2025 GMC Sierra HD AT4
2025 GMC Sierra HD AT4 OVERVIEW 
2025 GMC Sierra HD AT4 For Sale
- 6.6L V8 Gas engine
- Allison® 10-speed automatic transmission
- Remote Keyless Entry
- Automatic Emergency Braking
2025 GMC Sierra HD AT4 MODELS
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Sierra HD AT4
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Sierra HD AT4 AT4X
GMC Sierra HD AT4 For Sale
2025 GMC Sierra HD AT4 PERFORMANCE 
DURAMAX 6.6L TURBO-DIESEL V8 ENGINE
Sierra Heavy Duty’s available Duramax 6.6L Turbo-Diesel V8 engine features an efficient turbocharger and Allison 10-speed automatic transmission.
AT4 OFF-ROAD READINESS
AT4 features an off-road suspension with twin-tube Rancho shocks, skid plates and Hill Descent Control, which uses antilock braking to help you maintain control.
PROGRADE® TRAILERING TECH
This advanced suite of available intelligent technologies helps streamline the hitching and towing process with integrated tools that help enhance your sense of confidence and visibility.
2025 GMC Sierra HD AT4 APPEARANCE 
AT4 GRILLE
Stand out with AT4’s bold front-facing exterior design and LED projector headlamps with animated sequences.
20" AT4 WHEELS
Sierra HD AT4’s 20" gloss-black aluminum wheels with available BFGoodrich off-road tires are made for rough trails.
SPRAY-ON BEDLINER
Help protect the bed and enhance its style with durable cargo bed protection featuring a GMC logo.
2025 GMC Sierra HD AT4 COMFORT 
AT4X EXCLUSIVE OBSIDIAN RUSH INTERIOR
AT4X’s interior features authentic Vanta Ash wood, and seats include bold red and white double-needle stitching for athletic character.
PREMIUM ALL-WEATHER FLOOR LINERS
Help protect your interior with available floor liners with removable carpet inserts.
PREMIUM GMC INFOTAINMENT SYSTEM*
With available Google built-in compatibility,* this system offers a helpful, personalized and seamless way to enhance the entertainment in your truck.
2025 GMC Sierra HD 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
REAR PARK ASSIST
Rear Park Assist* can provide distance alerts to nearby detected objects behind your vehicle to help you park and avoid collisions when you’re in Reverse at low speeds.
*Feature will not function on certain models without dealer retrofit; see dealer for details.
BLIND ZONE STEERING ASSIST
Blind Zone Steering Assist can provide a brief, firm turn of the steering wheel when a potential collision is detected with a moving vehicle in the lane you’re entering.
FORWARD COLLISION ALERT
Forward Collision Alert can warn you if it detects a potential front-end collision with a vehicle you’re following so you can quickly take action. It can also provide a tailgating alert if you’re following a vehicle much too closely.