Fuel systems include the fuel tanks and lines that supply fuel to a motor vehicle’s engine. Fuel systems for commercial vehicles and auxiliary equipment are subject to location, installation, and other requirements that ensure drivers and other road users stay safe.
See 49 CFR 393.65 for requirements that apply to all types of fuel systems. For requirements specific to liquid fuel tanks, see 49 CFR 393.67. For requirements specific to compressed natural gas fuel containers, see 49 CFR 393.68. For requirements specific to liquefied petroleum gas systems, see 49 CFR 393.69. Gravity or syphon feeds directly to the carburetor or injector are prohibited for all types of fuel systems.