“Man, this thing is big,” I thought to myself when I first got inside the 2017 GMC Sierra Denali 3500HD. It was a Friday night, and I had just got back from an eight-day trip in Canada, where we drove the three American off-road trucks on the Trans-Labrador Highway. This time, back in Los Angeles, the terrain was different; there were no wide-lane roads or open spaces like we experienced in Atlantic Canada, and the spacious parking lots were hugely missed. The South Bay’s narrow roads and tight parking spaces proved to be a challenge for this big work truck, but thanks to its diesel engine, it got us around quickly.
Our model was the top of the line, equipped with the most powerful engine that GMC offers. The new 6.6-liter Duramax diesel delivers 445 hp and a whooping 910 lb-ft of torque. The engine is mated to a six-speed automatic Allison transmission sending the power to the rear wheels. A four-wheel-drive system is in place, thanks to an electronic transfer case that allows you to drive in 4Hi or 4Low. And speaking of the rear tires, you’ll notice this is a dually, which means it can tow more. Towing figures for the Crew Cab model with an 8-foot bed range from 20,000 pounds with a ball hitch to 23,100 pounds with a gooseneck hitch and two-wheel drive. Payload capacity ranges from 4,930 (4WD) to 5,381 pounds (2WD). We couldn’t test this heavy-duty truck while towing, but we’ll be sure to update you once we run it through our Truck of the Year tests.
On the other hand, we found out through our standardized tests that the 8,400-pound truck went from 0 to 60 mph in 6.6 seconds, impressive for its size. That’s actually a full second faster than our current Truck of the Year, the 2017 Ford F-350 Lariat 4×4 6.7-liter diesel. The quarter mile was completed in 15.0 seconds at 90.5 mph, also beating the Ford (15.8 seconds at 87.7 mph). On the road, the Sierra Denali feels quick, catching up to freeway speeds in a breeze.
But all that speed and all that weight must be stopped at some point, and it took 141 feet to brake from 60 to 0 mph. “No signs of fade after five runs, nor were there any funny smells or anything else out of the ordinary,” associate road test editor Erick Ayapana, who conducted the test, said. The F-350 diesel beat the GMC 3500HD on braking, stopping completely in 135 feet. The Flint, Michigan–built truck completed our figure eight in 29.1 seconds, and testing director Kim Reynolds enjoyed performing the test. “It’s kind of fun because you can boot the tail out and drift it and all like crazy,” he said. “It fundamentally understeers, but if you completely stand on the throttle and wait, the power will eventually build, and then you’re off to the races.”
With such a big truck, you could expect the interior to be roomy—and it is. The heated and ventilated front seats provided wide comfort, and those sitting in the back will enjoy plenty of legroom. The rear bench can fold in a 60/40 configuration, allowing you to put large or small items in the back. The 8.0-inch screen was equipped with GMC Intellilink, which is compatible with Apple CarPlay and Android Auto. Despite this being a work truck, the Denali badge carried faux wood and chrome trim to the interior, making it better looking. A Bose audio system rounds up the upscale touches.
But how does it drive? The narrow lanes of the South Bay were a big challenge for this GMC. I had to constantly look to the side mirrors to make sure the dually wasn’t running over the lane, and getting out of a parking spot usually took at least a five-point turn. To help the driver in this regard, GMC equipped the Sierra Denali 3500HD with a suite of safety features, including lane departure warning and a forward collision alert, which warns the driver to stop when the traffic ahead is reducing the speed. Two cameras mounted on the side-view mirrors project a lateral view when the turn signal is activated, giving the driver a better view when changing lanes or making turns. Its short turning ratio made it difficult to make U-turns, but I thought its rear suspension did a great job absorbing the bumps and cracks on the asphalt. The Allison transmission was pretty smooth throughout the days that we drove it, and we think it played an important role in helping the GMC beat the Ford in the 0–60-mph run, along with a 5-hp increase and a weight difference of 243 pounds.
Behind the cab you’ll find an 8-foot bed. Our model was already equipped with a gooseneck ball and chain tie-down kit (a $295 premium) and a special equipment fifth wheel/gooseneck trailer hitch prep package ($370). There are several hooks in the bed, which is illuminated by LEDs, and the tailgate came with standard damping. The roof marker lamps make this truck a little easier to see at night.
But all of this comes with a price, and it is quite hefty. Add to the $59,420 starting price of the 2017 GMC Sierra Denali 3500HD the Duramax engine ($9,255) and the power sunroof our tester had, and you’ll end up with a $69,585 truck. However, GMC says that the Denali models account for nearly 50 percent of the Sierra HD sales, making this a popular trim for its clients.