I am the owner of a 1988 Corvette coupe with appx. 19 thousand miles. The car is equipped with the performance package and is driven like most corvettes, a little hard. The best mileage I have ever got was 23.5 per gallon on a trip to Kentucky. Driving at the speed limit or maybe a little more. I put Microlon engine treatment and trans treatment in appx. May.1st. This year I drove to the muscle car drags in Stanton, Mi. in July 300 miles round trip and to my amazement I got 27.3 mpg at the speed limit plus a little more. The engine is smoother and the city mileage has gone up 2 to 3 mpg. The car is equipped with a computer read out on mileage, which makes it easy to know the mpg. It is easy to Recommend Microlon.