Adding acetone to your fuel for improved mpg?

[leopard]

As usual, snopes have an article on this subject:
http://www.snopes.com/autos/techno/acetone.asp

For goodness sake, even the US Federal Trade Commission agrees with me:
http://www.ftc.gov/bcp/conline/pubs/.../fuelalrt.shtm
[/b]

"Stay within posted speed limits. Gas mileage decreases rapidly at speeds above 60 miles per hour."

good article, I only found this limitation may vary, the more conservative rules said that it shouldn't exceed 70 kph or about 45 mph (?)

This optimum speed depends on engine capacity of the car, the bigger engine has relative higher optimum speed, the new car has higher optimum speed.