How does a HHO generator work on vehicles?

Answer 1

The simple is that HHO generators don't work!

The idea behind the HHO generator is that a small concentration of hydrogen gas (between 2% and 5%) can increase the speed of the flame front, the leading edge of the burning gases in the combustion chamber. In turn, this would allow an engine to be run in a lean condition, allowing a higher compression ratio, thereby increasing the efficiency (by around 10%).

HOWEVER, the compression ratio of your engine is fixed. Even if the HHO device could provide the 2% hydrogen, running your engine lean would simply be running your engine lean. Without changing the compression ratio, you cannot increase the efficiency of the engine (without nasty side effects).

Yes. Real experts have indeed tested these devices, and they have been widely debunked. The most prominent test was a Mythbusters episode in which they tested and debunked several fuel saver schemes. Popular Mechanics has performed their own test of what many scammers would called a "super" HHO system guaranteed to produce results, and found that it did pretty much nothing. Further more, many of the HHO scams use the freely available HHO devices as a leader to hook people on far more expensive gadgets that don't work. Even though there are some convincing videos on places like YouTube, and testimonials on websites, to date, no qualified expert has been able to show any HHO device actually improving fuel economy. There is even a million dollar challenge to demonstrate a working HHO device which improves fuel economy that has gone unclaimed for several years.

There are applications in development and availabe to the end user that requires very little end user knowledge to install and operate. With the use of a pulse width modulator you can gain a great deal more efficiency from a hydrogen generator. The truth is these do work but you have to think harder than the naysayers.