40 CFR § 1037.610 - Vehicles with off-cycle technologies.
(a) You may ask us to apply the provisions of this section for CO2 emission reductions resulting from vehicle technologies that were not in common use with heavy-duty vehicles before model year 2010 that are not reflected in GEM. While you are not required to prove that such technologies were not in common use with heavy-duty vehicles before model year 2010, we will not approve your request if we determine that they do not qualify. These may be described as off-cycle or innovative technologies. You may apply these provisions for CO2 emission reductions reflected in the specified test procedures if they are not reflected in GEM, except as allowed under paragraph (g) of this section. We will apply these provisions only for technologies that will result in measurable, demonstrable, and verifiable real-world CO2 emission reductions.
(b) The provisions of this section may be applied as either an improvement factor or as a separate credit, consistent with good engineering judgment. Note that the term “credit” in this section describes an additive adjustment to emission rates and is not equivalent to an emission credit in the ABT program of subpart H of this part. We recommend that you base your credit/adjustment on A to B testing of pairs of vehicles differing only with respect to the technology in question.
(1) Calculate improvement factors as the ratio of in-use emissions with the technology divided by the in-use emissions without the technology. Use the improvement-factor approach where good engineering judgment indicates that the actual benefit will be proportional to emissions measured over the test procedures specified in this part.
(2) Calculate separate credits (g/ton-mile) based on the difference between the in-use emission rate with the technology and the in-use emission rate without the technology. Subtract this value from your GEM result and use this adjusted value to determine your FEL. Use the separate-credit approach where good engineering judgment indicates that the actual benefit will not be proportional to emissions measured over the test procedures specified in this part.
(3) We may require you to discount or otherwise adjust your improvement factor or credit to account for uncertainty or other relevant factors.
(c) You may perform A to B testing by measuring emissions from the vehicles during chassis testing or from in-use on-road testing. You may also ask to use modified powertrain testing. If you use on-road testing, we recommend that you test according to SAE J1321, Fuel Consumption Test Procedure - Type II, revised February 2012, or SAE J1526, SAE Fuel Consumption Test Procedure (Engineering Method), Revised September 2015 (see § 1037.810 for information on availability of SAE standards), subject to the following provisions:
(1) The minimum route distance is 100 miles.
(2) The route selected must be representative in terms of grade. We will take into account published and relevant research in determining whether the grade is representative.
(3) Control vehicle speed over the route to be representative of the drive-cycle weighting adopted for each regulatory subcategory, as specified in § 1037.510(c), or apply a correction to account for the appropriate weighting. For example, if the route selected for an evaluation of a combination tractor with a sleeper cab contains only interstate driving at 65 mi/hr, the improvement factor would apply only to 86 percent of the weighted result.
(4) The ambient air temperature must be between (5 and 35) °C, unless the technology requires other temperatures for demonstration.
(5) We may allow you to use a Portable Emissions Measurement System (PEMS) device for measuring CO2 emissions during the on-road testing.
(d) Send your request to the Designated Compliance Officer. We recommend that you do not begin collecting test data (for submission to EPA) before contacting us. For technologies for which the engine manufacturer could also claim credits (such as transmissions in certain circumstances), we may require you to include a letter from the engine manufacturer stating that it will not seek credits for the same technology. Your request must contain the following items:
(2) A list of the vehicle configurations that will be equipped with the technology.
(3) A detailed description and justification of the selected test vehicles.
(5) A complete description of the methodology used to estimate the off-cycle benefit of the technology and all supporting data, including vehicle testing and in-use activity data. Also include a statement regarding your recommendation for applying the provisions of this section for the given technology as an improvement factor or a credit.
(e) We may seek public comment on your request, consistent with the provisions of 40 CFR 86.1866. However, we will generally not seek public comment on credits or adjustments based on A to B chassis testing performed according to the duty-cycle testing requirements of this part or in-use testing performed according to paragraph (c) of this section.
(f) We may approve an improvement factor or credit for any configuration that is properly represented by your testing.
(2) For model years 2021 and later, you may not rely on an approval for model years before 2021. You must separately request our approval before applying an improvement factor or credit under this section for Phase 2 vehicles, even if we approved an improvement factor or credit for similar vehicle models before model year 2021. Note that Phase 2 approval may carry over for multiple years.
(g) You normally may not calculate off-cycle credits or improvement factors under this section for technologies represented by GEM, but we may allow you to do so by averaging multiple GEM runs for special technologies for which a single GEM run cannot accurately reflect in-use performance. For example, if you use an idle-reduction technology that is effective 80 percent of the time, we may allow you to run GEM with the technology active and with it inactive, and then apply an 80% weighting factor to calculate the off-cycle credit or improvement factor. You may need to perform testing to establish proper weighting factors or otherwise quantify the benefits of the special technologies.