I'm on my third tank with acetone. I am using 1 oz per 5 gallons. The first tankful I used 3 oz with the full 18 gallon tank. I filled up with 11 gallons and I added 2 oz, last night I filled 15 gallons so I added 3 oz. My car gets about 20 mpg average, so it is easy to figure out. I pour the acetone into a lucas fuel additive bottle at homne and the dump it in just before I fill up. My MPG is as follows.
1st tank 19
2nd tank 20
3rd tank 20.5
Don't read to much into these figures as the weather is warming up here, so teh car may be getting out of "warm up mode" sooner