Federal Motor Vehicle Safety Standards; Fuel Systems Integrity

In this document, NHTSA is upgrading the rear impact test in the Federal motor vehicle safety standard on fuel system integrity. To simulate being struck in the rear by another vehicle, that standard currently specifies that the full width of the rear of the test vehicle be impacted with a flat, rigid barrier at speeds up to 48 km/h (30 mph). This final rule replaces that full rear impact test procedure with an offset rear impact test procedure specifying that only a portion of the width of the rear of the test vehicle be impacted at 80 km/h (50 mph). Under the new rear impact procedure, a lighter, deformable barrier is used. The barrier is very similar to the one used for dynamic testing in the agency's side impact protection standard, except that the rear impact barrier's face is mounted slightly lower to simulate the diving of the front end of a vehicle during pre-crash braking. The agency has concluded that the new, more stringent rear impact test procedure will save lives and prevent injuries. This final rule replaces the standard's lateral (side) impact test procedure with the procedure specified in the agency's side impact protection standard at an impact speed range of 53 +/- 1 km/h. The agency has concluded that this change will provide a more realistic test, increase safety, and reduce testing costs.