2026 GMC Sierra 2500 HD AT4
Vehicle Make:
2026 GMC Sierra 2500 HD
Configuration Options:
Crew Cab, Standard bed
Trim Options:
AT4, AT4X
Engine Options:
6.6L V8 Petrol, 6.6L Duramax Turbo diesel
Built for Work. Engineered for Adventure.
The 2026 GMC Sierra 2500 AT4 and AT4X push heavy-duty capability even further, built for the places where roads end and the real challenges begin. These aren’t trucks wearing off-road badges — they’re factory-engineered systems designed to take on Australia’s toughest terrain while preserving the premium refinement you expect from GMC.
From the updated AT4 with its off-road tuned suspension, skid plates, and advanced 4WD system, to the flagship AT4X equipped with Multimatic DSSV dampers and front and rear electronic locking differentials, every element is calibrated to perform as one.
Ready for Tough Australian Conditions.
Converted to right-hand drive by Autogroup International with full ADR compliance, the 2026 Sierra 2500 AT4 and AT4X bring authentic American capability to Australian conditions. Power comes from a choice of high-torque Duramax diesel (470 hp / 1,324 Nm) or the proven 6.6L V8 petrol, both paired with a heavy-duty 10-speed automatic transmission and advanced towing systems rated up to 7,326 kg.
Backed by a 5-year unlimited kilometre warranty and nationwide support, the Sierra 2500 AT4 range delivers uncompromising strength and capability without sacrificing refinement or comfort.
Experience The GMC Sierra 2500
choose your Vehicle Trim
AT4
The AT4 is available exclusively in Crew Cab configuration. Featuring off-road tuned suspension, skid plates, advanced 4WD with hill descent control, and Twin-Tube Rancho® shocks. Includes a 13.4″ infotainment display and premium leather-appointed interior with distinctive accents.
AT4X
The AT4X is also offered only in Crew Cab configuration. Equipped with Multimatic DSSV dampers, front and rear electronic locking differentials, and trail-optimized calibration for maximum control. Features a 12.3″ driver information display, 16-way power front seats with massage function, and premium Obsidian Rush interior trim.
AT4
Luxurious pickup with standard off-road suspension, active exhaust, and 3.0L Duramax Turbo Diesel. Includes GMC MultiPro Tailgate, ventilated seats, HD Surround Vision, keyless start, and GMC Pro Safety. Optional 6.2L V8 and CarbonPro bed available.
AT4X
The Sierra 1500 AT4X is the most off-road capable factory Sierra ever. Features driver-selectable locking differentials, 2" lift with Multimatic dampers, and luxurious Obsidian Rush interior with massaging leather seats and 12-speaker Bose system. Standard 3.0L Duramax Turbo-Diesel, optional 6.2L V8.
DENALI
Luxury pickup featuring standard 5.3L EcoTec3 V8, with optional 3.0L Duramax Turbo Diesel or 6.2L V8. Includes AT4/AT4X features plus Super Cruise, collision alert, pedestrian braking, lane keep assist, automatic emergency braking and advanced safety technologies.
DENALI ULTIMATE
The ultimate luxury pickup with exclusive 22" wheels, power steps, sunroof and Bose 12-speaker system with head-up display. Features leather steering wheel, rear camera mirror and premium exterior styling. Standard 6.2L EcoTec3 V8 with optional 3.0L Duramax Turbo Diesel available.
HUMMER EV 2X
Lighten the load, Increase efficiency
- Interior Options: Granite Drift, Premium leather-alternative seating surfaces, Stealth Eclipse (Late Availability)
- Front Bucket Seats.
- Infinity Roof, with removable opaque Sky Panels.
- 12.3" diagonal color Driver Information Center
- Bose 14-speaker Surround with CenterPoint® audio system
HUMMER EV 3X
Flagship Performance and Power
- Interior Options: Granite Drift, Premium leather-alternative seating surfaces, Stealth Eclipse (Late Availability)
- Front Bucket Seats.
- Infinity Roof, with removable opaque Sky Panels.
- 12.3" diagonal color Driver Information Center
- Bose 14-speaker Surround with CenterPoint® audio system
3X CARBON FIBRE EDITION
Limited Edition
- Velocity Ember Interior.
- Front Bucket Seats.
- Infinity Roof, with removable opaque Sky Panels
HUMMER EV 2X
Lighten the load, Increase efficiency
- Optional 18" Grazen Face Beadlock capable wheels with Tech Bronze Decorative Ring.
- Front Off-Road Auxiliary Lights.
- GMC MultiPro tailgate with Step Lights.
- Optional Illumination Package.
- Optional Lifestyle Adventure Package
HUMMER EV 3X
Flagship Performance and Power
- Optional 18" Grazen Face Beadlock capable wheels with Tech Bronze Decorative Ring.
- Front Off-Road Auxiliary Lights.
- GMC MultiPro tailgate with Step Lights.
- Optional Illumination Package.
- Optional Lifestyle Adventure Package.
- Two additional exterior paint colors available – Coastal Dune and Auburn Matte
3X CARBON FIBRE EDITION
Limited Edition
- 22” Black Carbon Fiber wheels with black wheel center cap featuring HUMMER EV Logo
Carbon Fiber skid plate insert, black-painted metal approach shield, available Carbon Fiber hood insert and available Carbon Fiber mirror caps. - Black Emblems.
- All Terrain Tyres
HUMMER EV 2X
Lighten the load, Increase efficiency
- StabiliTrak, electronic stability control system with traction control.
- Trailer Side Blind Zone Alert.
- Forward Collision Alert.
- Safety Alert Seat.
- Tire Pressure Monitoring System with Tire Fill Alert.
- Enhanced Automatic Emergency Braking
HUMMER EV 3X
Flagship Performance and Power
- StabiliTrak, electronic stability control system with traction control.
- Trailer Side Blind Zone Alert.
- Forward Collision Alert.
- Safety Alert Seat.
- Tire Pressure Monitoring System with Tire Fill Alert.
- Enhanced Automatic Emergency Braking
3X CARBON FIBRE EDITION
Limited Edition
- StabiliTrak, electronic stability control system with traction control.
- Trailer Side Blind Zone Alert.
- Forward Collision Alert.
- Safety Alert Seat.
- Tire Pressure Monitoring System with Tire Fill Alert.
- Enhanced Automatic Emergency Braking
Leader in Right Hand Drive American Vehicle...
Is there a warranty for the vehicles you sell?
Every vehicle includes a Factory-Backed 3-Year Warranty with conditions identical to the original manufacturer's warranty.
Are your right-hand drive conversions compliant with Australian standards?
Absolutely. Our vehicles meet Australian Motor Vehicle Standards Act requirements and we're ISO 9001:2015 certified for RHD conversions.
Where do you provide servicing in Australia?
All servicing is performed at our Australian facility, based in Melbourne, by our trained technicians who specialise in converted American vehicles.
Do you supply genuine spare parts?
Yes. Our Australian parts team stocks OEM-grade service parts, accessories, and consumables specifically for converted American vehicles.
Can I schedule a test drive?
Absolutely! You can schedule a test drive by heading over to the contact page and getting in touch with our team.