HyPower fuel was formed in 1996 to develop new methods of hydrogen production and delivery for vehicles. Over the last ten years they have worked on improving the efficiency of the electrolysis process for producing hydrogen. Electrolysis has long been the easiest method of producing hydrogen from water. However, it takes a substantial amount of energy to do the electrolysis. HyPower has now developed a system they call the Hydro Power Pak. This is intended as a transitional technology to help reduce both fuel consumption and emissions.
The system is designed to be retro-fitted to tractor-trailers and generators. They use a water tank with an on-board electrolysis system to produce hydrogen and oxygen on the fly. The hydrogen is then injected into the fuel stream of the engine to supplement the diesel or gasoline fuel. The hydrogen injection should definitely be effective on the engine side. They claim 10-25% improvement in fuel efficiency which, depending on how much hydrogen they inject, may be plausible. HyPower is not saying much about the electrolysis system and the test report links on their site don't seem to work. Presuming that they are taking power for the engine to power the electrolysis system, it seems unlikely that there is actually a net improvement in fuel efficiency and in fact a reduction is more likely.
HyPower have announced that the US Defense Department has expressed interest in the Hydro Power Pak system. They want to investigate the possible purchase and installation of the system on the US Army vehicle fleet. More than likely the Army will find that the HyPower system will be about as effective as cold fusion and all the perpetual motion machines.
[Source: HyPower Fuels]