I'd like to think I have an open mind on this subject...and I'm willing to try it out. However, since I know nothing of chemistry, or combustion, or whatever else is required to fully study this, I question a couple of things. Could there be a hidden reason for the 2 to 3 mpg boost? Maybe the reason doesn't matter, only the end result. Anyway, does acetone actually add energy to the fuel, or does it act as an additive and make the fuel components operate cleaner and smoother? One post I saw on a link shown above claimed Seafoam had acetone in it. I Googled the ingredients (ingredients are only given in CAS numbers) and it appears that acetone is NOT in it. (it has aliphatic naphtha, hydrotreated heavy naphthenic, and isopropanol). However, acetone may still be an effective "additive"...it's just a much cheaper additive than something you buy at the autoparts store.
If acetone adds energy to the fuel, then that's really cool. If it's just an effective additive/cleaner, that's a good thing too, since it's cheap. Two to three mpg is worth the effort. However, I would think the fuel and the engine can only get so clean and the benefit would diminish over time.
