I was talking to a couple of guys who use acetone, they add about 2-1/4 ounces to 13 gallons of gas. One of them has done a lot of research and experimentation, they both claim about a 20 percent increase in mileage. According to them, the reason is that acetone breaks the surface tension of the gas, so there is better atomization of the fuel, so it's a more efficient burn. More gas is burned instead of going out the exhaust. Just what I have heard, I think I will try it.