“Be prepared for issues with the DEF system, I wish the government would not make them mandatory”
2021 GMC Sierra 2500: What's New, Specs & Features
Last updated August 13, 2026
The biggest change for the 2021 GMC Sierra 2500 is expanded towing-camera equipment, led by standard HD Surround Vision and a Bed View Camera on Denali. This is a light update rather than a redesign, with the engines, body, cabin and heavy-duty structure largely carrying over.
About the 2021 GMC Sierra 2500
4th-generation Sierra HD (2020-2023), second model year after the 2020 redesign.
The 2021 Sierra 2500 is GMC’s premium take on a heavy-duty pickup: a truck built first for towing, hauling and work, but marketed with more upscale design, cabin materials and trailering technology than a typical job-site truck. GMC leans hard on its "Professional Grade" identity here, pairing big-truck capability with features like the MultiPro tailgate, extensive trailer-camera support and higher-end trims such as AT4 and Denali for buyers who want more comfort or a distinct look.
The 2021 Sierra 2500 ranges from a straightforward base work truck to the better-equipped SLE and leather-lined SLT. AT4 adds an off-road suspension, skid plates and red recovery hooks, while Denali focuses on luxury with premium leather, real wood trim, Bose audio, navigation and a wider set of standard cameras.
What changed, by category
Powertrain
The core engine lineup carried over, but gas-powered work-truck models added E85 fuel capability.
Styling
GMC made minor trim-specific appearance and color updates, with no meaningful body or front-end redesign.
Tech
Trailer-camera functions expanded. SLE gained a standard MultiPro tailgate, Denali gained standard HD Surround Vision and a Bed View Camera, and the base trim added a front bench seat with covered storage plus two dashboard USB ports.
2021 GMC Sierra 2500 specs and features by trim
| Feature | |||||
|---|---|---|---|---|---|
| Engine | V8, 6.6 Liter / V8, Turbo Diesel, 6.6 Liter | V8, 6.6 Liter / V8, Turbo Diesel, 6.6 Liter | V8, 6.6 Liter / V8, Turbo Diesel, 6.6 Liter | V8, 6.6 Liter / V8, Turbo Diesel, 6.6 Liter | V8, 6.6 Liter / V8, Turbo Diesel, 6.6 Liter |
| Transmission | Automatic, 10-Spd Allison | Automatic, 10-Spd Allison | Automatic, 10-Spd Allison | Automatic, 6-Spd HD w/Overdrive | Automatic, 10-Spd Allison |
| Drivetrain | 4WD | 4WD | 4WD | 4WD | 4WD |
| Fuel Type | Gas / Diesel | Gas / Diesel | Gas / Diesel | Gas / Diesel | Gas / Diesel |
| Horsepower | 401–445 hp | 401–445 hp | 401–445 hp | 401–445 hp | 401–445 hp |
| Torque | 464–910 lb-ft | 464–910 lb-ft | 464–910 lb-ft | 464–910 lb-ft | 464–910 lb-ft |
| Max Towing | 14500 lb | 14500–17890 lb | 14500 lb | 14500–17890 lb | 14500 lb |
| Rear Legroom | 43.4 in | 35.2–43.4 in | 35.2–43.4 in | 35.2–43.4 in | 43.4 in |
| Seats | 3–6 | 5–6 | 3–6 | 5 | |
| Doors | 4 | 2–4 | 4 | 2–4 | 4 |
| Alarm System | |||||
| Automatic Emergency Braking | |||||
| Automatic High Beams | |||||
| Blindspot Sensors | |||||
| Cruise Control | |||||
| Hill Descent Control | |||||
| Lane Departure Warning | |||||
| Park Assist | |||||
| Rear View Camera | |||||
| 360 Camera | |||||
| Alloy Wheels | |||||
| Auto-Dimming Exterior Mirrors | |||||
| Fog Lights | |||||
| HID Headlights | |||||
| Heated Mirrors | |||||
| LED Headlights | |||||
| Memory Exterior Mirrors | |||||
| Power Moonroof | |||||
| Power Liftgate/Trunk Release | |||||
| Power Mirrors | |||||
| Power Side Steps | |||||
| Privacy Glass | |||||
| Side Steps | |||||
| Head-Up Display | |||||
| Navigation System | |||||
| Premium Audio | |||||
| SD Card Slot | |||||
| Satellite Radio | |||||
| Smartphone Interface | |||||
| Subwoofer | |||||
| Touch Screen Monitor | |||||
| Auto-Dimming Interior Mirror | |||||
| Dual Power Front Seats | |||||
| Dual-Zone Climate Control | |||||
| Heated Front Seats | |||||
| Heated Rear Seats | |||||
| Heated Steering Wheel | |||||
| Integrated Garage Door Opener | |||||
| Leather Seats | |||||
| Leather-Wrapped Steering Wheel | |||||
| Memory Driver's Seat | |||||
| Power Driver Seat | |||||
| Remote Start | |||||
| Remote Keyless Entry | |||||
| Tilt Wheel | |||||
| Tilt/Telescoping Steering Wheel | |||||
| Ventilated Front Seats | |||||
Frequently asked questions
Was the 2021 GMC Sierra 2500 redesigned?
No. The 2021 GMC Sierra 2500 received a light equipment update after its 2020 redesign, while its body, cabin, frame, cab choices and core engines carried over.
What changed on the 2021 GMC Sierra 2500 Denali?
The 2021 Sierra 2500 Denali gained standard HD Surround Vision and a standard Bed View Camera. These cameras provide a clearer look around the truck, into the bed and toward the hitch area.
What changed on the 2021 GMC Sierra 2500 SLE?
The 2021 Sierra 2500 SLE gained the MultiPro tailgate as standard equipment. Its multiple opening positions make it easier to access the bed and handle different cargo tasks.
Did the 2021 GMC Sierra 2500 get new engines?
No. The 2021 Sierra 2500 kept its core engine lineup, though gas-powered work-truck models added E85 fuel capability.
What changed on the base 2021 GMC Sierra 2500?
The base 2021 Sierra 2500 added a 40/20/40 front bench seat with covered storage and two USB ports in the dashboard. It remained the straightforward work-focused trim.
2021 GMC Sierra 2500 Reviews
What owners are saying about the 2021 GMC Sierra 2500.
4.3
2021 GMC Sierra 2500
(83 reviews)
“Adaptive cruise, bed lighting operation from inside the bed, power adjustable steering wheel and audible blind spot warning are absolutely must…nice would be a panoramic sunroof and updated infotainment screen (ie larger preferably wider)”
“I STRONGLY RECOMMEND THE GMC 2500 HD WITH THE 6.6 BECAUSE IT RIDES AND DRIVES LIKE A CAR. HAS THE POWER OF A SPORTS CAR. HANDLES LIKE A SPORTS CAR, QUIET ON THE ROAD.”