I've been doing some research and have found in multiple readings of a ratio for advancing timing based on octane. The ratio I've found ON AVG was 1 degree of advance required .5 to .75 increase in octane. So for ex an 06 10 is suppose to use 90 octane (although I believe manufactures play it safe so 89 maybe 88 would be fine for stock) if you increase the octane to 92 then using the 1 degree to .5 octane increase ratio you could safely advance the timing 4 degrees. If we go back to some old posts from Ivan where he mechanically advanced the timing 4 degrees (by slotting some plate) and said it was fine on 92 octane without pinging it works out. Anyway just wondering if anyone else knows of this ratio between timing advance and octane ratio?