The 2026 GMC Sierra 2500HD AT4X Crew Cab Standard Box blends heavy-duty diesel power, premium craftsmanship, and serious off-road capability. With its bold AT4X styling, advanced trailering technology, and luxurious interior, this rugged pickup is engineered to handle demanding jobs and adventurous escapes while delivering exceptional comfort and confidence. Built for drivers who expect professional-grade strength without sacrificing refinement, the Sierra AT4X is ready for work, towing, and life beyond the pavement. 

Performance & Capability 

Engine: Duramax 6.6L V8 Turbo-Diesel delivering impressive torque and heavy-duty performance for demanding workloads. 

Transmission: Allison 10-speed automatic transmission for smooth, confident power delivery. 

Drivetrain: Four-wheel drive with a two-speed Autotrac transfer case for dependable traction across challenging terrain. 

Rear Differential: Electronic locking rear differential for enhanced grip on loose surfaces and uneven trails. 

Off-Road Suspension: AT4X-specific off-road suspension package engineered for rugged terrain and confident handling. 

Axle Ratio: 3.42 rear axle ratio designed to support strong pulling capability. 

Exhaust Brake: Helps manage vehicle speed and reduce brake demand when descending with a heavy load. 

Trailering Equipment: Integrated trailer brake controller, Hitch View, trailer camera provisions, and a dedicated trailering app. 

Gooseneck & Fifth-Wheel Prep: Factory-installed provisions for compatible heavy-duty towing setups. 

Hill Descent Control: Helps maintain controlled speed when navigating steep downhill terrain. 

Winter & Weather Comfort 

Heated and Ventilated Front Seats for year-round comfort in changing Canadian weather. 

Heated Second-Row Outboard Seats and Heated Steering Wheel for added warmth on cold mornings. 

Engine Block Heater to support cold-weather starting. 

Reinforced Heating and Defrosting System for added cabin comfort during winter conditions. 

Dual-Zone Automatic Climate Control with rear air vents for personalized comfort. 

Rain-Sensing Windshield Wipers and Rear Window Defogger to help maintain visibility in unpredictable weather. 

Winter Grille Cover and Premium All-Weather Floor Liners for added cold-weather practicality and interior protection. 

Interior Comfort & Convenience 

Premium Jet Black and Ceramic White Interior with distinctive AT4X styling and upscale finishes. 

Power Front Bucket Seats with memory settings, power lumbar support, adjustable bolsters, and massage functionality. 

Crew Cab Interior offering generous passenger space and rear-seat storage for everyday versatility. 

Power Sliding Rear Window for convenient ventilation. 

Power Sunroof that brings natural light into the cabin. 

13.4-Inch GMC Premium Infotainment Touchscreen with Google built-in compatibility for connected navigation and entertainment features. 

12-Inch Digital Driver Display providing customizable vehicle information at a glance. 

Wireless Apple CarPlay and Android Auto Compatibility for seamless smartphone integration. 

Wireless Charging and Multiple USB Ports to keep compatible devices connected. 

Bose Premium Audio System for rich, immersive sound. 

Head-Up Display and Rear Camera Mirror for convenient access to key driving information and improved rearward visibility. 

Heated Power-Retractable Black Assist Steps with LED Lighting for easier entry and exit. 

Safety & Driver Assistance 

GMC Pro Safety features designed to enhance awareness and driver confidence. 

Forward Collision Alert and Automatic Emergency Braking to help mitigate potential frontal collisions. 

Lane Departure Warning and Following Distance Indicator to support attentive highway driving. 

Adaptive Cruise Control for added convenience on longer journeys. 

Front and Rear Park Assist with HD Surround Vision to help simplify parking and maneuvering. 

Rear Cross Traffic Alert for additional awareness when reversing. 

Trailer Side Blind Zone Alert to help monitor surrounding traffic while towing. 

Front Pedestrian Braking for added awareness in busy environments. 

Bed View Camera and Hitch View to assist with cargo monitoring and trailer alignment. 

Safety Alert Seat, Teen Driver Mode, and Buckle-to-Drive for additional safety support. 

Exterior Styling & Utility 

Exterior Colour: Summit White a crisp, clean finish that complements the AT4Xs rugged character. 

18-Inch Aluminum Wheels paired with aggressive 305/70R18 mud-terrain tires for a purposeful off-road stance. 

Black AT4X Exterior Accents for a bold, distinctive appearance. 

Red Front Recovery Hooks adding both functional capability and signature off-road styling. 

LED Headlamps, LED Fog Lamps, and Roof Marker Lamps for modern illumination and a commanding presence. 

GMC MultiPro Tailgate offering versatile configurations for easier loading, unloading, and cargo access. 

Spray-On Bedliner and LED Cargo Bed Lighting to help protect the bed and improve visibility after dark. 

120V Bed-Mounted Power Outlet for convenient power access at the jobsite or campsite. 

Power-Retractable Running Boards that provide easy access while maintaining a clean exterior profile. 

Rear Bumper CornerSteps for convenient access to the truck bed. 

Whether youre hauling equipment, towing a fifth-wheel trailer, navigating winter roads, or exploring rugged backcountry trails, the 2026 GMC Sierra 2500HD AT4X delivers a commanding combination of Duramax diesel strength, serious off-road capability, advanced technology, and premium comfort. Its a heavy-duty truck built to work hard, explore farther, and make every journey feel exceptional. 

 



AMVIC Licensed Dealer

*Every reasonable effort is made to ensure the accuracy of the information shown. The Standard Equipment listed is provided at the time of the manufacture and may not match the exact vehicle displayed. Please confirm with a sales representative the accuracy of this information.

Engine: 8 Cylinder Engine 6.6L
Safety EquipmentAirbags, Dual-stage frontal airbags for driver and front outboard passenger; Seat-mounted side-impact airbags for driver and front outboard passenger; Head-curtain airbags for front and rear outboard seating positions; Includes front outboard Passenger Sensing System for frontal outboard passenger airbagFront and Rear Park Assist, ultrasonicRear Cross Traffic AlertTeen Driver a configurable feature that lets you activate customizable vehicle settings associated with a key fob, to help encourage safe driving behaviour. It can limit certain available vehicle features, and it prevents certain safety systems from being turned off. An in-vehicle report card gives you information on driving habits and helps you to continue to coach your new driverStabiliTrak, stability control system with Proactive Roll Avoidance and traction control, includes electronic trailer sway control and hill start assistDaytime Running Lamps, LED signature lightingHitch Guidance dynamic single line to aid in truck trailer alignment for hitchingRear Seat Belt IndicatorTire Pressure Monitoring System, auto learn includes Tire Fill Alert (does not apply to spare tire)Safety Alert SeatTrailer Side Blind Zone AlertHitch Guidance with Hitch View with image adjustment, Pan/Zoom/TiltFront Pedestrian Braking (Included and only available with (PDI) Sierra HD Pro Safety.)Automatic Emergency Braking (Included and only available with (PDI) Sierra HD Pro Safety.)LED Signature DRL'sHD Surround Vision provides the driver with an overhead view of the scene around the vehicle on a centre stack display. Includes front camera washer.Bed View Camera, camera in the CHMSL to show a view of the cargo bed display located in infotainment screen, includes Two Trailer Camera ProvisionsTrailer Camera Provisions and trailer viewing softwareForward Collision Alert (Included and only available with (PDI) Sierra HD Pro Safety.)Following Distance Indicator (Included and only available with (PDI) Sierra HD Pro Safety.)Lane Departure Warning (Included and only available with (PDI) Sierra HD Pro Safety.)Seat Belt Adjustable Guide Loops, front row onlyBuckle to Drive prevents vehicle from being shifted out of Park until driver seat belt is fastened; times out after 20 seconds and encourages seat belt use (Included and only available with (PDI) Sierra HD Pro Safety.)Trailering Information Label provides max trailer ratings for tongue weight, conventional, gooseneck and 5th wheel traileringOnStar Services capable (See onstar.ca for details and limitations. Services vary by model. Service plan required.)Trailer Tire Pressure Monitor Sensors includes set of 4 sensors. Sensor functionality requires (UET) In-Vehicle Trailering App to be ordered with the vehicle and installed by the factory. Sensors will be shipped loose with the truck and will need to be installed on trailer by customer. System is capable of monitoring up to 6 wheels. Additional or replacement sensors are available through GM AccessoriesOnStar Basics (OnStar Fleet Basics for Fleet) Drive more confidently with up to 8 years of core OnStar services including mobile app commands, connectivity for select apps that provide in-vehicle voice assistance and navigation with real-time traffic, and Automatic Crash Response. (Requires (UE1) OnStar. Term begins on vehicle delivery date. Paid subscription required after expiry. Services are dependent on compatible wireless networks provided by third-party wireless service providers, working vehicle electrical systems, GPS signal and other factors outside GM control. Changes in technology and wireless networks may limit or prevent the operation of certain services. Services, connectivity, and capabilities have additional terms and limitations and are subject to change, and will vary by model, vehicle configuration, software version, conditions, and geographical and technical restrictions. Compatible smartphone required for mobile app commands. Not all vehicles may transmit all crash data; OnStar links to emergency services; Voice and Maps apps are subject to change at any time and may be provided by third parties. Non-refundable and no cash value. See onstar.ca/en/info for terms and details.)Interior EquipmentSeating, heated driver and front outboard passengerSeats, ventilated driver and front passengerSeats, heated second row outboard seatsCentre Console, floor-mounted with cup holders, cell phone storage, power cord management, hanging file folder capabilityFloor covering, colour-keyed carpetingSteering wheel, leather-wrappedSteering wheel, heatedSteering wheel audio controlsCompass, located in instrument clusterWindow, power front, passenger express up/downWindows, power rear, express downDoor locks, powerRemote vehicle starter systemUniversal Home RemoteTheft-deterrent system, unauthorized entryPower outlet, instrument panel, 120-volt (400 watts shared with (KC9) bed mounted power outlet)Power outlet, bed mounted, 120-volt (400 watts shared with (KI4) instrument panel mounted power outlet)Defogger, rear-window electricAssist handles front A-pillar mounted for driver and passenger, rear B-pillar mountedAir conditioning, dual-zone automatic climate controlExterior Temperature Display, located in radio displaySteering column, manual Tilt-Wheel and telescopingRear Seat ReminderAdaptive Cruise ControlWireless ChargingUSB Ports, 2 (first row) located on consoleAir vents, rearDriver Information Centre, enhanced, 12.3" diagonal reconfigurable multicolour digital displayWindows, power front, drivers express up/downDriver memory recalls driver "presets" for power driver seat and outside mirrorsWindow, power, rear sliding with rear defoggerUSB Ports, 2, Charge/Data ports located inside centre consoleSeats, front bucket with centre consoleSeat, Up-level Rear with Storage Package 60/40 folding bench for Crew Cab models, includes full-length bench seat, seatback storage on left and right side, centre fold out armrest with 2 cupholders, full cab width under-seat storage, (includes child seat top tether anchor)Premium Floor Liners with removable carpet insert, frontPremium Floor Liners with removable carpet insert, rearGMC Premium information Display- 13.4" diagonal Multicolour touch screenKeyless Open and Start includes remote keyless entryUSB ports, (2) charge-only, rearRear Camera Mirror inside rearview auto-dimming with full camera displaySeat adjuster, driver 16-way power including lumbar and massageSeat adjuster, passenger 16-way power including lumbar and massageMulticolour 15" Diagonal Head-Up DisplaySeat trim, Full Grain LeatherExterior EquipmentTire carrier lock keyed cylinder lock that utilizes same key as ignition and doorCargo tie downs (12), fixed, rated at 500 lbs (226.8 kg) per cornerLamps, cargo area cab mounted integrated with centre high mount stop lamp, with switch in bank on left side of steering wheelGlass, deep-tintedTailgate and bed rail protection caps, topMouldings, beltline, BlackMirror caps, high gloss BlackWheelhouse liners, rearWipers, front rain-sensingFog lamps, LEDBed Step, Black integrated on forward portion of bed on driver and passenger sideHeadlamps, Animated LED projectors LED turn signals and Daytime Running LampsIntelliBeam, automatic high beam on/off (Included and only available with (PDI) Sierra HD Pro Safety.)LED Cargo Area Lighting located in cargo bed activated with switch on centre switch bank or key fobTaillamps, Animated LED Signature Tail, Stop, turn and Reverse lampsMirrors, outside power-adjustable vertical trailering with heated and auto-dimming upper glass, (driver and passenger), lower convex mirrors, turn signal indicators, puddle lamps, (U12) perimeter lighting, auxiliary lighting, power folding/extending (extends 3.31" [84.25mm]) lightingTailgate, GMC MultiPro Tailgate with six functional load/access features NOTE: Auto release can be disabled if ball hitch is installed. See Owner's manual for detailsTailgate, gate function manual with EZ Lift includes power lock and release, includes hitch area lightSunroof, powerWheels, 18" (45.7 cm) machined aluminum wheel with High Gloss black accentsTires, LT305/70R18-126/123R, 35" M/TTire, spare, LT305/70R18-126/123R, 35" M/TWheel, Spare 18" (50.8 cm)Assist steps, power retractable, Black includes LED lighting (Not available with any other assist steps.)CornerStep, rear bumper (Not available with (ULV) AT4X AEV Edition.)Grille (Gloss Black header and grille insert bars with Dark Nickel inserts.)Lamps, Smoked Amber roof marker, (LED)Door handles, body-colour (With (ULV) AT4X AEV Edition door handles will be Gloss black.)Bedliner, Spray-on, Pickup bedliner with GMC logo (does not include spray-on liner on tailgate due to Black composite inner panel)Bumper, front, body-colour lower (Bumper color will be High Gloss Black.)Bumper, rear body-colour with bumper CornerSteps (Bumper color will be High Gloss Black.)Entertainment EquipmentBluetooth for phone connectivity to vehicle infotainment systemWi-Fi Hotspot capable (Terms and limitations apply. See onstar.ca or dealer for details.)Wireless phone projection for Apple CarPlay and Android AutoAudio System, 13.4" diagonal Premium GMC Infotainment System with Google built in apps such as navigation and voice assistance includes colour touch-screen, multi-touch display, AM/FM stereo, Bluetooth streaming audio for music and most phones; featuring wireless Android Auto and Apple CarPlay capability for compatible phonesBose Premium Series with 12-speaker system with Centerpoint Richbass woofer and AudioPilotLPO, MultiPro Tailgate Audio System by KickerSiriusXM Trial SubscriptionSiriusXM with 360L Trial Subscription. SiriusXM with 360L transforms your customers' ride with our most extensive and personalized radio experience on the road. (IMPORTANT: The SiriusXM trial subscription is not provided on vehicles that are ordered for Fleet Daily Rental ("FDR") use. Certain features and/or content may not be available unless an active data connection is enabled in the vehicle. Content varies by SiriusXM subscription plan. Features and display may vary by vehicle. All SiriusXM services require a subscription, sold separately by SiriusXM after the trial period. Your SiriusXM service will automatically stop at the end of your trial unless you decide to subscribe. If you decide to continue service after your trial, the subscription plan you choose will continue for an indeterminate term and you will be charged according to your chosen payment method at the then current rates unless and until you cancel. Taxes apply. Please see the SiriusXM Customer Agreement at siriusxm.ca/terms for complete terms and how to cancel, which includes calling SiriusXM at 1-888-539-7474. All rates, content, and programming are subject to change. SiriusXM uses personal information in accordance with SiriusXM Privacy Policy, available at siriusxm.ca/privacy. SiriusXM Canada Inc. "SiriusXM", the SiriusXM logo, channel names and logos are trademarks of Sirius XM Radio Inc. and are used under license.)Mechanical EquipmentEngine, 6.6L V8 with Direct Injection and Variable Valve Timing, gasoline (401 hp [299 kW] @ 5200 rpm, 464 lb-ft of torque [629 N-m] @ 4000 rpm)Air filtration monitoringFour wheel driveCooling, external engine oil coolerCooling, auxiliary external transmission oil coolerBattery, heavy-duty 720 cold-cranking amps/80 Amp-hr maintenance-free with rundown protection and retained accessory power (Included and only available with (L8T) 6.6L V8 gas engine.)Alternator, 170 amps (Requires (L8T) 6.6L V8 gas engine.)Trailer brake controller, integratedFrame, fully-boxed, hydroformed front section and a fully-boxed stamped rear sectionSteering, Digital Variable Steering Assist this system automatically adjusts steering based on speed, road conditions, and other inputs to reduce driver effort and fatigueBrakes, 4-wheel antilock, 4-wheel disc with DURALIFE rotorsBrake lining wear indicatorRear axle, 3.73 ratio (Requires (L8T) 6.6L V8 gas engine.)Pickup bed includes bed assist stepPush Button StartAir filter, heavy-dutyHill Descent ControlTransfer case, two-speed active, electronic Autotrac with push button controlIn-Vehicle Trailering App, System includes checklist, trailer maintenance reminders, trailer security alerts, trailer mileage, tow/haul reminder, trailer electrical diagnostics and Trailer Tire Pressure Monitor System module (Includes trailer tire pressure monitoring alert when (PTT) trailer tire pressure monitor sensors are installed.)Capless Fuel Fill (Requires (L8T) 6.6L gas V8 engine.)Differential, driver-selectable full-locking rear, e-lockingRecovery hooks, Red (Deleted with (ULV) AT4X AEV Edition.)Skid Plates, front aluminumSkid Plates, Transfer case, steelSuspension, Off-Road Includes, 1.5" suspension lift: front suspension lift composed of: Control Arms, Ball Joints, Knuckles, DSSV Dampers, rear suspension lift composed of spacer block and DSSV Dampers and Half shafts w/ revised joints, 3-stage Leaf springs from 3500Transmission, 10-Speed automaticGVWR, 11,025 lbs. (5001 kg) (Included and only available with TK20743 model and (L8T) 6.6L V8 gas engine with 18", 20" or 22" wheels.)Other EquipmentTrailering Package includes trailer hitch, 7-pin and 4-pin connectors and (CTT) Hitch GuidanceSierra HD Pro Safety includes (UEU) Forward Collision Alert, (UE4) Following Distance Indicator, (UKJ) Front Pedestrian Braking, (TQ5) IntelliBeam, (UFL) Lane Departure Warning, (T8Z) Buckle to Drive and (UHY) Automatic Emergency BrakingProGrade Trailering System includes (PZ8) Hitch Guidance with Hitch View and (UET) In-vehicle Trailering App