2020 GMC Sierra 2500HD AT4
2020 GMC Sierra 2500HD AT4 OVERVIEW 
2020 GMC Sierra 2500HD AT4 For Sale
The First Ever Sierra AT4 Heavy Duty truck features rugged exterior stylings that match its off-road performance.
- 6.6L gas V8 engine with 6-speed automatic transmission
- Off-road suspension, Rancho shocks and skid plates
- 18" all-terrain tires
- Red front recovery hooks
- Premium GMC Infotainment System
2020 GMC Sierra 2500HD AT4 MODELS
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Sierra 2500HD AT4
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Sierra 2500HD AT4 Denali
2020 GMC Sierra 2500HD AT4 CONFIGURATIONS
* Model and trim configurations may vary
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Sierra 2500HD AT4 Crew Cab Standard Bed
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Sierra 2500HD AT4 Crew Cab Long Bed
GMC Sierra 2500HD AT4 For Sale
2020 GMC Sierra 2500HD AT4 PERFORMANCE 
Park Grade Hold Assist
Prevents movement when shifting out of park on a hill and moving a foot from brake to accelerator pedal by automatically applying brakes at each wheel for an extended period of time while trailering.
Traction Select System with Off-Road Mode
The Traction Select System allows you to quickly switch between multiple traction configurations, including Off-Road mode and Tow/Haul mode, to help improve traction and control while driving on gravel or in muddy conditions. The system will retain the tow/haul setting configurations for up to 4 hours after the vehicle is turned off, eliminating the need to re-engage the system when returning from a brief stop on a long journey.
Allison® 10-Speed Automatic Transmission
The first of its kind in a heavy-duty truck in its class, the all-new Allison 10-speed automatic transmission features closer gear spacing that allows the engine to operate in an optimal range at all times with varying load and terrain conditions. This, combined with fortified components used throughout Sierra AT4 Heavy Duty’s driveline, provides maximum torque to the wheels at all times.
2020 GMC Sierra 2500HD AT4 APPEARANCE 
Advanced Lighting
Purpose meets high style with advanced lighting.
- High-Intensity LED headlamps
- LED taillamps
- LED daytime running lamps
- LED fog lamps
- LED cargo bed lighting
- LED cargo lamp
- Available smoked amber roof marker lamps
- Wheel molding amber arch lamps over each wheel
Side Bed Step
The new standard Side Bed Step, located just in front of the rear wheel arches, complements the large CornerStep rear bumper to provide easier access when grabbing equipment from the cargo bed.
New Trailering Mirrors
Power-adjustable black capped trailering mirrors that power fold, extend and retract at the touch of a button. The door mounted mirrors feature the following lights:
- Heated and auto-dimming upper glass (driver and passenger)
- Power extend/retract and fold
- Lower manually adjustable convex mirrors
- LED turn signal indicators/clearance lamps
- LED perimeter lighting
- LED rear guidance lamps
- LED forward auxiliary task lighting
2020 GMC Sierra 2500HD AT4 COMFORT 
Best-in-Class Crew Cab Front Head and Leg Room
The athletic interior features Best-in-Class Crew Cab front head room (43.0") and leg room (44.5") and a driver seat that sits 1" taller than the previous generation Sierra Heavy Duty and offers seats that provide support during long hauls.
Athletic Design with Premium Comfort
- Durable Jet Black leather-appointed front seats with Kalahari accents
- Real aluminum trim
- Heated and ventilated front seats
- Heated rear outboard seats
- Heated leather-wrapped steering wheel
- Enhanced HVAC system with dual-zone climate control and rear-seat outlets
Available Bose® Premium Sound System
The Bose Premium Sound system supplies impressive sound through seven different speakers including a rich bass subwoofer.
2020 GMC Sierra 2500HD AT4 SAFETY & WARRANTY 
PRO GRADE PROTECTION
Standard on every new GMC - GMC Pro Grade Protection has you truly protected with features and services including:
- 3-year / 36,000-mile Bumper-to-Bumper Limited Warranty
- 5-year / 60,000-mile Powertrain Limited Warranty
- 5-year / 60,000-mile Roadside Assistance & Courtesy Transportation
- 3-year / 36,000-mile Corrosion Protection
- 6-year / 100,000-mile Rust-Through Protection
- First maintenance visit
Forward Collision Alert
Forward Collision Alert can alert you when it detects a front-end collision is imminent with a vehicle ahead you are following. The system also can alert you if you are following a detected vehicle much too closely.
Rear Cross Traffic Alert
Rear Cross Traffic Alert can alert you to detected left- or right-cross traffic behind you when in Reverse.