A hydrogen generating apparatus and control system for use in an internal combustion engine of a vehicle for increasing the efficiency of the engine and decreasing emissions from the engine in a safe manner for a moving vehicle, having close-spaced metal electrolysis plates in the generator housing, configured to inject hydrogen into the intake manifold or alternatively into the combustion chamber, and monitoring and controlling gas level, liquid levels, temperature, pressure, flow rate, electric current, and tachometer, with monitoring and overriding control from the cab of the vehicle.