A quick Google search is all that is required to find hundreds of stories of people who claim to have increased their fuel mileage by installing a hydrogen generator which extracts hydrogen and oxygen from water and funnels the gas into the engine. Some of the claims are pretty wild, and the Japanese company Genepax has again lit a fire under the topic of running a car on water. While the Genepax car uses a conventional fuel cell, most of the "kits" available on the Internet introduce a bit of gas into the engine which is then combusted along with the liquid gasoline.

It is, of course, natural to feel a desire to buy into the hype promised by these systems. The truth, though, is that large fuel economy gains are highly unlikely. Popular Mechanics has decided to build themselves one of these systems for testing. The mag intends to install the finished product in an automobile and report back. We're keenly interested in their findings, though we're pretty sure we already know what will happen. Stay tuned.

[Source Popular Mechanics]