Used 2015 GMC Sierra 2500 HD Double Cab

When you need a full-size truck to haul heavy objects, the muscle provided by the 2015 GMC Sierra HD will be more than sufficient. Like the 2015 Chevrolet Silverado 2500 and 3500 HD, the Sierra HD is General Motors’ other answer the Ford F-Series and Ram HD trucks. Both the Sierra 2500 and 3500 HD offer you the choice of a 6.0-liter V8 gasoline engine or a 6.6-liter Duramax turbodiesel V8, as well as rear-wheel-drive and 4-wheel-drive configurations. The choices go on from different cab configurations and bed lengths to trim levels. Even though it’s not the best heavy-duty truck in its class, the Sierra HD offers plenty of muscle to get the job done.

When we spent some time with the 2015 Sierra HD, the drive route consisted mostly of long highway stretches and the miles slipped by thanks to the spacious cabin and a drivetrain that did its part to keep quiet. After a few hours of seat time with and without a trailer in tow, we never felt worse for wear. After we had our fill of towing everyday things like the fifth wheel, we hooked up to a trailer carrying 10,000 pounds and drove GMC’s heavy-duty truck up and down a steep grade, rising as high as 5,000 feet above sea level at one point. The full-size Sierra HD demonstrated that it can control just about anything you’ll ever need to tow. Each trailer had minimal wag, and the 6-speed Allison automatic transmission (paired with the Duramax) working in conjunction with an exhaust brake kept everything under control going downhill.

Major restyling points go to the 2015 GMC Sierra HD interior, and it was achingly overdue. The base model brings basic amenities like a front split-bench seat, air conditioning, and power windows and locks. Move up to the SLE and you’ll get features like a leather steering wheel and rubberized vinyl floor mats. The top-tier SLT trim offers everything mentioned plus dual-zone climate control, a high-capacity air cleaner, and a suspension package. Then there’s the Denali trim, which is GMC’s halo trim across the board. It brings things like contrast stitching, perforated leather seats, and aluminum trim on the instrument panel.

Besides the interior, the Sierra HD’s exterior styling is a major change for the 2015 model year. Like the interior, the exterior styling of the Sierra HD now more closely reflects that of its light-duty offering. Headlights with LED running lights, a more prominent grille (a common theme in the pickup truck segment, lately), CornerStep rear bumper, and a raised power-dome hood are some noticeable new additions when just looking at the Sierra HD. The same two models, the 2500 and 3500 heavy-duty, are still offered.

INTERIOR
An all-new upright instrument cluster features six gauges and a slew of large, easy-to-use rubberized knobs responsible for various things like climate control and radio volume. Ambient lighting illuminates all of the vital switches in the cabin, making each easier to locate when driving at night.

6.6-LITER DURAMAX ENGINE
Paired with a 6-speed Allison automatic transmission, the Duramax turbodiesel engine runs strong and quiet, all while providing power on demand in an even fashion.

With the base Sierra HD truck, you get a robust V8 engine, antilock disc brakes, air conditioning, and stability control. An automatic locking rear differential is also standard on all Sierra HD trucks with the exception of the 2500 HD base model. Climbing up the trim ladder brings you leather seats, steering-wheel-mounted controls, and Bluetooth. Both Sierra 2500 and 3500 HD models equipped with a Duramax engine also get an all-new electric assist heater, which helps to warm the cabin quickly.

The 6.6-liter V8 Duramax turbodiesel engine is, without question, the option to get when outfitting your 2015 Sierra 2500 or 3500 HD. Going with the Duramax engine and 4-wheel drive will save you some major headaches in the future. Other notable options for the 2500 and 3500 truck include a touch-screen navigation system, an EZ-Lift tailgate, and a snow-plow prep package.

A 6.0-liter V8 gasoline engine or a 6.6-liter Duramax turbodiesel V8 engine provide power to the 2015 GMC Sierra HD. A 6.0-liter V8 powered by compressed natural gas (CNG) is also available, if that’s how you roll. Rated at 360 horsepower and 380 lb-ft of torque, the gasoline engine is stout in its own right, but the Duramax diesel is the real star of the show. Power numbers for the 6.6-liter Duramax turbodiesel V8 check in at 397 horsepower and 765 lb-ft of twist. The Duramax engine also brings an exhaust braking system that helps keep the Sierra HD’s speed in check going downhill. A 6-speed automatic transmission reports for duty with either engine, but the Duramax gets the added shift-technology benefits of an Allison 6-speed automatic.

6.0-liter CNG V8
301 horsepower @ 5,000
333 lb-ft of torque @ 4,200
EPA city/highway fuel economy: NA

6.0-liter V8
360 horsepower @ 3,000
380 lb-ft of torque @ 4,200
EPA city/highway fuel economy: NA

6.6-liter turbodiesel V8
397 horsepower @ 4,200 rpm
765 lb-ft of torque @ 1,600 rpm
EPA city/highway fuel economy: NA