We tow about 6500 lbs. So far we have 4800 miles on our 1500, ecodiesel, 2600 towing. No problems, transmission maintains speed and temps through all conditions. Always tow in tow/haul mode, milage towing arround 14mpg, when not towing in mixed driving ,about 50/50 it delivers a solid 22 mpg us.so far so good, We have the air suspension and the ride is great. You do have to be cautious about weights in the bed. Overload it and you will get an engine warning light. Although we ordered a 3.92 rear our truck was delivered with the 3.55. Again so far so good.