlation....  pound force per mile   lbf/(mi/hr)2 or   m-2[middot]kg.  
                                                        per hour squared or    N[middot]s2/m2.  
                                                        newton second  
                                                        squared per meter  
                                                        squared.  
DF............................  dilution factor......  .....................  ................  1.  
e.............................  mass weighted          grams/mile...........  g/mi.  
                                 emission result.  
F.............................  force................  pound force or newton  lbf or N........  kg[middot]s-2.  
[fnof]........................  frequency............  hertz................  Hz..............  s-1.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 264/268[fnof]n.......................  angular speed (shaft)  revolutions per        r/min...........  [pi][middot]30[m  
                                                        minute.                                  iddot]s-1.  
FC............................  friction compensation  horsepower or watt...  W...............  m2[middot]kg[mid  
                                 error.                                                          dot]s-3.  
FR............................  road-load force......  pound force or newton  lbf or N........  kg[middot]s-2.  
[gamma].......................  ratio of specific      (joule per kilogram    (J/               1.  
                                 heats.                 kelvin) per (joule     (kg[middot]K))/  
                                                        per kilogram kelvin).  (J/  
                                                                               (kg[middot]K)).  
H.............................  ambient humidity.....  grams water vapor per  g H2O vapor/kg    g H2O vapor/kg  
                                                        kilogram dry air.      dry air.          dry air.  
[Delta]h......................  change in height.....  meters...............  m...............  m.  
I.............................  inertia..............  pound mass or          lbm or kg.......  kg.  
                                                        kilogram.  
I.............................  current..............  ampere...............  A...............  A.  
i.............................  indexing variable.  
IR............................  inertia work rating.  
K.............................  correction factor....  .....................  ................  1.  
Kv............................  calibration            .....................  m4[middot]s[midd  m4[middot]kg-  
                                 coefficient.                                  ot]K0.5/kg.       1[middot]s[midd  
                                                                                                 ot]K0.5.  
[mu]..........................  viscosity, dynamic...  pascal second........  Pa[middot]s.....  m-  
                                                                                                 1[middot]kg[mid  
                                                                                                 dot]s-1.  
M.............................  molar mass...........  gram per mole........  g/mol...........  10-3[middot]kg[m  
                                                                                                 iddot]mol-1.  
Me............................  effective mass.......  kilogram.............  kg..............  kg.  
m.............................  mass.................  pound mass or          lbm or kg.......  kg.  
                                                        kilogram.  
N.............................  total number in  
                                 series.  
n.............................  total number of  
                                 pulses in a series.  
[[Page 34586]]  
  
p.............................  pressure.............  pascal...............  Pa..............  m-  
                                                                                                 1[middot]kg[mid  
                                                                                                 dot]s-2.  
[Delta]p......................  differential static    pascal...............  Pa..............  m-  
                                 pressure.                                                       1[middot]kg[mid  
                                                                                                 dot]s-2.  
pd............................  saturated vapor        kilopascal...........  kPa.............  m-  
                                 pressure at ambient                                             1[middot]kg[mid  
                                 dry bulb temperature.                                           dot]s-1.  
PF............................  penetration fraction.  
[rho].........................  mass density.........  kilogram per cubic     kg/m3...........  m-3[middot]kg.  
                                                        meter.  
R.............................  dynamometer roll       revolutions per        rpm.............  [pi][middot]30-  
                                 revolutions.           minute.                                  1[middot]s-1.  
r.............................  ratio of pressures...  pascal per pascal....  Pa/Pa...........  1.  
r2............................  coefficient of  
                                 determination.  
Re...........................  Reynolds number.  
RF............................  response factor.  
RH............................  relative humidity.  
S.............................  Sutherland constant..  kelvin...............  K...............  K.  
SEE...........................  standard error of the  
                                 estimate.  
SG............................  specific gravity.  
[Delta]s......................  distance traveled      meters...............  m...............  m.  
                                 during measurement  
                                 interval.  
T.............................  absolute temperature.  kelvin...............  K...............  K.  
T.............................  Celsius temperature..  degree Celsius.......  [deg]C..........  K-273.15.  
T.............................  torque (moment of      newton meter.........  N[middot]m......  m2[middot]kg[mid  
                                 force).                                                         dot]s-2.  
t.............................  time.................  hour or second.......  hr or s.........  s.  
[Delta]t......................  time interval,         second...............  s...............  s.  
                                 period, 1/frequency.  
U.............................  voltage..............  volt.................  V...............  m2[middot]kg[mid  
                                                                                                 dot]s-3[middot]  
                                                                                                 A-1.  
v.............................  speed................  miles per hour or      mi/hr or m/s....  m[middot]s-1.  
                                                        meters per second.  
V.............................  volume...............  cubic meter..........  m3..............  m3.  
V.............................  flow volume rate.....  cubic feet per minute  ft3/min or m3/s.  m3[middot]/s-1.  
                                                        or cubic meter per  
                                                        second.  
VP............................  volume percent.  
x.............................  concentration of       part per million.....  ppm.  
                                 emission over a test  
                                 interval.  
y.............................  generic variable.  
Z.............................  compressibility  
                                 factor.  
----------------------------------------------------------------------------------------------------------------  
* * * * *  
    (c) Superscripts. This part uses the following superscripts for  
modifying quantity symbols:  
                Table 3 of Sec.   1066.1005--Superscripts  
------------------------------------------------------------------------  
                Superscript                            Meaning  
------------------------------------------------------------------------  
overbar (such as y).......................  arithmetic mean.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 265/268overdot (such as y).......................  quantity per unit time.  
------------------------------------------------------------------------  
    (d) Subscripts. This part uses the following subscripts for  
modifying quantity symbols:  
                 Table 4 of Sec.   1066.1005--Subscripts  
------------------------------------------------------------------------  
          Subscript                             Meaning  
------------------------------------------------------------------------  
0............................  reference.  
abs..........................  absolute quantity.  
AC17.........................  air conditioning 2017 test interval.  
act..........................  actual or measured condition.  
actint.......................  actual or measured condition over the  
                                speed interval.  
adj..........................  adjusted.  
air..........................  air, dry.  
atmos........................  atmospheric.  
b............................  base.  
bkgnd........................  background.  
c............................  cold.  
comp.........................  composite.  
cor..........................  corrected.  
cs...........................  cold stabilized.  
ct...........................  cold transient.  
cUDDS........................  cold-start UDDS.  
D............................  driven.  
dew..........................  dewpoint.  
dexh.........................  dilute exhaust quantity.  
dil..........................  dilute.  
e............................  effective.  
emission.....................  emission specie.  
error........................  error.  
[[Page 34587]]  
  
EtOH.........................  ethanol.  
exh..........................  raw exhaust quantity.  
exp..........................  expected quantity.  
fil..........................  filter.  
final........................  final.  
flow.........................  flow measurement device type.  
gas..........................  gaseous.  
h............................  hot.  
HFET.........................  highway fuel economy test.  
hs...........................  hot stabilized.  
ht...........................  hot transient.  
hUDDS........................  hot-start UDDS.  
i............................  an individual of a series.  
ID...........................  driven inertia.  
in...........................  inlet.  
int..........................  intake.  
init.........................  initial quantity, typically before an  
                                emission test.  
IT...........................  target inertia.  
liq..........................  liquid.  
max..........................  the maximum (i.e., peak) value expected  
                                at the standard over a test interval;  
                                not the maximum of an instrument range.  
meas.........................  measured quantity.  
mix..........................  dilute exhaust gas mixture.  
out..........................  outlet.  
PM...........................  particulate matter.  
record.......................  record.  
ref..........................  reference quantity.  
rev..........................  revolution.  
roll.........................  dynamometer roll.  
s............................  settling.  
s............................  slip.  
s............................  stabilized.  
sat..........................  saturated condition.  
SC03.........................  air conditioning driving schedule.  
span.........................  span quantity.  
sda..........................  secondary dilution air.  
std..........................  standard conditions.  
T............................  target.  
t............................  throat.  
test.........................  test quantity.  
uncor........................  uncorrected quantity.  
w............................  weighted.  
zero.........................  zero quantity.  
------------------------------------------------------------------------  
    (e) Other acronyms and abbreviations. This part uses the following  
additional abbreviations and acronyms:  
      Table 5 of Sec.   1066.1005--Other Acronyms and Abbreviations  
------------------------------------------------------------------------  
           Acronym                              Meaning  
------------------------------------------------------------------------  
A/C..........................  air conditioning.  
AC17.........................  air conditioning 2017 test interval.  
ALVW.........................  adjusted loaded vehicle weight.  
ASME.........................  American Society of Mechanical Engineers.  
CFR..........................  Code of Federal Regulations.  
CFV..........................  critical-flow venturi.  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 266/268CNG..........................  compressed natural gas.  
CVS..........................  constant-volume sampler.  
EPA..........................  Environmental Protection Agency.  
ETW..........................  equivalent test weight.  
EV...........................  electric vehicle.  
FID..........................  flame-ionization detector.  
FTP..........................  Federal test procedure.  
GC...........................  gas chromatograph.  
GEM..........................  greenhouse gas emissions model.  
GHG..........................  greenhouse gas (including CO2, N2O, and  
                                CH4).  
GPS..........................  global positioning system.  
GVWR.........................  gross vehicle weight rating.  
[[Page 34588]]  
  
HEV..........................  hybrid electric vehicle, including plug-  
                                in hybrid electric vehicles.  
HFET.........................  highway fuel economy test.  
HLDT.........................  heavy light-duty truck.  
HPLC.........................  high pressure liquid chromatography.  
IBR..........................  incorporated by reference.  
LA-92........................  Los Angeles 1992 driving schedule.  
MDPV.........................  medium-duty passenger vehicle.  
NIST.........................  National Institute for Standards and  
                                Technology.  
NMC..........................  nonmethane cutter.  
PDP..........................  positive-displacement pump.  
PHEV.........................  plug-in hybrid electric vehicle.  
PM...........................  particulate matter.  
RESS.........................  rechargeable energy storage system.  
ppm..........................  parts per million.  
SAE..........................  Society of Automotive Engineers.  
SC03.........................  air conditioning driving schedule.  
SEA..........................  selective enforcement audit.  
SFTP.........................  Supplemental Federal Test Procedure.  
SI...........................  International System of Units.  
SSV..........................  subsonic venturi.  
UDDS.........................  urban dynamometer driving schedule.  
US06.........................  aggressive driving schedule.  
U.S.C........................  United States Code.  
WWV..........................  NIST radio station call sign.  
------------------------------------------------------------------------  
    (f) Densities of chemical species. This part uses the following  
densities of chemical species:  
                           Table 6 of Sec.   1066.1005--Densities of Chemical Species  
----------------------------------------------------------------------------------------------------------------  
                   Symbol                                Quantity a b                  g/m3            g/ft3  
----------------------------------------------------------------------------------------------------------------  
[rho]CH4...................................  density of methane.................         666.905         18.8847  
[rho]CH3OH.................................  density of methanol................         1332.02         37.7185  
[rho]C2H5OH................................  C1-equivalent density of ethanol...         957.559         27.1151  
[rho]C2H4O.................................  C1-equivalent density of                    915.658         25.9285  
                                              acetaldehyde.  
[rho]C3H8..................................  density of propane.................         611.035         17.3026  
[rho]C3H7OH................................  C1-equivalent density of propanol..          832.74         23.5806  
[rho]CO....................................  density of carbon monoxide.........         1164.41         32.9725  
[rho]CO2...................................  density of carbon dioxide..........         1829.53         51.8064  
[rho]HC-gas................................  effective density of hydrocarbon--          (see 3)         (see 3)  
                                              gaseous fuel c.  
[rho]CH2O..................................  density of formaldehyde............         1248.21         35.3455  
[rho]HC-liq................................  effective density of hydrocarbon--          576.816         16.3336  
                                              liquid fueld.  
[rho]NMHC-gas..............................  effective density of nonmethane             (see 3)         (see 3)  
                                              hydrocarbon--gaseous fuel c.  
[rho]NMHC-liq..............................  effective density of nonmethane             576.816         16.3336  
                                              hydrocarbon--liquid fuel d.  
[rho]NMHCE-gas.............................  effective density of nonmethane             (see 3)         (see 3)  
                                              equivalent hydrocarbon--gaseous  
                                              fuel c.  
[rho]NMHCE-liq.............................  effective density of nonmethane             576.816         16.3336  
                                              equivalent hydrocarbon--liquid  
                                              fuel d.  
[rho]NOx...................................  effective density of oxides of               1912.5          54.156  
                                              nitrogen e.  
[rho]N2O...................................  density of nitrous oxide...........         1829.66         51.8103  
[rho]THC-liq...............................  effective density of total                  576.816         16.3336  
                                              hydrocarbon--liquid fuel d.  
[rho]THCE-liq..............................  effective density of total                  576.816         16.3336  
                                              equivalent hydrocarbon--liquid  
                                              fuel d.  
----------------------------------------------------------------------------------------------------------------  
a Densities are given at 20 [deg]C and 101.325 kPa.  
b Densities for all hydrocarbon containing quantities are given in g/m3-carbon atom and g/ft3-carbon atom.  
c The effective density for natural gas fuel and liquefied petroleum gas fuel are defined by an atomic hydrogen-  
  to-carbon ratio, [alpha], of the hydrocarbon components of the test fuel. [rho]HCgas = 41.57[middot](12.011 +  
  ([alpha][middot]1.008)).  
d The effective density for gasoline and diesel fuel are defined by an atomic hydrogen-to-carbon ratio, [alpha],  
  of 1.85.  
e The effective density of NOX is defined by the molar mass of nitrogen dioxide, NO2.  
* * * * *  
PART 1068--GENERAL COMPLIANCE PROVISIONS FOR HIGHWAY, STATIONARY,  
AND NONROAD PROGRAMS  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 267/2680 
393. The authority citation for part 1068 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
394. Amend Sec.  1068.1 by revising paragraph (a) and removing and  
reserving paragraph (d)(2) to n reads as follows:  
Sec.  1068.1  Does this part apply to me?  
    (a) The provisions of this part apply to everyone with respect to  
the engine and equipment categories as described in this paragraph (a).  
The provisions of this part apply to everyone, including owners,  
operators, parts manufacturers, and persons performing maintenance.  
[[Page 34589]]  
Where we identify an engine category, the provisions of this part also  
apply with respect to the equipment using such engines. This part  
applies to different engine and equipment categories as follows:  
    (1) This part applies to motor vehicles we regulate under 40 CFR  
part 86, subpart S, to the extent and in the manner specified in 40 CFR  
parts 85 and 86.  
    (2) This part applies for heavy-duty motor vehicles we regulate  
under 40 CFR part 1037, subject to the provisions of 40 CFR parts 85  
and 1037. This includes trailers. This part applies to other heavy-duty  
motor vehicles and motor vehicle engines to the extent and in the  
manner specified in 40 CFR parts 85, 86, and 1036.  
    (3) This part applies to highway motorcycles we regulate under 40  
CFR part 86, subparts E and F, to the extent and in the manner  
specified in 40 CFR parts 85 and 86.  
    (4) This part applies to aircraft we regulate under 40 CFR part 87  
to the extent and in the manner specified in 40 CFR part 87.  
    (5) This part applies for locomotives that are subject to the  
provisions of 40 CFR part 1033. This part does not apply for  
locomotives or locomotive engines that were originally manufactured  
before July 7, 2008, and that have not been remanufactured on or after  
July 7, 2008.  
    (6) This part applies for land-based nonroad compression-ignition  
engines that are subject to the provisions of 40 CFR part 1039.  
    (7) This part applies for stationary compression-ignition engines  
certified using the provisions of 40 CFR parts 1039 and 1042 as  
described in 40 CFR part 60, subpart IIII.  
    (8) This part applies for marine compression-ignition engines that  
are subject to the provisions of 40 CFR part 1042.  
    (9) This part applies for marine spark-ignition engines that are  
subject to the provisions of 40 CFR part 1045.  
    (10) This part applies for large nonroad spark-ignition engines  
that are subject to the provisions of 40 CFR part 1048.  
    (11) This part applies for stationary spark-ignition engines  
certified using the provisions of 40 CFR part 1048 or 1054, as  
described in 40 CFR part 60, subpart JJJJ.  
    (12) This part applies for recreational engines and vehicles,  
including snowmobiles, off-highway motorcycles, and all-terrain  
vehicles that are subject to the provisions of 40 CFR part 1051.  
    (13) This part applies for small nonroad spark-ignition engines  
that are subject to the provisions of 40 CFR part 1054.  
    (14) This part applies for fuel-system components installed in  
nonroad equipment powered by volatile liquid fuels that are subject to  
the provisions of 40 CFR part 1060.  
* * * * *  
0 
395. Amend Sec.  1068.10 by revising the section heading and paragraphs  
(b) and (c) to read as follows:  
Sec.  1068.10  Confidential business information.  
* * * * *  
    (b) We will store your confidential business information as  
described in 40 CFR part 2. Also, we will disclose it only as specified  
in 40 CFR part 2. This paragraph (b) applies both to any information  
you send us and to any information we collect from inspections, audits,  
or other site visits.  
    (c) If you send us a second copy without the confidential business  
information, we will assume it contains nothing confidential whenever  
we need to release information from it.  
* * * * *  
0 
396. Amend Sec.  1068.240 by revising paragraphs (b)(6) and (c)(1) and  
(3) to read as follows:  
Sec.  1068.240  Exempting new replacement engines.  
* * * * *  
    (b) * * *  
    (6) Engines exempt under this paragraph (b) may not be introduced  
into U.S. commerce before you make the determinations under paragraph  
(b)(2) of this section, except as specified in this paragraph (b)(6).  
We may waive the restriction in this paragraph (b)(6) for engines  
identified under paragraph (c)(5) of this section that you ship to a  6/29/2021 Federal Register , Volume 86 Issue 122 (T uesday , June 29, 2021)
https://www .govinfo.gov/content/pkg/FR-2021-06-29/html/2021-05306.htm 268/268distributor. Where we waive the restriction in this paragraph (b)(6),  
you must take steps to ensure that the engine is installed consistent  
with the requirements of this paragraph (b). For example, at a minimum  
you must report to us annually whether engines we allowed you to ship  
to a distributor under this paragraph (b)(6) have been placed into  
service or remain in inventory. After an engine is placed into service,  
your report must describe how the engine was installed consistent with  
the requirements of this paragraph (b). Send these reports to the  
Designated Compliance Officer by the deadlines we specify.  
    (c) * * *  
    (1) You may produce a limited number of replacement engines under  
this paragraph (c) representing 0.5 percent of your annual production  
volumes for each category and subcategory of engines identified in  
Table 1 to this section or five engines for each category and  
subcategory, whichever is greater. Calculate this number by multiplying  
your annual U.S.-directed production volume by 0.005 (or 0.01 through  
2013) and rounding to the nearest whole number. Determine the  
appropriate production volume by identifying the highest total annual  
U.S.-directed production volume of engines from the previous three  
model years for all your certified engines from each category or  
subcategory identified in Table 1 to this section, as applicable. In  
unusual circumstances, you may ask us to base your production limits on  
U.S.-directed production volume for a model year more than three years  
prior. You may include stationary engines and exempted engines as part  
of your U.S.-directed production volume. Include U.S.-directed engines  
produced by any affiliated companies and those from any other companies  
you license to produce engines for you.  
* * * * *  
    (3) Send the Designated Compliance Officer a report by September 30  
of the year following any year in which you produced exempted  
replacement engines under this paragraph (c).  
    (i) In your report include the total number of replacement engines  
you produce under this paragraph (c) for each category or subcategory,  
as appropriate, and the corresponding total production volumes  
determined under paragraph (c)(1) of this section. If you send us a  
report under this paragraph (c)(3), you must also include the total  
number of complete and partially complete replacement engines you  
produced under paragraphs (b) and (e) of this section (including any  
replacement marine engines subject to reporting under 40 CFR 1042.615).  
    (ii) Count exempt engines as tracked under paragraph (b) of this  
section only if you meet all the requirements and conditions that apply  
under paragraph (b)(2) of this section by the due date for the annual  
report. In the annual report you must identify any replaced engines  
from the previous year that you were not able to recover by the due  
date for the annual report. Continue to report those engines in later  
reports until you recover the replaced engines. If any replaced engine  
is not recovered for the fifth annual report following the production  
report, treat this as an untracked replacement in the fifth annual  
report for the preceding year.  
    (iii) You may include the information required under this paragraph  
(c)(3) in  
[[Page 34590]]  
production reports required under the standard-setting part.  
* * * * *  
PART 1074--PREEMPTION OF STATE STANDARDS AND PROCEDURES FOR WAIVER  
OF FEDERAL PREEMPTION FOR NONROAD ENGINES AND NONROAD VEHICLES  
0 
397. The authority citation for part 1074 continues to read as follows:  
    Authority:  42 U.S.C. 7401-7671q.  
0 
398. Add appendix A to subpart A to read as follows:  
Appendix A to Subpart A of Part 1074--State Regulation of the Use and  
Operation of Nonroad Internal Combustion Engines  
    (a) This appendix describes EPA's interpretation of the Clean  
Air Act regarding the authority of states to regulate the use and  
operation of nonroad engines.  
    (b) EPA believes that states are not precluded under 42 U.S.C.  
7543 from regulating the use and operation of nonroad engines, such  
as regulations on hours of usage, daily mass emission limits, or  
sulfur limits on fuel; nor are permits regulating such operations  
precluded, once the engine is no longer new. EPA believes that  
states are precluded from requiring retrofitting of used nonroad  
engines except that states are permitted to adopt and enforce any  
such retrofitting requirements identical to California requirements  
which have been authorized by EPA under 42 U.S.C. 7543.  
[FR Doc. 2021-05306 Filed 6-28-21; 8:45 am]  
 BILLING CODE 6560-50-P