i have one , its not too comlicated, you have to do a base cal, and it cals itself when you out it on the windshield. (centering axis) you do have to put in weight, rpm shiftpoints, g's, # of cylinders, and some other stuff, but other than that its pretty simple. Another thing, the road has to be flat with no turns (for closest readouts). they say to do 4 runs and average them and the numbers will be real close. You can also dload the software from gtechpro.com and look at all your plots n stuff on a computer.