Well to take things from a chemistry standpoint...the difference btwn octance ratings is the length/makeup of the hydrocarbon chains, b/c thats just what fuels are n-ane hydrocarbon groups that when pressurized and/or ignited they combust. A 93 octane would have a longer chain, and therefore a higher heat of combustion, which means a longer lasting fuel in the chamber. Longer lasting in the chamber = cleaner burning (this is why its good for S/C and T/C engines, is b/c it maximizes the fuel/air burn ratios). SORRY I'm done now just wanted to throw that out for anyone that was wondering!