Mildenberger Motors

1717 N First Street Hamilton, MT 59840

2021 GMC Sierra 2500 AT4 OVERVIEW Overview Icon

2021 GMC Sierra 2500 AT4 in Hamilton

  • 6.6L gas V8 engine with 6-speed automatic transmission
  • Off-road suspension, Rancho shocks and skid plates
  • 18" all-terrain tires and available 20" all-terrain tires
  • Heated and ventilated leather-appointed 10-way power front seats and heated rear outboard seats
2021 GMC Sierra 2500 AT4 Main Img

2021 GMC Sierra 2500 AT4 CONFIGURATIONS

* Model and trim configurations may vary
  • Sierra 2500 AT4 Crew Cab Standard Bed
    Sierra 2500 AT4 Crew Cab Standard Bed
  • Sierra 2500 AT4 Crew Cab Long Bed
    Sierra 2500 AT4 Crew Cab Long Bed

GMC Sierra 2500 AT4 Dealer in Hamilton

2021 GMC Sierra 2500 AT4 PERFORMANCE Performance Icon

2021 GMC Sierra 2500 AT4 performance

HIGH-STRENGTH CHASSIS AND SUSPENSION

The strong chassis and suspension are built upon a fully boxed, ladder-type frame built from high-strength steel using front hydroformed rails with clamshell design. The powerful frame and optimized body structure works in conjunction with larger driveline components that feature high-strength axles and ring gears to bring immediate torque to ground for increased power while towing and off-roading.

2021 GMC Sierra 2500 AT4 performance

OFF-ROAD SUSPENSION WITH RANCHO® SHOCKS AND SKID PLATES

AT4’s Twin-Tube Rancho shocks provide dampening when going off road, skid plates provide added protection for underbody components and Eaton® locking rear differential helps give you traction to handle rugged terrain.

2021 GMC Sierra 2500 AT4 performance

ADVANCED ENGINES

  • Standard 6.6L V8 Gas Engine with 6-Speed Automatic Transmission
    o    401 hp and 464 lb-ft of torque
  • Available 6.6L Duramax® Turbo-Diesel V8 Engine with Allison® 10-Speed Automatic Transmission
    o    445 hp and 910 lb-ft of torque
    o    Large variable-speed cooling fan and dual path air induction system
    o    Factory-installed diesel after-run function maintains an ideal temperature for performance and minimizes fuel consumption
    o    Intelligent diesel exhaust brake system  
2021 GMC Sierra 2500 AT4 performance

MADE FOR OFF-ROAD

  • First HD in its class to offer a 2-speed AutoTrac transfer case with an active automatic 4WD drive setting which provides seamless shifting between two- and four-wheel drive based on road conditions
  • Hill Descent Control
  • Skid plates provide added underbody protection
  • Equipped with Off-Road Mode
  • Standard 18" machined aluminum wheels with Dark Grey metallic accents with standard All Terrain blackwall tires and available mud terrain tires
  • Available 20" machined aluminum wheels with high-gloss black accents with All Terrain black wall tires

2021 GMC Sierra 2500 AT4 APPEARANCE Appearance Icon

2021 GMC Sierra 2500 AT4 Appearance Main Img
2021 GMC Sierra 2500 AT4 appearance

AVAILABLE AT4 HIGH CLEARANCE STEP

The sturdy AT4 high clearance step is designed to help you and passengers get in and out of your vehicle. Textured surface helps provide increased traction and accessibility, even in wet and muddy conditions. Made to withstand harsh elements and environments.

2021 GMC Sierra 2500 AT4 appearance

NEXT-LEVEL GROUND CLEARANCE

To assist in clearing rugged terrain, available Sierra HD AT4 offers up to 11.18" of ground clearance along with a maximum approach angle of 27 degrees.

2021 GMC Sierra 2500 AT4 appearance

ADVANCED LIGHTING

  • LED headlamps (high-intensity on SLT, AT4 and Denali)
  • LED taillamps
  • LED daytime running lamps
  • Available LED fog lamps (available on SLE/standard on SLT, AT4 and Denali)
  • Available LED cargo bed lighting (available on SLE/standard on SLT, AT4 and Denali)
  • Wheel molding amber arch lamps over each wheel (Only on SRW models. Available on SLE, SLT, AT4. Standard on Denali)
  • Available Roof Marker Lamps (Standard on DRW and Denali. Available on SRW)

2021 GMC Sierra 2500 AT4 COMFORT Comfort Icon

2021 GMC Sierra 2500 AT4 comfort

PURPOSEFUL ACCOMMODATIONS & ACCENTS

  • Premium front and rear floor liners with removable carpet inserts
  • Embroidered AT4 logos
  • Heated and ventilated front only perforated leather seats
  • Exclusive Jet Black with Kalahari interior 
  • Heated leather-wrapped steering wheel
  • Rear seatback and under-seat storage
  • Powerful HVAC system with dual-zone climate control and rear-seat outlets
2021 GMC Sierra 2500 AT4 comfort

EYE-CATCHING INTERIOR OPTIONS

Jet Black Perforated Front Leather Seating Surfaces with Kalahari Accents. GMC Sierra HD AT4 Crew Cab Full Interior Overhead View Shown.

2021 GMC Sierra 2500 AT4 comfort

AVAILABLE JACKKNIFE ALERT

  • Tracks the position of the compatible trailer in relation to the vehicle and if the front of the trailer approaches the rear of the vehicle, an alert is displayed that you’re in a potential jackknife situation
  • A yellow warning alert will be displayed when truck/trailer angle is 75% into a jackknife scenario
  • A red warning alert will be displayed when truck/trailer angle is 90% into a jackknife scenario (i.e., collision is imminent)
  • Depending on customer settings for alerts and Safety Alert Seat availability, there will be a chime or haptic alerts associated with warnings
2021 GMC Sierra 2500 AT4 comfort

AVAILABLE AMAZON ALEXA BUILT-IN

Connect to Amazon Alexa Built-In for instant, hands-free access to music, directions, calls, news, weather and more.

2021 GMC Sierra 2500 AT4 SAFETY & WARRANTY Safety Icon

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
2021 GMC Sierra 2500 AT4 Safety Main Img
2021 GMC Sierra 2500 AT4 safety

AVAILABLE FOLLOWING DISTANCE INDICATOR

Following Distance Indicator displays the gap time in seconds between your vehicle and a detected vehicle you’re following. This can help you decide if you are following much too closely. Available on base Sierra HD, SLE, SLT and AT4. Standard on Denali.

2021 GMC Sierra 2500 AT4 safety

AVAILABLE AUTOMATIC EMERGENCY BRAKING

Automatic Emergency Braking works with Forward Collision Alert to help you avoid or reduce the severity of a front-end collision with a detected vehicle you are following. This feature works at speeds below 50 MPH. Camera technology is used to automatically provide hard emergency braking or enhance the driver’s hard braking. Available on base Sierra HD, SLE, SLT and AT4. Standard on Denali.

2021 GMC Sierra 2500 AT4 safety

AVAILABLE REAR CROSS TRAFFIC ALERT

Rear Cross Traffic Alert can alert you to detected left- or right-cross traffic behind you when in Reverse. Available on Sierra HD, SLE, SLT, and AT4. Standard on Denali.

We're sorry, but we do not have a 2021 GMC Sierra 2500 AT4 in our current inventory.

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