I'm not a scientist but this seems like a bunch of nonsense. They talk about HHO gas. What is that? H2O. Which we all know is water and what is water in the form of gas? It's called steam! I seriously doubt that too many gas engines would run very long on steam.
With all the tree huggers out there if this were true it would be trumpeted from all the mountain tops around the world. Not even the oil companies could pay enough to keep their mouths shut.