We live in Southern California and in the last years have gone to Oklahoma City twice, southern Colorado once, and Yellowstone once. Our 2012 Ram 2500 w/6.7 CTD and a 68 tranny does magnificently towing our 32ft Montana (not the lightest of beasts). Peak HP and torque is as most folks are saying 1800-2000 RPM. I have an Edge Evolution tuner and have a economy/towing power setting loaded. We drive along like there's nothing behind us at all. The most shifting I do is manually dropping to 5th on some climbs just so the tranny doesn't shift back and forth, as they're prone to do at times. I have noticed my pre-turbine exhaust temp edging up to 1000F deg when flat and cruising at 65mph in 6th, manually dropping to 5th causes the temp to drop into the normal 700-800 range.