By Jim Prueter
MotorwayAmerica.com

(September 13, 2019) GMC has just introduced its full line of heavy-duty trucks for 2020 at a media drive event in Jackson Hole, Wyoming. Engineers at the event emphasized that the new trucks are the most capable heavy-duty truck they’ve ever built, and promised world-class towing capability, out muscling the likes of Ford Super Duty and Ram HD with a class leading maximum towing capacity of 35,500 pounds.

On sale later this year, the new GMC 2500HD and 3500HD make big news with the available 6.6-liter turbodiesel V-8 with 445 horsepower and a massive 910 lb-ft of torque, delivered through an all-new Allison 10-speed automatic transmission.

A gas-powered 6.6-liter 401-horsepower V-8 engine paired with a six-speed automatic transmission will be offered later this year. But GMC claims that 93 percent of heavy-duty truck buyers buy the vehicle for towing, and three-quarters of those buyers will opt for the more powerful turbodiesel under the hood.

Consistent with its competitors, and sibling Chevrolet Silverado HD trucks, the Sierra HD will be available in regular, double, and crew cab configurations in 2500HD and 3500HD models.

We spent all of our time behind the wheel of the diesel-powered trucks, split between a 3500HD Denali trimmed dually pulling a 40-foot long, 14,000-pound Keystone Fuzion hauler on the fifth-wheel hitch in the cargo bed, and the new 2500HD Sierra AT4 off-road themed truck.

Our drive route with both vehicles took us through the steep, twisty mountain roads of U.S. Route 89 and 26 between Jackson Hole and Alpine, Wyoming, and to the Idaho border. The route was designated by GMC to show off the truck’s impressive capabilities. Both trucks were easily up to the challenge, and never felt close to reaching their maximum towing, hauling, and performance capabilities. On sections of the four-lane highway, even passing was executed absent any white-knuckled experiences.

It was an absolutely delightful and confident pilgrimage where acceleration, braking, and handling were easily up to the tasks. The scenery was pretty spectacular too.

Both of our test trucks were equipped with a comprehensive suite of cameras, with a class-leading 15 different views to aid driver-towing confidence. We were especially fond of GM’s “transparent trailer” mode view that uses an accessory camera mounted on the rear bumper of the trailer to display a panoramic view of traffic and the road behind the trailer that cannot be seen with the outside rearview mirrors.


2020 GMC Sierra HD AT4

The AT4 trim level, first introduced late last year for the light-duty Sierra 1500 pickup, has now been introduced for the 2500HD. Aimed directly at the Ram Power Wagon, the AT4 is aimed for the more adventurous buyer who intends to take time off-road. It’s a trim level that we think most buyers are going to love. The AT4 comes with an off-road identity with dark chrome exterior finishes, a rugged black grille and distinctive red vertical recovery hooks.D AT4

The interior carries AT4-specific darkened trim about the steering wheel, center stack and sill plates as well as a unique Jet Black interior with Kalahari color accents in the seats and stitching. Leather-appointed seating,†with mini-perforated inserts and embroidered AT4 badging on the headrests, along with all-weather floor liners, are standard.

The off-road suspension includes Rancho Shocks, skid plates, Eaton locking rear differential, and eighteen-inch wheels with Michelin all-terrain tires. 20-inch wheels are available. One other point: the AT4 is available with a carbon-fiber composite box that GMC calls the CarbonPro box. It’s the first of its kind in the industry and was developed to significantly increase the durability, functionality and efficiency of the truck. It’s lightweight and virtually indestructible.

Other available features on all HD models include GMC’s MultiPro six-functioning tailgate that allows easier loading, unloading and bed access on all trim levels. Smart trailer technology is designed to allow access to select features of the iN∙Command control system from ASA Electronics through the myGMC mobile app, either on compatible Android and iOS smartphones or on the vehicle’s infotainment system via Apple CarPlay or Android Auto6. Similar to the features of a smart home, the iN∙Command control system acts as the central hub of operations to monitor and control an array of systems in trailers equipped with the next-generation technology.

Depending on how a compatibly equipped trailer is configured, owners of the 2020 Sierra HD may be able to turn on the trailer’s air conditioning or water heater, check water and holding tank levels, or monitor fuel levels on trailers equipped with generators — all before arriving at their destination.

Consistent with the light-duty half-ton Sierra, GMC designers intentionally worked to give the Sierra HD its own unique look to further distinguish it from its Chevrolet Silverado counterpart. We’re pleased to tell you the styling worked, considering the amount of unfavorable reaction to the new Silverado.

We could go on ad infinitum with superlatives regarding the new GMC Sierra HD trucks, their capabilities, functionality, features and technology advancements. Our conclusion is the trucks certainly are an improvement over the previous generation and it helps expand the lineup of product offerings for GMC. The towing and hauling results speak for themselves and the exterior design is certainly attractive, especially the luxurious top-trim Denali. GMC says just over one third of GMC sales are for the Denali and at an average transaction price just below a Mercedes-Benz and ahead of Jaguar.

Vital Stats
Base Price: $40,000 - $64,900
Price as Tested: 3500HD Denali: $78,915 – 2500HD AT4: $77,010
Engine: 445-hp 6.6-Liter V8 Turbo Diesel connected to a 10-speed automatic transmission
Fuel Economy: TBD
Seating: Up to 5

Where Built: Flint, Michigan

Competes With:
Chevrolet Heavy Duty
Ford Super Duty
RAM 3500, 3500

Fab Features
“Transparent Trailer” view technology
New AT4 Heavy Duty trim level
Six function “MultiPro” tailgate