The truck world moves a bit slower than the rest of the auto industry. That's because trucks are more about function than fashion, and if a truck works, there's not much point in messing with it. Which is why, typically, the life cycle of a truck is about double that of a car. Not surprisingly, only a small number of new or significantly upgraded trucks are launched each year.

Case in point: Only five trucks were eligible for the 2007 Truck of the Year title. And four of them were GMT900-based vehicles from General Motors. We had expected Toyota's all-new Tundra to be a contender, but the truck's launch was pushed past our January 1 deadline, partly because, say some observers, of last-minute changes to the interior to compete with the upscale interior GM is offering on the GMT900s.

To review, we judge all Truck of the Year contenders against our three key criteria--superiority, significance, and value--and not against each other. Naturally, some trucks are more work biased than others, so as part of the superiority criterion, we identify where each manufacturer has set its vehicle on the work/refinement continuum and determine how well each truck coped with the compromises in performance, ride, and handling that entailed.

This year we have five solid contenders--four are GM models (two share the SUV platform, two share the new pickup truck platform, and one makes its long-awaited second-generation debut). But there can only be one winner. Here's how we did the testing.

Day One: Track Day
We started with the regular battery of Truck Trend acceleration and braking tests. Each truck was tested unloaded and then loaded to three-quarters of its calculated payload capacity. To get the right payload, we weighed all the trucks (with a full fuel tank) and subtracted that number from the manufacturers' gross vehicle weight rating. We used two 350-pound water bladders in each truck and added 50-pound bags of rock salt as needed, and each truck was then retested.

Day Two: Payload Day
The trucks remained loaded for a full day of real-world driving that included stints on freeways in the San Fernando Valley and climbs up and over the Santa Monica Mountains on winding backroads. Here the judges were looking at everything from vehicle responsiveness in stop-start driving to handling and braking on twisting roads to ride comfort on freeways. Each judge drove each truck back to back over the same roads under the same conditions.

Day Three: Towing Day
We borrowed a boat and trailer from our friends at Castaic Boat & Marine and headed for a quiet backroad near Interstate 5 for back-to-back towing tests. In addition to driving each truck with the boat and trailer in tow, we also did some comparative testing, measuring the differences in acceleration over an eighth of a mile with and without the 6000-pound rig attached.

Day Four, Part 1: Drive Day
Off to Corona and a 35-mile loop that included most of the road conditions--everything from freeway to winding two-lanes to poorly paved asphalt to rutted dirt tracks--most truck owners would encounter. The trucks were each driven unloaded (as most are by most of their owners most of the time) by each of the judges back to back to rate performance, ride and handling, and refinement under typical, real-world operating conditions.

Day Four, Part 2: Judgment Day
A detailed walk-around of each truck reviewed features and equipment and checked build quality and functionality. The judges looked at fit and finish inside and out and ease-of-use and serviceability issues. Prices were checked for competitiveness and value quotients assessed. Then it was time to vote, each judge nominating the winner in a secret ballot. And this year, the result was unanimous.