We always stress that Motor Trend's "of the Year" programs are never straight-up comparison tests, but rather evaluations against our six key criteria (see below). But this year's battle for the Truck of the Year calipers came as close to a direct comparison as it gets.

In stark contrast to last year's free-for-all, which included a Baja racer; a unibody, front-drive mini-vanette; and two contractor-grade work trucks, this year's program was all about the heavy-duty haulers.

Three trucks qualified for 2011, all heavy-duty variants of established players in the full-size segment: the Chevrolet Silverado Heavy Duty, Ford F-Series Super Duty, and GMC Sierra Heavy Duty. All we needed to make this one of our standard comparison tests was the Ram Heavy Duty, but it won Truck of the Year 12 months ago.

As we did last year, we elected to bring two variants from each of the qualifying brands. Along with three gas-powered single rear-wheel trucks, we selected a turbodiesel, double cabin, and a dual rear wheel ("dualie") variant of each, for a total of six trucks.

Heavy-duty trucks demand heavy-duty testing, so we headed to a world-class vehicle-evaluation facility just outside Phoenix, Arizona, with a professional, knowledgable and helpful staff. Nissan's Arizona Test Center is a top-notch testing facility utilized not only by Nissan and its related companies, but also a number of well-known automobile and motorcycle manufacturers and suppliers on a contract basis.

In addition to our standard complement of acceleration, braking, and handling tests, we also performed acceleration tests with giant sandbag payloads ranging from 2000 to 4000 pounds, depending on the truck. We also evaluated the towing ability of each truck with 7000-pound trailers for the gasoline trucks and 12,000-pound trailers for the diesels. After the empty and laden test regimen, we ran all the trucks back-to-back through a driving loop that incorporated many of ATC's varied driving surfaces. You can see a more detailed description of the test surfaces and our handling loop in the graphic at right.

Along with the testing performed at ATC, the trucks were evaluated in the real world, on a rotating schedule, during the roughly 350-mile drive from Los Angeles to Phoenix.

After all the timing and testing, sandbag loading and note taking, we sat down to discuss the test results, review our driving impressions, and debate our individual selections. Then we put it to a vote. Read on to see which truck we chose, and why.