Your ignition does not constantly advance. It is a set map thru airflow, density and load. So you are not making anymore power with it. It is not advancing the timing enough to make the full potential possible. But if you are running forced induction then it is very beneficial. Just my two centsseth said:hey running ultra 94 in my car all the time is not a bad thing for it is it?
just makin sure.
Glauconite said:high octane = lower milage per tank...