From the Editors:
Before you concede that the Power Stroke had the deck stacked against it because the Duramax had a steeper rearend gear that would help it out in acceleration, keep in mind the gear ratios of both truck's six-speed automatics. The GMC's Allison 1000 transmission has ratios of 3.10, 1.81, 1.41, 1.00, .71, and .61. The Ford's 6R140's gear ratios are 3.97 2.32 1.52 1.15 .86 .67. Multiplied by each of their rearend ratios to get the final drive ratio, the GMC was at 11.56, 6.75, 5.26, 3.73, 2.65, and 2.28, while the Ford was at 14.09, 8.23, 5.39, 4.08, 3.05, and 2.37. That explains how the Ford was able to feel quicker off the line, but it should have had an acceleration advantage at every gear. The fact that the Duramax/Allison transmission was able to level the playing field despite the Ford's gearing advantage was why we picked it as our favorite powertrain combo.
By now, there are probably several of you out there reading this article wondering why we nit-picked so many little aspects of these four trucks. The reason is that we had to search to find faults in each of them. Maybe 100,000 miles of hard work will separate them further as little annoyances become serious pet peeves, or squeaks and rattles show up, but after a week of driving the trucks we had no real major complaints. Even small quirks that some drivers didn't like were appreciated by other drivers, so take our review as a stepping-stone to make your own call.
How we got our numbers:
We mounted a Racepak G2X data logger to our Suzuki Equator that was strapped to our Jimglo trailer (jimglo.com) to eliminate the variable of different mounting locations from truck to truck. The Racepak G2X uses GPS signals to track the location, speed, and acceleration of the vehicle. It can do much more, but for our purposes, that's all we needed. We compared the acceleration times on each truck from the same section of highway with the same grade on the same day. All tow tests were done using Softride's new Quietride anti-rattle aluminum ball mount with locking hitch pin. Visit softride.com to learn more.