Reviewed By Christopher H (Berkeley Springs, WV) Reviewed for a 1998 Jeep Grand Cherokee —8/18/2007 11:22 PM
Not sure about the gas mileage inprovement, but can tell the increase in horsepower.
Reviewed By John M (Evergreen, CO) Reviewed for a 2009 Chevy Silverado —5/19/2011 4:28 PM
I ordered this Hypertech in anticipation of the upcoming increase in gas prices and to improve my HP and to finally adjust my speedometer for my 35" tires. This programmer did all of that and more. I had been taking careful records of my Mpg's and my acceleration times before the programer and after and found the following: 2009 Chevy Silverado 1500 w/ 7.5" of lift, 35" Goodyear MTRs and a heavy aftermarket bumper and winch combo. Stock MPG = 13.8 MPG after Hypertech programmer = 15.4 Acceleration to 65 mph up a steep hill at 8000 ft elevation (three run average time) Stock to 65 mph = 18.3 seconds, acceleration after Hypertech install = 15.4 seconds. I am no scientist but it was easy to figure this one out, it worked. It fixed my speedometer and allowed me to change my redline settings as well as bump up my top speed limit to 125 mph (god help me if I ever get going that fast on 35" tires). In all, I feel like this did what I was hoping it would do, you should get one.