Anyone tried adding acetone to their gasoline to increase fuel mileage? Any effect on the fuel tank? Yeah, I know, sounds like crap, do a web search for "acetone and gasoline". I have a buddy that's running the mix (3oz acetone - 10 gallons gasoline) in his Concours and picked 4 mpg. He is now running out his second tank on the mix, then will go back to straight gasoline and evaluate.