GMC‘s new heavy-duty pickups bring greater refinement, huge capabilities, and smarter convenience and trailering features. The 3.6-liter V6 does its job well with reliable power and torque available. I’m always nervous when we see a new 9-speed unit. Commonly calibrated towards fuel efficiency, these gearboxes often find themselves confused as to what gear to choose during hard accelerations. Burying the accelerator pedal on the 2020 GMC Acadia AT4 didn’t cause any hesitation, though, as the unit shifts quickly and seamlessly through gears.
The only vehicle offered with the new turbodiesel for on-road testing was a Denali, which is the range-topping model in the Sierra 1500 lineup. The downside to GMC’s decision to not make any other changes to the 2020 lineup is the fact that the Denali’s interior remains decidedly unimpressive, especially when compared to the Ram 1500s. This is especially egregious when you consider that Ram is not explicitly playing to a premium niche the way GMC is.
The standard engine for the Sierra 2500HD is a 6.6-liter gasoline V8, good for 401 horsepower and 464 lb-ft. of torque. The model we sampled featured the 6.6-liter Duramax turbo-diesel V8, which outputs 445 horsepower at 2,800RPM, and a staggering 910 lb-ft. of torque at a low 1,600RPM. This isn’t by any means a straight-line bandit, but the diesel 2500HD drove around the foothills of Yellowstone National Park effortlessly and blended in perfectly with the other heavy-duty trucks in the area.
When it comes to the powertrain, things will remain pretty much the same. The 2020 Sierra 1500 will continue with standard 4.3-liter V6, which is good for about 280 horsepower. Of course, a new 2.7-liter four-cylinder is in the offer as well. This one delivers around 310 horsepower and 350 pound-feet of torque. Two familiar V8 units are in the offer as well. A 5.3-liter unit is good for about 355 horsepower, while a bigger 6.2-liter engine delivers around 420 hp. Finally, there is a 3.0-liter turbodiesel engine, which delivers around 282 horsepower and 450 pound-feet of torque.
Longer in wheelbase (rear legroom grows nearly three inches), these crew cab models shed 450 pounds over their predecessors — the result of a hotly-debated decision to use aluminum for some of the body panels (hood, doors, tailgate). GMC claims its 5’8″ short box is the most voluminous in the industry (62.9 cubic feet), even more so than the 6’6″ long boxes found on Ford and Ram crew cabs. The jury’s out, at least for this author, on the visual appeal of those strange wheel wells. Inside, it’s again a case of evolution over revolution. A line of driver-assist and convenience switches still adorns the bottom of the aluminum-trimmed center stack.
Like its Chevrolet Silverado 1500 stablemate, the 2020 GMC Sierra 1500 is a full-size pickup truck that is available in crew-cab, double-cab and regular-cab configurations. No surprises there. For 2020, there are some new trim options of its new 5202 led bulb conversion kit and, most notably, a new powerplant. Along with the previously available gas engines, the Sierra 1500 now offers an optional turbocharged diesel inline-six engine. The hotly anticipated 3.0-liter Duramax diesel engine option has been talked about for over a year.