Used 2006 GMC Sierra 1500HD

A powerful drivetrain and stout underpinnings make the Sierra 1500HD (and its Silverado twin) a good option for buyers who like the size of a half-ton pickup but require extra towing capacity. If you don't plan to tow, the Nissan Titan and Dodge Ram are better overall trucks.

GMC's full-size pickup has been around in one form or another since the early '60s. Now into its sixth generation, the Sierra, as it's now called, boasts classic styling and a variety of body styles and drivetrains. A perennial competitor to the full-size offerings from Ford and Dodge, GMC now positions itself as the professional-grade truck in GM's lineup. Although its sales numbers are far below those of its competitors, when combined with its sister vehicle, the Chevrolet Silverado, sales of the two trucks outdo the F-Series.

The half-ton Sierra presents a compelling package for anyone in the market for a well-rounded full-size pickup. With a class-leading tow rating of 10,300 pounds, the Sierra 1500HD is the way to go if you need all-out towing capability in a light-duty pickup. In fact, the HD is a nice compromise; the work capabilities of the truck are close to those of the 2500-series pickups, and the day-in and day-out livability is just as good as a regular 1500.

The Sierra is really starting to show its age, however, compared to the newer full-size offerings from Dodge, Ford and Nissan. The F-150 trumps the Sierra in terms of ride comfort and interior design, while the Ram and Titan boast superior overall refinement, not to mention outstanding V8s of their own (though neither match the 1500HD's tow rating). And all three surpass the Sierra when it comes to interior design. Unless towing capacity is your primary reason for buying a Sierra 1500HD (or its Silverado twin), we would encourage you to try out the competition before you buy.

The Sierra 1500HD comes in the crew-cab body style only, and is available in three levels of trim: SLE1, SLE2 and SLT. Intended as a truck for recreational use rather than hard-core work duty, the crew-cab configuration provides a spacious passenger cabin without the harsh ride typical of most workhorse crew cabs. Well-equipped SLE1 models include cruise control, keyless entry, an AM/FM/CD stereo, dual-zone manual air conditioning and a driver message center that monitors multiple vehicle systems. The SLE2 adds automatic climate control, a power driver seat and Bose audio. The SLT includes dual 10-way power heated leather seats, a six-disc CD changer and alloy wheels.

Under the hood is a 6.0-liter V8 rated at 300 horsepower and 360 pound-feet of torque. While these used to be impressive numbers, Dodge, Ford and Nissan all offer V8s with as much or more power. Handling the shifting needs of the 6.0-liter V8 is a heavy-duty four-speed automatic transmission. With overdrive and a tow-haul mode that adjusts shift points for better performance under load, this transmission-engine combo allows the 1500HD to tow up to 10,300 pounds, the highest rating of any half-ton pickup. Larger four-wheel disc brakes borrowed from the three-quarter-ton lineup assure that you'll be able to haul the load down to speed as quickly as the burly V8 engine gets it going.

The Sierra's dual-stage front airbags deploy with varying levels of force depending on the crash severity, while the passenger sensor will deactivate the passenger-side airbag if it detects the presence of a child. All Sierras include four-wheel antilock brakes as standard equipment. In IIHS frontal offset crash testing, the GMC earned a "Marginal" rating (the second lowest on a scale of four).

Despite its hefty tow rating, the 1500HD is still comfortable enough to be a daily driver. The big V8 provides swift acceleration and the heavy-duty automatic transmission shifts with authority. The steering feels vague on center, but it's light and precise enough for easy maneuvering. A combination of torsion bars up front and leaf springs in the rear give the Silverado a comfortable, if not refined, ride in most situations.

Inside, Sierra buyers will find a logically laid-out interior, with easy-to-use dual-zone climate controls and clear, uncluttered gauges. Materials quality is unimpressive, and build quality, though improved over the last few years, is still behind the competition. The large cabin offers room for six passengers if you stick with a front bench seat. The Sierra also offers an optional Bose audio system and XM Satellite Radio, as well as a rear-seat DVD entertainment system.