The Sierra is mostly unchanged for 2014. Axle ratios have changed slightly on gas models, and the 6.0L bi-fuel engine is available in the 2500 crew cab. A spray-on bedliner is also available.
The GMC Sierra 2500 and 3500 heavy-duty pickup trucks come with a 6.0L V8 engine standard, though a 6.6L turbo-diesel V8 is available. In 2500 crew cab models, a bi-fuel version of the 6.0L V8 is a no-cost option and operates on gasoline or compressed natural gas. All Sierras come with a heavy-duty 6-speed automatic transmission. The 2500 and 3500 can be had as either a regular or crew cab, with a standard or long bed, and with either a 2- or 4-wheel drivetrain. Dual rear wheels are available on some models. There are four trim levels: Work Truck, SLE, SLT and Denali.
The 6.0L V8 engine is capable of 360 horsepower and 380 pound-feet of torque (301 hp and 333 ft-lb when operating on compressed natural gas. Meanwhile, the 6.6L turbo-diesel engine puts out 397 horsepower and 765 pound-feet of torque. When properly equipped with the diesel engine and fifth-wheel tow package, the 3500HD is capable of towing more than 23,000 pounds.
The Sierra HD features a high-strength frame and heavy-duty front and rear suspension systems. Rated at 6,000 pounds, all 4-wheel drive front suspension systems can easily support a snow plow when properly equipped. There are two suspension packages available for the 2500: the Z85 handling and trailering suspension and the Z71 off-road package, which adds high-performance shocks and a bigger stabilizer bar.
Some standard features cross all Sierra trim lines, such as driver and passenger air bags, 4-wheel disc brakes with anti-lock brakes and tire pressure monitoring. GM's OnStar system is standard on the SLE trim and better. The system includes crash response, roadside assistance and remote door unlock services.
The Sierra Denali brings the Sierra HD pickup's towing/hauling capabilities in a luxury and style-oriented package. The model is available in both 2500 and 3500 trim and both 2-wheel and 4-wheel drive, but only as a crew cab. The Denali comes with heavy-duty trailering gear, an electronic shift-on-the-fly transfer case on 4-wheel drive models, special wheels, body-color panels and molding and chrome trim, fog lights, power, heated mirrors, a high-performance Bose audio system and leather power-adjustable seats.
Equipment availability is dependent on trim. Pretty much anything available in a pickup is available on a Sierra -- power everything, remote keyless entry, heated mirrors, privacy glass, bed liner, front tow hooks and chrome or aluminum wheels are all available across the lineup. Navigation is an option as is rear-seat entertainment for the crew cab models. Heated power seats are available, as is cruise control, sunroof and a rear window defogger.
High-tech touches such as a rearview camera and rear parking assist are optional, too and would probably come in handy on a big truck like the Sierra. MP3-compatible stereo with XM satellite radio can be found on some models and a Bose system with USB interface is available.