Just a quick note to let you know that after you installed the system on my ‘89 Chev. Celebrity my mileage increased from about 19 mpg to 27 mpg. I was more impressed to see the immediate increase in horsepower & smoothness. Thanks a lot, Dean H., Salem, OR P.S. - No more hesitation, either! 8/1/00Dear AquaTune,I did not get the 30% better that you had estimated instead I got 32% better. What a neat system you have. Love it. The horsepower is great. I've been telling all my friends about this.