Stanley Meyer believed that one gallon of water contains as much energy as many thousands of barrels of oil. This was based on the fact that a nuclear reaction releases far more energy than can be produced by a chemical reaction involving a similar amount of mass. In his Cold Fusion patent (#4,826,581), he specifies that completely ionized Oxygen which is subjected to additional HV pulses from a VIC will release an electron from the nucleus, accompanied by a considerable amount of explosive thermal energy. But the only way a nucleus can release an electron is through neutron decay, in which an electron and an anti-neutrino are emitted as the neutron reverts to a proton. As a result, the Oxygen atom transforms into the next higher element, with one additional proton, and the Oxygen atom itself dissapears. In nuclear physics, this is refered to as a Weak Force interaction (Low Energy Nuclear Reaction, or LENR), and isn't actually fusion. It's just stimulated neutron decay, which is still manytimes more energetic that burning hho.
The patent also specifies that heat from burning a fuel gas is part of the energy needed to produce the nuclear reaction, and that the 'atomic' energy adds to that of the combustion, resulting in Thermally explosive energy which is greater than the heat of combustion from the fuel. Since the dune buggy required such a small amount of input energy, together with a rather minute amount of hho, it's likely that some kind of Cold Fusion was involved in the operation. However, I can do this without fuel gas - just atmospheric gasses - using the HOT side of gotoluc's Open Source water sparkplug circuit, so Stan's Oxygen theory may not be accurate. He may have been producing some other nuclear reaction without understanding what was involved.