I've read a lot of conflicting things on this (thank you internet) and I am curious to know what people here think. The consensus seems to be that running an engine lean results in higher overall engine temperatures which can lead to weirdness in the combustion chamber if left unchecked. What I want to know is what effect HHO has on combustion temperatures when running on the leaner side using gasoline. My application is an older truck, 302 V8 with a 2bbl carburetor naturally aspirated. I've never worked with HHO before so I'm not really sure where my goals are with it - this is mostly just an experiment sort of thing to see what happens.