FMCSA proposes to add an exception to the prohibition on gravity and syphon feeds for auxiliary pumps with a fuel tank capacity of less than 5 gallons mounted on the trailer chassis frame or trailer bed, for purposes other than operation of the motor vehicle, that are operational only when the motor vehicle is not in motion. This proposal is in response to a petition for rulemaking from the Truck Trailer Manufacturers Association. The proposed change would provide relief from a regulatory requirement without impacting safety.