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 Charles C (Marquette, MI) Reviewed for a 2007 Jeep Grand Cherokee —4/1/2015 7:07 AM
I was super stoked on when this arrived. The first tune was 91 Performance that I used. Holy cow my Hemi was another animal in sound, and it was a lot faster and K and N intake helps. But when i put it in eco mode i get worse gas mpg. and the shifting is touchy around 2,000 RPM. It jerks pretty ofter when i'm driving. They really need to fix that especially for Eco mode. Pretty disappointing Because I think it is over priced.And shirting is what you notice the most, its not like im flooring cons