Abstract: A system for an automobile has a compressed fuel source (14) having a first fuel pressure. An expansion device (26) is coupled to the compressed fuel source (14) and reduces the first pressure to a second pressure lower than the first pressure. The expansion device (26) generates a first quantity of work and forms a reduced pressure fuel. A chemical energy conversion engine (16) is coupled to the expansion device (26) and receives a reduced pressure fuel. The chemical energy conversion engine (16) generates a second quantity of work in response to the decompressed fuel. In one aspect of the invention, the first quantity of work and the second quantity of work may be coupled to an output shaft (20) such as the crankshaft of an internal combustion engine. In another aspect of the invention, the first quantity of work may be coupled to an accessory (40) either directly or indirectly. Indirect coupling may, for example, be performed using an accessory drive belt of the internal combustion engine.