As the owner of a 2007 Chevy Avalanche with a 5.3 flex fuel V8,I tried 4 oz. of Acetone with a full tank(31 gal.) and after 2 refills I got an increase of about 1.2 mpg. better milage. So far, I've gone thru almost 2 gallons of it and no problems. I figure sin... Login to read more.