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2026 GMC Sierra 3500HD AT4
Vehicle Details
Body Style
Truck
Engine
6.6L 8Cyl
Exterior Colour
Black
Interior Colour
Black
Transmission
Automatic
Drivetrain
4×4
Stock #
302070
Trim Details
4WD Crew Cab Standard Box AT4
The 2026 GMC Sierra 3500HD AT4 brings unstoppable strength, bold off-road attitude, and premium craftsmanship to the heavy-duty segment. Purpose-built for demanding work and rugged adventure, this truck blends diesel power, intelligent capability, and upscale comfort — engineered for those who expect their HD pickup to exceed every expectation.Â
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Performance & CapabilityÂ
Engine: 6.6L Duramax Turbo-Diesel V8 delivering immense torque and dependable long-haul performanceÂ
Transmission: 10-Speed Automatic, tuned for smooth power delivery and confident towing controlÂ
Drivetrain: Autotrac 4WD with Two-Speed Transfer Case for seamless shifts between terrain demandsÂ
Rear Axle Ratio: 3.42, optimized for heavy towing and HD torque responseÂ
Exhaust Brake & Diesel-Specific Cooling Systems for better control on steep grades and under max loadÂ
Gooseneck/5th-Wheel Prep Package for maximum trailering compatibilityÂ
Integrated Trailer Brake Controller, Hitch Guidance & Hitch View, plus in-vehicle trailering toolsÂ
Off-Road Suspension with Skid Plates & Hill Descent Control designed for real AT4 capabilityÂ
20" Black Aluminum Wheels & All-Terrain Tires for bold stance and rugged tractionÂ
High-Capacity Alternator & HD Air Filter engineered for extreme use and harsh environmentsÂ
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Winter & Weather ComfortÂ
Heated & Ventilated Front Seats for comfort whether blazing hot or bitterly coldÂ
Heated Second-Row Outboard Seats to keep all passengers winter-readyÂ
Heated Steering Wheel for cold-morning comfortÂ
Remote Start System to warm or cool the cabin before you step insideÂ
Dual-Zone Automatic Climate Control with rear vents for consistent cabin temperaturesÂ
Engine Block Heater & Winter Grille Cover for dependable starts in extreme Canadian wintersÂ
Premium All-Weather Floor Liners to protect during slush, mud, or jobsite grimeÂ
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Interior Comfort & ConvenienceÂ
Front Bucket Seats with 10-Way Power Adjustments and driver memory settingsÂ
Power Sliding Rear Window & Rear Seat Storage Package for flexible everyday utilityÂ
13.4" GMC Premium Infotainment Touchscreen with Google Built-In and advanced navigationÂ
12" Reconfigurable Digital Driver Display with customizable layoutsÂ
Wireless Apple CarPlay® & Android Autoâ„¢, plus wireless chargingÂ
USB ports for all rows, including charge-only ports in the rearÂ
Bose Premium Audio System delivering crisp, immersive soundÂ
Push-Button Start & Keyless Open for seamless entry and ignitionÂ
Universal Home Remote & Sunroof adding premium convenienceÂ
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Safety & Driver AssistanceÂ
Forward Collision Alert with Automatic Emergency Braking for modern protectionÂ
Lane Departure Warning & Following Distance Indicator to enhance awarenessÂ
Rear Cross Traffic Alert & Trailer Side Blind Zone Alert for advanced trailering safetyÂ
HD Surround Vision & Bed View Camera offering a full 360° perspectiveÂ
Front & Rear Park Assist for confident maneuvering in tight spacesÂ
Adaptive Cruise Control for smooth long-distance drivingÂ
Front Pedestrian Braking & Rear Pedestrian AlertsÂ
Teen Driver & Buckle-to-Drive for added safety oversightÂ
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Exterior Styling & UtilityÂ
Onyx Black Exterior with AT4 Signature Styling — bold, premium, and athleticÂ
LED Headlamps, Fog Lamps, Cargo Lamps, & Roof Marker Lamps for exceptional visibilityÂ
GMC MultiPro Tailgate with versatile configurations for work or playÂ
EZ Lift & Power Lock/Release Tailgate for easy bed accessÂ
Spray-On Bedliner & 120V Bed-Mounted Outlet built for real jobsite durabilityÂ
Power-Retractable Assist Steps with LED Lighting for confidence in low-light conditionsÂ
Red Recovery Hooks & Rugged Front Bumper Design emphasizing AT4 strengthÂ
Single Rear Wheel Configuration for maneuverability and everyday usabilityÂ
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With uncompromising diesel strength, advanced trailering intelligence, and the premium ruggedness of the AT4 trim, the 2026 GMC Sierra 3500HD AT4 is built for those who demand power without sacrificing refinement. This is heavy-duty capability elevated to a new level — ready for the worksite, the backcountry, and everything in between.Â
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Packages & Options
Standard Equipment
Technical Specifications
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AM/FM Stereo
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Auxiliary Audio Input
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Bluetooth Connection
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MP3 Player
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Navigation System
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Smart Device Integration
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Requires Subscription
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Satellite Radio
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Premium Sound System
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WiFi Hotspot
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Aluminum Wheels
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Tires - Front All-Terrain
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Tires - Rear All-Terrain
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Conventional Spare Tire
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Tire carrier lock keyed cylinder lock that utilizes same key as ignition and door
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Bumper, front, body-colour lower
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Bumper, rear body-colour with bumper CornerSteps
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CornerStep, rear bumper
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Bed Step, Black integrated on forward portion of bed on driver and passenger side
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Mouldings, beltline, Black
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Wheelhouse liners, rear
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Bed Liner
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Cargo tie downs (12), fixed, rated at 500 lbs per corner
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Grille, Gloss Black header and grille insert bars with Black chrome accents
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Daytime Running Lights
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LED Headlights
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Automatic Highbeams
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Fog Lamps
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Taillamps, Animated LED Signature Tail, Stop, turn and Reverse lamps
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Lamps, cargo area, cab mounted integrated with centre high mount stop lamp, with switch in bank on left side of steering wheel
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LED Cargo Area Lighting located in cargo bed activated with switch on centre switch bank or key fob
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Heated Mirrors
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Integrated Turn Signal Mirrors
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Power Folding Mirrors
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Power Mirror(s)
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Mirror caps, high gloss Black
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Intermittent Wipers
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Rain Sensing Wipers
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Variable Speed Intermittent Wipers
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Privacy Glass
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Door handles, body-colour
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Integrated Tailgate Step
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Tailgate and bed rail protection caps, top
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Tailgate, gate function manual with EZ Lift includes power lock and release, includes hitch area light
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Bucket Seats
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Leather Seats
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Driver Adjustable Lumbar
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Power Driver Seat
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Passenger Adjustable Lumbar
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Power Passenger Seat
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Pass-Through Rear Seat
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Rear Bench Seat
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Heated Front Seat(s)
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Cooled Front Seat(s)
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Heated Rear Seat(s)
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Mirror Memory
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Seat Memory
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Centre Console, floor-mounted with cup holders, cell phone storage, power cord management, hanging file folder capability
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Floor covering, colour-keyed carpeting
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Floor Mats
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Heated Steering Wheel
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Adjustable Steering Wheel
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Steering Wheel Audio Controls
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Driver Information Centre, enhanced, 12.3" diagonal reconfigurable multicolour digital display
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GMC Premium information Display- 13.4" diagonal Multicolour touch screen
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Exterior Temperature Display located in radio display
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Compass, located in instrument cluster
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Tire Pressure Monitor
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Window, power front, drivers express up/down
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Power Windows
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Power Door Locks
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Remote Engine Start
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Keyless Entry
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Keyless Start
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Adaptive Cruise Control
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Cruise Control
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Security System
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Wireless Charging
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Power outlet, instrument panel, 120-volt (400 watts shared with (KC9) bed mounted power outlet)
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USB ports, (2) charge-only, rear
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Auxiliary Audio Input
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MP3 Player
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Power outlet, bed mounted, 120-volt (400 watts shared with (KI4) instrument panel mounted power outlet)
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A/C
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Climate Control
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Multi-Zone A/C
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Air vents, rear
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Rear Defrost
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Auto-Dimming Rearview Mirror
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Assist handles, front A-pillar mounted for driver and passenger, rear B-pillar mounted
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8 Cylinder Engine
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Gasoline Fuel
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10-Speed A/T
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A/T
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Rear axle, 3.73 ratio (Requires (L8T) 6.6L V8 gas engine.)
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Running Boards/Side Steps
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GVWR, 11,550 lbs. (5239 kg) with single rear wheels (Included and only available with TK30743 model and (L8T) 6.6L V8 gas engine. Requires single rear wheels.)
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Keyless Start
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Air filter, heavy-duty
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Air filtration monitoring
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Transfer case, two-speed active electronic Autotrac with push button control
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Locking/Limited Slip Differential
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Four Wheel Drive
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Cooling, external engine oil cooler
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Cooling, auxiliary external transmission oil cooler
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Battery, 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.)
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Alternator, 170 amps (Requires (L8T) 6.6L V8 gas engine.)
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Trailer brake controller, integrated
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Tow Hooks
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Frame, fully-boxed, hydroformed front section and a fully-boxed stamped rear section
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Skid Plates protect the oil pan, front axle and transfer case
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Suspension, Off-Road includes twin-tube shocks
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Power Steering
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4-Wheel Disc Brakes
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ABS
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Brake lining wear indicator
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Capless Fuel Fill (Requires (L8T) 6.6L gas V8 engine.)
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Automatic Highbeams
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Front Collision Mitigation
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Front Collision Warning
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Lane Departure Warning
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X31 Off-Road Package includes (JHD) Hill Descent Control, (NZZ) skid plates, Off-Road suspension and Twin-tube Rancho shocks
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Tow Hitch
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ProGrade Trailering System includes (PZ8) Hitch Guidance with Hitch View and (UET) In-vehicle Trailering App
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Trailering Information Label provides max trailer ratings for tongue weight, conventional, gooseneck and 5th wheel trailering
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Front Collision Mitigation
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Front Collision Warning
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Stability Control
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Traction Control
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Hill Descent Control
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Daytime Running Lights
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Driver Air Bag
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Front Head Air Bag
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Front Side Air Bag
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Passenger Air Bag
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Passenger Air Bag Sensor
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Rear Head Air Bag
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Requires Subscription
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Telematics
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Rear Parking Aid
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Aerial View Display System
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Back-Up Camera
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Bed View Camera camera in the CHMSL to show a view of the cargo bed, display located in infotainment screen, includes Two Trailer Camera Provisions
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Hitch Guidance dynamic single line to aid in truck trailer alignment for hitching
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Trailer Camera Provisions and trailer viewing software
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Cross-Traffic Alert
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Blind Spot Monitor
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Lane Departure Warning
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Following Distance Indicator (Included and only available with (PDI) Sierra HD Pro Safety.)
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Safety Alert Seat
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Rear Seat Reminder
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Driver Restriction Features
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Seat Belt Adjustable Guide Loops, front row only
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Rear Seat Belt Indicator (Requires Crew Cab or Double Cab model.)
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Buckle 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)
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Tire Pressure Monitor
No matches were found.
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Vehicle NameGMC Sierra 3500HD
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Body StyleCrew Cab Pickup
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Body CodeE63
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DrivetrainFour Wheel Drive
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Trans Order CodeMGM
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Trans Type10
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Trans Description Cont.Automatic
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First Gear Ratio (:1)4.54
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Second Gear Ratio (:1)2.87
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Third Gear Ratio (:1)2.06
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Fourth Gear Ratio (:1)1.72
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Fifth Gear Ratio (:1)1.48
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Sixth Gear Ratio (:1)1.26
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Seventh Gear Ratio (:1)1.00
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Eighth Gear Ratio (:1)0.85
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Ninth Gear Ratio (:1)0.69
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Tenth Gear Ratio (:1)0.63
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Reverse Ratio (:1)4.54
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Passenger Capacity5
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Front Head Room (in)43.03
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Front Leg Room (in)44.53
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Front Shoulder Room (in)66.02
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Front Hip Room (in)61.18
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Second Head Room (in)40.12
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Second Leg Room (in)43.4
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Second Shoulder Room (in)65.3
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Second Hip Room (in)60.24
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Gross Axle Wt Rating - Front (lbs)5600
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Gross Axle Wt Rating - Rear (lbs)7250
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Gross Vehicle Weight Rating Cap (lbs)12100
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Gross Combined Wt Rating (lbs)30000
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Dead Weight Hitch - Max Trailer Wt. (lbs)5000
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Dead Weight Hitch - Max Tongue Wt. (lbs)500
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Wt Distributing Hitch - Max Trailer Wt. (lbs)20000
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Wt Distributing Hitch - Max Tongue Wt. (lbs)2000
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Fifth Wheel Hitch - Max Trailer Wt. (lbs)21300
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Fifth Wheel Hitch - Max Tongue Wt. (lbs)5325
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Maximum Trailering Capacity (lbs)20000
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Engine Order CodeL5P
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Engine TypeTurbocharged Diesel V8
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Displacement6.6L
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Fuel SystemDirect Injection
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SAE Net Horsepower @ RPM470 @ 2800
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SAE Net Torque @ RPM975 @ 1600
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Engine Oil CoolerYes
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Cold Cranking Amps @ 0° F (Primary)720
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Maximum Alternator Capacity (amps)220
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Frame TypeHydroformed
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Suspension Type - FrontShort/Long Arm w/Torsion Bars
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Suspension Type - Rear3-Stage Multi-Leaf
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Axle Type - FrontIndependent
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Axle Ratio (:1) - Front3.42
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Axle Ratio (:1) - Rear3.42
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Shock Absorber Diameter - Front (mm)51
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Shock Absorber Diameter - Rear (mm)51
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Stabilizer Bar Diameter - Front (in)1.38
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Front Tire Order CodeQF9
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Rear Tire Order CodeQF9
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Spare Tire Order CodeZYG
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Front Tire SizeLT275/65R20
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Rear Tire SizeLT275/65R20
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Spare Tire SizeLT275/70R18
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Front Wheel Size (in)18 x 8
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Rear Wheel Size (in)18 x 8
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Spare Wheel Size (in)18 x 8
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Front Wheel MaterialAluminum
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Rear Wheel MaterialAluminum
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Spare Wheel MaterialSteel
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Steering TypePwr Recirculating Ball
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Steering Ratio (:1), At LockN/A
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Turning Diameter - Curb to Curb (ft)52.7
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Turning Diameter - Wall to Wall (ft)N/A
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Brake TypePwr
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Brake ABS System4-Wheel
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Disc - FrontYes
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Disc - RearYes
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Front Brake Rotor Diam x Thickness (in)14 x 1.6
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Rear Brake Rotor Diam x Thickness (in)14.1 x 1.3
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Fuel Tank Capacity, Approx (L)136
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Wheelbase (in)158.94
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Length, Overall (in)250.75
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Width, Max w/o mirrors (in)81.85
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Height, Overall (in)81.2
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Cab to Axle (in)42.17
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Ground Clearance, Front (in)11.18
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Ground Clearance, Rear (in)11.18
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Cargo Box Length @ Floor (in)82.2
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Cargo Box Width @ Floor (in)71.4
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Cargo Box Width @ Wheelhousings (in)51.85
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Cargo Box (Area) Height (in)21
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Cargo Volume (ft³)69.5
No matches were found.
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* Every reasonable effort is made to ensure the accuracy of the information listed above. Vehicle pricing, incentives, options (including standard equipment), and technical specifications listed is for the 2026 GMC Sierra 3500HD AT4 may not match the exact vehicle displayed. Please confirm the accuracy of this information with a sales representative.