I was talking to my buddy, who meets many customers as he is an credit employee at Home Depot, (I use to work there). Anyways, he was talking to this retired engineer who has some mercury car with 325k miles on it getting 41mpgs and it runs strong still. He says he adds Lucas oil additive and he puts in 2oz. of acetone to every 10gals of fuel he puts in. He gets the acetone at the $1 store.
I did a quick search and came up with this info.
http://pesn.com/2005/03/17/6900069_Acetone/