The 2020 Sierra HD represents the fourth-generation of the nameplate. As such, the 2020 model year features a complete overhaul (redesign and re-engineering) of the 2500HD and 3500HD Heavy Duty models, making it the strongest, most capable Sierra HD ever. Max towing capability increases an enormous 52 percent to an available 35,500 pounds.
GMC says the all-new Sierra HD is “bigger, stronger and smarter,” and that it combines greater trailering capability with technologies designed to provide customers with a world-class towing experience.
“The all-new 2020 Sierra HD is the most capable heavy-duty truck that we’ve ever offered,” said Duncan Aldred, vice president of Global GMC. “For customers who demand a premium, innovative heavy-duty truck that supports their passions, the next-generation Sierra HD can pull like a pro.”
| Assembly Location | GM Flint Assembly in Flint, Michigan, USA | |
| Body Style(s) | Regular Cab, Double Cab, Crew Cab | |
| Layout | Front-Engined, Longitudinal | |
| Engine(s) | 6.6L L8T V8, 6.6 L5P V8 Duramax (Diesel) | |
| Transmission(s) | 6-Speed Auto, Allison 6-Speed Auto | |
| Drive Wheels | Rear-Wheel-Drive, Four-Wheel-Drive | |
| Availability | U.S.A., Canada, Mexico | |
| Predecessor | 2019 GMC Sierra HD | |
| Successor | 2021 GMC Sierra HD | |
2020 GMC Sierra HD Denali
Body Styles
The 2020 Sierra HD is available as a 2500 or 3500 heavy-duty full-size pickup truck model with several cab and box configurations:
2500HD
- Regular Cab, Long Bed
- Double Cab, Standard Bed
- Double Cab, Long Bed
- Crew Cab, Standard Bed
- Crew Cab, Long Bed
3500HD
- Regular Cab, Long Bed
- Double Cab, Long Bed
- Crew Cab, Standard Bed
- Crew Cab, Long Bed
Notably, sources familiar with GM’s production operations have told GMA that the automaker has instructed dealers to no longer accept orders for Regular or Double Cab units of the 2020 GMC Sierra HD. Other configurations that will not be available to order are Chassis Cab / Box Delete units, 2WD trucks equipped with the 6.6L V8 L5P turbo-diesel Duramax engine. The restrictions went into effect in June and will remain in place until production of the 2021 GMC Sierra HD begins in the fourth quarter of 2020.
Models & Trims
The 2020 GMC Sierra HD is offered as a retail or fleet model, with the Sierra (1SA) being the base model.
2020 Sierra HD Retail & Fleet Models:
2500HD
- Standard Bed Crew Cab
- 2WD (TC20743)
- 4WD (TK20743)
- Long Bed Crew Cab
- 2WD (TC20943)
- 4WD (TK20943)
- Standard Bed Double Cab
- 2WD (TC20753)
- 4WD (TK20753)
- Long Bed Double Cab
- 2WD (TC20953)
- 4WD (TK20953)
- Long Bed Regular Cab
- 2WD (TC20903)
- 4WD (TK20903)
3500HD
- Standard Bed Crew Cab with Single Rear Wheel
- 2WD (TC30743)
- 4WD (TK30743)
- Long Bed Crew Cab with Single or Dual Rear Wheel
- 2WD (TC30943)
- 4WD (TK30943)
- Long Bed Double Cab with Single or Dual Rear Wheel
- 2WD (TC30953)
- 4WD (TK30953)
- Long Bed Regular Cab with Single or Dual Rear Wheel
- 2WD (TC30903)
- 4WD (TK30903)
2020 Sierra HD Retail & Fleet Trims:
2500HD
- Sierra base
- SLE
- SLT
- AT4
- Denali
3500HD
- Sierra base
- SLE
- SLT
- AT4
- Denali
Introducing the All-New Sierra AT4 HD
The all-new 2020 Sierra Heavy Duty AT4 continues the AT4 brand’s growth with what GMC describes as a distinctive off-road identity to complement its robust HD capability. Driven by dark chrome exterior finishes and contemporary detailing, Sierra HD AT4 features front and rear bumpers and a grille surround finished in body color. The bold grille design, with its rugged texture, is finished in black chrome and set off by the AT4’s distinctive red vertical recovery hooks.
The athletic interior also carries AT4-specific darkened trim, including dark-tinted and textured aluminum finishes on the steering wheel, center stack and sill plates, as well as a unique Jet Black interior with Kalahari color accents in the seats and live stitching. Leather-appointed seating, with mini-perforated inserts and embroidered AT4 badging on the headrests, along with all-weather floor liners, is standard delivering durability with uncompromising comfort.
The new Sierra AT4 Heavy Duty’s off-road capabilities are rooted in a unique suspension and supporting technologies that include:
- Off-road suspension, Rancho Shocks, skid plates, Eaton locking rear differential
- Eighteen-inch wheels wrapped with Michelin all-terrain tires
- 20-inch wheels available
- Traction Select System with specific Off-Road mode
- Hill Descent Control and Hill Start Assist
- Segment-exclusive 15-inch diagonal Head-Up Display with Off-Road Inclinometer
- HD Surround Vision for low-speed views of vehicle surroundings
Color Options
The all-new 2020 GMC Sierra HD offers a total of ten exterior colors in addition to four interior color options and four different seat trims.
The 2020 Sierra 2500HD and 3500HD color options include:
- 10 Exterior Colors:
- White Frost Tricoat
- Cardinal Red
- Pacific Blue Metallic
- Quicksilver Metallic
- Summit White
- Onyx Black
- Dark Sky Metallic
- Cajun Red Tintcoat
- Carbon Black Metallic
- Brownstone Metallic
- 4 Interior Colors:
- Jet Black
- Dark Walnut with Slate
- Jet Black with Kalahari
- Dark Walnut with Dark Ash Gray
Exterior Design Highlights
The 2020 Sierra HD has a commanding, powerful design rooted in a new architecture with larger proportions. It’s both taller and longer, and flaunts a more confident stance defined by a bold design that epitomizes GMC’s signature refinement and technologically driven attention to detail.
“We took every opportunity to visually express the strength and capability that lies beneath the surface,” says Matt Noone, director of GMC exterior design. “The elevated hood line, the strong shoulders, the striking front grille — these cues communicate the strength and performance that have been engineered and built into each and every Sierra Heavy Duty.”
The all-new Sierra HD is highlighted by new signature lighting, including prominent “light blades” that deliver LED illumination for the daytime running lamps. LEDs are also used for the headlamps, taillamps, available fog lamps and other illuminative elements, including the available roof marker lights standard on all dual-rear-wheel HDs and all Sierra HD Denali models except where prohibited by law.
Interior Design Highlights
Inside, the all-new Sierra HD Crew Cab model boasts best-in-class front head- and legroom (maximum). A higher seating position complements the truck’s taller profile to offer a confident view from behind the wheel. Additional optimized ergonomics emphasize easy, intuitive interaction with the vehicle’s available technologies, such as a segment-first, heavy-duty head-up display and GMC’s latest touchscreen infotainment systems.
Denali-exclusive materials — including premium leather-appointed seating, authentic open-pore wood trim and dark-finish aluminum decor — raise the interior’s refinement. The leather appointments have a distinctive, large-pebbled grain with a contrasting stitch pattern that is premium in appearance and touch without sacrificing durability, and the wood trim features an open-pore texture evocative of hand-planed furniture.
Technology
The 2020 Sierra HD offers the latest, ultra-modern automotive technology, including the aforementioned segment-exclusive 15-inch diagonal Head-Up Display with Off-Road Inclinometer and HD Surround Vision for low-speed views of vehicle surroundings on AT4 models. The fourth-gen Sierra HD also features all-new trailering enhancements, such as the ProGrade Trailering System and up to 15 unique camera views.
First introduced with the 2019 Sierra light duty, the ProGrade Trailering System leverages technology advancements to offer additional features and functionality for the 2020 Sierra Heavy Duty.
“Trailering is the most important consideration for Sierra Heavy Duty customers, and the new features and technologies in the 2020 Sierra HD make it easier than ever to hitch a trailer and tow it confidently,” said Jaclyn McQuaid, vehicle chief engineer, Heavy Duty Trucks. “We’ve developed this new truck to offer the greatest trailering experience ever offered by GMC.”
The class-leading 15 unique camera views, includes an industry-first transparent trailer view, which helps optimize the driver’s view around the truck and compatible trailers to provide added confidence when towing. The revolutionary transparent trailer feature uses the tailgate-mounted camera and an available accessory camera mounted on the rear of the trailer. The resulting display helps the driver to virtually see through the trailer, a benefit when navigating parking lots, merging into traffic or making tight turns.
Owners of the 2020 Sierra HD will also have access to available smart trailer technology designed to allow access to select features of the iNCommand 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 Auto. Similar to the features of a smart home, the iNCommand 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.
The ProGrade Trailering System also includes an in-vehicle Trailering App with Trailer Light Test, Trailer Electrical Diagnostics, Trailer Tire Pressure and Temperature Monitoring, Pre- Maintenance Reminders and Departure Checklist. Many of the Trailering app’s functions, including the lighting test and pre-departure checklist, are also available with the myGMC mobile app, a feature that offers great convenience when outside the truck or trailer.
Additional available technologies and hardware to aid trailering include:
- Auto Electric Park Brake to automatically apply the parking brake to help maintain truck position when hitching
- All-new Park Grade Hold Assist enhances hill hold by using braking effort at each wheel for an extended period of time
- All-new larger, door-mounted trailering mirrors with a four-bar link providing power extend and retract for the driver and passenger sides
- Integrated trailer brake controller that works with the trailer profile in the Trailering App to recall a specified trailer’s most recent gain setting
- Tow/Haul mode that remains engaged on the next key-on cycle, for up to four hours; includes a reminder the feature is engaged
- Hill Start Assist and Hill Descent Control
- Trailer Sway Control
- Auto Grade Braking and Diesel Exhaust Braking
- Digital Variable Steering Assist that dynamically optimizes power steering according to driving scenarios, including trailering, and enables features like road pull compensation
- Trailering Info Label placed on the driver’s door jamb that clearly calls out the truck’s specific trailering information, including curb weight, GVWR, GCWR, maximum payload, maximum tongue weight and rear GAWR
Powertrain
The 2020 GMC Sierra HD is offered with the following engine and transmission choices:
| Engine | Fuel | Aspiration | Transmission | Horsepower @ RPM | Torque @ RPM | Axle |
|---|---|---|---|---|---|---|
| 6.6L L8T V8 | Gasoline | Naturally Aspirated | 6-Speed Automatic (MYD) | 401 @ 5200 | 464 @ 4000 | 3.73 |
| 6.6L Duramax L5P V8 | Diesel | Turbocharged | 10-Speed Automatic (MGM, MGU) | 445 @ 2800 | 910 @ 1600 | 3.42 |
Platform
The 2020 Sierra Heavy Duty rides on a more capable version of the GM T1 platform that also underpins the 2020 Sierra 1500, 2020 Yukon, as well as other full-size GM trucks and SUVs.
Production
The 2020 GMC Sierra HD was assembled at the GM Flint Assembly plant in Flint, Michigan, USA.
Availability
The 2020 Sierra HD became available in the third quarter of 2019.
Beyond 2020
We expect the fourth-generation Sierra HD to remain in production thru the 2026 model year.
An all-new, next GMC Sierra HD will launch after the 2026 model year.
Discussion
Discuss the 2020 GMC Sierra HD in our GMC forum.
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