Hydrogen power might be just down the road

If it was possible to get a net energy gain through the electrolysis of water into Hydrogen & Oxygen, our cars would run solely on water, No? How can you use fossil fuels to decompose water, burn those constituents with the fuel, and get "better" fuel performance??

The blurb gives the impression that the hydrogen improves combustion efficiency. I would suspect that the combustion efficiency in a modern diesel engine is somewhere around 99%, in that 99% of the fuel is converted to end products of mostly water and carbon dioxide. Which does not leave much improvement there. With direct injection, the ratio of fuel to oxygen is set. Putting hydrogen into the mix could upset this ratio and possible result in incomplete combustion. If the claims are true, somehow the hydrogen must improve the conversion of combustion energy to mechanical energy. Diesel engines achieve up to 35% mechanical efficiency, the rest of the energy being the lost as heat in the exhaust, water jacket and oil lubricant.

I did hear of a patent for a car which does just this - runs on water that it. I believe the rights to the patent were bought by Ford who have declared the technology "uneconomic".

I wonder why they paid for and continue to hold the patent rights then?

I likewise encountered a similar product a few years ago that unfortunately ended up in the hands of a couple of 'BIG marketing types' that turned it into a VERY pricy & dicey pyramid scam. The device is exactly what you describe and would be relatively easy to DYI &/or produce & sell for anyone relatively handy and knowledgeable. From my general understanding, I'm skeptical that 'the math is there'. Given the inefficiency of electrolysis to start with, the relatively small volumes of hydrogen and oxygen produced, though this can of course be scaled up: within reason - power limitations etc (Drive your Arc Welder TODAY!) This being related to some of my own areas of intense interest, I requested and received the ~ 75 page technical report including lab & field tests [primarily heavy duty, long haul diesels]. As doubtful as I was, the results WERE there! Perhaps some sort of 'leveraging' or ??? was at work! I was impressed enough to be willing to spend the $300 ~ $400 Canadian to 'become a distributor' which I hoped sincerely to sell the units to the great benefit of many if it proved out to be anywhere near what the claims and data foretold. I would put the unit that I bought along with my distributorship on my own vehicle first and see what, if anything happened. In a matter of less than two weeks, the 'entry fee' became a 'required weekend training seminar' at over $8,000 US! As you can imagine, that was the end of that. Which IS a pity if it somehow turned out to be true. Similarly the emissions were significantly reduced and it makes it perhaps very important for this to be brought to fruition. I've thought about trying it on my own vehicle; especially when I had an old Honda CVCC Civic wagon: i.e. an old rattler that wasn't complicated or computerized (anymore). Their device was very simple: 1 – A thin walled (high temp)plastic bottle, with a readily available & replaceable electrolyte: water (& antifreeze as needed). 2 - Two replaceable electrodes (anode and cathode). 3 - A current amplifier/control that increased the power to the electrodes (cVdc) as the throttle opens (alternator field wire for control perhaps). On the removable top: 4 - A small vacuum hose connects to a hole drilled in the (cleaned) engine air intake (just up stream of the mass air flow sensor) and thus injecting the hydrogen & oxygen gases into the air(/fuel) mixture. 5 – A small hole in the lid to help control the quantity of this mixture being drawn into the engine and to vent any residual gasses accumulated &/or generated when the engine is off. The volume above the electrolyte being kept to a minimum to reduce accumulation of the now explosive combination of hydrogen & oxygen gas. A tall skinny container is thus likewise used. You can see that this could be done relatively easily by a great many DIYers as well as a fairly readily producible low cost product at even small volumes. It would be wonderful if it turns out to be true and valid. I also have a development path (for heat engines) utilizing water: Starting with immediate significant improvements in (mostly) existing technology. Eventually it will hopefully ultimately come to full fruition when it results in a process that will facilitate the VERY efficient conversion of liquid water directly to (burning) hydrogen & oxygen gases resulting in the production of heat (work), the consumption of some of the water (conversion to energy) and exhaust only some heat and water (vapor) which could then be scrubbed out of the exhaust and reused. The ready possibility of utilizing this process for fuel cells as well as heat engines likewise exists.