EPA Decision Document:
Off-Cycle Credits for General Motors
and Toyota Motor Corporation
oEPA
United States
Environmental Protection
Agency

-------
EPA Decision Document:
Off-Cycle Credits for General Motors
and Toyota Motor Corporation
Compliance Division
Office of Transportation and Air Quality
U.S. Environmental Protection Agency
United States
Environmental Protection
tl	Agency
EPA-420-R-18-014
June 2018

-------
EPA Decision Document: Off-Cycle Credits for
General Motors and Toyota Motor Corporation
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 testing based
option, and (3) an alternative methodology proposed by the manufacturer that includes opportunity for
public comment. These are described in more detail in Section II. Pursuant to those rules, General
Motors (GM) and Toyota Motor Corporation (Toyota) submitted applications requesting off-cycle credits
for a several technologies and model years.
This decision document evaluates demonstrations for credits made using the public process pathway.
GM applied for credits from high-efficiency alternators. EPA requested comment on a similar application
from Ford Motor Company in June of 2017/ and subsequently approved those credits in December of
2017.2 Toyota applied for credits for the Denso air conditioning compressor with variable crankcase
suction valve technology. EPA requested comment on a similar application from General Motors (GM)
for credits from the Denso device in June of 2015,3 and subsequently approved those credits in
September of that year.4
EPA published a notice in the Federal Register on February 26, 2018 announcing a 30-day public
comment period for these applications.5 EPA received comments from the Alliance of Automobile
Manufacturers (AAM),6 Global Automakers,7 the Motor & Equipment Manufacturers Association
(MEMA), Denso International America, Gentherm Inc., The ITB Group, Valeo North America, and The
International Council on Clean Transportation (ICCT).
Section II of this document provides background on EPA's off-cycle credits program. Section III provides
EPA's decision. This decision document applies only to the applications referenced herein.
*80 FR 31598, June 3, 2015.
2	"EPA Decision Document: Off-cycle Credits for BMW Group, Ford Motor Company, and Hyundai Motor
Company," EPA-420-R-17-010, December 2017.
3	80 FR 31598, June 3, 2015.
4	"EPA Decision Document: Off-cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company, and
General Motors Corporation," EPA-420-R-15-014, September 2015.
5	83 FR 8262, February 26, 2018.
6	The Alliance of Automobile Manufacturers is a trade group representing 12 vehicle manufacturers,
including BMW and Ford.
7	Global Automakers is a trade group representing 12 vehicle manufacturers, including Hyundai.
1

-------
II. EPA's Off-cy "edits 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
credit values for specific off-cycle technologies that may be used beginning in model year 2014.8 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.9
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 that they propose for determining the off-cycle C02 credits.10 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.
8	40 CFR 86.1869-12(b).
9	40 CFR 86.1869-12(c).
10	40 CFR 86.1869-12(d).
2

-------
Further, the regulations specify the following requirements regarding an application for off-cycle CO2
credits using an alternative methodology:
	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.
	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.11 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. 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.
Ml, EPA Decisions on Off-cycle Credit Applications
A. General Motors Corporation
1. High-Efficiency Alternator
General Motors Corporation (GM) requested GHG credits for alternators with improved efficiency
relative to a baseline alternator, for the 2010 to 2016 model years. Automotive alternators convert
11 40 CFR 86.1869-12(d)(2).
3

-------
mechanical energy from a combustion engine into electrical energy that can be used to power a
vehicle's electrical systems. Alternators inherently place a load on the engine, which results in increased
fuel consumption and C02 emissions. High efficiency alternators use new technologies to reduce the
overall load on the engine yet continue to meet the electrical demands of the vehicle systems, resulting
in lower fuel consumption and lower C02 emissions. GM proposed a methodology that would scale
credits based on the efficiency of the alternator (as measured using an accepted industry standard
procedure). This is essentially the same methodology approved by EPA for Ford Motor Company in
December of 2017.12 Details of the testing and analysis can be found in the manufacturer's application.
EPA reviewed the application for completeness and made it available for public review and comment as
required by the regulations. The GM off-cycle credit application (with confidential business information
redacted) is available in the public docket and on EPA's web site.
EPA did not receive any adverse comments on the application from GM. EPA has evaluated the
application and finds that the methodologies described therein are sound and appropriate. Therefore,
EPA is approving the credits requested by GM for the 2010 to 2016 model years for all GM vehicles using
this technology as described in GM's application. These credits must be reported to EPA not later than
May 1, 2019, the date on which reporting of GHG credits for the 2018 model year is due. GM must
include all information necessary to determine the total Megagrams of credits, and they should also
include the total Megagrams for each fleet and model year in a summary of credit averaging, banking,
and trading.
2, Active Climate Control Seats
GM requested GHG credits for the use of active climate control seat technologies, for the 2010-2016
model years. This request is for a larger amount of credit than could be earned by these designs using
the pre-defined regulatory "menu" of default off-cycle credits for ventilated seats (1.0 and 1.3
grams/mile for cars and trucks, respectively). The technology used by GM uses a combination of
ventilation fans and cooling devices. Active cooling to the seat back is provided by the installation of
thermoelectric devices (TED) and a blower which provides positive, temperature controlled airflow
pushed towards the occupant. The seat cushion also features a blower operating in a pull mode,
drawing the air surrounding the occupant into the seat cushion. The foams in both seating surfaces
include a textile spacer fabric that facilitates lateral airflow under occupant load. The seat covers are
made of cloth and backed by an additional layer of textile spacer fabric to promote airflow to the
occupant.
GM performed a series of simulations on three vehicle platforms. The analysis also accounted for
emissions associated with the power consumption of the ventilated seat technology. Based on GM's
12 "EPA Decision Document: Off-cycle Credits for BMW Group, Ford Motor Company, and Hyundai Motor
Company," EPA-420-R-17-010, December 2017.
4

-------
analysis, they are requesting credits equal to 2.3 grams per mile for passenger cars and 2.9 grams per
mile for trucks on all models that use these seats in both front seating locations.
EPA did not receive any adverse comments on the application from GM. EPA has evaluated the
application and finds that the methodologies described therein are sound and appropriate. Therefore,
EPA is approving the credits requested by GM for the 2010 to 2016 model years for all GM vehicles using
this technology as described in GM's application. These credits must be reported to EPA not later than
May 1, 2019, the date on which reporting of GHG credits for the 2018 model year is due. GM must
include all information necessary to determine the total Megagrams of credits, and they should also
include the total Megagrams for each fleet and model year in a summary of credit averaging, banking,
and trading.
B. Toyota Motor Norl erican
1, Denso Air-Conditioning Compressor
Toyota Motor North America (Toyota) applied for off-cycle credits for an air conditioning compressor
manufactured by Denso that has been shown to result in efficiency improvements warranting air
conditioning efficiency credits beyond those provided in the regulations. This compressor, known as the
Denso SAS compressor, improves the internal valve system within the variable-displacement compressor
to reduce the internal refrigerant flow necessary throughout the range of displacements that the
compressor may use during its operating cycle. The addition of a variable crankcase suction valve allows
a larger mass flow under maximum capacity and compressor start-up conditions (when high flow is
ideal), and then it can reduce to smaller openings with reduced mass flow in mid- or low-capacity
conditions. The refrigerant exiting the crankcase is thus optimized across the range of operating
conditions, reducing the overall energy consumption of the air conditioning system. EPA previously
approved credits for the use of the Denso SAS compressor for BMW, Ford, GM and Hyundai.13 14
The credits calculated by Toyota for the Denso SAS compressor would be in addition to the credits for
variable-displacement A/C compressors already allowed under EPA regulations. However, it is
important to note that EPA regulations place a limit on the cumulative credits that can be claimed for
improving the efficiency of A/C systems. The rationale for this limit is that the additional fuel
consumption of A/C systems can never be reduced to zero, and the limits established by regulation
reflect the maximum possible reduction in fuel consumption projected by EPA. These limits, or caps, on
credits for A/C efficiency, must also be applied to A/C efficiency credits granted under the off-cycle
credit approval process. In other words, cumulative A/C efficiency credits for an A/C system - from the
13	"EPA Decision Document: Off-cycle Credits for Fiat Chrysler Automobiles, Ford Motor Company, and
General Motors Corporation." Compliance Division, Office of Transportation and Air Quality, U.S. Environmental
Protection Agency. EPA-420-R-15-014, September 2015.
14	"EPA Decision Document: Off-cycle Credits for BMW Group, Ford Motor Company, and Hyundai Motor
Company," EPA-420-R-17-010, December 2017.
5

-------
A/C efficiency regulations and those granted via the off-cycle regulations - must comply with the stated
limits.
Toyota requested an off-cycle GHG credit of 1.1 grams CO2 per mile for the Denso SAS compressor (the
same as has been approved for some other manufacturers). Toyota cited the bench test modeling
analysis referenced in the original GM application, which demonstrated a benefit of 1.1 grams/mile. Like
other manufacturers, Toyota also ran vehicle tests using the AC17 test. Six tests were conducted on a
Toyota Corolla, resulting in a calculated benefit of 1.4 grams/mile, thus substantiating the bench test
results. Based on these results, Toyota requested a credit of 1.1 grams/mile for all Toyota vehicles
equipped with the Denso SAS compressor with variable crankcase suction valve technology, starting
with 2013 model year vehicles. Details of the testing and analysis can be found in the manufacturer's
application. EPA reviewed the application for completeness and made it available for public review and
comment as required by the regulations. The Toyota off-cycle credit application (with confidential
business information redacted) is available in the public docket and on EPA's web site.
EPA did not receive any adverse comments on the application from Toyota. EPA has evaluated the
application and finds that the methodologies described therein are sound and appropriate. Therefore,
EPA is approving the credits requested by Toyota for the 2013 and later model years for all Toyota
vehicles using this technology as described in Toyota's application. Caps or limits on credits that are
specified in the regulations also apply to the credits being approved in this document. Credits for the
2013-2017 model years must be reported to EPA not later than May 1, 2019, the date on which
reporting of GHG credits for the 2018 model year is due. Toyota must include all information necessary
to determine the total Megagrams of credits, and they should also include the total Megagrams for each
fleet and model year in a summary of credit averaging, banking, and trading.
6

-------