Important Registration update:  A new federal law was passed by Congress in late 2015 addressing the construction of "replica" cars.  Among the many requirements addressed by the new law the outstanding one is that "replica" cars built and registered under this new law "must meet USA EPA emissions"


What about registration - how can I be sure my specially constructed car can be successfully registered when it initially gets delivered and in the future ?

The days of using old titles and defeating emission systems are gone !

The days of using JDM engines and off road use only drive trains are gone !

     We get a lot of questions about legal registration of specially constructed automobiles of all types.  These are legitimate concerns that will only become more strict in the future.

    There are a lot of industry opinions and slight of hand methods exchanged, but fortunately there is a Federal EPA policy explicitly published for the registration of kit cars, street rods, specially constructed cars, and similar products.

     Recently California paved the road in eliminating the past processes of disguising a specially constructed vehicle by using an old VW title or abandoned junkyard title for a similarly described specially constructed carIn fact CA is offering amnesty during the 2010 year for any who have registered in this manner in the past.  All that is required is to properly register the car and pay the back taxes that were avoided.  Use of SB100 is the only proper registration method CA acknowledges.

    There are quite a few notable examples of fines and penalties handed down to those who have participated in that process.  At least 21 states have adopted CA regulations for emission controls and legal registrations.

    EPA makes it very clear as to what are the requirements for specially constructed  vehicles.


     The principle federal regulation controlling this issue is the published EPA policy which addresses the Federal Clean Air Act emissions requirements. 

   Each State, city, or community might have additional emissions requirements, and almost always has basic safety requirements.  These safety requirements are common sense issues that no automobile builder should avoid anyhow so they seldom present a problem.

    It is the ultimate responsibility of the automobile assembler to address and incorporate the requirements, but it is the burden of the purchaser to pass the car through the local registration process.

Unfortunately those vehicles which have slipped through the crack in the past can be reevaluated upon resale and registration to a second owner or even a registration update of an existing owner.  We feel that getting the cars registered legally and correctly at first is paramount.

The EPA policy as defined is clear and provides a successful path for registration; however, each builder and purchaser of a specially constructed car must interpret and apply this requirement at his own risk.


Here is what the formal EPA regulation says:


EPA Kit Car Policy

(key elements have been highlighted in blue)

July 8, 1994 -
Previous versions are obsolete

The following represents a clarification of EPA's policy concerning the regulation of imported and domestically produced kit cars and kit car packages. Kit vehicles are understood by EPA to typically involve new bodies, used drive trains and new or used chassis. Used components may or may not be refurbished. This policy applies to kits or assembled kit cars only. This policy does not apply to regular production vehicles offered for importation into or produced in the United States.

  1. Fully-assembled kit cars are "motor vehicles" under the Clean Air Act. Complete kit car packages are also "motor vehicles" under the Clean Air Act. These are packages which contain all of the major components needed for assembly (i.e., body, chassis, engine and transmission). As "motor vehicles" they are subject to all applicable emission regulations. If an assembled kit car or complete kit car package is offered for importation and the kit is not covered by an EPA certificate of conformity issued to an original equipment manufacturer, an EPA Form No. 3520-1 must be filed at the port of entry and the vehicle must be imported by an Independent Commercial Importer (ICI) eligible to import such vehicles or kits. The ICI then must ensure that the vehicle or kit complies with all applicable emission requirements.
  2. An assembled kit car or complete kit car package which meets the following guidelines will be considered to be a rebuilt vehicle of a previously certified configuration and will be considered to be covered by that configuration's original EPA certificate of conformity.
    1. The components of the drive train (engine, transmission, differential) must be exclusively or substantially used and/or rebuilt. Regardless of the combination of new and used components, the engine must be used or used and rebuilt. The engine block and cylinder head (s) must be used, other components of the engine may be new. "Used" means the component has been in a vehicle that has been titled to an ultimate purchaser. A rebuilt component is defined as a used component which has been refurbished with new or other used parts.
    2. All emission-related components and settings must conform in all material respects to those of one previously certified configuration. Therefore, all part numbers for the emission-related components of a fully assembled kit vehicle or complete kit car package must match or be traceable to the numbers specified in the application for certification of a previously certified configuration.
    3. Consistent with EPA Advisory Circular (AC) 64, which deals with modifications performed before sale to the ultimate purchaser, the vehicle weight of the kit configuration can be no more than 500 pounds greater than the weight of the originally certified configuration.
    4. All catalytic converters, oxygen sensors, and charcoal canisters must be new, original equipment parts.
    5. Kit vehicles must: (1) have the same transmission configuration (i.e., manual, automatic, semi-automatic, number of forward gears, and shift calibration) as the originally certified configuration; and (2) consistent with AC 17F, have an N/V ratio (speed of vehicle in miles per hour/speed of engine in revolutions per minute) which matches the N/V ratio of the originally certified configuration within three (3) percent in every gear.*
      • *The Agency would consider minor variations to these limitations upon an appropriate demonstration that the altered configuration will meet Federal emission requirements.
    6. Each vehicle and its accompanying documentation must be clearly labeled as to the make, model year, engine family, subfamily, and tune-up specifications represented by the originally certified vehicle.
    7. If the originally certified configuration required unleaded fuel, then the vehicles must have fuel filler neck restrictors and unleaded fuel labels which meet the requirements of 40 CFR 80.24.
  3. The production, sale and importation of automotive bodies alone (i.e., no chassis, engine or transmission) are not regulated by EPA since such units are not considered "motor vehicles" under the Clean Air Act. EPA form 3520-1 is not required for imported automotive bodies. A motor vehicle from which the engine has been removed is still a motor vehicle and is not considered a body.
  4. The production, sale and importation of vehicle parts (engines, transmissions, chassis, vehicle bodies, etc.) are not regulated by EPA because parts are not considered motor vehicles under the Clean Air Act.

    However if the parts constitute a disassembled vehicle or an approximate disassembled vehicle, the combination is considered a motor vehicle under the Clean Air Act. Any attempt to use this policy to circumvent the Clean Air Act or the Imports regulations will be considered a violation of the Clean Air Act and will be strictly enforced.

     An example of such circumvention is:
    • A kit car maker who also provides the engine and transmission before or after production/importation of the body/chassis.
  5. "Motor vehicles" must comply with the Clean Air Act and may not be disassembled nor purchased in a disassembled form for the purposes of evading the Clean Air Act or the Imports regulations. In these situations the kit car body/chassis combination must be certified by the manufacturer, must be in a configuration which was previously certified by EPA subject to the guidelines discussed at "2" above or, in the case of an importation, an EPA form 3520-1 must be filed at the port of entry and the vehicle imported by an eligible ICI who must ensure that the kit car body/chassis complies with all applicable emission requirements. At the present time, there are no ICIs eligible to import kit cars.
  6. Except with regard to kit vehicles meeting the guidelines at "2" above; an individual or firm that assembles kits for hire or resale, that produces assembled kit cars for resale or that produces complete kit car packages for resale will be considered to be a manufacturer of new motor vehicles under the Clean Air Act. Such manufacturers and their vehicles are subject to all applicable regulations under the Act including civil penalties of up to $25,000 per vehicle for each new motor vehicle distributed in commerce, sold, offered for sale, or introduced, or delivered for introduction, into commerce, unless such vehicle is covered by a certificate of conformity issued by EPA.

The supplement contains definitions from the Clean Air Act and justification used to derive the position of the Kit car Policy.

Section 216 (1) defines a "manufacturer" as."any person engaged in the manufacturing or assembling of new motor vehicles or new motor vehicle engines, or importing such vehicle or engines for resale."

Section 216 (2) defines a "motor vehicle" as ."any self-propelled vehicle designed for transporting persons or property on a street or highway."

Section 216 (3) defines a "new motor vehicle" as..."a motor vehicle the equitable or legal title to which has never been transferred to the ultimate purchaser."

Section 216 (5) defines a "ultimate purchaser" as."the first person who in good faith purchases such new motor vehicle or new engine for purposes other than resale".

Section 203(a)(1) prohibits:."in the case of a manufacturer of new motor vehicles...the sale, or offering for sale, or the introduction,.into commerce..any new motor vehicle...unless such covered by a certificate of conformity.."

Section 205 states.."any person who violates Section 203(a)(1)..shall be subject to a civil penalty of not more than $25,000...Any such violation...shall constitute a separate offense.."


Here is what EPA says about engine switching and engine alteration   


March 13, 1991

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.

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 engine 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

For heavy-duty vehicles, the resulting vehicle must contain a heavy-duty engine which is identical to a
certified configuration 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 any 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
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
anti-tampering 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.