Trim levels include the commercial-grade Work Truck (WT), the popular SLE, and the premium SLT that resembles a Yukon sport-utility up front.

The base WT model comes with a split vinyl bench seat (and split rear seat on four-door cabs), XM satellite radio, air conditioning, tire pressure monitors, and ABS.

Mid-level SLE models include all basic equipment and add cruise control, chromed steel wheels, electronic shift for 4WD, auto-dimming mirror and compass, driver lumbar, locking seat cushion storage, and leather-wrapped steering wheel. You can add fog lamps and interior upgrades such as cloth-upholstered power-adjustable front seats and redundant controls on the steering wheel.

SLT badges are reserved for the priciest Sierras, those with an interior modeled after GMC luxury utilities. These include as standard leather upholstery with 12-way power and heated front seats, two-person driver memory, heated windshield washer fluid system, locking differential, remote start, towing package, 17-inch aluminum wheels, and a Bose audio system with subwoofer.

The standard gasoline engine for all GMC Sierra HD models is the 6.0-liter V8, which rates 360 hp and 380 lb-ft of torque (322 hp for GVWR above 10,000 pounds). The sole option is a 6.6-liter Duramax turbodiesel, at 365 hp and 660 lb-ft of torque. A six-speed automatic is the only transmission offered.

Options include moonroof, satellite radio, navigation, snow plow prep, integral trailer brake control, remote start, a power takeoff (PTO). Determining exactly the right model and options will take careful and honest shopping because of the sheer number of choices.

Safety equipment includes frontal airbags, front seat belt pretensioners, ABS, and OnStar. Electronic stability control is available on many models.