I have tried to read as much as possible on the subject of tuning. I have a 2500HD that is looking for a little more grunt. I'm seriously looking into Nelson. My dilema is for the long term reliability of a vehicle with a tune. The pick-up has less than 10,000 miles on it and I plan on keeping it for a long time. My concern is with the TM. I understand that if you take it out you can increase useable power and possibly some better mileage. However, isn't the TM what protects the tranny and give it long life? I don't pull very often, but when I do it is a heavy stock trailer loaded with about 12-14,000 #'s. If I eliminated the TM I don't think the tranny would like that, or am I wrong? Why would GM "detune" there vehicles if there is no problem with a mild custom tune? It would seem to me that better mileage and more power would be a huge selling point for them. Maybe I just paranoid, but I'm a stickler with maintainace and pride myself with getting alot of trouble free miles out of my vehicles by keeping them stock. Anyone out there have a pick-up with 100,000 miles on a custom tune? If the mileage truely does increase then that should easily pay for the tune's initial cost I would guess. Does the elimination of the TM give the increase in mileage? Also if you keep the TM is a tune even worth getting?