Search Interpretations


Mr. and Mrs. Samuel Yeager

664 Church Avenue

Nekoosa, WI 54457

Dear Mr. and Mrs. Yeager:

Senator Herb Kohl has requested that we respond to the concerns you expressed to him in an email message about converting your model year (MY) 2004 TrailBlazer and MY 2005 Colorado into dual fuel vehicles capable of running on either gasoline or ethanol. You reported that your dealer said that a Federal law prevents it from making such a conversion.

As background information, the National Highway Traffic Safety Administration (NHTSA) is authorized to issue Federal motor vehicle safety standards (FMVSSs) that specify performance requirements for new motor vehicles and items of equipment. NHTSA has used this authority to issue a FMVSS to ensure the fuel system integrity of vehicles powered by gasoline and those powered by an alcohol fuel (e.g., methanol, ethanol). Specifically, FMVSS No. 301, Fuel system integrity, regulates the fuel system integrity of gasoline and alcohol-powered light vehicles with a gross vehicle weight rating (GVWR) under 10,000 pounds. FMVSS No. 301 requires each vehicle subject to it not to leak more than a limited amount of fuel after being crash tested. As both the TrailBlazer and the Colorado are light vehicles with GVWRs under 10,000 pounds, they were required to meet that standard when they were manufactured and sold.

This agency does not administer any law or regulation that prohibits the conversion of either of these vehicles into a dual fuel vehicle. However, the laws we administer do require that special care be taken when such a conversion is made by a motor vehicle manufacturer, distributor, dealer, or repair business.

Section 30122(b), 49 U.S.C., prohibits those entities from removing, disabling or otherwise "making inoperative" any of the safety systems or devices installed on the vehicles to comply with a FMVSS:

(b) Prohibition. A manufacturer, distributor, dealer, or motor vehicle repair business may not knowingly make inoperative any part of a device or element of design installed on or in a motor vehicle or motor vehicle equipment in compliance with an applicable motor vehicle safety standard . . . unless the manufacturer, distributor, dealer, or repair business reasonably believes the vehicle or equipment will not be used (except for testing or a similar purpose during maintenance or repair) when the device or element is inoperative.

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Mr. and Mrs. Samuel Yeager

If one of the above-named businesses were to modify a gasoline vehicle (after the first purchase of the vehicle in good faith other than for resale) so that it can use either gasoline or ethanol, that business would be required to ensure that it did not knowingly make inoperative, in whole or in part, the compliance of that vehicle to any applicable safety standard, e.g., FMVSS No. 301. Accordingly, since all light trucks and multipurpose passenger vehicles (which include passenger vans and sport utility vehicles) with a GVWR of 10,000 pounds or less must meet FMVSS No. 301, any aspect of their conversion to dual fuel vehicles must not make them more vulnerable to fuel leakage or otherwise impair their fuel system integrity.

The make inoperative provision does not apply to individual vehicle owners who convert their own vehicles. Thus, under the laws administered by NHTSA, a vehicle owner may modify his or her own vehicle regardless of the modifications effect on compliance with the FMVSSs. NHTSA, however, encourages vehicle owners not to degrade the safety of their vehicles. Finally, please also note that individual States may regulate the modifications that affect the emission control systems of used dual fuel vehicles.

I hope this information is helpful. If you have any further questions, please feel free to contact me personally or to have your staff contact me at this address or by telephone at (202) 366-9511.

Sincerely yours,

Anthony M. Cooke

Chief Counsel

cc: The Honorable Herb Kohl