I have 2010-F150 SuperCab w/5.4-V8, Trailer-Towing package.-3.73 rear end gears (Not heavy duty-3.55-4.10 gears). The truck has LT tires. TT- 2011 Rockwood Windjammer 3065. Loaded wieght 8350-lbs. 34'-10". We've pulled down Rt-15 (NY-PA) I-81S,I-77S(VA,NC)I-95 into FL. and back to NY. Big Mountain pull up I-77N (Fancy-Gap,NC) and several inclines on I-81N. We didnt have any problems pulling the TT, but it did slow coming up I-77N in Fancy-Gap, but we were able to mantain 45-50mph up that grade in NC.(Didnt over heat anything). No problem anywhere else!. We only drive 55-62mph even if the speed limit is 65 or 75. So take that into consideration. We dont push with that whale behind us!! Its been fun so far!