Towing at the Milford Proving Ground

All of the pickup trucks in this lineup were set up for towing. GM hooked 10,000 pound trailers to the heavy duty trucks and 7,500 pound trailers to the standard duty pickups.

A portion of the test track includes a long, uphill grade. To start the test, we put two trucks side by side and took off from a stop on the grade to see how each truck performed with a trailer in the back. The return portion of the track was the opposite -- a long downhill grade, which showed us how well each truck's tow mode controlled its transmission and speed while descending.

I drove a Ford Super Duty diesel, a Dodge diesel, and a GMC diesel on this track. The Dodge and the Ford both pulled stronger at takeoff than the GMC truck. When the Dodge shifted into third gear, there was a noticeable drop in power -- the truck's third gear ratio was too high for heavy towing. The Ford pulled well up to about 65 mph, but seemed to level off after that -- keep in mind we're still going uphill. The GMC truck, while not quite as quick on takeoff, had the best high speed pulling ability.

I think at least part of the difference between the performance of the Ford and GMC trucks had a lot to do with the way each manufacturer programs its computers for power and economy.