In a short word, YES- adding 1 oz of acetone per every 10 gallons of fuel does help your gas mileage! I know, people are on both sides of the fence on this discussion, but I have personally used acetone in 3 different vehicles over a period of 18 months and have seen improvements ranging from 1.95% to 3.80%.
The success of this is using 1oz of acetone to 10 gallons of gasoline. NO MORE and NO LESS. I do not care what the results of the Mythbusters Episode showed (I watch them too, but they goofed on the ratio during their tests) and I can verify these results with a Scangauge II. I do highly recommend the use of this product and it shows your true- real-time mileage as you drive. No guessing or math calculations, you see your true gas mileage! For under $200.00 it's well worth the cost if you are serious about improving the gas mileage of your car.