CAPABLE HANDS; At work or at play, GM's HD trucks offer a smorgasbord of choices.(News)

Byline: ROGER HART

Rolling along through the countryside northeast of San Diego aboard a Chevrolet Silverado 2500HD, it was difficult suppressing the urge to head off-road, find an old barn and yank it out of the ground-just for kicks. Driving a big truck with 660 lb-ft of torque at your disposal does strange things to a man's mind.

"You have the feeling of driving something enormously capable,'' said General Motors product guru Bob Lutz, on hand at the launch of the 2007 Silverado and GMC Sierra heavy-duty pickups. Bob's right.

Thoughts of heavy-duty trucks may not cross the average consumer's mind, but Lutz's presence spoke volumes about the importance of these vehicles to GM. Big trucks make big bucks for the company, and the heavy-duty segment is the last remaining battleground populated only by GM, Ford and Chrysler (Dodge). How long it will stay a Detroit-only party remains to be seen, but Ford, with the release of its new Super Duty line ("Gloves Off,'' AW, Feb. 19), and GM are not taking their truck customers for granted. The Silverado and Sierra HD models were pulled ahead by more than three months to square off against the new Fords.

Heavy-duty-truck buyers are a loyal bunch, and while the segment is not necessarily recession-proof-big-truck sales are dependent on the housing market, where more contractors working means more trucks sold-but they're not as susceptible to the up-and-down whims of the consumer market. In recent years, the heavy-duty line has seen an increase in buyers who make the purchase to pull trailers for recreation-for travel trailers, livestock trailers or any assortment of big toys. If you've got a big load to pull, a heavy-duty truck is better fitted for the job than even a big SUV. To that end, making trailering easier, the new GM trucks have an optional factory-installed brake modulator, matching what Ford offers. Maximum towing is 16,700 pounds for trucks fitted with a fifth-wheel hitch, 13,000 pounds with a conventional hitch.

Both the Chevy and GMC HD trucks look like enlarged cartoon versions of their handsome half-ton siblings. The trucks have distinctive sheetmetal while sharing components beneath the skin. There are two powerplants to choose from, with a 6.0-liter V8 making 353 hp and ...