A fuel system is provided that includes a fuel system frame and in some cases access steps. The frame can be mounted to a vehicle frame rail. Bracket assemblies can be coupled to the fuel system frame at a plurality of positions. The fuel tank can be mounted at neck portions thereof and can be supported on the frame rail between the neck portions, e.g., spaced a distance from the neck portions in a longitudinal direction of the fuel system. The access steps can be non-rectangular to provide a wide stepping portion even if the fuel system includes large tanks. The steps can be directly supported by an outside surface of the tank.