volumes are used to determine whether and how many sources are required
to be tested or, in some cases, whether the testing program needs to be
undertaken at all. In this way, production volume is tied to compliance
with the PLT and in-use testing requirements and is paragraph B
information necessary for demonstrating compliance with an applicable
standard. Note, that the production volume category is emission data
for multiple reasons, as discussed in Sections XI.A.1.i.a and
XI.A.1.i.c.
---------------------------------------------------------------------------

    \563\ 40 CFR 2.301(a)(2)(i)(B).
---------------------------------------------------------------------------

    Test Information and Results: The test information and results
category includes the testing conducted by manufacturers and is
necessary to demonstrate that the test parameters meet the requirements
of the regulations. This ensures that the test

results are reliable and consistent. If a test does not meet the
requirements in the applicable regulations, then the results cannot be
used for certification or compliance purposes. The parameters and
underlying information of an emissions test is information necessary to
understanding the test results themselves. Adjustable parameter
information is necessary to understand the tests used to certify a
source and, therefore, also necessary to understand the test results
and whether the source achieved compliance with the applicable
standard. For these reasons, we are determining that the test
information and results category is ``necessary to determine the
identity, amount, frequency, concentration, or other characteristic (to
the extent related to air quality) of the emissions which, under an
applicable standard or limitation, the source was authorized to emit
(including, to the extent necessary for such purposes, a description of
the manner or rate of operation of the source[.]'' \564\ Test
information and results collected under the standard-setting parts
includes the following: Test temperature, adjustable test parameters,
exhaust emission standards and family emission limits (FELs), emission
deterioration factors, fuel type used, intended application, CO
standard, particulate matter (``PM'') standard, NOX + HC
standard, NOX standard, HC standard, CO2
alternate standard, alternate standard approval code, CO2
family emission limit (``FEL''), CO2 family certification
level (``FCL''), NOX and NMHC + NOX standard,
NOX and NMHC + NOX alternate standard,
N2O standard, N2O FEL, CH4 standard,
CH4 FEL, NOX or NMHC + NOX FEL, PM
FEL, test number, test time, engine configuration, green engine factor,
the test article's service hours, the deterioration factor type, test
location, test facility, the manufacturer's test contact, fuel test
results, vehicle mileage at the start of the test, exhaust
aftertreatment temperatures, engine speed, engine brake torque, engine
coolant temperature, intake manifold temperature and pressure, throttle
position, parameter sensed, emission-control system controlled, fuel-
injection timing, NTE threshold, limited testing region, meets vehicle
pass criteria (i.e., whether the test passes the applicable emission
standard), number of engines tested, number of engines still needing to
be tested, number of engines passed, purpose of diagnostics, instances
for OBD illuminated or set trouble codes, instance of misfuelling,
incomplete or invalid test information, the minimum tests required,
diagnostic system, and the number of disqualified engines. For the
reasons given, we are determining that test information and results is
emission data because it is both necessary to understand how the source
meets the applicable standards, including, but not limited to, ABT
compliance demonstrations, and to ensure a source is complying with its
certificate of conformity.\565\ Additionally, a portion of the
information included in the test information and results category is
emissions data under another subsection of the regulatory definition of
emissions data, as discussed in more detail in Section XI.A.1.i.a, as
it is also ``[i]nformation necessary to determine the identity, amount,
frequency, concentration, or other characteristics (to the extent
related to air quality) of any emission which has been emitted by the
source (or of any pollutant resulting from any emission by the source),
or any combination of the foregoing[.]'' \566\
---------------------------------------------------------------------------

    \564\ Id.
    \565\ Id.
    \566\ 40 CFR 2.301(a)(2)(i)(A).
---------------------------------------------------------------------------

    Defect and Recall Information: We are determining that the defect
and recall information category is emission data and not entitled to
confidential treatment because it is information necessary to determine
compliance with an applicable standard or limitation.\567\ The only
defects and recalls that manufacturers are required to report to EPA
are ones that impact emissions or could impact emissions. Therefore, if
a defect is reported to us, it is because it causes or may cause
increased emissions and information relating to that defect is
necessarily emission data, as it directly relates to the source's
compliance with an applicable standard. The defect and recall
information category, including information collected under the
standard-setting parts, includes: System compliance reporting type, EPA
compliance report name, manufacturer compliance report, manufacturer
compliance report identifier, contact identifier, process code,
submission status, EPA submission status and last modified date,
submission creator, submission creation date, last modified date, last
modified by, EPA compliance report identifier, compliance report type,
defect category, defect description, defect emissions impact estimate,
defect remediation plan explanation, drivability problems description,
emission data available indicator, OBD MIL illumination indicator,
defect identification source/method, plant address where defects were
manufactured, certified sales area, carline manufacturer code,
production start date, defect production end date, total production
volume of affected engines or vehicles, estimated or potential number
of engines or vehicles affected, actual number identified, estimated
affected percentage, make, model, additional model identifier, specific
displacement(s) impacted description, specific transmission(s) impacted
description, related defect report indicator, related EPA defect report
identifier, related defect description, remediation description,
proposed remedy supporting information, description of the impact on
fuel economy of defect remediation, description of the impact on
drivability from remediation, description of the impact on safety from
remediation, recalled source description, part availability method
description, repair performance/maintenance description, repair
instructions, nonconformity correction procedure description,
nonconformity estimated correction date, defect remedy time, defect
remedy facility, owner demonstration of repair eligibility description,
owner determination method description, owner notification method
description, owner notification start date, owner notification final
date, number of units involved in recall, calendar quarter, calendar
year, quarterly report number, related EPA recall report/remedial plan
identifier, number of sources inspected, number of sources needing
repair, number of sources receiving repair, number of sources
ineligible due to improper maintenance, number of sources ineligible
for repair due to exportation, number of sources ineligible for repair
due to theft, number of sources ineligible for repair due to scrapping,
number of sources ineligible for repair due to other reasons,
additional owner notification indicator, and the number of owner
notifications sent. We are not including defect investigation reports
in this category, instead the part 2 process will continue to apply as
described in Section XI.A.1.iv for defect investigation reports.
Additionally, a portion of the information included in this category is
emissions data under another subsection of the regulatory definition of
emissions data, as discussed in more detail in Section XI.A.1.i.a, as
it is also ``[i]nformation necessary to determine the identity, amount,
frequency, concentration, or other characteristics (to the extent
related to air quality) of any emission which has been emitted by the
source (or of any pollutant resulting

from any emission by the source), or any combination of the
foregoing[.]'' \568\
---------------------------------------------------------------------------

    \567\ 40 CFR 2.301(a)(2)(i)(B).
    \568\ 40 CFR 2.301(a)(2)(i)(A).
---------------------------------------------------------------------------

    SEA Compliance Information: We are determining that the SEA
compliance information category is emission data because it is
necessary to determine whether a source complies with its certificate
and the standards. This category includes the facility name and
location where the SEA was conducted, number of tests conducted, model
year, build date, hours of operation, location of accumulated hours,
the date the engines shipped, how the engines were stored, and, for
imported engines, the port facility and date of arrival. This
information collected through SEAs is necessary for determining whether
a source that was investigated through an SEA complies with the
applicable standards. For that reason, EPA is determining that this
category is emission data as defined at 40 CFR 2.301(a)(2)(i)(B).
Additionally, certain information collected during an SEA is included
in the test information and results category. We determine that SEA
compliance information is emission data because it is both paragraph B
information and ``[i]nformation necessary to determine the identity,
amount, frequency, concentration, or other characteristics (to the
extent related to air quality) of any emission which has been emitted
by the source (or of any pollutant resulting from any emission by the
source), or any combination of the foregoing[.]'' \569\
---------------------------------------------------------------------------

    \569\ Id.
---------------------------------------------------------------------------

    iv. Information that is emission data because it provides a general
description of the location and/or nature of the source to the extent
necessary to identify the source and to distinguish it from other
sources (including, to the extent necessary for such purposes, a
description of the device, installation, or operation constituting the
source).
    We are determining that certain categories of information meet the
regulatory definition of emission data under 40 CFR 2.301(a)(2)(i)(C)
because they convey a ``[g]eneral description of the location and/or
nature of the source to the extent necessary to identify the source and
to distinguish it from other sources (including, to the extent
necessary for such purposes, a description of the device, installation,
or operation constituting the source).'' \570\ We will refer to
subparagraph (C) in the definition of emission data as ``paragraph C
information'' throughout this section. We are determining that two
categories of information fall primarily under this regulatory
definition of emissions data: (1) Source family information, and (2)
production volume information. We determine these categories are
paragraph C information and are, therefore, emission data and not
entitled to confidential treatment. However, under this determination,
consistent with 40 CFR 2.301(a)(2)(ii), we will not release information
included in an application for certification prior to the introduction-
into-commerce-date, except under the limited circumstances already
provided for in that regulatory provision.
---------------------------------------------------------------------------

    \570\ 40 CFR 2.301(a)(2)(i)(C).
---------------------------------------------------------------------------

    Source Family Information: The information included in the source
family information category includes engine family information, vehicle
family information, evaporative family information, equipment family
information, subfamily name, engine family designation, emission family
name, and test group information. The engine, vehicle, and evaporative
family information includes information necessary to identify the
emission source for which the certificate was issued; this determines
the emission standards that apply to the source and distinguishes the
source's emissions from other sources. Manufacturers request
certification using the family name of the engines, vehicles, or
equipment they intend to produce for sale in the United States. Test
group information identifies the sources tested and covered by a
certificate. The source family is the basic unit used to identify a
group of sources for certification and compliance purposes. The source
family is a code with 12 digits that identifies all parts of that
source. More specifically, information conveyed in the source family
code include the model year, manufacturer, industry sector, engine
displacement, and the manufacturer's self-designated code for the
source family. We are determining that the source family information
category of information is emission data because it is information that
provides a ``[g]eneral description of the location and/or nature of the
source to the extent necessary to identify the source and to
distinguish it from other sources (including, to the extent necessary
for such purposes, a description of the device, installation, or
operation constituting the source).'' \571\
---------------------------------------------------------------------------

    \571\ 40 CFR 2.301(a)(2)(i)(C).
---------------------------------------------------------------------------

    Production Volume: Additionally, we are determining that production
volume is emission data necessary to identify the source. Where the
source is each individual engine, vehicle, or equipment produced, the
production volume provides information necessary for EPA or the public
to identify that source (the certificate only identifies one source,
where the production volume identifies all the sources) and distinguish
that source's emissions from the emissions of other sources. In other
words, actual production volume provides necessary information to
identify the number of sources operating under a certificate of
conformity and distinguish their total emissions from other sources. In
this way, the total number of sources operating under a certificate of
conformity provides a ``[g]eneral description . . . of nature of the
source'' or, alternatively, provides information necessary such that
the source can be identified in total, since it is generally unlikely
that only a single unit of any engine, vehicle, or equipment would be
produced under a certificate. For this additional reason, we determine
that the production volume category is emission data, not only for the
reasons provided in Sections X.A.1.i.a and b, but also because it also
provides a ``[g]eneral description of the location and/or nature of the
source to the extent necessary to identify the source and to
distinguish it from other sources (including, to the extent necessary
for such purposes, a description of the device, installation, or
operation constituting the source).'' \572\
---------------------------------------------------------------------------

    \572\ Id.
---------------------------------------------------------------------------

    v. Information submitted as preliminary and superseded will have
the same confidentiality treatment as the final reported information.
    In the course of certifying and demonstrating compliance,
manufacturers may submit information to EPA before the applicable
deadline, and may update or correct that information before the
deadline for certification or compliance reporting. Similarly,
manufacturers routinely update their applications for certification to
include more or different information. EPA treats this information as
an Agency record as soon as it is received through the Engine and
Vehicle Certification Information System (EVCIS). We are applying the
same confidentiality determinations to this ``early'' information by
category as we are making for the information included in the final
certification request or compliance report in the categories generally.
EPA generally does not intend to publish or release such preliminary or
superseded information, because we believe the inclusion of preliminary
information in Agency publications could lead to an inaccurate or
misleading understanding of emissions or of a manufacturer's compliance
status. However, because

such early information becomes an Agency record upon receipt, we may be
obligated to release information from those preliminary or superseded
documents that is not entitled to confidential treatment if a requester
specifically requests such pre-final information in a FOIA request. In
such circumstances, we intend to provide a statement regarding the
preliminary or superseded nature of the information in the final FOIA
response. EPA also does not intend to disclose information in submitted
reports until we have reviewed them to verify the reports' accuracy,
though the Agency may be required to release such information if it is
specifically requested under the FOIA. Note that this subsection's
determinations and intended approaches for preliminary and superseded
information submitted as part of the certification and compliance
reporting processes apply only to such information for those categories
of information where we are making confidentiality determinations in
this final rule. In other words, this subsection is not intended to
address preliminary or projected information for the types of
information we are not including in the determinations made in this
final rule and that remain subject to the part 2 process (see Section
XI.A.1.iv).
    vi. Information that is never entitled to confidential treatment
because it is publicly available or discernible information or becomes
public after a certain date.
    We are also determining that information that is or becomes
publicly available under the applicable standard-setting parts is not
entitled to confidential treatment by EPA. Information submitted under
the standard-setting parts generally becomes publicly available in one
of two ways: (1) Information is required to be publicly disclosed under
the standard-settings parts, or (2) information becomes readily
measurable or observable after the introduction-to-commerce date.
Information that is required to be publicly available under the
standard-setting parts includes: Information contained in the fuel
economy label, the vehicle emission control information (``VECI'')
label, the engine emission control information label, owner's manuals,
and information submitted by the manufacturer expressly for public
release. The information in the labels is designed to make the public
aware of certain emissions related information and thus is in no way
confidential. Similarly, manufacturers submit documents specifically
prepared for public disclosure to EPA with the understanding that they
are intended for public disclosure. We determine that these public
facing documents are not entitled to confidential treatment, as they
are prepared expressly for public availability.
    Additionally, we are determining that the types of information
provided in the next paragraph that are measurable or observable by the
public after the source is introduced into commerce are not entitled to
confidential treatment by EPA after the introduction-to-commerce date.
This information may also be emission data and included in the one of
the categories established in this action, accordingly, we determine
that it is emission data as described in Section XI.A.1.i. The fact
that this information is or becomes publicly available is an additional
reason for it to be not entitled to confidential treatment after the
introduction into commerce date, and is an independent alternative
basis for our determination that the information is not entitled to
confidential treatment.
    This information includes: Model and parts information, source
footprint information, manufacturer, model year, category, service
class, whether the engine is remanufactured, engine type/category,
engine displacement, useful life, power, payload tons, intended
application, model year, fuel type, tier, and vehicle make and model.
Footprint information is readily observable by the public after the
introduction-to-commerce date, as one can measure and calculate that
value once the source is introduced into commerce. Additionally, models
and parts information is also readily available to the public after the
source is introduced into commerce. Because this information is
publicly available, it is not entitled to confidential treatment.
Therefore, we will not provide any additional notice or process prior
to releasing these type of information in the future.
    vii. Information not included in this rule's determinations will be
treated as confidential, if the submitter claimed it as such, until a
confidentiality substantiation is submitted and a determination made
under the 40 CFR part 2 process.
    We are not making a confidentiality determination under 40 CFR
1068.11 for certain information submitted to EPA for certification and
compliance. This information, if claimed as confidential by the
submitters, will be treated by EPA as confidential until such time as
it is requested under the FOIA or EPA otherwise goes through a case-by-
case or class determination process under 40 CFR part 2. At that time,
we will make a confidentiality determination in accordance with 40 CFR
part 2, and as established in this rulemaking under 40 CFR 2.301(j)(4).
This final action supersedes the Table 3 CBI class determinations that
EPA previously made in 2013, such that the same categories of
information in Table 3 will not have an applicable class determination
and will now be subject to the 40 CFR part 2 process.
    The types of information we are not including in the determinations
made in this final rule, and remain subject to the part 2 process,
includes:
    (1) Projected production and sales,
    (2) Production start and end dates outside of the defect and recall
context,
    (3) Specific and detailed descriptions of the emissions control
operation and function,
    (4) Design specifications related to aftertreatment devices,
    (5) Specific and detailed descriptions of auxiliary emission
control devices (AECDs),
    (6) Plans for meeting regulatory requirements (e.g., ABT pre-
production plans),
    (7) Procedures to determine deterioration factors and other
emission adjustment factors and any information used to justify those
procedures,
    (8) Financial information related to ABT credit transactions
(including dollar amount, parties to the transaction and contract
information involved) and manufacturer bond provisions (including
aggregate U.S. asset holdings, financial details regarding specific
assets, whether the manufacturer or importer obtains a bond, and copies
of bond policies),
    (9) Serial numbers or other information to identify specific
engines or equipment selected for testing,
    (10) Procedures that apply based on the manufacturers request to
test engines or equipment differently than we specify in the applicable
standard-setting parts,
    (11) Information related to testing vanadium catalysts in 40 CFR
part 1065, subpart L (established in this rule),
    (12) GPS data identifying the location and route for in-use
emission testing, and
    (13) Defect investigation reports. The information contained in
defect investigation reports may encompass both emission data and
information that may be CBI, so we are not making a determination for
this report as whole. Instead, procedurally we will treat these reports
in accordance with the existing part 2 process.
    Additionally, we are creating a category of information to include
information EPA received through

``comments submitted in the comment field,'' where the Agency's
compliance reporting software has comment fields to allow manufacturers
to submit clarifying information in a narrative format. We are not
making a determination on this broad category of potential information
at this time, as the narrative comments may or may not contain emission
data. Therefore, EPA will undertake a case-by-case determination
pursuant to 40 CFR part 2 for any information provided in a comment
field. As explained earlier in this subsection, after further
consideration, this final action supersedes the Table 3 CBI class
determination made in 2013 and EPA is also not making a determination
at this time regarding whether the information in Table 3 of the 2013
determination may meet the definition of emission data or otherwise may
not be entitled to confidential treatment in certain circumstances
under individual standard-setting parts, and instead thinks that a
case-by-case determination process is better suited to these categories
of information.
2. Adjustable Parameters
    One of the goals of the certification process is to ensure that the
emission controls needed to meet emission standards cannot be bypassed
or rendered inoperative. Consistent with this goal, the standard-
setting parts generally require that engines, vehicles, and equipment
with adjustable parameters meet all the requirements of part 1068 for
any adjustment in the physically adjustable range. This applies for
testing pre-production engines, production engines, and in-use engines.
    The underlying principles of the current regulations and policy can
be traced to the early emission standards for mechanically controlled
engines. The regulations at 40 CFR 86.094-22(e) illustrate how the
relevant provisions currently apply for heavy-duty highway engines. The
earliest generation of engines with emission control technology subject
to emission standards included components such as simple screws to
adjust a variety of engine operating parameters, including fuel-air
ratio and idle speed. Owners were then able to adjust the engines based
on their priority for power, efficiency, or durability. At the same
time, manufacturers sought to reduce emissions by limiting the physical
range of adjustment of these parameters, so EPA developed regulations
to ensure that the engines' limitations were sufficiently robust to
minimize operation outside the specified range (48 FR 1418, January 12,
1983).
    Since then, heavy-duty highway engine manufacturers have developed
new technologies that did not exist when we adopted the existing
regulations related to adjustable parameters. The regulations at 40 CFR
86.094-22(e) therefore provide a limited framework under which to
administer the current certification for heavy-duty highway engines.
Current certification practice consists of applying these broad
principles to physically adjustable operating parameters in a way that
is similar for both highway and nonroad applications. EPA developed
guidance with detailed provisions for addressing adjustable parameters
at certification for land-based nonroad spark-ignition engines at or
below 19 kW.\573\ To date, programmable operating parameters have
generally not been treated as adjustable parameters for Federal
regulatory purposes, except that manufacturers need to identify all
available operating modes (such as eco-performance or rabbit/turtle
operation).
---------------------------------------------------------------------------

    \573\ ``Clean Air Act Requirements for Small Nonroad Spark-
Ignition Engines: Reporting Adjustable Parameters and Enforcement
Guidance,'' EPA Guidance CD-12-11 (Small SI Guidance), August 24,
2012.
---------------------------------------------------------------------------

    EPA's Office of Enforcement and Compliance Assurance (OECA) has
found extensive evidence of tampering with the electronic controls on
heavy-duty engines and vehicles nationwide, although EPA lacks robust
data on the exact rate of tampering.\574\ Recently, OECA announced a
new National Compliance Initiative (``NCI'') to address the
manufacture, sale, and installation of defeat devices on vehicles and
engines through civil enforcement.\575\ Section VI.C includes a
discussion on the potential for significant increases in emissions from
tampering with current heavy-duty engines, and the provisions in the
final rule that we expect will reduce incentives to tamper with model
year 2027 and later heavy-duty engines.
---------------------------------------------------------------------------

    \574\ U.S. EPA. ``Tampered Diesel Pickup Trucks: A Review of
Aggregated Evidence from EPA Civil Enforcement Investigations'',
November 20, 2021, Available online: https://www.epa.gov/enforcement/tampered-diesel-pickup-trucks-review-aggregated-evidence-epa-civil-enforcement.
    \575\ U.S. EPA. National Compliance Initiative: Stopping
Aftermarket Defeat Devices for Vehicles and Engines. Available
online: https://www.epa.gov/enforcement/national-compliance-initiative-stopping-aftermarket-defeat-devices-vehicles-and-engines.
---------------------------------------------------------------------------

    Manufacturers are required by existing regulations to describe in
their application for certification how they address potentially
adjustable operating parameters. As with all elements of certification,
the regulations require manufacturers to use good engineering judgment
for decisions related to adjustable parameters. The regulations also
describe a process for manufacturers to ask for preliminary approval
for decisions related to new technologies, substantially changed engine
designs, or new methods for limiting adjustability. See, for example,
40 CFR 1039.115 and 1039.210. Note that the certification requirements
described in this section for manufacturers apply equally to anyone
certifying remanufactured engines or associated remanufacturing systems
where such certification is required.
    We are adopting a new 40 CFR 1068.50 to update the current
regulatory provisions such that the established principles and
requirements related to adjustable parameters also apply for current
technologies. Thus, the new provisions indicate how our established
principles regarding adjustable parameters apply for the full range of
emission control technologies.
    The provisions are largely based on regulations that already apply
for highway engines and vehicles under 40 CFR 86.094-22(e) and 86.1833-
01. Most of what we are adopting in 40 CFR 1068.50 is an attempt to
codify in one place a set of provisions that are consistent with
current practice. Some provisions may represent new or more detailed
approaches, as described further in the following paragraphs,
especially in the context of electronic controls. The provisions in the
final 40 CFR 1068.50 are intended to apply broadly across EPA's engine,
vehicle, and equipment programs. The language is intended to capture
the full range of engine technologies represented by spark-ignition and
compression-ignition engines used in highway, nonroad, and stationary
applications. We are accordingly applying the new provisions for all
the types of engines, vehicles and equipment that are broadly subject
to 40 CFR part 1068, as described in 40 CFR 1068.1. For example, the
provisions apply for nonroad sectors and for heavy-duty highway
engines, but not for highway motorcycles or motor vehicles subject to
standards under 40 CFR part 86, subpart S. Note that regulatory
provisions for adjustable parameters refer to engines, because most
adjustable parameters are integral to the engine and its controls. In
the case of equipment-based standards and alternative power
configurations such as electric vehicles, the requirement to meet
emission standards across the physically adjustable range. As with
other provisions in 40 CFR part 1068, if the standard-setting part
specifies some

provisions that are different than 40 CFR 1068.50, the provisions in
the standard-setting part apply instead of the provisions in 40 CFR
1068.50. For example, we will continue to rely on the provisions
related to adjusting air-fuel ratios in 40 CFR part 1051 for
recreational vehicles in addition to the new provisions from 40 CFR
1068.50. In this final rule, we are also making some minor adjustments
to the regulatory provisions in the standard-setting parts to align
with the language in 40 CFR 1068.50.
    The regulations in this final rule include several changes from the
proposed rule. We have added the word ``significant'' as a qualifying
term for the amount of emissions impact required from the adjustment of
an operating parameter for an operating parameter to be considered an
adjustable parameter. This term was missed in the proposed migration of
adjustable parameter language from 40 CFR 86.094-22(e)(1)(ii) to 40 CFR
1068.50. We have also updated the language and organization of 40 CFR
1068.50 to make the regulation easier to read. This update in language
is not meant to change the meaning of the terms, only to provide
greater consistency in the intent of our regulation. We did this by
changing ``mechanically controlled parameter'' to ``physically
adjustable parameter'' and ``electronically controlled parameter'' to
``programmable parameter''. We updated our terminology of tools used to
determine whether operating parameters are considered practically
adjustable by changing from ``simple tools'' to ``ordinary tools''. We
also updated the list of ordinary tools to be a specific list of tools
used in their intended manner for engines less 30 kW, expanding this
list for 30-560 kW engines, and allowing any available tools for
engines above 560 kW. We did this to stay consistent with the existing
Small SI Guidance. We added a time limit for determining whether
operating parameters are considered practically adjustable for engines
above 560 kW as it would be unreasonable to allow an unlimited amount
of time for a mechanic to modify an engine in this determination. We
have updated 40 CFR 1068.50 to address crimped fasteners and bimetal
springs and removed the limitation of only applying the physically
adjustable parameter requirements of crimped fasteners and bimetal
springs to mechanically controlled engines since bimetal springs and
crimped fasteners are not limited in use to mechanically controlled
engines. To remain consistent with the Small SI Guidance, we have added
extraordinary measures as an exception for determining the practical
adjustability of an operating parameter. We have also added removal of
cylinder heads as an extraordinary measure as any modification of
internal engine components requires specialty knowledge and there can
be a high degree of difficulty in removing cylinder heads. To address
concerns about listing all programmable variables as operating
parameters, which could affect thousands of different control
strategies, we will allow all programmable parameters not involving
user-selectable controls to be a single, collective operating
parameter. We have removed the requirement for potting or encapsulating
circuit boards in a durable resin as a requirement for tamper-proofing
programmable controls since anyone tampering with programmable controls
would almost certainly accomplish that as a software change through
reflashing rather than modifying circuit boards directly. We have
adjusted the date for implementing the new adjustable-parameter
provisions as described in the next section. See the Response to
Comments for a more thorough discussion of the comments.
i. Lead Time
    We proposed to apply the adjustable-parameter requirements of 40
CFR 1068.50 starting in model year 2024. This short lead time was based
on (1) the expectation that the new regulation was only modestly
different than existing requirements for physically adjustable
operating parameters and (2) the proposed requirements for programmable
operating parameters were intended to substantially align with
manufacturers' current and ongoing efforts to prevent in-use tampering.
Considering these factors, we -proposed model year 2024 to provide a
short lead time that would be sufficient for manufacturers. This lead
time would also allow EPA time to prepare internal processes for
handling the additional information.
    As detailed in the Response to Comments document, the Truck and
Engine Manufacturers Association, the Outdoor Power Equipment
Institute, and Cummins suggested that the final rule should allow more
time to comply with the new requirements.
    We are revising the final rule from the proposal to specify that
the final adjustable-parameter provisions in 40 CFR 1068.50 start to
apply in model year 2027. Until then, manufacturers may optionally
comply with 40 CFR 1068.50 early, but will otherwise continue to be
subject to adjustable parameter provisions as established for each
standard-setting part.
    Our starting expectation is that EPA and manufacturers have a
mutual interest in preventing tampering with in-use engines. We also
understand, as described further in this section, that it is not
possible to adopt a single standard for tamper-proofing electronic
controls that will continue to be effective years into the future.
Discussion of the certification process in section XI.A.2.iii therefore
clarifies that EPA reviewers intend to consider the totality of the
circumstances as we determine whether a manufacturer's effort to
prevent inappropriate in-use adjustments is adequate. That
consideration may involve, for example, EPA assessing the most recent
provisions adopted in voluntary consensus standards, the extent to
which manufacturers of similar engines have taken steps to prevent
tampering, any reports of tampering with an individual manufacturer's
in-use engines, and the availability of replacement parts or services
intended to bypass emission controls. EPA review of engine designs
would account for the practical limitations of designing engine
upgrades, both for initial approval under 40 CFR 1068.50 and for year-
by-year review of certification applications as time passes.
    As a result, we expect to work with manufacturers to establish and
implement plans to incorporate reasonable tamper-proofing designs,
consistent with prevailing industry practices, in a reasonable time
frame. We understand that tying compliance to prevailing industry
practices creates a measure of ambiguity regarding the deadline to
comply for model year 2027. We would generally expect manufacturers to
successfully certify based on their current and upcoming efforts to
protect their engines from maladjustment. Some manufacturers will have
plans for making additional changes to their engines beyond model year
2027. We can also work with such manufacturers to plan for making those
additional changes in later model years if, for example, their further
technology development moves them in the direction of improving engine
control module (ECM) security with up-and-coming designs. Manufacturers
might also need additional time to deploy established technologies for
niche products after implementing those improvements in their high-
volume product lines. This dynamic regarding the lead time for meeting
requirements in model year 2027 is no different than what will apply in
the future any time there is a development or innovation

that leads manufacturers to integrate the next generation of tamper-
proofing across their product line.
ii. Operating Parameters, Adjustable Parameters, and Statement of
Adjustable Range
    The regulation establishes that operating parameters are features
that can be adjusted to affect engine performance, and that adjustable
parameters are operating parameters that are practically adjustable by
a user or other person by physical adjustment, programmable adjustment,
or regular replenishment of a fluid or other consumable material.
However, we do not consider operating parameters to be adjustable
parameters if the operating parameters are permanently sealed or are
not practically adjustable, or if we determine that engine operation
over the full range of adjustment does not affect emissions without
also degrading engine performance to the extent that operators will be
aware of the problem. For example, while spark plug gap and valve lash
are operating parameters that can be adjusted to affect engine
performance, we do not treat them as adjustable parameters because
adjusting them does not affect emissions without also degrading engine
performance to the extent that operators will be aware of the problem.
The following sections describes how we consider whether parameters are
practically adjustable.
a. Physically Adjustable Operating Parameters
    In the final 40 CFR 1068.50(e), a physically adjustable parameter
is considered ``practically adjustable'' for engines at or below 30 kW
if a typical user can adjust the parameter with ordinary tools within
15 minutes using service parts that cost no more than $30.\576\
Similarly, a physically adjustable parameter is considered
``practically adjustable'' for 30-560 kW engines if a qualified
mechanic can adjust the parameter with ordinary tools within 60 minutes
using service parts that cost no more than $60. The term ``ordinary
tools'' is defined in the final regulations based on the size of the
engine. For engines at or below 30 kW, the definition includes slotted
and Phillips head screwdrivers, pliers, hammers, awls, wrenches,
electric screwdrivers, electric drills, and any tools supplied by the
manufacturer, where those tools are used for their intended purpose.
For 30-560 kW engines, the definition includes all ordinary tools
specified for engines at or below 30 kW and also includes solvents, or
other supplies that are reasonably available to the operator and any
other hand tools sold at hardware stores, automotive parts supply
stores, or on the internet. These thresholds are intended to be
consistent with the provisions that apply under current regulations but
tailored to represent an appropriate level of deterrence relative to
typical maintenance experiences for the different sizes of engines.
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    \576\ The cost thresholds do not include the cost of labor or
the cost of any necessary tools or nonconsumable supplies; the time
thresholds refer to the time required to access and adjust the
parameter, excluding any time necessary to purchase parts, tools, or
supplies or to perform testing. These costs are in 2020 dollars.
Manufacturers will adjust these values for certification by
comparing to the most recently available Consumer Price Index for
All Urban Consumers value published by the Bureau of Labor
Statistics www.bls.gov/data/inflation_calculator.htm.
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    For engines above 560 kW, a physically adjustable parameter is
considered ``practically adjustable'' if a qualified mechanic can
adjust the parameter using any available tools within 60 minutes. We
are not setting a cost threshold for engines above 560 kW because of
the very large costs for purchasing, servicing, and operating these
engines. Owners of these low-volume, high-cost engines are more likely
to have ready access to experienced mechanics to continuously manage
the maintenance and performance of their engines. For example, owners
of marine vessels often have engineers traveling with vessels to always
be ready to perform extensive repairs or maintenance as needed. Owners
of engines above 560 kW also commonly do their own work to
substantially overhaul engines. We expect this arrangement for
qualifying adjustable parameters will cause manufacturers to develop
designs for properly limiting adjustability of engines above 560 kW.
    Physically adjustable parameters usually have physical limits or
stops to restrict adjustability. Specific characteristics are
identified in the final 40 CFR 1068.50(f) to illustrate how physical
limits or stops should function to control the adjustable range. For
example, a physical stop defines the limit of the range of
adjustability for a physically adjustable operating parameter if
operators cannot exceed the travel or rotation limits using the
appropriate tools without causing damage exceeding specified
thresholds.
    We are changing the proposed provisions in this final rule to
include reference to extraordinary measures. We will not require
manufacturers to extend the physically adjustable range to account for
such extraordinary measures. The final regulation establishes the
following steps as extraordinary measures: Removing a cylinder head
from the engine block, fully or partially removing a carburetor,
drilling or grinding through caps or plugs, causing damage to the
engine or equipment that would exceed the specified time or cost
thresholds, or making special tools to override design features that
prevent adjustment. Note that extraordinary measures do not include
purchase of such special tools if they become available for purchase.
b. Programmable Operating Parameters
    The final 40 CFR 1068.50(e)(2) states that programmable operating
parameters will be considered ``practically adjustable'' if they can be
adjusted using any available tools (including devices that are used to
alter computer code). This will apply for engines with any degree of
electronic control. The final 40 CFR 1068.50(e) will also include
special provisions for determining whether electronic control modules
that can be adjusted by changing software or operating parameters
(``reflashed'') are practically adjustable and to determine the
practically adjustable range. First, where any of the following
characteristics apply for a given electronic parameter, it will be
considered practically adjustable:
     If an engine family includes multiple operating modes or
other algorithms that can be selected or are easily accessible, the
operating parameter will be practically adjustable and each of the
selectable or accessible modes or settings will be within the
practically adjustable range.
     If the manufacturer sells software (or other tools) that
an experienced, independent mechanic could use to reflash or otherwise
modify the electronic control module, the operating parameter will be
practically adjustable and all those settings will be within the
practically adjustable range.
     If the engines/equipment have other electronic settings
that can be adjusted using any available service tools (such as fuel
injection maps), the operating parameter will be practically adjustable
and all those settings will be within the practically adjustable range.
    Injection fuel maps and other similar electronic parameters will
not be considered practically adjustable if the manufacturer adequately
prevents access to the electronic control modules with encryption or
password protection consistent with good engineering judgment, such as
having adequate protections in place to prevent distribution and use of
passwords or encryption keys. Manufacturers will be able to exclude
electronic operating

parameters from being considered adjustable parameters (or identify
them as adjustable parameters but narrow the adjustable range) where
they appropriately determine that the operating parameters will not be
subject to in-use adjustment; EPA retains the right to review the
appropriateness of such statements. The final regulations also allow us
to specify conditions to ensure that the certified configuration
includes electronic parameter settings representing adjustable ranges
that reflect the expected range of in-use adjustment or modification.
    To address the safety, financial liability, operational, and
privacy concerns which can result from tampering, manufacturers,
industry organizations, and regulators have been working to develop
standards and design principles to improve the security of ECMs. Three
such efforts where cybersecurity guidelines and procedures are either
under development or already in publication are ISO/SAE J21434, UNECE
WP29 Cybersecurity Regulation, and SAE J3061.\577\ \578\ \579\ Since
security principles are constantly evolving as new threats are
identified, it is impractical to codify specific requirements to be
applied in an annual emission certification process. However, we expect
to require manufacturers to update their tamper-resistance features
over time to keep up with industry best practices. In addition,
manufacturers may choose to utilize different mixes of technical
standards or principles of those recommended by these organizations,
and a one-size-fits-all approach with detailed requirements for ECM
security will be neither practical nor prudent. Manufacturers need the
flexibility to quickly implement measures to address new or emerging
threats and vulnerabilities. Accordingly, the final regulation
specifies that the manufacturer's application for certification must
identify their ECM security measures. Manufacturers need to describe
the measures they are using, whether proprietary, industry technical
standards, or a combination of both, to prevent unauthorized access to
the ECM. At a minimum, for determining whether the parameter is an
operating parameter or an adjustable parameter, this documentation will
need to describe in sufficient detail the measures that a manufacturer
has used to prevent unauthorized access; ensure that calibration
values, software, or diagnostic features cannot be modified or
disabled; and respond to repeated, unauthorized attempts at
reprogramming or tampering.
---------------------------------------------------------------------------

    \577\ ``Road vehicles--Cybersecurity engineering'', ISO/SAE FDIS
21434, https://www.iso.org/standard/70918.html.
    \578\ United Nations Economic Commission for Europe, ``UNECE
WP29 Automotive Cybersecurity Regulation'', Available online:
unece.org/DAM/trans/doc/2020/wp29grva/ECE-TRANS-WP29-2020-079-Revised.pdf.
    \579\ Society of Automotive Engineers, ``Cybersecurity Guidebook
for Cyber-Physical Vehicle Systems''. SAE J3061, Available online:
https://www.sae.org/standards/content/j3061_201601/.
---------------------------------------------------------------------------

    Some commenters expressed a concern that state or Federal ``right
to repair'' legislation may conflict with EPA's requirement to limit
access to an engine's electronic controls, and one commenter suggested
edits creating an exception in EPA's proposed regulation intended to
address such a conflict. Commenters did not specifically identify how
any specific existing state or Federal law conflicts with EPA's
regulation, and we are finalizing the requirements as described in this
section without the suggested exception. See section 30.2 of the
Response to Comments for further detail on comments received and EPA's
responses.
c. Aftermarket Fuel Conversions
    Aftermarket fuel conversions for heavy-duty highway engines and
vehicles are a special case. We expect aftermarket converters to
continue their current practice of modifying engines to run on
alternative fuels under the clean alternative fuel conversion program
in 40 CFR part 85, subpart F. The anti-tampering provisions in the
final 40 CFR 1068.50 are not intended to interfere with actions
aftermarket converters may need to take to modify or replace ECMs as
part of the conversion process consistent with 40 CFR part 85, subpart
F. The final provisions direct manufacturers to prevent unauthorized
access to reprogram ECMs. Aftermarket converters will presumably need
to either use a replacement ECM with a full calibration allowing the
engine to run on the alternative fuel or perhaps create a piggyback ECM
that modifies the engine's calibration only as needed to accommodate
the unique properties of the alternative fuel. Aftermarket converters
can alternatively work with engine manufacturers to access and change
the engine's existing ECM programming for operation on the alternative
fuel.
d. Consumption, Replenishment, and the Certified Configuration
    Certain elements of design involving consumption and replenishment
may be considered adjustable parameters. Two significant examples are
DEF tank fill level and hybrid battery state of charge. The final
provisions in 40 CFR 1068.50(h) address these issues.
    For these adjustable parameters, the range of adjustability is
determined based on the likelihood of in-use operation at a given point
in the physically adjustable range. We may determine that operation in
certain subranges within the physically adjustable range is
sufficiently unlikely that the subranges may be excluded from the
allowable adjustable range for testing. In such cases, the engines/
equipment are not required to meet the emission standards for operation
in an excluded subrange.
    The final 40 CFR 1068.50(h) describes how we will not require new
engines to be within the range of adjustability for a certified
configuration for adjustments related to consumption and replenishment.
Specifically, manufacturers will not violate the prohibition in 40 CFR
1068.101(a)(1) by introducing into commerce a vehicle with an empty DEF
tank or an uncharged hybrid battery.
    Except for these special cases related to consumption and
replenishment, final 40 CFR 1068.50(k) specifies that engines are not
in the certified configuration if manufacturers produce them with
adjustable parameters set outside the range specified in the
application for certification. Similarly, engines are not in the
certified configuration if manufacturers produce them with other
operating parameters that do not conform to the certified
configuration. Such engines will therefore not be covered by a
certificate of conformity in violation of 40 CFR 1068.101(a)(1).
iii. Certification Process
    The existing regulations in each standard-setting part describe how
manufacturers need to identify their adjustable parameters, along with
the corresponding physical stops and adjustable ranges. The existing
certification process includes a review of the manufacturer's specified
adjustable parameters, including consideration of the limits of
adjustability. This has generally focused on physically adjustable
parameters. Under the new regulations, we intend to consider the
totality of the circumstances as we determine whether a manufacturer's
effort to prevent inappropriate adjustment is adequate. See text
further clarifying this principle in final 40 CFR 1068.50(i). Under the
existing certification process, we may also evaluate the
appropriateness of a manufacturer's statement regarding an adjustable
parameter if we learn from

observation of in-use engines with such parameters or other information
that a parameter was in fact practically adjustable or that the
specified adjustable range was in fact not correct.
    We are requiring manufacturers in the certification application to
state, with supporting justification, that they designed physically
adjustable operating parameters to prevent in-use adjustment outside
the intended adjustable range, that they designed physically adjustable
parameters to prevent in-use operation outside the intended adjustable
range, and that they have limited access to the electronic controls as
specified in 40 CFR 1068.50 to prevent in-use adjustment of operating
parameters and prevent in-use operation outside the intended adjustable
range. We are clarifying in this rule that manufacturers must consider
programmable parameters to be operating parameters that may also be
adjustable. All operating modes available for selection by the operator
must be described in the certification application and are considered
adjustable parameters and fall within the engine's practically
adjustable range; however, programmable parameters that do not involve
user-selectable controls can be described as a single operating
parameter. The manufacturer must describe in the certification
application how they have restricted access to the electronic controls
to prevent unauthorized modification of in-use engines. Manufacturers
will need to follow accepted industry best practices to include
password restrictions, encryption, two-step authentication, and other
methods as appropriate. Manufacturers will need to implement those
newer methods as practices change over time, especially where there are
observed cases of unauthorized changes to in-use engines.
    Manufacturers must name all available operating modes in the
application for certification and describe their approach for
restricting access to electronic controls. This description must
include naming any applicable encryption protocols, along with any
additional relevant information to characterize how the system is
designed to prevent unauthorized access. Manufacturers must separately
identify information regarding their auxiliary emission control
devices. Manufacturers will not need to report additional detailed
programming information describing electronically adjustable operating
parameters that are inaccessible to owners.
    While EPA retains the right to review the manufacturer's specified
adjustable parameters in the certification process, the manufacturer
will be responsible for ensuring all aspects of the manufacturer's
statements regarding adjustable parameters are appropriate for each
certification application. EPA may review this information each year to
evaluate whether the designs are appropriate. As industry practices
evolve to improve tamper-resistance with respect to electronic
controls, manufacturers will need to upgrade tamper-resistance features
to include more effective protocols to support their statement that the
electronic controls are both restricted from unauthorized access and
limited to the identified practically adjustable range.
    The provisions in 40 CFR 1068.50 are not intended to limit the
tampering prohibition of 40 CFR 1068.101(b)(1) or the defeat-device
prohibition of 40 CFR 1068.101(b)(2). For example, it would be
prohibited tampering to bypass a manufacturer's stops. Similarly,
aftermarket software that reduces the effectiveness of controls
specified by the manufacturer in the application for certification
would be a prohibited defeat device.
    If EPA discovers that someone manufactures or installs a modified
ECM or reflashes an engine's ECM in a way that is not a certified
configuration represented in the application for certification, those
persons will be liable for violating the tampering prohibition of 40
CFR 1068.101(b)(1) or the defeat-device prohibition in 40 CFR
1068.101(b)(2). As we gather information about cases where third
parties have successfully penetrated ECM access restrictions, the
manufacturer will be responsible in each certification application for
ensuring all aspects of the manufacturer's statements regarding such
adjustable parameters are still appropriate and we may also engage with
the manufacturer to see if there is need or opportunity to upgrade
future designs for better protection.
iv. Engine Inspections
    EPA may want to inspect engines to determine if they meet the final
specifications for adjustable parameters as described in 40 CFR
1068.50. These inspections could be part of the certification process,
or we could inspect in-use engines after certification. For example, we
may request a production engine be sent to an EPA designated lab for
inspection to test the limits of the adjustable parameters as described
in 40 CFR 1068.50(j).
3. Exemptions for Engines, Vehicles, and Equipment Under 40 CFR Part
1068, Subparts C and D
    40 CFR part 1068, subparts C and D, describe various exemption
provisions for engines, vehicles and equipment that are subject to
emission standards and certification requirements. We are amending
several of these exemption provisions. We received no comments on the
proposed exemption provisions and are finalizing the proposed changes
without modification. The following paragraphs use the term engines to
refer generically to regulated engines, vehicles, and equipment.
    The test exemption in 40 CFR 1068.210 applies for certificate
holders performing test programs ``over a two-year period''. We are
removing this time limitation. We may impose reasonable time limits on
the duration of the exemption for individual engines under another
existing provision (40 CFR 1068.210(e)). Such limitations may take the
form of a defined time for manufacturers to produce exempt engines, or
a defined time for individual engines to remain in exempt status. This
exemption applies for a wide range of products and experience has shown
that circumstances may call for the exemption to apply for longer than
(or less than) two years. We may therefore continue to apply a two-year
limit for producing or using exempt engines based on a case-specific
assessment of the need for the exemption. We could alternatively
identify a shorter or longer exemption period based on the
circumstances for each requested exemption. The exemption approval
could also allow test engines to operate indefinitely, perhaps with
additional conditions on modifying the engine to include software or
hardware changes that result from the test program or other design
improvements. This approach may be appropriate for manufacturing one or
more engines as part of a pilot project to prove out designs and
calibrations for meeting new emission standards. Separate provisions
apply for importing engines under the testing exemption in 40 CFR
1068.325, which we discuss further later in this section.
    The display exemption in 40 CFR 1068.220 applies for using
noncompliant engines/equipment for display purposes that are ``in the
interest of a business or the general public.'' The regulation
disallows the display exemption for private use, private collections,
and any other purposes we determine to be inappropriate. We have been
aware of several cases involving displays we may

have considered to be in the interest of the general public, but they
did not qualify for the display exemption because they were mostly for
private use. Experience has shown that it may be difficult to
distinguish private and public displays. For example, private
collections are sometimes shared with the general public. We are
accordingly preserving the fundamental limitation of the display
exemption to cases involving the interest of a business or the general
public. We are revising 40 CFR 1068.220 to no longer categorically
disallow the display exemption for engines and vehicles displayed for
private use or for engines in private collections. We are retaining the
discretion to disallow the display exemption for inappropriate
purposes. This would apply, for example, if engines or vehicles from a
private collection will not be displayed for the general public or for
any business interest. Consistent with longstanding policy, such
private displays do not warrant an exemption from emission standards.
    The regulation defines provisions that apply for ``delegated
assembly'' of aftertreatment and other components in 40 CFR 1068.261.
Under the current regulation, manufacturers must follow a set of
detailed requirements for shipping partially complete engines to
equipment manufacturers to ensure that the equipment manufacturer will
fully assemble the engine into a certified configuration. A much
simpler requirement applies for engine manufacturers that produce
engines for installation in equipment that they also produce.
Manufacturers have raised questions about how these requirements apply
in the case of joint ventures, subsidiary companies, and similar
business arrangements. We are revising 40 CFR 1068.261(b) through (d)
to clarify that the simpler requirements for intra-company shipments
apply for engines shipped to affiliated companies. Conversely, engine
manufacturers shipping partially complete engines to any unaffiliated
company would need to meet the additional requirements that apply for
inter-company shipments. We define ``affiliated companies'' in 40 CFR
1068.30.
    The identical configuration exemption in 40 CFR 1068.315(h) allows
for importation of uncertified engines that are identical to engines
that have been certified. This might apply, for example, for engines
that meet both European and U.S. emission standards but were originally
sold in Europe. We are modifying the regulatory language from
``identical'' to ``identical in all material respects.'' This change
allows for minor variation in engines/equipment, such as the location
of mounting brackets, while continuing to require that engines/
equipment remain identical to a certified configuration as described in
the manufacturer's application for certification.
    The ancient engine/equipment exemption in 40 CFR 1068.315(i)
includes an exemption for nonconforming engines/equipment that are at
least 21 years old that are substantially in their original
configuration. We originally adopted these for nonroad spark-ignition
engines in 2002 to align with a similar exemption that was in place for
light-duty motor vehicles (67 FR 68242, November 8, 2002). Now that
part 1068 applies for a much wider range of applications, many with
very long operating lives, it has become clear that this exemption is
no longer appropriate for importing nonconforming engines. Keeping the
exemption would risk compromising the integrity of current standards to
the extent importers misuse this provision to import high-emitting
engines. This was not the original intent of the exemption. We are
therefore removing the ancient engine/equipment exemption. The
identical configuration exemption will continue to be available to
allow importation of nonconforming engines/equipment that continue to
be in a configuration corresponding to properly certified engines.
    The regulations at 40 CFR 1068.325 describe provisions that apply
for temporarily exempting engines/equipment from certification
requirements. As noted in the introduction to 40 CFR 1068.325, we may
ask U.S. Customs and Border Protection (CBP) to require a specific bond
amount to make sure importers comply with applicable requirements. We
use the imports declaration form (3520-21) to request CBP to require a
bond equal to the value of these imported engines/equipment for
companies that are not certificate holders. Several of the individual
paragraphs describing provisions that apply for specific exemptions
include a separate statement requiring the importer to post bond for
these products. We are removing the reference to the bond requirement
in the individual paragraphs because the introduction addresses the
bonding requirement broadly for all of 40 CFR 1068.325.
    We are revising the diplomatic or military exemption at 40 CFR
1068.325(e) to clarify that someone qualifying for an exemption needs
to show written confirmation of being qualified for the exemption to
U.S. Customs and Border Protection, not EPA. This may involve
authorization from the U.S. State Department or a copy of written
orders for military duty in the United States. Consistent with current
practice, EPA would not be involved in the transaction of importing
these exempted products, except to the extent that U.S. Customs and
Border Protection seeks input or clarification of the requirements that
apply.
    The regulations at 40 CFR 1068.260(c) currently include an
exemption allowing manufacturers to ship partially complete engines
between two of their facilities. This may be necessary for assembling
engines in stages across short distances. It might also involve
shipping engines across the country to a different business unit under
the same corporate umbrella. The regulation at 40 CFR 1068.325(g)
includes additional provisions for cases involving importation. Multi-
national corporations might also import partially complete engines from
outside the United States to an assembly plant inside the United
States. We are revising 40 CFR 1068.325(g) to require that imported
engines in this scenario have a label that identifies the name of the
company and the regulatory cite authorizing the exemption. This will
provide EPA and U.S. Customs and Border Protection with essential
information to protect against parties exploiting this provision to
import noncompliant engines without authorization.
    Most of the exemptions that allow manufacturers to import
uncertified engines include labeling requirements to identify the
engine manufacturer and the basis of the exemption. We are adding a
general requirement in 40 CFR 1068.301 to clarify that labels are
required on all exempted engines. In cases where there are no labeling
specifications for a given exemption, we are creating a default
labeling requirement to add a label for exempted engines to identify
the engine manufacturer and the basis of the exemption.
4. Other Amendments to 40 CFR Part 1068
    We are adopting the following additional amendments to 40 CFR part
1068:
     Section 1068.1: Clarifying how part 1068 applies for older
engines. This is necessary for nonroad engines certified to standards
under 40 CFR parts 89, 90, 91, 92, and 94 because those emission
standards and regulatory provisions have been removed from the CFR.
These amendments were inadvertently omitted

from the rule to remove those obsolete parts.
     Section 1068.1: Changing 40 CFR 1068.1(a)(4) to include
references to 40 CFR parts 1030 and 1031 for aircraft and aircraft
engines, instead of the currently listed 40 CFR part 87. 40 CFR part
1068 contains several general compliance provisions, but the only
provisions from part 1068 that are relevant to and referenced by the
regulations for aircraft and aircraft engines are related to procedures
for handling confidential business information and the definition and
process for ``good engineering judgment.'' Revising 40 CFR 1068.1 to
reference 40 CFR parts 1030 and 1031 would not impose any new
requirements; rather, the updated reference aligns with the existing
requirements already established in 40 CFR parts 1030 and 1031. This
amendment was not included in the proposal for this rulemaking.
However, adopting this change will help readers understand the
regulations without adding any new requirements.
     Section 1068.1: Clarifying how part 1068 applies for motor
vehicles and motor vehicle engines. Vehicles and engines certified
under part 86 are subject to certain provisions in part 1068 as
specified in part 86. Vehicles and engines certified under parts 1036
and 1037 are subject to all the provisions of part 1068. This
correction aligns with regulatory text adopted in previous rulemakings.
     Section 1068.101(a): The regulations at 40 CFR 1068.101(a)
set forth the prohibitions that apply for engines and equipment that
are subject to EPA emission standards and certification requirements.
The regulation includes at 40 CFR 1068.101(a)(2) a prohibition related
to reporting and recordkeeping requirements. Section 1068.101(a)(3)
similarly includes a prohibition to ensure that EPA inspectors have
access to test facilities. These prohibitions derive from CAA section
208(a), which applies the information and access requirements to
manufacturers ``and other persons subject to the requirements of this
part or part C.'' The very first provision of 40 CFR part 1068 at 40
CFR 1068.1(a) clearly makes the provisions of part 1068 applicable ``to
everyone with respect to the engine and equipment categories as
described in this paragraph (a)[, . . .] including owners, operators,
parts manufacturers, and persons performing maintenance''. However, the
regulation in 40 CFR 1068.101(a) as written inadvertently limits the
prohibitions to manufacturers. We are accordingly revising the scope of
the prohibitions in 40 CFR 1068.101(a) to apply to both manufacturers
and ``other persons as provided in 40 CFR 1068.1(a)'' in accord with
those in CAA section 203(a).
     Section 1068.101(b)(5): Removing extraneous words.
     Section 1068.240(a): Removing reference to paragraph (d)
as an alternative method of qualifying for the replacement engine
exemption. Paragraph (d) only describes some administrative provisions
related to labeling partially complete engines so it is not correct to
describe that as an additional ``approach for exempting'' replacement
engines.
     Section 1068.240(b) and (c): Adding text to clarify that
owners may retain possession of old engines after installing an exempt
replacement engine. This is intended to address a concern raised by
engine owners that they generally expect to be able to continue to use
a replaced engine.\580\ Engine owners stated that they expect to use
the replaced engine for either replacement parts or continued use in a
different piece of equipment and were surprised to learn that engine
manufacturers were insisting that the owner turn ownership of the old
engine to the engine manufacturer. The existing regulation disallows
simply installing those replaced engines in a different piece of
equipment, but destroying the engine block and using the engine core as
a source of replacement parts is acceptable under the existing
regulation.
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    \580\ Email exchange regarding replacement engines, August 2020,
Docket EPA-HQ-OAR-2019-0055.
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     Sections 1068.601 and 1068.630: Adding provisions to
establish procedures for hearings related to an EPA decision to approve
maintenance procedures associated with new technology for heavy-duty
highway engines. As described in Section IV.B.5.v, we are updating
regulatory provisions related to engine maintenance for heavy-duty
highway engines. Section XI.A.9 describes how we may eventually extend
those same provisions for nonroad engines. The provisions adopted in
this rule include a commitment for EPA to describe approved maintenance
for new technology in a Federal Register notice, along with an
allowance for any manufacturer to request a hearing to object to EPA's
decision. The general provisions related to hearing procedures in 40
CFR part 1068, subpart G, cover the maintenance-related hearing
procedures. We are amending the regulation to provide examples of the
reasons a manufacturer may request a hearing, including if a
manufacturer believes certain EPA decisions may cause harm to its
competitive position, and to add detailed specifications for requesting
and administering such a hearing for maintenance-related decisions for
heavy-duty highway engines.
5. Engine and Vehicle Testing Procedures (40 CFR Parts 1036, 1037, 1065
and 1066)
    The regulations in 40 CFR part 1036, subpart F, 40 CFR part 1037,
subpart F, and 40 CFR parts 1065 and 1066 describe emission measurement
procedures that apply broadly across EPA's emission control programs
for engines, vehicles, and equipment. This final rule includes several
amendments to these regulations.
    We are deleting the hybrid engine test procedure in 40 CFR 1036.525
as it was applicable only for model year 2014 to 2020 engines and has
been replaced with the hybrid powertrain test procedure for model 2021
and later engines in the existing 40 CFR 1037.550.
    We are updating the engine mapping test procedure in 40 CFR
1065.510. To generate duty cycles for each engine configuration, engine
manufacturers identify the maximum brake torque versus engine speed
using the engine mapping procedures of 40 CFR 1065.510. The measured
torque values are intended to represent the maximum torque the engine
can achieve under fully warmed-up operation when using the fuel grade
recommended by the manufacturer across the range of engine speeds
expected in real-world conditions. Historically, the mapping procedure
required the engine to stabilize at discrete engine speed points
ranging from idle to the electronically limited highest RPM before
recording the peak engine torque values at any given speed. We adopted
a provision in the final 40 CFR 1065.510(b)(5)(ii) that allows
manufacturers to perform a transient sweep from idle to maximum rated
speed, which requires less time than stabilizing at each measurement
point.
    The updates to the engine mapping test procedure in 40 CFR 1065.510
are intended to ensure the resulting engine map achieves its intended
purpose. The current test procedure is intended to generate a ``torque
curve'' that represents the peak torque at any specific engine speed
point. The transient sweep from idle to maximum rated speed can create
engine conditions that trigger electronic control features on modern
heavy-duty spark-ignition engines that result in lower-than-peak torque
levels. Engine control features that can cause variability in the

maximum torque levels include spark advance, fuel-air ratio, and
variable valve timing that temporarily alter torque levels to meet
supplemental goals (such as torque management for transmissions
shifts).\581\ If the engine map does not capture the true maximum
torque, the duty cycles generated using the map may not accurately
recreate the highest-load conditions; this could lead to higher in-use
emissions.
---------------------------------------------------------------------------

    \581\ These AECDS are typically electronic controls that are
timer-based and initiated for a set duration. In a transient test,
measurements are taken continuously, and the controls remain
engaged; the same controls would ``time out'' if each measurement
was taken at stabilized conditions.
---------------------------------------------------------------------------

    We are finalizing updates to 40 CFR 1065.510(a) to require that the
torque curve established during the mapping procedure represent the
highest torque level possible when using the manufacturer's recommended
fuel grade. Specifically, we are requiring manufacturers to disable
electronic controls or other auxiliary emission control devices if they
are of a transient nature and impact peak torque during the engine
mapping procedure.\582\ Manufacturers would continue to implement their
engine control during duty-cycle testing, enabling their engines to
react to the test conditions as they would in real-world operation. The
changes to the mapping procedure will ensure that testing appropriately
represents torque output and emissions during high-load and transient
conditions.
---------------------------------------------------------------------------

    \582\ These electronic controls would be reported as an AECD
under 40 CFR 1036.205(b).
---------------------------------------------------------------------------

    This final rule includes the following additional amendments to 40
CFR parts 1065 and 1066, which we are finalizing as proposed unless
specifically noted otherwise:
     Sections 1065.301 and 1065.1001: Revising NIST-
traceability requirements to allow the use of international standards
recognized by the CIPM Mutual Recognition Arrangement without prior EPA
approval. The current regulation allows us to approve international
standards that are not NIST-traceable, but this was intended only to
accommodate laboratories in other countries that meet CIPM requirements
instead of following NIST-traceable protocols. With this approach there
will no longer be any need for a separate approval process for using
international standards that are not NIST-traceable. NIST-traceable
standards are traceable to the International System of Units (SI) as
specified in NIST Technical Note 1297, which is referenced in the
definition of NIST-traceable in 40 CFR part 1065. This same
traceability to the International System of Units is required of
standards recognized by the CIPM Mutual Recognition Arrangement, thus
putting them on par with NIST-traceable standards.
     Section 1065.298: Adopting a new 40 CFR 1065.298 with in-
use particulate matter (PM) measurement methods to augment real-time PM
measurement with gravimetric PM filter measurement for field-testing
analysis. These methods have been approved for use for over 10 years as
alternative methods under 40 CFR 1065.10 and 1065.12.
     Section 1065.410: Clarifying that manufacturers may
inspect engines using electronic tools to monitor engine performance.
For example, this may apply for OBD signals, onboard health monitors,
and other prognostic tools manufacturers incorporate into their engine
designs. As described in the current regulation, inspection tools are
limited to those that are available in the marketplace. This prevents
engine manufacturers from handling a test engine more carefully than
what would be expected with in-use engines. Extending that principle to
inspection with electronic tools, we are limiting the use of those
inspections to include only information that can be accessed without
needing specialized equipment.
     Section 1065.650(c)(6): Adding an allowance to determine
nonmethane nonethane hydrocarbon (NMNEHC) for engines fueled with
natural gas as 1.0 times the corrected mass of NMHC if the test fuel
has 0.010 mol/mol of ethane or more. This may result in a higher
reported NMNEHC emission value. The engine manufacturer may use this
method if reducing test burden is more important than the potential for
a slightly higher reported emission value.
     Section 1065.720: Removing the test fuel specification
related to volatility residue for liquefied petroleum gas. The
identified reference procedure, ASTM D1837, has been withdrawn, at
least in part, due to limited availability of mercury thermometers.
There is no apparent replacement for ASTM D1837. Rather than adopting
an alternative specification for volatility residue, we will instead
rely on the existing residual matter specification based on the
measurement procedure in ASTM D2158. This alternative specification
should adequately address concerns about nonvolatile impurities in the
test fuel.
     Section 1065.910(b): Adding a requirement to locate the
PEMS during field testing in an area that minimizes the effects of
ambient temperature changes, electromagnetic radiation, shock, and
vibration. This may involve putting the PEMS in an environmental
enclosure to reduce the effect of these parameters. We are also
removing (1) the recommendation to install the PEMS in the passenger
compartment because that does not necessarily lead to better mitigation
of temperature effects as the cab temperature can vary during vehicle
soaks, (2) ambient pressure as a parameter to minimize as there are no
known pressure effects on PEMS, and (3) ambient hydrocarbon as a
parameter because it is more of a PEMS design issue that is handled
with an activated carbon filter on the burner air inlet, which is
already covered in 40 CFR 1065.915(c).
     Section 1065.920: Broadening the PEMS calibration and
verification requirements to make them apply for the new emission
measurement bin structure we are adopting in 40 CFR part 1036. The
verification is now generic to verifications for both NTE and binned
windows for a shift-day of data over 6 to 9 hours. Data would then be
processed as they would be for an in-use test (either NTE or binned
windows) and compare the performance of the PEMS to the lab-based
measurement system.
     Section 1065.935(d): Updating the zero and span
verification requirements to include new provisions for the emission
measurement bin structure we are adopting in 40 CFR part 1036 and
retaining the current requirements for NTE testing only. The procedure
now includes the requirement to perform zero-verifications at least
hourly using purified air. Span verifications must be performed at the
end of the shift-day or more frequently based on the PEMS
manufacturer's recommendation or good engineering judgment.
     Section 1065.935(g)(5)(iii): Revising from the proposed
provisions for the final rule to clarify the consequences when PEMS gas
analyzers (used to determine bin emission values) do not meet zero- or
span-drift criteria. The intent is that all the test data would be
considered invalid when drift criteria are not met as this indicates a
malfunctioning analyzer, calling into question the quality of the data.
We have added regulatory text to 40 CFR 1065.935(g)(5)(iii) to
invalidate data for the entire shift day if measurements exceed either
of the NOX analyzer drift limits in 40 CFR
1065.935(g)(5)(iii).
     Section 1065.935(g)(6): Adding a new paragraph to include
new drift limits instead of those in 40 CFR 1065.550 for the emission
measurement bin structure we are adopting in 40 CFR part 1036. The
analyzer zero drift limit between the hourly or more frequent zero
verifications is 2.5 ppm, while the limit over the entire shift-day (or
more

frequently if you perform zero-adjustments) is 10 ppm. The analyzer
span drift limit between the beginning and end of the shift-day or more
frequent span verification(s) or adjustment(s) must be within 4 percent of the measured span value.
     Sections 1065.1123, 1065.1125, and 1065.1127: Adding new
regulatory sections to migrate the smoke test procedure in 40 CFR part
86, subpart I, into 40 CFR part 1065. This provides a common location
for the test procedure and analyzer requirements for all parts that
still require smoke measurement except for locomotive testing. The
locomotive test procedure continues to reside in 40 CFR part 1033,
subpart F, as it is specific to locomotive testing and operation at
specific notches. No updates were made to the procedure that affect
analyzer requirements and setup or how a laboratory reports test
results. For all engines required to carry out smoke testing, other
than locomotive engines, we are updating operation at curb idle speed
to instead reference warm idle speed, and we are changing from ``rated
speed'' to instead reference ``maximum test speed''. This change should
not adversely affect the acceleration and lugging modes of the test and
it will make smoke testing consistent with all other engine-based
testing that now use warm idle speed and maximum test speed.
     Part 1066, subpart D: Incorporating by reference and
making applicable as specified in this part an updated version of SAE
J2263 for coastdown measurements. The updated standard incorporates EPA
guidance for vehicles certified under 40 CFR part 86, subpart S.\583\
The updated version of the test method also reduces the wind speed
allowed for performing measurements, allows for adding ballast to
vehicles if needed, and adds clarifying procedures for testing on oval
tracks. These changes, which align with current practice for light-duty
vehicles, will have no substantial effect for measurements with heavy-
duty vehicles. We are therefore applying the updated version of SAE
J2263 for all light-duty and heavy-duty vehicles. After consideration
of comments, we have changed the final rule to make the new test
specifications optional through model year 2025.
---------------------------------------------------------------------------

    \583\ ``Determination and Use of Vehicle Road-Load Force and
Dynamometer Settings'', EPA Guidance Document CD-15-04, February 23,
2015.
---------------------------------------------------------------------------

     Section 1066.420: Adding the existing 40 CFR 86.140-94
requirement to zero and span calibrate the hydrocarbon analyzer by
overflowing the zero and span gas at the hydrocarbon sampling system
probe inlet during analyzer calibration when testing vehicles that are
14,000 GVWR or less. This requirement was inadvertently missed during
the migration of the light-duty test procedures to 40 CFR part 1066.
After consideration of comments, the final rule revises the proposal by
reducing the HC contamination limit in 40 CFR 1066.420(b)(1)(iii) from
2 [micro]mol/mol to 0.5 [micro]mol/mol for vehicles at or below 14,000
pounds GVWR with compression-ignition engines.
     Section 1066.831: Removing the reference to 40 CFR part
1065 regarding how to measure THC emissions, as the method for
measuring THC emission is already covered in 40 CFR part 1066, subparts
B and E.
    This final rule includes additional amendments that are regarded as
clarifications in the following sections of 40 CFR parts 1036, 1037,
1065, and 1066 (as numbered in this final rule): 40 CFR 1036.501,
1036.505, 1036.510, 1036.512, 1036.520, 1036.535, 1036.540, 1036.543,
and 1036.550; 40 CFR 1037.320, 1037.510, 1037.515, 1037.520, 1037.534,
1037.540, 1037.550, 1037.551, 1037.555, 1037.601, 1037.615, and
1037.725; 40 CFR 1065.1, 1065.5, 1065.10, 1065.12, 1065.140, 1065.145,
1065.190, 1065.210, 1065.284, 1065.301, 1065.305, 1065.307, 1065.308,
1065.309, 1065.315, 1065.320, 1065.325, 1065.330, 1065.345, 1065.350,
1065.410, 1065.501, 1065.510, 1065.512, 1065,514, 1065.530, 1065.543,
1065.545, 1065.610, 1065.630, 1065.650, 1065.655, 1065.660, 1065.667,
1065.670, 1065.675, 1065.680, 1065.695, 1065.715, 1065.720, 1065.790,
1065.901, 1065.915, 1065.920, 1065.1001, and 1065.1005; and 40 CFR
1066.110, 1066.220, 1066.301, 1066.415, 1066.420, 1066.710, 1066.815,
1066.835, 1066.845, 1066.1001, and 1066.1005.
    See Section 14 through 16 of the Response to Comments for a
discussion of comments related to engine and vehicle testing
provisions.
6. Vanadium-Based SCR Catalysts
    In certain diesel engine applications vanadium-based SCR catalysts
may provide a performance and cost advantage over other types of
catalysts. However, vanadium material can sublime from the catalyst in
the presence of high exhaust gas temperatures.\584\ Sublimation of
vanadium catalyst material leads to reduced NOX conversion
efficiency of the catalyst and possible exposure of the public to
vanadium emissions. In 2016 EPA provided certification guidance to
manufacturers of diesel engines equipped with vanadium-based SCR
catalysts (``2016 guidance'').\585\ The certification guidance
clarified EPA's expectations for manufacturers using vanadium-based SCR
catalysts and provided our views and recommendations on reasonable
steps manufacturers can take to protect against excessive loss of
vanadium from these SCR systems. We are now codifying these provisions
as regulatory requirements for using vanadium-based SCR catalysts. We
are adopting these requirements for all types of highway and nonroad
diesel engines. The regulatory provisions are consistent with the 2016
guidance and will begin to apply when the final rule becomes effective.
To facilitate this direct implementation for 2026 and earlier model
years, we are updating 40 CFR 86.007-11 to reference the new 40 CFR
1036.115(g)(2), which contains the requirements related to vanadium-
based SCR catalysts.
---------------------------------------------------------------------------

    \584\ The temperature at which vanadium sublimation occurs
varies by engine and catalyst and is generally 550 [deg]C or higher.
    \585\ ``Certification of Diesel Engines Equipped with Vanadium-
based SCR Catalyst'', EPA guidance document CD-16-09, June 13, 2016.
---------------------------------------------------------------------------

    To meet the new requirements, manufacturers of engines equipped
with vanadium-based SCR catalysts must determine vanadium sublimation
temperatures and thermal management strategies and include
documentation in their certification applications. EPA will use the
information submitted by manufacturers in evaluating a manufacturer's
engine and aftertreatment design as part of the application for
certification. Note that the certification requirements described in
this section for manufacturers apply equally to anyone certifying
remanufactured engines or associated remanufacturing systems where such
certification is required.
    In their certification applications, engine manufacturers must
provide information identifying the vanadium sublimation temperature
threshold for the specific catalyst product being used. To identify the
vanadium sublimation temperature, manufacturers must use the vanadium
sublimation sampling and analytical test method we are adopting in 40
CFR part 1065, subpart L, which is consistent with the procedures
identified in the 2016 guidance.\586\ Manufacturers must also identify
their thermal management strategy that prevents exhaust gas
temperatures from exceeding the vanadium sublimation temperature. In
addition, manufacturers

must identify how their thermal management strategy will protect the
catalyst in the event of high-temperature exotherms resulting from
upstream engine component failures, as well as exotherms resulting from
hydrocarbon buildup during normal engine operation. EPA expects to
approve applications describing thermal management strategies that
prevent exhaust gas temperatures from exceeding the vanadium
sublimation temperature.
---------------------------------------------------------------------------

    \586\ EPA is adopting the test method from CD-16-09 in 40 CFR
part 1065, subpart L; 40 CFR 1065.12 describes the process for
approving alternative test procedures.
---------------------------------------------------------------------------

    Commenters noted that the unit of measure for the method detection
limit should be a volume-normalized concentration for a gaseous sample,
rather than a solid mass volume, as this will address concerns with the
variable impact of dilution effect based on sample size. We are
finalizing a recommended method detection limit of 15 [mu]g/m\3\ based
on a target mass-based method detection limit of 2 ppm, a 60 g capture
bed mass, a 0.0129 L (1'' long x 1'' diameter core) catalyst volume, an
SV of 35,000 s-\1\, and an 18-hour test duration. We also
agree that the units in EPA guidance document CD-16-09 are inaccurate
and reflect a typographical error, and that the units should be in
[mu]g instead of pg to reflect a detection limit of ppm.
    If a manufacturer is interested in pursuing another means to
determine the vanadium sublimation threshold, for example by performing
an engine dynamometer-based test utilizing the full production
aftertreatment system, they may request the approval of alternative
vanadium sublimation test procedures as described in current 40 CFR
1065.10(c)(7).
7. ULSD-Related Exemption for Guam
    EPA's in-use fuel requirements at 40 CFR part 1090 include an
exemption from the 15-ppm sulfur standard for Guam, American Samoa, and
the Commonwealth of the Northern Mariana Islands (40 CFR 1090.620).
Diesel fuel meeting the 15-ppm standard is known as ultra-low sulfur
diesel or ULSD. EPA's emission standards for highway and nonroad diesel
engines generally involves SCR as a control technology. The durability
of SCR systems depends on the use of fuel meeting the 15-ppm ULSD
standard, so we adopted a corresponding exemption from the most
stringent emission standards for engines used in these three
territories (see 40 CFR 86.007-11(f) for heavy-duty highway engines and
40 CFR 1039.655 for land-based nonroad diesel engines).
    Guam has in the meantime adopted rules requiring the 15-ppm sulfur
standard for in-use diesel fuel for both highway and nonroad engines
and vehicles. As a result, there is no longer a reason to keep the
exemption from emission standards for engines used in Guam. We are
therefore removing the exemption for these engines in Guam. In response
to manufacturers' request for time to work through supply and inventory
logistics, the final rule removes the Guam exemption effective January
1, 2024.
    We are not aware of American Samoa and the Northern Mariana Islands
adopting ULSD requirements and we are therefore not removing the
exemption for those territories in this final rule.
    We are also clarifying that the exemption for land-based nonroad
diesel engines at 40 CFR 1039.655 applies only for engines at or above
56 kW. Smaller engines are not subject to NOX standards that
would lead manufacturers to use SCR or other sulfur-sensitive
technologies, so we do not expect anyone to be using this exemption for
engines below 56 kW in any area where the exemption applies. We note
that Guam's 15-ppm sulfur standard for in-use diesel fuel is now
identical to EPA's 15-ppm diesel fuel sulfur standards in 40 CFR part
1090 and as such could not be preempted under CAA section
211(c)(4)(A)(ii). We intend to revisit the exemption from the Federal
15-ppm ULSD standard for diesel fuel in Guam under 40 CFR part 1090 in
a future action. Removing the Federal exemption for diesel fuel in Guam
would likely involve new or revised regulatory provisions for parties
that make, distribute, and sell diesel fuel in Guam such as additional
reporting, recordkeeping, and other compliance-related provisions.
8. Deterioration Factors for Certifying Nonroad Engines
    Section IV describes an approach for manufacturers of heavy-duty
highway engines to establish deterioration factors (DFs) based on
bench-aged aftertreatment in combination with a plan for testing in-use
engines to verify that the original deterioration factor properly
predicts an engine's emission levels at the end of the useful life. As
described in Section IV.F, we are adopting the new approach for
establishing deterioration factors to take advantage of available
techniques for bench-aging aftertreatment devices to streamline the
certification and product-development timeline. The leaner up-front
testing can be complemented by measurements from in-use engines to
verify that the original deterioration factors are still appropriate
for certifying engines in later model years.
    This same dynamic applies for nonroad applications. We are
therefore adopting amendments to allow manufacturers of all types of
nonroad diesel engines and manufacturers of land-based nonroad spark-
ignition engines above 19 kW to use these same procedures to establish
and verify DFs. These amendments apply for 40 CFR parts 1033, 1039,
1042, and 1048. We are not adopting any changes to the existing
certification and durability procedures for these nonroad engines if
the manufacturer does not rely on the new DF verification protocol.
    Most of the new DF verification procedures for heavy-duty highway
engines apply equally for nonroad engines, but unique aspects of each
certification program call for making the following adjustments:
     Marine and land-based nonroad diesel engines are subject
to not-to-exceed standards and corresponding test procedures that will
continue to apply instead of the in-use measurement protocols adopted
in this rule for heavy-duty highway engines.
     Land-based nonroad spark-ignition engines above 19 kW
(Large SI engines) are subject to field-testing standards and
corresponding test procedures that will continue to apply instead of
the in-use measurement protocols adopted in this rule for heavy-duty
highway engines.
     Locomotives are not subject to off-cycle emission
standards or emission measurement procedures that apply during normal
in-use operation. However, manufacturers can perform in situ testing on
in-use locomotives that meets all the specifications for certification
testing in a laboratory. This allows for testing in-use engines to
verify that deterioration factors based on bench-aged aftertreatment
devices are appropriate for predicting full-life emissions.
     Each type of nonroad diesel engine already has sector-
specific methods for calculating infrequent regeneration adjustment
factors.
    We are not adding the option to use this approach for certifying
recreational vehicles, land-based nonroad spark-ignition engines at or
below 19 kW, or marine spark-ignition engines. These engines are
generally subject to certification of a useful life that is much
shorter than the values that apply for the types of engines for which
we are adding the option to use the new DF verification protocol. Many
nonroad spark-ignition engines are also certified without
aftertreatment. As a result, it is not clear that manufacturers of
these other types of engines would find a benefit of using the new DF
verification procedures.
    We are adopting the proposed changes without modification. See

Section 30.4 of the Response to Comments for a discussion of the
comments submitted regarding deterioration factors for nonroad engines.

B. Heavy-Duty Highway Engine and Vehicle Emission Standards (40 CFR
Parts 1036 and 1037)

1. Timing of Annual Reports
    We are adopting amendments to simplify annual reporting
requirements to account for the extensive information submissions
related to the greenhouse gas emission standards. Vehicle manufacturers
are required to report on GEM results and production volumes for
thousands of distinct vehicle configurations at the end of the model
year to show that emission credits related to calculated average
CO2 emission rates are sufficient to comply with standards.
The regulation currently requires an interim end-of-year report by
March 31 and a final report by September 30 (see 40 CFR 1037.730). This
same schedule is typical for documentation related to emission credits
for various types of nonroad engines and vehicles. In contrast to those
nonroad programs, compliance with the heavy-duty highway CO2
emission standards relies on a detailed assessment of GEM results and
corresponding production volumes to determine all the necessary credit
calculations for the model year. We are amending 40 CFR 1037.730 to no
longer require the interim end-of-year report, because we have observed
that manufacturers need more time to complete their effort to fully
document their compliance for the model year and we believe the interim
end-of-year report is unnecessary for heavy-duty vehicles. The
regulation allows us to waive this interim report, and we have
routinely approved such requests. We are not adopting any change to the
content of the final report due in September and will continue to rely
on that final report to evaluate compliance with standards.
    Engine manufacturers generate and use emission credits based on
production volumes that correspond to the vehicle production. As a
result, it is beneficial for both EPA and engine manufacturers to align
the emission credit reporting requirements for engines and vehicles. We
are therefore amending 40 CFR 1036.730 to also omit the interim end-of-
year report and instead rely only on the final report submitted by
September 30 following each model year. In addition, the regulations at
40 CFR 1036.250 and 1037.250 currently specify that engine and vehicle
manufacturers must report their production volumes within 90 days after
the end of the model year. For the same reasons given for modifying the
schedule for credit reports, we are aligning this production reporting
with the final ABT report, requiring manufacturers to report their
production volumes also by September 30 following the end of the model
year.
    We received no comments on these proposed amendments for credit
reporting and are finalizing the proposed changes without modification.
2. Scope and Timing for Amending Applications for Certification
    Engines must be produced in a certified configuration to be covered
by the certificate of conformity. Manufacturers routinely need to amend
their applications for certification during the model year to reflect
ongoing product development. These amendments may involve new
configurations or improvements to existing configurations. The current
regulations describe how manufacturers can make these amendments in a
way that allow them to comply with the general requirement to produce
engines that are in a certified configuration (see 40 CFR 1036.225 and
1037.225). We generally refer to these amendments as running changes.
Manufacturers apply these running changes to new engines they continue
to build during the model year. Applying these running changes to
engines that have already been produced is referred to as a ``field
fix''. We have provided ``field-fix'' guidance since the earliest days
of EPA emission standards.\587\
---------------------------------------------------------------------------

    \587\ ``Field Fixes Related to Emission Control-Related
Components,'' EPA Advisory Circular, March 17, 1975.
---------------------------------------------------------------------------

    We recently adopted regulatory provisions in 40 CFR parts 1036 and
1037 to describe how manufacturers may modify engines as reflected in
the modified application for certification, which included essential
elements of the 1975 field-fix guidance (80 FR 73478, October 25,
2016).
    There is also a related field-fix question of how to allow for
design changes to produced engines (before or after initial shipment)
that the manufacturer identifies after the end of the model year. The
preamble for that recent final rule explained that the regulatory
provisions also included how manufacturers may amend an application for
certification after the end of the model year to support intended
modifications to in-use engines.
    After further consideration, we are revising 40 CFR 1036.225 and
1037.225 to limit manufacturers to having the ability to amend an
application for certification only during the production period
represented by the model year. These revisions apply starting with the
effective date of the final rule. Manufacturers can continue to apply
field fixes to engines they have already produced if those engine
modifications are consistent with the amended application for
certification.
    The process for amending applications for certification under 40
CFR 1036.225 and 1037.225 does not apply for field fixes that the
manufacturer identifies after the end of the model year. Like our
approach in other standard-setting parts for nonroad applications, we
refer manufacturers to the 1975 field-fix guidance for recommendations
on how to approach design changes after the end of the model year.
EPA's certification software is already set up to accommodate
manufacturers that submit documentation for field fixes related to
engine families from earlier model years. We believe this approach is
effective, and it involves less burden for EPA implementation than
allowing manufacturers to amend their application for certification
after the end of the model year.
    We received no comments on the proposed provisions related to
amending applications for certification and are finalizing the proposed
changes without modification.
    We expect to propose further regulatory provisions in a future
rulemaking to update and clarify implementation of the field-fix policy
for design changes that occur after the end of the model year. We
expect that rulemaking to include consideration of such provisions for
all types of highway and nonroad engines and vehicles.
3. Alternate Standards for Specialty Vehicles
    The final rule adopting HD GHG Phase 2 standards for heavy-duty
highway engines and vehicles included provisions allowing limited
numbers of specialty motor vehicles to have engines meeting alternate
standards derived from EPA's nonroad engine programs (80 FR 73478,
October 25, 2016). The provisions applied for amphibious vehicles,
vehicles with maximum operating speed of 45 mph or less, and all-
terrain vehicles with portal axles. The provisions also apply for
hybrid vehicles with engines that provide energy for a Rechargeable
Energy Storage System, but only through model year 2027.
    We continue to recognize the need for and benefit of alternate
standards that

address limitations associated with specialty vehicles. We are
therefore, as proposed, migrating these alternate standards from 40 CFR
86.007-11 and 86.008-10 into 40 CFR 1036.605 without modification. See
section 29.1 of the Response to Comments for a discussion of the
comment submitted regarding alternate standards for specialty vehicles.
    We are mindful of two important regulatory and technological
factors that may lead us to revise the alternate standards for
specialty vehicles in a future rulemaking. First, certifying based on
powertrain testing addresses the testing limitations associated with
nonstandard power configurations. Second, emission control technologies
may support more stringent alternate emission standards than the
current nonroad engine standards. Furthermore, CARB has not adopted
that same approach to apply alternate standards for specialty vehicles
and we are unaware of manufacturers certifying any of these types of
specialty vehicles to the full engine and vehicle standards.
4. Additional Amendments
    We are amending 40 CFR parts 1036 and 1037 to describe units for
tire rolling resistance as newtons per kilonewton (N/kN) instead of kg/
tonne. SAE J2452 treats these as interchangeable units, but ISO 28580,
which we incorporated by reference at 40 CFR 1037.810, establishes N/kN
as the appropriate units for measuring rolling resistance. Since the
units in the numerator and denominator cancel each other out either
way, this change in units has no effect on the numerical values
identified in the regulation or on data submitted by manufacturers.
    The regulation at 40 CFR 1037.115(e) describes how manufacturers
demonstrate that they meet requirements related to air conditioning
leakage. Paragraph (e) allows for alternative demonstration methods
where the specified method is impossible or impractical, but limits
that alternative to systems with capacity above 3000 grams of
refrigerant. We recognize alternative demonstrations may also be
necessary for systems with smaller capacity and are therefore removing
this qualifying criterion. This change is also consistent with
amendments CARB adopted in the Omnibus rule.\588\
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    \588\ California Air Resources Board, ``Appendix B-3 Proposed
30-Day Modifications to the Greenhouse Gas Test Procedures'', May 5,
2021, Available online: https://ww2.arb.ca.gov/sites/default/files/barcu/regact/2020/hdomnibuslownox/30dayappb3.pdf, page 20.
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    The SET duty cycle specified in 40 CFR 86.1362 contains the engine
speed and load as well as vehicle speed and road grade to carry out
either engine or powertrain testing. The table defining the duty cycle
contains two errors in the vehicle speed column for modes 1a and 14.
The vehicle speed is set to ``warm idle speed'' in the table, which is
an engine test set point. Since this is an idle mode and the vehicle is
not moving, the vehicle speeds should be set to 0 mi/hr. This
correction will have no effect on how powertrain testing over this duty
cycle is carried out.
    We are correcting a typo in 40 CFR 1036.235(c)(5)(iv)(C) regarding
EPA's confirmatory testing of a manufacturer's fuel map for
demonstrating compliance with greenhouse gas emission standards. We are
changing the reference to ``greater than or equal to'' and instead
saying ``at or below'' to be consistent with the related interim
provision in 40 CFR 1036.150(q). The intent of the EPA testing is to
confirm that the manufacturer-declared value is at or below EPA's
measured values.
    We are clarifying that ``mixed-use vehicles'' qualify for alternate
standards under 40 CFR 1037.105(h) if they meet any one of the criteria
specified in 40 CFR 1037.631(a)(1) or (2). In contrast, vehicles
meeting the criterion in 40 CFR 1037.631(a)(1) and at least one of the
criteria in 40 CFR 1037.631(a)(2) automatically qualify as being exempt
from GHG standards under 40 CFR part 1037.
    We are amending 40 CFR 1036.250(a) to clarify that engine
manufacturers' annual production report needs to include all engines
covered by EPA certification, which includes total nationwide
production volumes. We inadvertently used the term ``U.S.-directed
production volume'', which we define in 40 CFR 1036.801 to exclude
engines certified to state emission standards that are different than
EPA emission standards. That exclusion applies only for emission credit
calculations under 40 CFR part 1036, subpart H, and reports under the
ABT program. Manufacturers typically already report nationwide
production volumes in their reports under 40 CFR 1036.250(a), so this
change will have little or no impact on current certification
practices.
    We received no comments on the proposed amendments described in
this section and are finalizing the proposed changes without
modification.

C. Fuel Dispensing Rates for Heavy-Duty Vehicles (40 CFR Parts 80 and
1090)

    EPA adopted a regulation limiting the fuel dispensing rate to a
maximum of 10 gallons per minute for gasoline dispensed into motor
vehicles (58 FR 16002, March 24, 1993). The dispensing limit
corresponded with the test procedure for vehicle manufacturers to
demonstrate compliance with a refueling spitback standard adopted in
the same final rule. Spitback involves a spray of liquid fuel during a
refueling event if the vehicle cannot accommodate the flow of fuel into
the fuel tank. The spitback standard applied only for vehicles at or
below 14,000 pounds GVWR, so we provided an exemption from the
dispensing limit for dispensing pumps dedicated exclusively to heavy-
duty vehicles (see 40 CFR 80.22(j) and 1090.1550(b)). Just like for
spitback testing with vehicles at or below 14,000 pounds GVWR, vehicles
designed with onboard refueling vapor recovery systems depend on a
reliable maximum dispensing rate to manage vapor flow into the carbon
canister.
    Now that we are adopting a requirement for all gasoline-fueled
heavy-duty highway vehicle manufacturers to comply with refueling
standards, it is no longer appropriate to preserve the exemption from
the dispensing rate limit for dispensing pumps dedicated exclusively to
heavy-duty vehicles. Retail stations and fleets rarely have dispensing
pumps that are dedicated to heavy-duty vehicles. Since there are no
concerns of feasibility or other issues related to meeting the 10
gallon per minute dispensing limit, we are removing the exemption upon
the effective date of the final rule.
    We received no adverse comments on these proposed amendments
related to in-use gasoline dispensing rates and are finalizing the
proposed changes without modification.
    We note that existing dispensing rate limits relate only to
gasoline-fueled motor vehicles. There is no rate restriction on
dispensing diesel fuel into motor vehicles, or on dispensing any kind
of fuel into aircraft, marine vessels, other nonroad equipment, or
portable or permanently installed storage tanks. We are also not
adopting new dispensing rate limits for these fuels in this action.

D. Refueling Interface for Motor Vehicles (40 CFR Parts 80 and 1090)

    We proposed to remove the filler-neck restriction in 40 CFR 80.24.
The proposal included a decision not to migrate that restriction to 40
CFR part 86, subpart S, for chassis-certified motor vehicles.
Commenters highlighted the continued commercial and regulatory need for
EPA to keep the requirement for engine manufacturers to standardize the
size of the filler-necks orifice for

gasoline-fueled vehicles. We are therefore moving the filler-neck
requirement from 40 CFR 80.24 to 40 CFR 86.1810-17 without changing the
substantive requirement. See Section 31.2 of the Response to Comments.
This requirement applies for vehicles with gross vehicle weight rating
up to 14,000 pounds. We are including no lead time for this requirement
because it is consistent with the requirement from 40 CFR 80.24.

E. Light-Duty Motor Vehicles (40 CFR Parts 85, 86, and 600)

    EPA's emission standards, certification requirements, and fuel
economy provisions for light-duty motor vehicles are in 40 CFR part 85,
40 CFR part 86, subpart S, and 40 CFR part 600.
1. Testing With Updated Versions of SAE J1634
i. Existing BEV Test Procedures
    EPA's existing regulations for testing Battery Electric Vehicles
(BEVs) can be found in 40 CFR part 600--Fuel Economy and Greenhouse Gas
Emissions of Motor Vehicles. The existing EPA regulations (40 CFR
600.116-12(a) and 600.311-12(j) and (k)) reference the 2012 version of
the SAE Standard J1634--Battery Electric Vehicle Energy Consumption and
Range Test Procedure.
    Current regulations (40 CFR 600.116-12(a)) allow manufacturers to
perform either single cycle tests (SCT) or the multi-cycle test (MCT)
as described in the EPA regulations and the 2012 version of SAE J1634.
The SCT and MCT are used to determine the unrounded and unadjusted city
and highway range values and the city and highway mile per gallon
equivalent (MPGe) fuel economy values.
    The 2012 version of SAE J1634 specifies 55 miles per hour (mph) as
the speed to be used during the mid-test and end-of-test constant-speed
cycles of the MCT. The 2017 version of SAE J1634 specifies 65 mph as
the speed to be used during the constant-speed cycles of the MCT.
Manufacturers have reached out to the Agency and requested to use the
2017 version of SAE J1634 to reduce the time required to perform the
MCT and the Agency has generally approved these requests. EPA's fuel
economy regulations allow manufacturers to use procedures other than
those specified in the regulations. The special test procedure option
is described in 40 CFR 600.111-08(h). This option is used when vehicles
cannot be tested according to the procedures in the EPA regulations or
when an alternative procedure is determined to be equivalent to the EPA
regulation.
    EPA regulations found in 40 CFR 600.210-12(d)(3) specify three
options for manufacturers to adjust the unrounded and unadjusted 2-
cycle (city and highway) results for fuel economy labeling purposes.
The three methods include: Generating 5-cycle data; multiplying the 2-
cycle values by 0.7; and asking the Administrator to approve adjustment
factors based on operating data from in-use vehicles. To date the
Agency has not approved any requests to use operating data from in-use
vehicles to generate an adjustment factor.
    Many manufacturers use the option to multiply their 2-cycle fuel
consumption and range result by the 0.7 adjustment factor. The benefit
of this option for the manufacturer is that the manufacturer does not
need to perform any of the additional 5-cycle tests to determine the
label result. This method is equivalent to the derived 5-cycle method
which allows manufacturers to adjust their 2-cycle fuel economy test
results for gasoline vehicles based on the EPA determined slope and
intercept values generated from 5-cycle testing performed on emission
data vehicles (EDVs).
    A few manufacturers have been using the option to generate 5-cycle
data which is then used for determining a 5-cycle adjustment factor.
The specific 5-cycle adjustment factor is then multiplied by the
unrounded, unadjusted 2-cycle results to determine fuel economy label
values.
    EPA's current regulations do not specify a method for performing 5-
cycle testing for BEVs. EPA acknowledged this in the 2011 rulemaking
that created the fuel economy label requirement for BEVs:
    The 5-cycle testing methodology for electric vehicles is still
under development at the time of this final rule. This final rule will
address 2-cycle and the derived adjustments to the 2-cycle testing, for
electric vehicles. As 5-cycle testing methodology develops, EPA may
address alternate test procedures. EPA regulations allow test methods
alternate to the 2-cycle and derived 5-cycle to be used with
Administrator approval. (76 FR 39501, July 6, 2011)
    The first manufacturer to approach EPA and request to perform 5-
cycle testing for BEVs was Tesla, and EPA approved Tesla's request. The
method Tesla proposed is known as the BEV 5-cycle adjustment factor
method, and it was added to Appendices B and C of the SAE J1634
Standard in the 2017 update.
    Since publication of the 2017 version of SAE J1634, BEV
manufacturers in addition to Tesla have been approaching the Agency and
seeking to use the 5-cycle adjustment factor methodology outlined in
Appendices B and C. EPA has generally approved manufacturer requests to
use this method.
    The 5-cycle method outlined in the 2017 version of SAE J1634 is
essentially the same method that EPA uses to determine 5-cycle fuel
economy for vehicles with internal combustion engines. There are,
however, two differences between the EPA approved BEV 5-cycle
adjustment factor method compared to the 5-cycle calculation
methodology outlined in 40 CFR 600.114-12, Vehicle-specific 5-cycle
fuel economy and carbon-related exhaust emission calculations. The
first difference is that the numerator of the City and Highway fuel
economy equations is 0.92 rather than 0.905. This was done to remove
the ethanol correction from the 5-cycle fuel economy equation for BEVs.
The second change was to allow BEV manufacturers to use the results of
a full charge depleting Cold Temperature Test Procedure (CTTP or 20
[deg]F FTP) in the City fuel economy calculation when calculating the
running fuel consumption. Vehicles with internal combustion engines
(ICE) use only the bag 2 and bag 3 fuel economy results from the CTTP.
The CTTP is performed at an ambient temperature of 20 [deg]F after the
vehicle has cold-soaked in the 20 [deg]F test chamber for a minimum of
12 hours and a maximum of 36 hours. In addition, to reduce the testing
burden the current BEV 5-cycle procedure allows manufacturers to skip
the 10-minute key-off soak between UDDS cycles after the second UDDS
cycle. This test procedure allowance was made to reduce the time burden
for performing full charge depletion testing in the cold test chamber.
ii. Summary of Changes
    The final rule amends the revisions to Sec.  600.116-12(a) and
Sec. Sec.  600.311-12(j)(2) and 600.311-12(j)(4)(i).
    EPA is adopting the proposal to update the SAE J1634 standard
referenced in 40 CFR part 600 from the 2012 version to the 2017
version. This update will require manufacturers to use 65 mph for the
constant-speed cycles of the MCT. In addition, this update will allow
manufacturers to use the BEV 5-cycle adjustment factor methodology
outlined in Appendices B and C of the 2017 version of SAE J1634 with
the revisions described in this section.

    EPA received comments requesting the Agency adopt the 2021 version
of SAE J1634. The 2021 version of SAE J1634 includes several additional
test procedure changes not included in the 2017 version. Updates for
the 2021 version include the development of additional test procedures
including the shortened multi-cycle test (SMCT) and the shortened
multi-cycle test plus (SMCT+); and, the capability to pre-condition the
BEV prior to performing any of the test procedures, including the 20
[deg]F UDDS, also known as the cold temperature test procedure (CTTP).
    At this time the Agency is not prepared to adopt the 2021 version
of SAE J1634 with these additional test procedures and pre-conditioning
process. The Agency is evaluating the new test procedures (SMCT and
SMCT+) to ensure they produce results equivalent to those generated
using the existing SCT and MCT test procedures. In addition, the Agency
is assessing the use of pre-conditioning the battery and cabin of BEVs
prior to performing tests. The Agency is not prepared to adopt
preconditioning for BEVs during the soak period prior to starting the
drive cycle for the CTTP. The intent of the 12 to 36 hour cold soak
period prior to the start of the drive cycle for the CTTP is to
stabilize the vehicle and its components at 20 [deg]F prior to starting
the driving portion of the test. While BEVs have technology and have
operating modes that allow the battery and cabin to be preconditioned
while the vehicle is soaking, for this technology to function the
vehicle must have access to a dedicated EVSE and the operator must
enable this operation. The Agency does not expect that a predominance
of BEVs will have access to a dedicated EVSE while the vehicle is `cold
soaking' prior to many cold starts and that the operator will have
enabled the preconditioning mode during the soak period. Therefore, the
Agency is not adopting the 2021 version of SAE J1634 in this final
rule.
    EPA proposed for model year 2023, that manufacturers could continue
to perform full charge depletion testing on BEVs when running the CTTP
to determine the 5-cycle adjustment factor. However, EPA proposed
requiring in model year 2023 that manufacturers perform a 10-minute
key-off soak between each UDDS cycle as part of the charge depleting
CTTP. The Agency has decided not to adopt this proposal based on
stakeholder comments and the effort required to update test cells for a
procedural change which would only be in effect for one model year.
    We are not changing the existing requirement to submit a written
request for EPA approval to perform 5-cycle testing prior to beginning
5-cycle adjustment procedure testing. Manufacturers must attest that
the vehicle was not preconditioned or connected to an external power
source during the 20 [deg]F cold soak period.
    The Agency proposed requiring manufacturers to perform only two
UDDS cycles when running the CTTP, with a 10-minute key-off soak
between the UDDS cycles to generate their BEV 5-cycle adjustment factor
beginning in model year 2024. The Agency is adopting this proposal and
is delaying the start from model year 2024 to the 2025 based on
comments received from stakeholders and the timing of the final
rulemaking. The running fuel consumption for the City fuel economy
equation comes from a modified form of the equation provided in
Appendix C of the 2017 version of SAE J1634. The charge-depletion value
is replaced with the results from Bag 2 of the first and second UDDS
and Bag 1 from the second UDDS. Manufacturers may use their existing
CTTP test results to make these calculations, or they may perform new
tests with the option to select the vehicle's state-of-charge so it can
capture regeneration energy during the first UDDS cycle.