EPA Announces Final Rulemaking
                    for Clean Alternative Fuel Vehicle
                    and  Engine  Conversions
                       The U.S. Environmental Protection Agency (EPA) is adopting
                       changes to the regulations found in 40 CFR part 85 subpart F
                   for clean alternative fuel conversion manufacturers. This action
                   affects regulations applicable to manufacturers of light-duty
                   vehicle and heavy-duty highway vehicle and engine clean alterna-
                   tive fuel conversion  systems. The revisions will streamline the
                   compliance process while maintaining environmentally protective
                    With the vast majority of vehicles in the United States designed to operate on
                    gasoline or diesel fuel, there has been a long and growing interest by the public
                    in clean alternative fuel conversion systems. These systems allow gasoline or
                    diesel vehicles to operate on alternative fuels such as natural gas, propane,
                    alcohol, or electricity. Use of alternative fuels opens new fuel supply choices
                    and can help consumers address concerns about fuel costs, energy security, and
                    emissions. EPA supports such innovation and encourages the development
                    of clean aftermarket technologies that enable broader transportation fuel
                    choices. At the same time EPA is responsible for ensuring that all vehicles and
                    engines sold in the United States, including clean alternative fuel conversions,
                    meet emission standards. EPA is adopting a new approach that simplifies
                    and streamlines the process by which manufacturers of clean alternative fuel
                    conversion systems may demonstrate compliance with these vehicle and
                    engine emissions requirements. The new options will reduce some economic
                    and procedural impediments to clean alternative fuel conversions while
                    maintaining environmental safeguards to ensure that acceptable emission
                    levels from converted vehicles and engines are sustained. The final rule covers
                    alternative fuel conversion of light-duty vehicles and heavy-duty highway
                    vehicles and engines.
United States
Environmental Protection
Office of Transportation and Air Quality
                      March 2011

Previous EPA regulations required vehicle and engine conversion systems to be covered
by a certificate of conformity to gain a regulatory exemption from potential tampering
charges. EPA evaluated the requirement and determined that it is appropriate to
introduce new flexibilities for all clean alternative fuel converters and to expand
the compliance options for certain categories of conversions. EPA is amending the
regulatory procedures in 40 CFR part 85 subpart F and part 86 to establish these new
compliance options. The new approach builds upon the concept that it is appropriate
to treat conversions differently based on the age of the vehicle or engine being
converted. Under the new regulations, testing and compliance procedures differ based
on the age category of the vehicle or engine that is converted: new and relatively
new, intermediate age, or outside useful life. All conversion manufacturers seeking
an exemption must demonstrate compliance, but the requirements differ among age
categories. EPA expects the streamlined approach to result in a cost savings for many
Key Elements of the Rulemaking
The Clean Air Act prohibits altering a vehicle or engine from its certified configuration.
Alternative fuel conversion systems alter one or more elements of a vehicle's or engine's
original configuration to enable operation on a new fuel. The revised regulations
provide compliance options that allow conversion manufacturers to make the necessary
changes without violating the law. This rule provides clear and comprehensive
compliance pathways for alternative fuel  converters to gain exemption from the
prohibition against tampering.

The new compliance program enables conversion manufacturers to qualify for an
exemption from tampering by demonstrating that the converted vehicle or engine
satisfies EPA emissions requirements. The specific demonstration and notification
requirements differ based on the age of the vehicle  or engine being converted. The
demonstration and notification requirements for new and relatively new vehicles and
engines will continue to involve a certification process that is very similar to previous
practice. Once certified, however, annual recertification will no longer be required to
maintain the tampering exemption. The  notification and demonstration requirements
for intermediate age vehicles and engines include testing and submission of data to
show that the converted vehicle or engine continues to meet applicable standards.
The notification and demonstration process for outside useful life vehicles and engines
involves submission of a description of the conversion system that provides sufficient
technical detail to determine that the conversion will not increase emissions.

Overview of Program Elements
Vehicle/Engine Age
useful life
MY >= current
calendar year
- 1
MY <= current
calendar year -
2 and < useful
Exceeds useful
Example for 20111
MY 2010, 2011,
2012 and < useful
life mileage
MY 2002, 2003,
2004, 2005, 2006,
2007, 2008, 2009
and < useful life
MY2001 and older or
> full useful life in
Conversion Manufacturer
Exhaust, Evap,
and OBD testing2
Exhaust and
Evap testing2 +
OBD scan tool
test and
Technical justifi-
cation4 and OBD
scan tool test
and attestation

1  This example is for light-duty Tier 2 vehicles operating in the 2011 calendar year which have a useful
  life of 10 years or 120,000 miles.
2  Exhaust and evap refers to all exhaust emission testing and all evaporative emission and refueling
  emission testing required for OEM vehicle/engine certification, unless otherwise excepted. OBD test
  ing refers to all OBD demonstration testing as required for OEM vehicle/engine certification.
3  The compliance notification process for intermediate age and outside useful life conversions will be
  electronic submission of data and supporting documents.
4  The technical justification may include data from exhaust and evaporative emissions testing.
Age-Based Demonstration and Notification Requirements
All conversion manufacturers will be required to demonstrate to EPA that the convex
sion satisfies technical criteria, but the demonstration and notification process will differ
depending on vehicle or engine age. The demonstration and notification apply to a group
of vehicles or engines that share similar technology, known as a test group or engine fam-
ily and evaporative/refueling family. The test group/engine family criteria  will also differ
somewhat based on age of the vehicles or engines being converted,

New vehicles and engines
      The new and relatively new category includes vehicles and engines less than about
       two years old: those of a model year that is greater than or equal to the current
       calendar year minus one,
      The compliance demonstration requirement remains very similar to the previous
       certification requirement. Manufacturers must conduct certification tests to demon-
       strate that the converted vehicle or engine complies with exhaust  and evaporative
       emission standards and with on-board diagnostics (OBD) requirements.

       The notification requirement also remains the same as the previous certification
       application process,
       Converted vehicles and engines that satisfy the demonstration and notification
       requirements will be issued a certificate of conformity,
       The new regulations introduce some important flexibilities that will be available to
       most manufacturers of new vehicle/engine conversion systems:
             Manufacturers may apply a single set of test data to a broader set of candi-
              date vehicles and engines,
             A certified conversion system retains its tampering exemption even after
              the certificate expires such that annual re-certification is no longer required.

Intermediate age vehicles and engines
       The intermediate age category covers vehicles and engines at least two years old
       (those of a model year less than or equal to the current calendar year minus two)
       but still within their regulatory useful life,
       The compliance demonstration involves conducting exhaust and evaporative
       emissions tests to show that the converted vehicle or engine meets applicable
       standards. The notification requirement includes submitting a full description of
       the conversion system as well as the test data to EPA,
       In addition, manufacturers must submit an OBD scan tool report to show that the
       OBD system on the converted vehicle or engine continues to function properly,
       plus applicable statements of attestation,
       Converters are permitted further flexibilities for expanded test groups,
       No certificate is issued, and annual re-certification is not required.

Outside useful life vehicles and engines
       The outside useful life age category covers vehicles and engines that have exceeded
       their regulatory  useful life,
       Conversion manufacturers must submit a sufficiently detailed description to show
       that the conversion technology is technically sound and is applied according to
       principles of good engineering judgment,
       The notification requirement, as for the intermediate age program, involves sub-
       mitting the required information, data, and/or attestations to EPA,
       In addition, manufacturers must submit an OBD scan tool report to show that the
       OBD system on the converted vehicle or engine continues to function properly,
       plus applicable statements of attestation,
       The outside useful life program permits the same expanded test group flexibilities
       as the intermediate age program,
       No certificate is issued, and annual re-certification is not required.

Technical Amendments
EPA is finalizing several technical amendments to 40 CFR part 86, subpart S that update
the exhaust and evaporative emission testing requirements for both OEM and converted
gaseous-fueled vehicles. The amendments allow flexibility in determining compliance with
EPA non-methane organic material standards, and allow manufacturers of gaseous-fueled
vehicles to submit statements of compliance in lieu of test data to demonstrate compliance
with exhaust formaldehyde  and evaporative emissions standards. Other technical amend-
ments provide clarity and consistency to regulatory references for clean alternative fuel
conversion and technical corrections and clarifications for the light-duty greenhouse gas
clean alternative fuel conversion procedures.
This fact sheet is a brief informational summary. Regulated parties should always refer to
the regulations for compliance purposes.
For More Information
For further information about this rule, please contact:

          Amy Bunker
          U.S. Environmental Protection Agency
          Office of Transportation Air Quality
          2000 Traverwood Drive
          Ann Arbor, MI48105
          (734) 214-4160
          Fax: (734) 214-4053
          Email: bunker.amy@epa.gov