According to the article I read, the increase in mpg comes as the result of the acetone reducing the surface tension of the gasoline, leading to more complete vaporization and combustion. A solution of one or two tenths of one percent acetone in gasoline is not likely to hurt anything in the fuel system.
Yes, the guy comes across somewhat like a crackpot if you take the time to read his ramblings on line, but, he repeatedly says, "don't take my word for it, experiment for yourself". He's not trying to sell anything, I guess he may be an Acetone Industry Stooge. Maybe he owns a lot of Dupont stock. I don't know. I'm convinced it helps the CJ and I will keep monitoring fuel consumption to see if the apparent increase in milage drops off like you suggest, Fred.

I filled up the YJ today, the last mileage check shows 21MPG (8.3 gals to go 175.3 miles). Thats as good as I have ever gotten with the MPI 4.0. I added 4 ounces of pure acetone to the 20 gal tank. So far driving around town I have not noticed any difference in the way it runs, It's got power to spare so I can't tell if there has been any slight increase like I can with the CJ. Time will tell! If it blows up or melts down I will holler loud and clear on this and many other boards! <img src="/forums/images/graemlins/cheers.gif" alt="" />