Mobile Sources
Final Rule: Mandatory Reporting of Greenhouse Gases
              United States
              Environmental Protection
              Agency
Under the Mandatory Reporting of Greenhouse Gases (GHGs) rule, all vehicle and engine manufacturers1
outside of the light-duty sector2 must report emission rates of carbon dioxide (CO2), nitrous oxide (N2O), and
methane (CH4) from the products they supply. EPA is not requiring reporting of mobile source emissions or
activity data from fleet operators or state and local governments.

EPA incorporated the GHG reporting requirements for vehicle and engine manufacturers into the long-
standing conventional ("criteria") pollutant testing and reporting requirements under Title II of the Clean
Air Act.  Wherever possible, we based the new reporting requirements on existing measurement methods and
plan to use existing data collection systems.

How Is This Source  Category Defined and What GHGs Must Be Reported?
Manufacturers of the
following mobile source
categories...
Highway heavy-duty
vehicles (chassis-certified)
Highway heavy-duty
engines
Highway motorcycles
Nonroad diesel engines
Marine diesel engines
Locomotive engines
Nonroad small spark
ignition engines
Nonroad large spark
ignition engines
Marine spark ignition
engines/personal
watercraft
Snowmobiles
Off-highway motorcycles
and ATVs
Aircraft engines0
must report the
following GHGs...
CO2, N2Oa, CKt
C02, N20a, CH4
C02, N20a, CH4
C02, N20a, CH4
CO2, N2O, a'b CH4b
C02, N20a, CH4
C02, N20a, CH4
C02, N20a, CH4
C02, N20a, CH4
C02, N20a, CH4
C02, N20a, CH4
C02, NOX
in units of. . .
grams per mile
grams per bhp-hour
grams per kilometer
grams per kilowatt-
hour
grams per kilowatt-
hour
grams per bhp-hour
grams per kilowatt-
hour
grams per kilowatt-
hour
grams per kilowatt-
hour
grams per kilowatt-
hour
grams per kilometer
grams per kilonewton
for new vehicles and engines
certified under or subject to the
Code of Federal Regulations (CFR)
Title 40, including amendments to
these parts.
86
86, 1065
86
89, 1039, 1065
94, 1042, 1065
1033, 1065
90, 1054, 1065
1048, 1065
1045, 1065
1051, 1065
86, 1051
87
 N2O requirements only apply to new engines equipped with NOX aftertreatment technology.
b Except C3 marine engines.
c Only applies to turbofan and turbojet engines in production in 2011 with a rated output greater than 26.7 kilonewtons.
1 The term "manufacturer" in this information sheet means a company that is subject to EPA's mobile source emission certification
requirements. This category primarily includes companies that manufacture engines domestically and foreign manufacturers that
import engines into the U.S. market. In some cases, it also includes domestic companies that are required to meet EPA certification
requirements when they import foreign-manufactured engines.
2 The light-duty sector includes cars, SUVs, small pickup trucks and vans.
September 2009
EPA-430-F-09-047(R)

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These new GHG reporting requirements do not apply to manufacturers treated as a "small business" or
"small-volume manufacturers" under EPA's existing mobile source emission regulations.3 Unique definitions
of "small" apply to manufacturers of different mobile source categories. See the respective sections of CFR
for details.

How Should GHG Emissions Be Calculated?

To measure emission rates, manufacturers must use prescribed testing and measurement procedures, most of
which are already used for existing criteria pollutant reporting requirements. These procedures vary by
mobile source category and pollutant. For more information on these procedures, please see the preamble and
the amendments to the respective sections of CFR.

What Information Must Be Reported?

Manufacturers must report GHG emission rates of new vehicles and engines at the same time and through the
same process as they currently follow for criteria pollutant emission certification. Reporting requirements
apply beginning with the 2011 model year for CO2 and the 2012 model year for CH4.  N2O reporting
requirements apply beginning  with the 2013 model year or when the manufacturer introduces NOX
aftertreatment technology, whichever is later.

In place of N2O and/or CH4test data for each engine family, manufacturers may submit alternative test data
and/or other information that will give EPA a reasonable basis for estimating the engine's emission rates.
For more information on this provision, see the preamble.

For More Information

This document is provided solely for informational purposes.  It does not provide legal advice, have legally
binding effect, or expressly or implicitly create, expand, or limit any legal rights, obligations, responsibilities,
expectations, or benefits in regard to any person. The series of information sheets is intended to assist
reporting parties in understanding key provisions of the final rule.

Visit EPA's Web site (www.epa.gov/climatechange/emissions/ghgrulemaking.html) for more information,
including the final preamble and rule, additional information sheets on specific industries, the schedule for
training sessions, and other documents and tools. For questions that cannot be answered through the Web
site,  please contact us at: ghgmrr@epa.gov.
3 Small business manufacturers will continue to be subject to measurement and/or reporting requirements for compliance with
existing regulations.
September 2009                                  2                             EPA-430-F-09-047(R)

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