well, im not gonna mention the typical replace air filter and spark plugs thing unless u ask. but on tip i recently found was 100% pure acetone. for every 10 gallons, pour in 2 oz. This guy put it in his car and had some gas mileage meter there, he started with 19 mpg. then he replaced the spark plugs and got 21 mpg, then the air filter, he got 24 mpg and when he put the acetone in, he got a whopping 34 mpg! i researched it and turns out to be true. it mixes in with the gas and makes it more cumbustible and burns the gas more complete. and i was wondering if it would damage ur engine at. it doesnt. some guy got engine compnents and submerged the parts in acetone and nothing happens over months and years. i put some this morning to test it myself. lets see if it really works.