: Be realistic and read the G-Tech instructions again. It explanes why the times obtained with it are looking better than the real times, and how the weight of the car is used in the formula. Are you sure you know EXACTLY the weight of your car? Do you change the input for weight of the car in relation to the fuel you're carrying? This makes a BIG difference. : A stock car will show REAL times around 6.3 seconds; the G-Tech will show 6.0 or maybe even just under. : With Jimmy's Dinan stuff a realistic REAL time would be 5.8/6.0 seconds, MAYBE 5.5 seconds with the other diff. : The G-Tech being optimistic and with maybe the wrong weight input will indeed show 5.0 seconds. But 4.7/4.8? You're not realistic. : The G-Tech is a good tool for "before/after" testing to check performance improvements. : So if you would find 1 second of improvement (which I seriously doubt) you're looking at a REAL 5.3 seconds. : Luc.