I've held back on the intune tuner myself for the same reason, I was a Ford dealer tech and I know we could see a lot more than people thought we could. I was told by diablo reps they leave no water marks but, I know GM better than that and figured the data logs were deeper than tune guidlines. Your post proves it; Any links to the range module you sited? I see your link above, but on the link you post the only thing I can see that module doing is increasing the use of AFM. I want to shut it off, my dealer said they could not when I asked.