This works!! I've been using acetone in my vehicles for about two years now. It makes a difference in fuel economy, and I've experienced no ill affects. I've found that slightly less than 3 oz per 10 gal of gas works best and less is better. If you add more acetone than this your milage will decrease from the formula I've given. One time to use more than 3 oz is when going for a smog check as the extra acetone will give cleaner emissions.