EPA Decision Document: Off Cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company, and Toyota Motor North America, Inc* -Low-Power- Consumption Compressor Clutch rnA United States Environmental Protection Agency ------- EPA Decision Document: Off Cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company, and Toyota Motor North America, Inc* -Low-Power- Consumption Compressor Clutch Implementation, Analysis and Compliance Division Office of Transportation and Air Quality U.S. Environmental Protection Agency Environmental Protectio Agency EPA-420-R-25-012 September 2025 ------- EPA Decision Document: Off-Cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company and Toyota Motor North America, Inc. - Low-Power- Consumption Compressor Clutch I. Introduction EPA's light-duty vehicle greenhouse gas (GHG) rules include opportunities for manufacturers to generate C02 credits for technologies that provide C02 reductions not captured by the 2-cycle emissions test. There are three pathways by which manufacturers can generate off-cycle credits: (1) a pre-determined "menu" of technologies and credits that is available for 2014 and later model years, (2) a 5-cycle test option, and (3) an alternative methodology that includes opportunity for public comment. These are described in more detail in Section II. Fiat Chrysler Automobiles (FCA), Ford Motor Company (Ford) and Toyota Motor North America, Inc. (Toyota) have all applied for off-cycle credits for use of Low-Power-Consumption Compressor Clutch technology. These applications (with confidential business information redacted) will be published on EPA's web site at https://www.epa.gov/ve-certification/compliance-information-light-dutv-greenhouse- gas-ghg-standards. EPA has determined these applications are substantially identical to the Nissan Low- Power-Consumption Compressor Clutch application. EPA published a Federal Register notice and provided a 30-day public comment period for the Nissan Low-Power-Consumption Compressor Clutch application.1 EPA received both critical and supportive comments regarding the methodology presented for determining the credits sought from this technology by Nissan. EPA addressed the comments received on the methodology proposed by Nissan in our Decision Document2 which can be found at https://www.epa.gov/ve-certification/nissan-motor-corporation-compliance-materials-light-dutv- greenhouse-gas-ghg. EPA received comments from the Alliance for Automotive Innovation (AAI) and the Union of Concerned Scientists (UCS). AAI comments were supportive of the methodology used by Nissan and commented that the AC17 test procedure was not intended for evaluating the impact of incremental changes to the A/C system. UCS raised concerns including: the A/C efficiency caps should apply to the Low-Power-Consumption Compressor Clutch technology; the A/C 17 test should be used to determine the credit value for the Low-Power-Consumption Compressor Clutch; the high fraction of A/C compressor clutch utilization was higher than previously observed by EPA; and, indicated, unless Nissan had informed EPA in pre-model year submittals of their intent to request credits for this technology, the first model year eligible for these credits is 2020 and not 2017. EPA addressed all these comments in the 1 86 FR 8631, February 8, 2021. 2 EPA Decision Document: Off-Cycle Credits for Nissan North America, Inc, May 2024, EPA-420-R-24-009 1 ------- Nissan Decision Document and, a summary of the comments received on the Nissan application and the EPA responses can be found in Section III. The credit calculation methodology used by FCA, Ford, and Toyota is the same as the methodology Nissan proposed and for which EPA sought comment. To determine the off-cycle credit value all manufacturers measured the reduction in electrical load due to the adoption of the Low-Power- Consumption Compressor Clutch, all manufacturers use the EPA determined value for C02 reductions from electrical load reductions and estimate the fraction of vehicle operation with the compressor clutch turned on. All the Low-Power-Consumption Compressor Clutch applications (FCA, Ford, Nissan, and Toyota) use the same value for the reduction in electrical load (13 W) and the same value for C02 reductions when reducing electrical loads (3.2 g/mi per 100 watts of load reduction). FCA and Toyota are seeking credit values equivalent to the initial credit value sought by Nissan for the use of the LE40 Compressor Clutch when combined with a variable displacement air conditioning compressor. Ford is seeking a reduced credit value for their application of the LE40 Compressor Clutch as Ford has determined the clutch cycles less based on the usage of other technologies present in Ford vehicles. Toyota is also seeking a reduced credit value for use of the LE40 Compressor Clutch when used with fixed displacement air-conditioning compressors. Detailed descriptions of the methods the manufacturers use to estimate the fraction of vehicle operation with the compressor clutch turned-on are described in Section III. As these applications are all substantially similar to the application submitted by Nissan, EPA is waiving the notice and comment requirement for these applications. EPA is approving the technology, the methodology for determining the credit values, and the credit values as described in the applications submitted by FCA, Ford, and Toyota which are all published on EPA's Compliance Information for Light-Duty Greenhouse Gas (GHG) Standards webpage, https://www.epa.gov/ve-certification/compliance-information-light-dutv-greenhouse-gas-ghg- standards. Section II of this document provides background on EPA's off-cycle credits program. Section III provides EPA's decision and response to the comments received on the Nissan Low-Power-Consumption Compressor Clutch. This decision document applies only to the applications referenced herein. II. EPA's Off-Cycle Credits Program EPA's light-duty vehicle greenhouse gas (GHG) program provides three pathways by which a manufacturer may accrue off-cycle carbon dioxide (C02) credits for those off-cycle technologies that achieve C02 reductions in the real world but where those reductions are not adequately captured on the test procedure used to determine compliance with the C02 standards. The first is a predetermined list of 2 ------- credit values for specific off-cycle technologies that may be used beginning in model year 2014.3 This pathway allows manufacturers to use conservative credit values established by EPA for a wide range of technologies, with minimal data submittal or testing requirements. In cases where additional laboratory testing can demonstrate emission benefits of an off-cycle technology, a second pathway allows manufacturers to use a broader array of emission tests (known as "5-cycle" testing because the methodology uses five different testing procedures) to demonstrate and justify off-cycle C02 credits.4 The additional emission tests allow emission benefits to be demonstrated over some elements of real- world driving not captured by the GHG compliance tests, including high speeds, hard accelerations, and cold temperatures. Credits determined according to this methodology do not undergo additional public review. The third and last pathway allows manufacturers to seek EPA approval to use an alternative methodology for determining the off-cycle C02 credits.5 This option is only available if the benefit of the off-cycle technology cannot be adequately demonstrated using the 5-cycle methodology. Manufacturers may also use this option for model years prior to 2014 to demonstrate off-cycle C02 reductions for technologies that are on the predetermined list, or to demonstrate reductions that exceed those available via use of the predetermined list. Under the regulations, a manufacturer seeking to demonstrate off-cycle credits with an alternative methodology (i.e., under the third pathway described above) must describe a methodology that meets the following criteria: • Use modeling, on-road testing, on-road data collection, or other approved analytical or engineering methods; • Be robust, verifiable, and capable of demonstrating the real-world emissions benefit with strong statistical significance; • Result in a demonstration of baseline and controlled emissions over a wide range of driving conditions and number of vehicles such that issues of data uncertainty are minimized; • Result in data on a model type basis unless the manufacturer demonstrates that another basis is appropriate and adequate. Further, the regulations specify the following requirements regarding an application for off-cycle C02 credits: • A manufacturer requesting off-cycle credits must develop a methodology for demonstrating and determining the benefit of the off-cycle technology and carry out any necessary testing and analysis required to support that methodology. • A manufacturer requesting off-cycle credits must conduct testing and/or prepare engineering analyses that demonstrate the in-use durability of the technology for the full useful life of the vehicle. 3 See 40 CFR 86.1869-12(b). 4 See 40 CFR 86.1869-12(c). 5 See 40 CFR 86.1869-12(d). 3 ------- • The application must contain a detailed description of the off-cycle technology and how it functions to reduce C02 emissions under conditions not represented on the compliance tests. • The application must contain a list of the vehicle model(s) which will be equipped with the technology. • The application must contain a detailed description of the test vehicles selected and an engineering analysis that supports the selection of those vehicles for testing. • The application must contain all testing and/or simulation data required under the regulations, plus any other data the manufacturer has considered in the analysis. Finally, the alternative methodology must be approved by EPA prior to the manufacturer using it to generate credits. As part of the review process defined by regulation, the alternative methodology submitted to EPA for consideration must be made available for public comment.6 EPA will consider public comments as part of its final decision to approve or deny the request for off-cycle credits. Although these credits are requested under regulatory provisions that don't explicitly require limitations, or caps, on credit values, EPA is stipulating here that credits for technologies for which there is a regulatory cap must be held to the applicable regulatory cap, if such credits are approved by EPA. For example, for reasons described in the implementing rulemaking documents and analyses, EPA established caps on thermal technology credits of 3.0 grams/mile for cars and 4.3 grams/mile for trucks. The rationale for these caps is applicable regardless of the off-cycle pathway being used to achieve such credits. EPA also established caps on technologies that improve the efficiency of air conditioning systems (5 grams/mile for cars and 7.2 grams per mile for trucks). Thus, credits approved in this Decision Document are being approved only to the extent that the regulatory caps on credits for certain technologies or categories of technologies are not exceeded. III. EPA Decision on Off-cycle Credit Application A. Low-Power-Consumption Compressor Clutch FCA, Ford, Nissan, and Toyota have all applied for off-cycle credits using the alternative demonstration methodology pathway for their Low-Power-Consumption Compressor Clutch technology. The compressor clutch is an electro-mechanical device powered by the vehicle's electrical system which activates by applying current through a coil. When the air conditioning system commands cooling, the clutch is activated by energizing the coil. When energized, the coil causes a friction plate to connect the compressor drive belt pulley to the compressor shaft allowing torque to be transmitted from the serpentine belt of the engine to operate the compressor. The compressor then compresses the gas- phase refrigerant and pumps it through the air conditioning system. The Low-Power-Consumption Compressor Clutch reduces the load of the vehicle's electrical system during compressor operation. 6 See 40 CFR 86.1869-12(d)(2). 4 ------- All the Low-Power-Consumption Compressor Clutch applications use the same methodology for determining the off-cycle greenhouse gas credit value. The reduction in the compressor clutch electrical load has been determined by each manufacturer to be 13 Watts (W). Each manufacturer uses the same value for the reduction in C02 due to the reduction in electrical load, .032 g/mi/watt. The C02 reduction due to a reduction in electrical load is the value EPA adopted in the Joint Technical Support Document: Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards.7 The reduction in electrical load is multiplied by the reduction in C02 and the result is then multiplied by the percent of vehicle miles travelled (VMT) when the compressor clutch is engaged. The applications from FCA, Toyota, and the initial Nissan application each used the percent VMT estimate from the Life Cycle Climate Performance (LCCP) model which estimated the compressor clutch would be engaged 69% of the time the vehicle is operated. The initial Nissan off-cycle credit application (with confidential business information redacted) is available in the public docket and on EPA's web site at https://www.epa.gov/ve-certification/nissan- motor-corporation-compliance-materials-light-dutv-greenhouse-gas-ghg. EPA received comments from the Alliance for Automotive Innovation (the Alliance) and the Union of Concerned Scientists (UCS) on the Nissan application. The Alliance commented that Nissan's choice to perform an engineering analysis and modeling was appropriate for this technology. The Alliance also commented on the strengths and weaknesses of the AC17 test procedure and noted that it results in an estimate of the air conditioning system performance under a single set of ambient conditions. The Alliance also noted that the AC17 test is not intended for evaluating the impact of incremental changes to an A/C system like reducing the electrical load of the compressor clutch. UCS commented that the Denso compressor should be considered as an efficiency improvement to the air-conditioning system, not as a credit under electrical load reduction and the A/C efficiency caps should apply to this technology. EPA concurs with UCS regarding this technology being an A/C efficiency technology and as noted in Section II above the A/C efficiency caps do apply to this technology. UCS commented that the Agency has established the AC17 test procedure specifically to evaluate technologies which improve A/C efficiency and Nissan should use this test to determine the C02 benefit for the lower-power-consumption compressor clutch. The AC17 test was designed to evaluate changes to both the vehicle and the A/C system as manufacturers upgrade the efficiency of the vehicle cabin and the performance of the A/C system during major vehicle redesigns. The Agency concurs with the Alliance position that the AC17 test is not an appropriate test procedure to measure the GHG reduction of a 13-watt reduction in load due to improvements in the compressor clutch. 7 Joint Technical Support Document: Final Rulemaking for 2017-2025 Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy, EPA-420-R-12-901, August 2012, page 5-69. 5 ------- UCS commented that the high fraction of A/C compressor utilization as claimed by Nissan is significantly higher than the utilization found by EPA based on prior studies and is also higher than was assumed by EPA in the 2017 through 2025 rulemaking. EPA staff had similar concerns regarding compressor clutch utilization and requested FCA, Nissan, and Toyota provide additional data. Most vehicles now have automatic air conditioning systems where the owner sets the desired ambient temperature, and the vehicle controls the A/C operation as opposed to manual systems where the vehicle operator would manually turn on air conditioning. In addition, variable displacement A/C compressors are in use now and the compressor is set so that it provides the appropriate amount of cooling which does not result in the A/C clutch being turned off to maintain the appropriate temperature at the heat exchanger as was done with fixed displacement compressors. Both the adoption of automatic controls and the proliferation of variable displacement A/C compressors have led to increases in the time the A/C compressor is engaged compared to the technology in use when EPA surveyed A/C operation in Phoenix, Arizona in 1994. In response to EPA's concerns that the LCCP model over-estimated A/C compressor clutch engagement Nissan proposed and gathered in-use compressor usage data during a 10-month period covering the temperature ranges in the LCCP model on the Nissan Rogue and Maxima models with Auto A/C. The data from the Rogue and Maxima were used to determine A/C compressor clutch usage rates. The results of this data gathering determined the A/C compressor clutch operation was greater than the LCCP modelled data for Auto A/C systems. Toyota captured a limited data set from vehicles in the field which supported the conclusion that the LCCP model usage value was a reasonable estimate of compressor clutch usage. FCA also provided EPA with data indicating the compressor clutch usage rates under the ambient conditions observed during the FCA data recording were consistent with the values in the LCCP model. Based on the data provided to the Agency by Nissan, Toyota, and FCA, EPA has determined the LCCP model usage rates for A/C clutch engagement are representative of compressor clutch operation for variable displacement A/C compressors and can be used for estimating the Low-Power-Consumption Compressor Clutch usage. In their application, Toyota also applied for credits for the Low-Power-Consumption Compressor Clutch when used with a fixed displacement A/C compressor. Toyota reduced the LCCP model value for compressor clutch operation based on the cycling frequency under the conditions included in the LCCP model. Toyota performed tests to determine the cycling frequency which results in the compressor clutch usage to be reduced from 69% to 34.6%. Ford requested to use a lower compressor clutch utilization value than determined from the LCCP model. Ford notes their enhanced window anti-fogging strategy (EWAFS) reduces the need to operate the A/C compressor in mid-ambient conditions where A/C operation was previously used to prevent window fogging. Ford collected data on 70 vehicles logging over 210,000 miles and found the A/C clutch 6 ------- operated 50% of the time compared to the 69% determined from the LCCP model. While not all Ford vehicles will be equipped with the EWAFS technology Ford believes the 50% usage rate from vehicles equipped with EWAFS will be representative of their fleet and believes this value should be used for estimating the credit for their vehicles. UCS in their comments on the Nissan application noted that unless Nissan had specified this credit request in their pre-model year reports for prior model years, Nissan should only be eligible for credits beginning in the 2020 model year. Prior to May 1, 2020, EPA had been allowing manufacturers to submit applications for retroactive alternative method off-cycle GHG requests. EPA ended the practice of accepting retroactive credit requests for all alternative method off-cycle GHG applications after May 1, 2020. Nissan submitted their initial application for the lower-power-consumption compressor clutch prior to the May 1, 2020, cut-off date and therefore the Agency agreed to allow Nissan to claim credits starting in the 20217 MY for this technology. Both FCA and Toyota submitted their original applications for the Low-Power-Consumption Compressor Clutch technology prior to the May 1, 2020, cut-off date and therefore the Agency agrees to allow FCA and Toyota to claim credits starting in the 2017 MY for this technology. Ford submitted their analytical plan for this application on May 1, 2020, and requested credits beginning in the 2020 MY. As Ford made their request by the deadline, the Agency is allowing Ford to claim credits beginning in the 2020 MY for this technology. EPA has evaluated the FCA, Ford, and Toyota applications and finds that the methodologies described therein are sound and appropriate. Therefore, EPA is approving the Low-Power-Consumption Compressor Clutch off-cycle credit applications requested by FCA and Toyota for the 2017 and later model years. EPA is also approving the Low-Power-Consumption Compressor Clutch application requested by Ford for the 2020 and later model years. Caps or limits on credits that are specified in the regulations also apply to the credits being approved in this document, as discussed above. As the function of the Low-Power-Consumption Compressor Clutch is to improve the efficiency of the A/C system the A/C efficiency cap does apply to this technology. All information necessary to determine the total Megagrams of credits must be included in the reporting to EPA, and the total Megagrams for each fleet and model year should be included in a summary of credit averaging, banking, and trading. 7 ------- |