2015 GMC Sierra 2500HD Denali and All Terrain Make the (Professional) Grade

GMC has been building trucks since 1902 and they are built under the mantra of “Professional Grade.” I recently tested a couple of the brand’s latest 2500HD models in the form of the Sierra Denali and All Terrain. This new crop of 2015 GMC Sierras is the most comfortable, most capable and most advanced GMCs yet, truly professional grade.

2015 GMC Sierra 2500HD All Terrain/Images by Author

2015 GMC Sierra 2500HD All Terrain/Images by Author

The 2500HD series is the three-quarter ton model of the GMC lineup and for model year 2015 receive some significant styling and content updates both inside and out. Sierra 2500 is offered in base, SLE, SLT, Denali and new All Terrain trim levels and arrive in Regular, Double and Crew cab models in 4×2 or 4×4 configuration. Our recent testers arrived in Crew Cab 4×4 form for both Denali and All Terrain models.

Engine choices offered by GMC for its big trucks include the 360hp, 380 lb. ft. of torque 6.0-liter Vortec gas V-8 or Duramax 6.6-liter turbodiesel V-8 generating 397hp and 765 lb. ft. of torque. Each engine is backed by six-speed automatic gearbox (Hydra-Matic 6L90 for gas, Allison 1000 for diesel) and offers tow/haul mode and manual shifting. Each of the 2500HD trucks we tested was outfitted with the Duramax diesel. While fuel economy is not required to be posted for these trucks we were experiencing 14-17 mpg in mixed driving with each being outfitted with a 3.73 rear axle ratio.


The Denali and All Terrain trim levels offer equipment and trim unique to each package but dress the GMC trucks to a higher level that most likely will have many of these trucks seeing very little work but will most likely be daily drivers. Even in 4×4 configuration the trucks are easy to drive, maneuver quite well and offer a very quiet, comfortable on- and off-road experience. The weather was quite nice during our time behind the wheel of the gorgeous, chrome laden Denali, but old man winter threw some frozen precipitation our way that proved absolutely no match for the All Terrain Sierra.

While base model 2015 GMC Sierra HD pickups offer a host of standard amenities, these test units arrived fully laden with GMC’s latest safety and technology equipment auto locking rear differential, trailer brake controller, Stabilitrak stability control with trailer sway control and hill start assist, EZ Lift and Lower tailgate, chrome rear bumpers with Cornerstep, leather interior appointments, 20-inch wheels and tires, Bose premium audio systems, 8-inch color touchscreen with navigation and multimedia control, satellite radio, Bluetooth connectivity and OnStar with 4G LTE Wi-Fi.

Interior shot courtesy GMC

Interior shot courtesy GMC

In addition to new integrated cruise control, auto grade braking and diesel exhaust braking, the 2015 HD models feature better cooling airflow, Duralife disc brake rotors and heater, power adjustable trailering mirrors with segment-first backup lamps. The big trucks also now offer forward collision alert, lane departure warning, front and rear park assist and (my personal favorite new technology) active driver safety seat.

One feature I am glad to finally see in GMC trucks is the availability of a spray on bedliner (as well as adjustable upper tie down hooks and LED cargo box lighting).

2015 GMC Sierra 2500HD Denali/Image courtesy GMC

2015 GMC Sierra 2500HD Denali/Image courtesy GMC

The 2015 GMC Sierra 2500HD is rated to tow 13,000 lbs. by ball hitch and 17,000 lbs. via 5th wheel. Double Cab models can carry a payload of 3,312 lbs. while Crew Cab models see a max payload of 2,793 lbs. Both Double and Crew Cab models seat up to five adults in full comfort offering ample of head- and legroom in both rows.

Pricing for this 2015 GMC Sierra 2500HD Crew Cab 4×4 All Terrain as tested is $62,300 and our Denali tester arrived with a final sticker of $64,575. Surprisingly, Denali models account for one-third of all GMC Sierra HD Crew Cab sales.


GMC trucks have certainly come a long way since 1902 and the class of 2015 is the most comfortable and most capable yet, and definitely the most advanced. While many may think of GMC as the “luxury” brand of Chevy trucks it cannot be denied they are surely “Professional Grade.”

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About the Author

David Goodspeed
David was editor of AutoworldToday at Today Newspapers in the Dallas suburbs until its closing in 2009. He was also webmaster and photographer/videographer. He got started doing photography for the newspaper while working as a firefighter/paramedic in one of his towns, and began working for the newspaper group full-time in 1992. David entered automotive journalism in 1998 and became AutoworldToday editor in 2002. On the average, he drives some 100 new vehicles each year. He enjoys the great outdoors and as an avid fly fisherman, as is his spouse Tish. He especially enjoys nature photography and is inspired by the works of Ansel Adams.