Is adding 2 oz of Acetone to 10 gallons of gas safe to improve MPG?
Safe, probably. Improve MPG, almost certainly not.
It works for Louis LaPointe (look him up). It doesn’t do a thing for all the other suckers who believed him.
Oh no! Not this again!
Acetone not only won’t improve your gas mileage but could attack plastics in your fuel system. Don’t do this.