2017 GMC Sierra HD: Going on diesel duty

If you're looking for high-end features with plenty of towing capability, look to the Sierra HD.

Emme Hall Former editor for CNET Cars
I love two-seater, RWD convertibles and own a 2004 Mazdaspeed Miata for pavement fun and a lifted 2001 Miata for pre-running. I race air-cooled Volkswagens in desert races like the Mint 400 and the Baja 1000. I have won the Rebelle Rally, seven-day navigational challenge, twice and I am the only driver to compete in an EV, the Rivian R1T.
Emme Hall
5 min read

Sitting around a fire pit in Moab, Utah, a fellow journalist described the adventure he'd had that day in the 2017 GMC Sierra heavy-duty pickup truck. It involved missing a turn, getting stuck in a mud bog and coming into the designated lunch spot on the dirt instead of the pavement.

My first thought: Some guys have all the luck.

GMC had flown me to Moab to sample the 2017 Sierra in the luxury-oriented Denali trim. Even though my day was much more predictable than my colleague's, I still enjoyed my time in the big truck.

2017 GMC Sierra HD

The GMC Sierra HD makes it easy to get off the beaten path.


Although the truck comes standard with a gas-powered 6.0-liter V8, I drove the new 6.6-liter Duramax turbo diesel V8. Paired with an Allison six-speed automatic transmission, the new powertrain has more power and torque than the outgoing model, all while producing 35 percent fewer emissions. The diesel has 445 horsepower on tap with a whopping 910 pound-feet of tough-as-nails diesel torque.

The first thing I noticed was the near lack of diesel chatter in the cabin. Every once in awhile I heard the engine's low rumbling, but by and large it is quiet and refined.

GMC's drive route took me from Moab to the mountain resort town of Telluride, Colorado. The truck handled the twisty mountain roads like a champ. The hydraulic power steering returns easily to center and offers all the feedback you could want in a truck. The independent front suspension helps the Sierra HD feel smooth on the pavement, and its automatic locking rear differential helps out in any off-road situations.

2017 GMC Sierra HD is big, beefy and bustin' a move

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Acceleration on the Sierra feels quick and powerful. I never felt like I had to urge the truck to accelerate and passing proved easy, even on steep mountain passes.

On the whole, this truck is a very easy, very comfortable ride. Leather abounds in the Denali model and heated and cooled seats keep your rear end at optimal temperature. The pedals are adjustable so even the most diminutive of truck enthusiasts should have no problem finding the right seating configuration. The front seats have access to two USB ports, two 12V ports and two 110-volt outlets. Unfortunately the rear passengers in this crew cab truck have to make due with just one USB port.

This truck is made for towing

The Denali model is only available in a crew cab with the standard 6.5-foot box for the 2500 model or the 8-foot box on the 3500. Your choice of model depends on your towing needs. The 3500 pulls 20,000 pounds on a ball hitch, 7,000 pounds more than the 2500 can handle.

During this drive event, I sampled a 2500 with an open trailer full of ATVs and a side-by-side. The Sierra towed the toys like it wasn't no thang, and I had to constantly remind myself of the 12 extra feet or so behind me. The Sierra has plenty of available cameras to help you see what's going on in the rear, including a view that automatically displays when you signal a turn. If you cut a turn too shallow you can see exactly how close your rear wheel is to the curb or monitor your position in the lane with just the push of a button.

2017 GMC Sierra HD

The GMC Sierra 3500 HD can tow 22,900 pounds on a fifth wheel.


Going up a steep grade with a trailer is one thing, coming down is quite another. To preserve its brakes, the Sierra HD's Tow/Haul mode keeps the transmission in a low gear, slowing the truck and trailer significantly. The truck's standard exhaust braking, engaged with a button on the console, creates back pressure to keep the engine speed slow. Between the Tow/Haul mode and the exhaust braking, I didn't have to touch the brakes at all going down hill.

The Sierra HD has all the tech we've come to expect from a GM product. Its Wi-Fi hotspot, powered by a 4G LTE data connection, found a signal where my AT&T phone could not. The Intellilink system is very easy to use, with large tiles, a quick responding 8-inch touchscreen and an intuitive interface. As a bonus, Intellilink also comes standard with Apple CarPlay and Android Auto. New for this year is the Teen Driver technology. It lets parents, or snoopy spouses, monitor the driving of their loved one, reporting on such behaviors as maximum speed and any emergency braking incidents. The Denali also gets standard wireless charging and a standard remote locking tailgate.

2017 GMC Sierra HD

The Sierra HD comes with the easy-to-use Intellilink infotainment system.


There are a few driver's aids on the Sierra, though some of the competition does better. Lane departure warning, forward collision alert, and front and rear park assist are all standard. Also included is the safety alert seat, which buzzes the driver's seat bottom to warn of any lane wandering or parking hazards.

Absent, however is any kind of adaptive cruise control. Not that I would want to let the truck have that kind of control when towing, but it's always nice to have when unladen and in traffic. The Ford Super Duty has it, and GMC would be well-advised to add adaptive cruise control for 2018.

Special edition Sierra

I also got a chance to sample the limited-edition All Terrain X series. It's essentially an appearance package for the Sierra HD 2500 aimed at off-road folks, although there are a few meaty changes that push the All Terrain X toward the dirt. It gets the Z71 off-road suspension package from GMC's brand cousin Chevrolet as well as skid plates and some aggressive tires. There is a sport bar mounted in the bed, to which you can add LED lights, available as an accessory, but it's so far back you'll mostly be lighting up your roof instead of the road ahead. Take my advice and mount your lights in the front grill. You'll thank me as soon as you find yourself in the middle of nowhere with no ambient light.


Of course there's a special edition.

Emme Hall/Roadshow

However, the rear differential still locks on its own when it senses a low-traction situation, so the driver doesn't have any control over it. The chin spoiler in the front hinders the approach angle and without a lift, there isn't much travel. It's an off-road truck made for slow-going through mud and sand, not for flat-out whoop running or changes in terrain.

If you need a truck with plenty of towing capability that can also double as a daily driver, the 2017 GMC Sierra HD should be on your short list. Both the Sierra HD Denali 2500 and 3500 start at just under $55,400, but you'll have to add $9,255 for the optional 6.6-liter Duramax diesel V8 engine. It's pricey for sure, but that's a bit less than the starting price for a similarly equipped Ram 2500 or 3500.

2017 GMC Sierra HD is big, beefy and bustin' a move

See all photos