“If you want a truck that is great for hauling, towing or great in the snow, this is the truck for you.”
2020 GMC Sierra 2500: What's New, Specs & Features
Last updated August 13, 2026
The 2020 GMC Sierra 2500 is fully redesigned, making this a major-change year. The headline is an all-new heavy-duty platform with a stronger frame, a roomier cab, a larger bed, and updated engines and towing technology.
About the 2020 GMC Sierra 2500
4th generation Sierra 2500HD/3500HD, first year of the redesign (introduced for 2020).
GMC positions the Sierra 2500 HD as a premium heavy-duty pickup that blends serious towing and hauling ability with easier-to-use trailering technology and more upscale trim choices than a typical work truck. The basic truck is still built for jobsite duty, but the model range stands out with the MultiPro tailgate, camera-based towing tools, AT4 off-road hardware, and Denali luxury touches. For most shoppers, it is the heavy-duty truck that aims to work hard without feeling stripped down.
The 2020 range runs from a work-focused base truck with a 7-inch touchscreen and smartphone integration to the Denali, which has leather seating, navigation, Bose audio, and a broad driver-assist suite. The new AT4 adds Rancho shocks, skid plates, an off-road driving mode, and a two-speed transfer case, while the SLT combines leather seating and trailer-focused technology with the MultiPro tailgate.
What changed, by category
Structural
The Sierra 2500 moves to a new heavy-duty platform with a stronger frame, a larger cab, and a larger bed.
Powertrain
A new standard 6.6-liter gas V8 replaces the previous 6.0-liter gas engine. The optional 6.6-liter Duramax diesel is paired with a new Allison 10-speed automatic. Flexible-fuel powertrains leave the Base, SLE, SLT, and Denali trims, while natural-gas powertrains leave the Base, SLE, and SLT.
Tech
Trailer-focused technology expands with features such as an in-vehicle trailering app on SLT and more advanced towing equipment across the redesigned range. The MultiPro tailgate becomes standard on SLT, and SLT also gains a standard heated steering wheel; satellite radio changes from standard to optional on SLE.
Trim lineup
AT4 joins the Sierra HD range for the first time, adding an off-road suspension with Rancho shocks, skid plates, a two-speed transfer case, an automatic locking rear differential, and an off-road driving mode.
2020 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 Mirrors | |||||
| Privacy Glass | |||||
| Side Steps | |||||
| Head-Up Display | |||||
| Navigation System | |||||
| Premium Audio | |||||
| Rear DVD Entertainment System | |||||
| SD Card Slot | |||||
| Satellite Radio | |||||
| Smartphone Interface | |||||
| Subwoofer | |||||
| Touch Screen Monitor | |||||
| USB Ports | |||||
| 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
Is the 2020 GMC Sierra 2500 a full redesign?
Yes. The 2020 GMC Sierra 2500 starts a new generation with a stronger frame, a roomier cab, a larger bed, new powertrain hardware, and more advanced towing technology.
What engine changes did the 2020 GMC Sierra 2500 receive?
The main engine change is a new standard 6.6-liter gas V8 replacing the previous 6.0-liter gas engine. The optional 6.6-liter Duramax diesel also gains an Allison 10-speed automatic transmission.
Was the GMC Sierra 2500 AT4 new for 2020?
Yes. The 2020 model introduces the first Sierra HD AT4, with Rancho shocks, skid plates, a two-speed transfer case, an automatic locking rear differential, and an off-road driving mode.
What towing upgrades came with the 2020 Sierra 2500 redesign?
The 2020 redesign brings more advanced trailer-focused equipment, including an in-vehicle trailering app on SLT, an integrated trailer brake controller on SLE, and Hitch Guidance on the base truck. Higher trims also feature the MultiPro tailgate.
What distinguishes the 2020 Sierra 2500 Denali?
The 2020 Denali is the luxury-focused Sierra 2500. It combines heated and ventilated leather front seats, heated rear outboard seats, navigation, Bose audio, the MultiPro tailgate, and a broad driver-assist suite.
2020 GMC Sierra 2500 Reviews
What owners are saying about the 2020 GMC Sierra 2500.
4.3
2020 GMC Sierra 2500
(286 reviews)
“It didn't take long for my family to name my truck. It has become a member of the family. We love it. There isn't a thing wrong with it.”
“If you plan to tow anything, this is the truck for that purpose. The trade off of fuel economy is due to the power output.”