How does FMVSS 303 apply to alternative fuel conversions?

If your conversion system were added to a new, previously-certified vehicle (e.g., a new completed school bus), the person who adds the system would be required to certify that, as altered, the vehicle continues to comply with all of the safety standards affected by the alteration. This means that if you convert a school bus prior to the first consumer purchase, then you would be responsible for certifying that the school bus as manufactured conforms to all applicable FMVSS, including FMVSS No. 301 and, once FMVSS No. 303 and 304 take effect, those standards as well.

If you convert a bus after the first consumer purchase, you would not have any certification responsibilities under NHTSA's regulations. However, an installer that is a vehicle manufacturer, distributor, dealer or repair business would have to ensure that it did not knowingly make inoperative, in whole or in part, the compliance of the vehicle with any applicable safety standard. Since all school buses are currently required to comply with FMVSS No. 301, any aspect of the conversion to a dual fuel school bus must not make the diesel school bus more vulnerable to diesel fuel leakage or otherwise impair the school bus' fuel system integrity. After the September 1, 1995 effective date for FMVSS No. 303, any aspect of your conversion to a CNG/diesel school bus to a dual fuel school bus must not make the school bus more vulnerable to fuel leakage.

For vehicle conversions after sale to the ultimate consumer the vehicle modifications related to natural gas operation should be made in compliance with NFPA 52.

As an additional resource see the Discussion on the issue of liability for complying with FMVSS 303 and other NHTSA standards:

http://isearch.nhtsa.gov/files/10469.html - full letter from NHTSA

More NHTSA FMVSS 303 Discussion –

from the preamble to the final rule issued in 1994 as it relates to multi-state manufacturers.

F. Other Considerations

1. Vehicles Manufactured In More Than One Stage

In the NPRM, NHTSA tentatively concluded that it would be practicable for final stage manufacturers of multi-stage vehicles to comply with this proposed rule. The agency reasoned that because the vehicle requirements in the proposed rule only involve those vehicles currently covered under Standard No. 301, final stage manufacturers are already subject to similar dynamic crash test requirements. NHTSA requested comment on the agency's tentative conclusion that final stage manufacturers could comply with the proposed requirements and provide the requisite level of safety. NHTSA requested comments about the effect of this rule on final stage manufacturers.

Twelve commenters addressed the issue of how this rule would affect vehicles manufactured in more than one stage. Blue Bird, Thomas, Navistar, Washington State, CNG Pittsburgh, CHP, and Chrysler stated it would be appropriate for the proposed requirements to apply to multi- stage vehicles. In contrast, four commenters--the National Truck Equipment Association (NTEA), NGV Systems, Ontario, and Niagara Mohawk Power Company--believed that the new standard should not apply to vehicles manufactured in more than one stage. These commenters were most concerned about how a final stage manufacturer could certify compliance to the Standard without performing crash tests.

NHTSA is aware of the concerns of final stage and intermediate stage manufacturers about crash testing their vehicles. The agency notes that its regulations already provide that certification of an incomplete vehicle can pass through to the final stage manufacturer, provided that the final stage manufacturers take the necessary precautions to ensure they do not invalidate the certification. More specifically, the final stage manufacturers must ensure that they complete the vehicle without exceeding the GAWRs, altering any fuel system component, moving the center of gravity of the completed vehicle with the body installed outside the envelope of specifications provided by the chassis manufacturer, or otherwise violating that envelope. If the final stage manufacturer takes care to comply with all of the chassis manufacturer's specifications, the final stage manufacturer will not have to recertify the vehicle.

If the final stage manufacturer decides not to comply with the specifications to the extent that the vehicle, in its final form, differed significantly from what was anticipated by the chassis manufacturer in specifying the envelope, and the basis for the incomplete vehicle manufacturer's certification was thus no longer valid, then the final stage manufacturer will have to accept the responsibility for certification.

Pass-through certification is also not available for vehicles built on chassis lacking sufficient components to be certified as an incomplete vehicle. Some of the manufacturers that build these vehicles may be small businesses that may be unable to conduct their own crash tests.

NHTSA notes that while manufacturers must certify that their vehicles meet all applicable safety standards, this does not necessarily mean that a manufacturer must conduct the specific tests set forth in an applicable standard. Certifications may be based on, among other things, engineering analyses, actual testing, and computer simulations.

Moreover, a manufacturer need not conduct these operations itself. Manufacturers can utilize the services of independent engineers and testing laboratories. They can also join together through trade associations to sponsor testing or analysis. Finally, they can rely on testing and analysis performed by other parties, including the CNG container manufacturers. The container manufacturers typically perform extensive analyses and tests of their products and, in order to sell those products, will have a strong incentive to provide their customers, the vehicle manufacturers, with information that can be used to certify the vehicle to the applicable standard. Based on the above discussion, NHTSA does not believe that the requirements pose any significant certification burdens for the final stage manufacturers or other small manufacturers.

For more information, contact John Lapetz, CVEF's Director of Technology, at jlapetz@cleanvehicle.org or 248 924 3120.