What kind of terrain? The same load in Florida is a LOT different than even where I live, lots of rolling hills. Going even more mountainous, and it makes a difference. For what it's worth, the engine in this truck has more horsepower than any previous PSD that ford has offered. The new 6.7 is only a few hp higher. The real difference is the torque, but these transmissions are geared fairly well, with a good steep 1st gear-so getting big loads started is not such a chore. I can only speak from experience of about 5-6,000 lbs towing with this truck so far, but I can assure you, I practically forgot the trailer was behind me. If you are in a position where you have the financial ability to switch to a new truck, I honestly do not think you would regret it. Just my 2 cents.