(MCT) -- If you have a small mountain to move, you may well be drawn to heavy-duty pickups. The four-star 2015 GMC Sierra HD 4WD Double Cab may well be your tool, or augmentation, of choice.
Heavy-duty pickups are among the most capable vehicles on the road. They're industrial grade haulers that offer creature comforts like ventilated seats and voice-controlled navigation and phone calls. Heavy-duty pickups get beefed-up versions of virtually every structural part and mechanical component of automakers' regular pickups, which are called "light duty" despite being able to tow up to 12,000 pounds, more than the average Indian bull elephant weighs.
Heavy-duty trucks are exempt from Environmental Protection Agency fuel economy tests and corporate average fuel economy ratings. Like UPS vans, semi trucks and farm tractors, they are considered commercial vehicles. They get a pass because they are classified as key to the U.S. economy, like freight trains.
Heavy duties account for a growing proportion of the pickup market. They're fabulously profitable and attract a surprising number of personal-use buyers in addition to the farmers, horse breeders and oil wildcatters you might expect.
Heavy-duty pickups are exclusively the domain of the Detroit Three. Chevrolet, Ford, GMC and Ram all build them. Toyota and Nissan don't.
The GMC Sierra 2500 HD has a wide range of wheelbases, bed lengths and drivetrains. It's available in rear- or four-wheel-drive and with a gasoline or diesel V-8 engine.
Prices start at $31,565 for a rear-drive two-door with a two-door cab, 360-horsepower 6.0-liter V-8 gasoline engine and six-speed automatic transmission.
I tested a four-door Double Cab SLT model with four-wheel-drive, diesel engine, leather interior, parking assist and many other features. It cost $61,485. All prices exclude destination charges.
Mechanically, the Sierra 2500 HD is nearly identical to the Chevrolet Silverado 2500 HD. The Sierra justifies a slightly higher price with a cushier interior, some extra features and unique visual elements.
The Sierra I tested competes with the Silverado 2500 HD Double Cab LTZ, Ford F-250 4WD Super Cab and Ram 2500 4WD Laramie Crew Cab.
The GMC is at the high end of the price range for those trucks.
All the HD pickups offer optional diesel engines and heavy-duty transmissions for more towing capacity and better fuel economy than the gasoline engines. The GMC's 6.6-liter, V-8 diesel produces 397 horsepower and 765 pound-feet of torque. The diesel and heavy-duty six-speed Allison transmission are an $8,395 option package. The other brands' HD diesels cost about the same.
While customers pay handsomely for the diesels, the fact that the EPA doesn't rate heavy-duty pickups' fuel economy makes it impossible to compare the vehicles accurately. The same goes for towing capacity. None of the manufacturers have yet adopted the SAE standard for towing, meaning that each student essentially grades his own homework.
The Sierra 2500's claimed towing capacity of truck is 800 pounds more than a comparable F-250, 50 pounds less than a Ram. The Sierra 2500's 17,900-pound maximum claimed towing capacity is greater than either Ford or Ram offers.
The Duramax diesel performs admirably in regular driving.
The Double Cab's interior is not as spacious as the crew cab, but the rear seat is more than serviceable. The front seat has plenty of room, a spacious bin in the center console and plenty of connections for power and USBs.
The interior materials look and feel great, with soft wraps for the dash and doors, brushed aluminum-look trim, a large touch screen and plenty of dials and buttons for easy use.
The 2500 HD is no picnic to park around town, but it's amazingly comfortable in everyday use.
It has enormous curb presence, standing so high that a man of average height must stretch to reach the top of an open hood. Women of average height will want the optional running boards for entry and exit.
With its bold GMC grille, LED running lights and bulging hood, the Sierra 2500 HD cuts an impressive figure on the road.
It's a fine truck for anybody who needs to haul industrial-sized loads.
2015 GMC SIERRA 2500 HD 4WD DOUBLE CAB SLT:
-Type of vehicle: Four-wheel-drive, heavy-duty, four-door pickup
-Rating: 4 (Out of four stars)
-Reasons to buy: Capability, comfort, features
-Shortcomings: Size makes it hard to park; no independent fuel-economy rating; towing capacity not tested to SAE standard
-Engine: 6.6-liter, 32-valve OHV turbocharged direct-injection V-8 diesel
-Power: 397 horsepower at 53,000 rpm; 765 pound-feet of torque at 1,600 rpm
-Transmission: Six-speed automatic
-Wheelbase: 144.2 inches
-Length: 239.3 inches
-Width: 80.1 inches
-Height: 78.0 inches
-Curb weight: 7,213 pounds
-Base price: $31,565
-Price as tested: $61,485 (excluding destination charge)