I have a 3875. Complete garbage on mine. Tried running the 87 tune and it made it a couple hundred miles and started pinging. I ran the mileage tune for a bit but not long enough to determine any MPG gains. My tuner has said "cannot detect key on" and lost communication with the ECM multiple times and basically froze itself up. The first time it did that, a couple days later my FDCM wigged out, caused major problems, and had to be completely replaced...coincidence, I don't know. After this last time the Jeep threw 11 codes. I bought the trans app and their system didn't recognize it, a tech had to force it onto my tuner. The only thing mine is good for is tire size changes and clearing 4WD codes. Needless to say I have no trust at all in SC and run mine stock.
2007 XK Limited