[oil pan 4]

That's just my hypothesis based on reading the only creditable sources I could find (reading about U.S. army air core ww2 piston driven engines in fighters and bombers).
I'm just trying to reapply what they were doing 60 to 70 years ago to on road use. Make a high compression engine, that uses water to control detonation under high load. Then lean out the air fuel mixture going into the engine to cruise along and get as far as possible on a load of fuel, not using water while cruising along, because water is heavy and takes up room.
That is how I'm going to try to do it. But I'm using a high compression engine, large but not insane cam, file fit rings. I have built the engine around this idea that should work. If it doesn't work I'm stuck burning premium gasoline all the time.
But if you apply what I'm doing to a production engine I don't think it will do anything. Of you have one of those hot euro, jap, or domestic engines that requires premium gas and won't run on regular it could work.
Hopefully t vargo can find something that works on production engies. If anyone can legitimately make it work or prove that it doesn't on milder mass produced engines he is our guy.