Interpretation ID: aiam2131
Director
Automotive Safety Office
Ford Motor Company
The American Road
Dearborn
MI 48121;
Dear Mr. Eckhold: This is in response to your letter of September 24, 1975, in which yo ask whether it is permissible to test certain 1978 vehicles for compliance with Standard No. 301, *Fuel System Integrity*, with open vapor vent tube pressure relief valves.; The Federal motor vehicle safety standards do not specify the test which you must perform. They do specify conditions and procedures under which the National Highway Traffic Safety Administration (NHTSA) will conduct its compliance testing. S7.1.1 and S7.1.2 of Standard No. 301 specify that the vehicle's fuel system shall contain Stoddard solvent rather than fuel and, by implication, that the engine shall not be running. If, as you indicate, one consequence of the engine's not running is that a certain pressure relief valve in the vapor vent tube is closed, then that valve must remain closed during the NHTSA's compliance testing, the existing standard could not be interpreted otherwise. Although in an actual collision any rollover would probably occur immediately after the initial impact, in some accidents vehicle occupants would be trapped for some period of time after rollover. Therefore, we do not consider that this interpretation creates, as you suggest, an artificial condition by subjecting the fuel tank to a potential vapor pressure build-up during preparation for the rollover test.; Sincerely, Frank A. Berndt, Acting Chief Counsel