A cheap way to get an increase of from 15 to 35%, mpg.
Using ordinary 100 % Acetone as a Fuel Additive 1 ½ oz. per 10 gallons
http://peswiki.com/index.php/Directory:Acetone_as_a_Fuel_Additive http://pesn.com/2005/03/17/6900069_Acetone/
For more just do search on Acetone MPG