Dear gracious people at AquaTune, This is my second testimonial and I feel that you should know the extra fuel economy and hp I received out of your AquaTunePlus system. I drive a '95 Cadillac Deville with the 4.9L engine. Originally my mileage was 14mpg no matter what I did to improve it. With your standard AquaTune I immediately jumped to 22.9mpg, and I was ecstatic with that increase. However, I took the system off and gave it to my grandson for his Cadillac. The only difference in the two models is the color. I put the AquatunePlus on mine and I am now getting 37mpg on the straightaway! Uphill I am getting 35.2mpg. I also noticed that my transmission is not having to go into overdrive to go up the steep grades. What a fantastic product! The gas savings are phenomenal. Now I am going to order a downstream generator to add to my grandson's car so that he will also have an AquaTunePlus. Thank you again.