UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
ENGINE SWITCHING FACT SHEET
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
March 13, 1991
OFFICE OF AIR AND RADIATION
Pursuant to frequent requests for information received by the U.S. Environmental
Protection Agency
(EPA) regarding the legality and effects of engine switching, this document will
summarize federal law
and policy pertaining to this matter, and will discuss other related issues.
A. Federal Law
The federal tampering prohibition is contained in section 203(a)(3) of the Clean
Air Act (Act), 42
U.S.C. 7522(a)(3). Section 203(a)(3)(A) of the Act prohibits any person from
removing or rendering
inoperative any emission control device or element of design installed on or in
a motor vehicle or motor
vehicle engine prior to its sale and delivery to an ultimate purchaser and
prohibits any person from
knowingly removing or rendering inoperative any such device or element of design
after such sale and
delivery, and the causing thereof. The maximum civil penalty for a violation of
this section by a
manufacturer or dealer is $25,000; for any other person, $2,500. Section
203(a)(3)(B) of the Act
prohibits any person from manufacturing or selling, or offering to sell, or
installing, any part or
component intended for use with, or as part of, any motor vehicle or motor
vehicle engine where a
principal effect of the part or component is to bypass, defeat, or render
inoperative any device or
element of design installed on or in a motor vehicle or motor vehicle engine,
and where the person
knows or should know that such part or component is being offered for sale or is
being installed for
such use. The maximum civil penalty for a violation of this section is $2,500.
EPA received many questions regarding the application of this law to a situation
where one engine is
removed from a vehicle and another engine is installed in its place. EPA's
policy regarding "engine
switching" is covered under the provisions of Mobile Source Enforcement
Memorandum No. lA
(Attachment 1). This policy states that EPA will not consider any modification
to a "certified
configuration" to be a violation of federal law if there is a reasonable basis
for knowing that emissions
are not adversely affected. In many cases, proper emission testing according to
the Federal Test
Procedure would be necessary to make this determination.
2
A "certified configuration" is an engine or engine chassis design which has been
"certified" (approved)
by EPA prior to the production of vehicles with that design. Generally, the
manufacturer submits an
application for certification of the designs of each engine or vehicle it
proposes to manufacture prior to
production. The application includes design requirements for all emission
related parts, engine
calibrations, and other design parameters for each different type of engine (in
heavy-duty vehicles), or
engine chassis combination (in light-duty vehicles). EPA then "certifies" each
acceptable design for use,
in vehicles of the upcoming model year.
For light-duty vehicles, installation of a light-duty eng~ne into a different
light-duty vehicle by any
person would be considered tampering unless the resulting vehicle is identical
(with regard to all
emission related parts, engine design parameters, and engine calibrations) to a
certified configuration of
the same or newer model year as the vehicle chassis, or if there is a reasonable
basis for knowing that
emissions are not adversely affected as described in Memo 1A. The appropriate
source for technical
information regarding the certified configuration of a vehicle of a particular
model year is the vehicle
manufacturer.
For heavy-duty vehicles, the resulting vehicle must contain a heavy-duty engine
which is identical to a
certified configura- tion of a heavy-duty engine of the same model year or newer
as the year of the
installed engine. Under no circumstances, however, may a heavy-duty engine ever
be installed in a
light-duty vehicle.
The most common engine replacement involves replacing a gasoline engine in a
light-duty vehicle with
another gasoline engine. Another type of engine switching which commonly occurs,
however, involves
diesel powered vehicles where the diesel engine is removed and replaced with a
gasoline engine.
Applying the above policy, such a replacement is legal only if the resulting
engine-chassis configuration
is equivalent to a certified configuration of the same model year or newer as
the chassis. If the vehicle
chassis in question has been certified with gasoline, as well as diesel
engines(as is common), such a
conversion could be done legally.
Another situation recently brought to EPA's attention involves the offering for
sale of used foreign-built
engines. These engines are often not covered by a certified configuration for
any vehicle sold in this
country. In such a case, there is no way to install such an engine legally. EPA
has recently brought
enforcement actions against certain parties who have violated the tampering
prohibition by performing
illegal engine switches.
It should be noted that while EPA's policy allows engine switches as long as the
resulting vehicle
matches exactly to anv certified configuration of the same or newer model year
as the chassis, there are
some substantial practical limitations to performing such a replacement. Vehicle
chassis and engine
designs of one vehicle manufacturer are very distinct from those of another,
such that it is generally not
possible to put an engine into a chassis of a different manufacturer and have it
match up to a certified
3
configuration. Therefore, practical considerations will generally limit engine
switches to installation of
another engine which was certified to be used in that same make and model (or a
"twin" of that make
and model, e.g., Pontiac Grand Am and Oldsmobile Calais). In addition,
converting a vehicle into a
different certified configuration is likely to be very difficult, and the cost
may prove prohibitive.
B. State Laws
Many states also have statutes or regulations prohibiting tampering in general.
Most of these laws
specifically prohibit tampering by individuals. A few specifically prohibit
engine switching, using
provisions similar to those stated in EPA's policy. To determine the state law
in any given state, the
state's Attorney General's office should be contacted. In addition, many states
have state or local
antitampering inspection programs which require a periodic inspection of
vehicles in that area, to
determine the integrity of emission control systems. Many programs have
established policies for
vehicles which have been engine switched. While EPA does not require these
programs to fail engine
switched vehicles which are not in compliance with federal policy, the Agency
does strongly
recommend that these programs set their requirements so as to be consistent with
the federal law. State
or local programs which pass illegally engine switched vehicles may mislead
federally regulated parties
into believing that engine switching is allowed by federal law.
copyright EPA.
This is printed here as information only... Aug 2009