I just bought a Flashpaq last week from a friend who wasn't happy with it. He bought it for his 1999 Jeep Grand Cherokee mainly to adjust the tire size and for improved shifting. For some reason the flashpaq wouldnt let him adjust his tire size and he couldnt get all the benefits from the flashpaq that we can on our Jeeps. Needless to say I bought it from him cheaper then I would have found it anywhere else and absolutely love it so far. I measured my tires and adjusted the tire size through the programmer and my speedometer is finally dead on. It has been off for almost two years. After that I messed around with the 87 Octane tune but really wasnt all that impressed. It almost seemed like I lost a little HP/TQ however the transmission shifted a lot better then prior to the Flashpaq. I drove around for a few days and decided to try the 91 performance tune. There was a noticable difference of HP/TQ. My gas mileage has improved a few miles per gallon but I think most of that is due to the proper tire size being programmed. In the next few days I plan on messing with the transmission shift schedules to fine tune the shifts.