A system for a gaseous-fueled engine, comprising: a gaseous fuel tank, a first pressure regulator comprising: a high pressure chamber coupled to the gaseous fuel tank, a low pressure chamber coupled to an engine fuel rail, and a reference chamber; a second pressure regulator coupled to the reference chamber; a first valve controlling fuel flow from the gaseous fuel tank to the engine fuel rail; a second valve controlling fuel flow from the second pressure regulator to the reference chamber; and a controller including memory with instructions therein for adjusting the valves based on a desired fuel rail pressure. In this way, the system enables at least two different fuel rail pressures such that peak fuel demand can be satisfied without maintaining peak fuel rail pressure at all times.