[dcb]

ok, but how do you account for the energy that goes into making pure high pressure O2? I doubt that was accounted for in the %70 efficiency figure, correct me if I'm wrong azmio.

But if you had to replace your throttle body and intake valves and air filter with something that could make enough high pressure O2 to keep the engine running, i think you will find that it is much less efficient.

Trick is getting it to work with AIR, I don't think you can expect cars to carry O2 bottles or make their own efficiently.

But without some way to compare the total energy needed, there is no basis for a comparison. The doc mentioned that it was "cheap" to make o2, but that isn't the same.