Q How would you describe the certification requirements for aftermarket
A Both the federal Environmental Protection Agency (EPA) and the California
Air Resources Board (CARB) require the manufacturers of aftermarket systems to
certify that their conversion systems meet emissions and onboard vehicle diagnostics
interface requirements. EPA and CARB can levy substantial fines for violating this
requirement, since it is against the law to tamper with emissions systems. The only
way to protect against a tampering violation is to have valid certificate of conformity
from EPA or a CARB Executive Order for the conversion system. (See below for
vehicles that are pre-2003 model year and/or beyond their “useful life.”)
Q How does the EPA have this authority?
A The EPA has the authority under the Clean Air Act to regulate vehicle
emissions for all new motor vehicles. Moreover, it also has authority to regulate
modifications of in-use vehicles if the modification tampers with the vehicles emission
control systems. For a history of EPA’s regulatory authority, see
Q How many companies are offering certified systems?
A The number of Small Volume Original Equipment Manufacturers (SVM)
continues to increase as new companies with automotive engineering expertise see the
aftermarket retrofit opportunity. Currently, there are nearly a dozen manufacturers
offering EPA-certified systems for about a dozen GM and Ford light-duty “engine
families” covering about 40 vehicle models (and various iterations of the same base
models). These include the GM 3.5L, 3.9L, 4.8L, 5.3L, and 6.0L engines and the Ford
2.0L, 2.3L, 4.6L, 5.4L, 6.2L and 6.8L engines. Note: Not all vehicles with these
engines are covered in the engine test groups for which certifications have been
granted. In addition, there are no certified natural gas engine conversion systems
available in the U.S. for any other light-duty vehicle brands.
Q Where can I find a list of manufacturers?
A Visit http://www.ngvamerica.org/pdfs/marke...Analyses.NGVsa
pdf for an up-to-date list of EPA- and CARB-certified engines retrofit and repower
Q How do retrofit system manufacturing companies get engines certified?
A To obtain an EPA Certificate or a CARB Executive Order, the retrofit system
manufacturer must submit substantial emissions performance data and related
documentation for each engine family for review. Additionally, new converters may
be asked to submit a converted vehicle for rigorous testing to verify this data.
Q How expensive is it to comply with these requirements?
A The process of engineering, manufacturing, installing, pre-testing and then
submitting a proposed retrofit system to an EPA- or CARB-approved laboratory for
certification is a time-consuming and expensive process that may cost as much as
$200,000 or more per engine family.
Q How long does this certification last?
A EPA certification applies only to the installation of that system for a limited
time period, usually no longer than December 31 of the year following the year the
certificate was granted. Manufacturers may opt to ‘carry-over” their certifications into
future years by filing additional documentation and paying a fee, thus allowing them
to convert a previous model-year vehicle (for which they obtained certification) in
later years. However, Executive Orders issued by the California Air Resources Board
for a particular vehicle model year and test group do not expire.
Q What about retrofitting older vehicles?
A The U.S. EPA has indicated that its certification procedures are appropriate for
vehicles that are within their useful life, which is roughly defined as 10 years or
120,000 miles, although the exact definition of useful life has changed over time. The
EPA is expected to issue future guidance on this issue. In addition, manufacturers
generally do not maintain active certifications for vehicles with high (or even medium)
mileage due to technical complications caused by long-term operation on gasoline.
For any pre-2000 vehicles or any vehicle with mileage exceeding the useful life
definition for that model and model-year, EPA guidance appears to indicate that
certification is not required, although the manufacturer must have a reasonable basis
to believe that the system will not increase emissions. For 2000 to 2003 vehicles that
have not yet reached 120,000, EPA guidelines indicate that certification of the retrofit
system is required, which does not make this option economically attractive. See
EPA’s web site for further clarification on this issue including guidance on converting
vehicles older than 10 years or beyond 100,000 - 120,000 miles.
Q Are aftermarket installers certified?
A Neither the federal government nor California require the businesses or
individuals who install aftermarket conversion systems to be certified or licensed to
do conversions. Because of the liability for in-use emissions and safety,
manufacturers of EPA- or California-certified conversion systems train companies,
often referred to as qualified system retrofitters, to install their systems, and typically
they do not sell their system to untrained or unapproved installers. In addition, some
states, including Oklahoma, have established state retrofit system installer training and
Q Can I install this system myself?
A Installation by a non-qualified installer could damage the retrofit equipment or
the engine, compromise vehicle performance, or render the vehicle unsafe to operate.
Q Are there other safety considerations?
A The installer is responsible for obtaining the fuel storage system components
(cylinders, high-pressure tubing, press release device, brackets, protective plates) and
for installing them in accordance with the National Fire Protection Association’s
Vehicular Fuel System Code (NFPA 52). These safety-oriented issues are the domain
of the local fire marshal, and most jurisdictions have adopted NFPA 52 as their
standard for proper installation of natural gas vehicle systems. Consumers should ask
installers to confirm that the installation meets NFPA 52 requirements.