2026 GMC Sierra 2500HD / 3500HD
4th generation (2020–present, refreshed for 2024)
Spec plateChecked Sep 2026
- Starting price
- $47,000
- 4x4 from
- $49,800
- Max towing
- 36,000 lb
- Max payload
- 7,290 lb
- Most power
- 470 hp
- Ground clearance
- 11.8 in
2500HD AT4X AEV Edition
Our verdict
The Sierra HD is a Silverado HD with nicer cabins and higher prices, and the AT4X is effectively a ZR2 with leather: DSSV dampers, 35s and one rear locker. The AT4 is the more sensible buy for rough roads and towing, since it keeps the full 20,000-lb conventional rating. The AEV package is mostly armor and styling, and it costs you approach angle and some tow rating.
Best for
Heavy towers who want a premium cabin, plus buyers who need an HD that can handle rough trail access, which is where the AT4X comes in.
Skip it if
You want a front locker or a crawler-focused HD, or you can get the same hardware for less in a Silverado HD ZR2.
Strengths
- Duramax 6.6L diesel with 470 hp and 975 lb-ft, backed by a 10-speed Allison
- 3500HD tows up to 36,000 lb (gooseneck) and carries up to 7,290 lb
- AT4X gets Multimatic DSSV dampers, a rear e-locker and 35-in MT tires
- AT4X AEV Edition reaches 11.8 in of ground clearance
Weak spots
- AT4X starts at $85,200 before destination, and the AEV Edition costs more
- No front locker on any trim
- AT4X AEV Edition's conventional tow rating drops to 18,400 lb, and its diesel gooseneck rating to 14,800 lb
- AEV bumpers cut the approach angle to 29.8 degrees from the AT4X's 31.6
Capability vs other heavy-duty trucks
- Cabs
- Regular Cab, Double Cab, Crew Cab
- Bed lengths
- 6.9 ft, 8 ft
- Fuel economy
- Not EPA-rated (heavy-duty pickups over 8,500 lb GVWR are exempt from EPA fuel-economy labels)
- Pricing notes
- Excluding destination: 2500HD Pro Regular Cab 2WD $47,000; 2500HD Pro Regular Cab 4WD $49,800 (cheapest 4x4, per Cars.com); 3500HD from $47,900. GMC.com trim starts: SLE $54,000, SLT $65,200, AT4 $72,200, Denali $75,200, AT4X $85,200, Denali Ultimate $94,200. The AT4X AEV Edition is a package on AT4X.
- Configurations
- Regular Cab (long bed), Double Cab and Crew Cab (6-ft-9-in standard or 8-ft long bed). 3500HD offers single or dual rear wheels. AT4 is a Crew Cab 4WD in 2500HD or 3500HD (single rear wheel); AT4X is a 2500HD Crew Cab standard-bed 4WD only.
Off-road hardware
4WD / AWD system
Part-time 4WD with a two-speed transfer case (4-High and 4-Low) on 4x4 models; AT4X adds a larger steel transfer-case skid plate. GM does not publish the low-range ratio or trim-by-trim transfer-case details on its consumer site.
Locking differentials
AT4X and AT4X AEV Edition: rear electronic locking differential. GMC's consumer pages don't spell out the rear axle on other trims; the mechanically identical Chevrolet Silverado HD lists an automatic locking rear differential as standard from its base WT. No front locker is offered.
| Approach angle | 29.8° |
|---|---|
| Breakover angle | 22.6° |
| Departure angle | 25.7° |
| Ground clearance | 11.8 in |
| Water fording | Not published |
Off-road tech
- Multimatic DSSV dampers (AT4X)
- Rear electronic locker (AT4X)
- Hill Descent Control (AT4)
- 15-in head-up display with off-road inclinometer (available on AT4)
- Up to 14 camera views including transparent trailer view
Engines & transmissions
| Engine | Power | Torque | Transmission |
|---|---|---|---|
| 6.6L gas V8Standard on Pro and most trims, including AT4X. | 401 hp | 464 lb-ft | 10-speed Allison automatic |
| Duramax 6.6L turbo-diesel V8Available across the lineup; standard on Denali Ultimate. | 470 hp | 975 lb-ft | 10-speed Allison automatic |
The off-road trims
X31 Off-Road Package (available on SLE)
Twin-tube Rancho shocks and skid plates on otherwise standard-height trucks.
AT4
Off-Road Suspension Package with twin-tube Rancho shocks, skid plates and Hill Descent Control, 20-in wheels with available BFGoodrich off-road tires; 10.1-in clearance (2500HD) or 11.1–11.2 in (3500HD).
AT4X (2500HD)
1.5-in lift, Multimatic DSSV dampers, rear e-locker, 35-in Goodyear Territory MT tires, larger steel transfer-case skid and aluminum front skid; 11.6-in clearance, 31.6/21.2/25.7-degree approach/breakover/departure.
AT4X AEV Edition (package on AT4X)
AEV stamped-steel bumpers, stamped-steel steering-gear and transfer-case skid plates and 18-in AEV Salta wheels; 11.8-in clearance and 22.6-degree breakover, but a lower 29.8-degree approach.
What's new for 2026
Largely unchanged. The MultiPro tailgate is no longer standard on SLT, and there are new exterior colors.
Rivals worth a look
Sources & data notes
These specs were checked on September 24, 2026 against the sources below, starting with the manufacturer's own material. When a figure isn't published, we leave it blank instead of estimating. Ratings are maximums for the best-equipped configuration; confirm yours on the door-jamb labels.
Sources for this page 11
- gmc.comgmc.com/trucks/sierra/2500hd-3500hd
- gmc.comgmc.com/trucks/sierra/2500hd-3500hd/at4
- gmc.comgmc.com/gmc-life/at4x-aev
- gmc.comgmc.com/content/dam/gmc/na/us/english/index/about/trailering-towing/2026-pdfs/2026-gmc-sierra-2500-trailering-charts.pdf
- gmc.comgmc.com/content/dam/gmc/na/us/english/index/about/trailering-towing/2026-pdfs/2026-gmc-sierra-3500-trailering-charts.pdf
- chevrolet.comchevrolet.com/trucks/silverado/2500hd-3500hd
- news.gm.comnews.gm.com/home.detail.html/Pages/news/us/en/2023/apr/0413-silveradohd.html
- gmauthority.comgmauthority.com/blog/gm/gmc/sierra/2027-gmc-sierra/
- cars.comcars.com/research/gmc-sierra_2500-2026/trims/
- edmunds.comedmunds.com/gmc/sierra-2500hd/2026/
- edmunds.comedmunds.com/chevrolet/silverado-2500hd/2026/features-specs/
Understand the hardware
