P.T. Barnum had a comment about people who use gas additives. A 5% mix of Diesel fuel/Gasoline will bump the octane number up a few points, if you're running compression above 9:1. It raises the specific gravity of the gas and slows down the burn rate for less detonation. I gallon of Diesel to 19 gallons of gas.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!