Yes and obviously you can get away with a lot more on E85 or 110 leaded. Those fuels will tremendously reduce the chance of knock, allowing you to get very aggressive in timing while leaning out the afr. Some guys brag about how much timing and the low pulley size they are running but are hesitant to tell you what fuel that was on. A lot of people fail to realize this and think they can run such and such pulley and timing because "he" did it. Or fail to realize the geographic differences and ability to adjust their tune year round.
