The auto as said is bulletproof. It's basically the same Trans for the V6. Also as said, drains power I guess. Seemed slower getting to speed. Once there, seemed to hold it easier. Inertia I would imagine of the heavier torque converter assembly. Never had an issue with my 5 speed. When I got it, it had 280,000 miles on it, it belonged to a traveling salesman. I put some new GL4 in it, along with a Tuff Pan. Ran 30,000 miles without any issues, using 31's, 32's, and 33's. Still shifted smooth as silk when I gave it to the eldest son, him running 35's.