2025 GMC Sierra 2500HD AT4X – Duramax Diesel 6.6L Duramax Turbo Diesel | Allison 10-Speed | 4WD | AT4X Luxury meets serious off-road capability in this 2025 GMC Sierra 2500HD AT4X! Equipped with the powerful 6.6L Duramax turbo-diesel engine and Allison 10-speed automatic transmission, this heavy-duty pickup combines impressive towing capability, premium comfort and aggressive styling. The AT4X package takes GMC's heavy-duty truck to another level with specialized off-road suspension, advanced four-wheel-drive technology and a premium interior designed for comfort on and off the pavement. Vehicle Highlights 6.6L Duramax turbo-diesel V8 470 horsepower and 975 lb-ft of torque Allison 10-speed automatic transmission Four-wheel drive AT4X off-road package Multimatic DSSV dampers Front and rear electronic locking differentials Factory suspension lift Heavy-duty towing capability Premium leather interior Heated and ventilated front seats Heated rear seats Large touchscreen infotainment system Bose premium audio Advanced trailering technology HEAVY-DUTY POWER MEETS PREMIUM LUXURY! Whether you're towing heavy equipment, heading off-road or looking for a premium daily driver, this Sierra AT4X delivers the power, comfort and versatility you'd expect from GMC's heavy-duty lineup. Available now at Lumpy's Auto Sales! Call or message Ben today for pricing, additional photos or to schedule a test drive.