Abstract: A fuel supply system (1) is disclosed for use with an internal combustion engine or a fuel cell system (408). The fuel supply system may include a water supply (4) for supplying water; a fuel supply (3) for supplying fuel; a fuel reformer (10) including an air inlet (52,70) converts the water, air, and fuel into hydrogen and byproducts, and supplies the hydrogen to combustion chambers (2) of an internal combustion engine; and an injector subsystem (5) coupled to the water supply injects water into the combustion chambers following ignition of the hydrogen in the combustion chambers. The fuel supply system may include a water recovery subsystem (6) coupled to an exhaust output (9) of the internal combustion engine, the internal combustion engine producing an exhaust including water vapor and CO2, the water recovery subsystem comprising a filter (13) for removing CO2, from the water vapor.