Don't know about the 2010 but I just traded my 04 f150 4.6l tow pkg 3.73 re ( 4 speed ). Manual said to not tow with od on. I think also cautioned against using cruise. I was towing about 4000lb TT. Would do ok with cruise on in flats but not in hills. Truck never overheated , engine or tranny, but it did not like hills. Actually it did ok with 4000lbs but I did not like the lack of power in the NC mountains. It or I would downshift in mountains and the truck would do ok w/o overheating, but too stressful for me. I never towed 4000lbs with od on.