I've got to get back into this..... years ago I had a chance to get several hundred hours on a Dyno with an nice engineer... . I learned a lot and tested more stuff than I knew what to do with... . The big key item the engineer taught me was to ""TEST, DON'T GUESS"". Think through the theory of how it works, test it and decide after the before and after tests if the theory proves out... .
We had the ability to measure fuel flow to the engine and return fuel back to the tank... these were gasoline vehicles but the math hold true... and so does the physics formulas... we could duplicate road conditions for fuel and measure MPG... in all the stuff we tested, and I mean a lot, we never found anything you could add to the tank, but you could improve MPG by adding Slick 50 to the engine and transmission... . the tests proved it... but you lost the effect when you changed the oil... . thus no value at the time... .
On the other hand your adding an additional fuel... and we know that if you add propane, natural gas, or other combustible gas you can improve performance because of the excess oxygen in the combustion chamber... ... but, remember no one has really proven that your adding H2 and 0 as separate gases... . just that the water goes away, for all we know your adding water vapor which is nothing more than water injection... . and water injection will improve fuel economy, but only sightly... .
My basic chemistry tells me that you can't add stuff to water, and than add a heater and break down the gases..... I've asked a chemist this... or at least a chemical engineer that I know and he can't see it working either... .
Chemistry does tell me that if you take an acid, like what is in a battery and over charge it... . you release gases that will explode. . you see this with a wrench touched across the terminals of a battery when its over charged... but you get a lot of acid spilled around in the resulting explosion..... and the energy expended to release the gas is not acceptable to run an engine just to overcharge the battery.....
But I do suggest that someone take the time to TEST by doing the following... ... .
Any service shop uses an exhaust gas analyzer which can measure, CO - carbon monoxide, HC - hydro-carbon, and O2 - oxygen... a simple wave of the wand over the gases would register O2 or oxygen and HC - raw hydro-carbon... if its just water vapor, the EGA will show nothing... . as it can't measure steam.....
I'm just taking the time to visit with the engineers, and learn, I'm lucky to have them available.....
Just my thoughts... . BTW - I'd love to hear comments by Joe Donally on this issue... are you reading this thread Joe???