Fuel Tank. The fuel tank shall: Have a minimum capacity of 22 gallons; Be filled and vented entirely outside the body; and Have a fill opening located so that accidental fuel spillage will not drip or drain to any part of the exhaust system. A fuel filter with replaceable element shall be installed between the fuel tank and the engine fuel system. The fuel lines shall be mounted to obtain maximum possible protection from the chassis frame. If mounted on the right-hand side, the fill opening shall be equipped with a door. If a fuel other than gasoline or diesel is used, the fuel system shall meet all applicable federal standards.