Listen to the 6.6L Duramax growl... 🔊 There’s something about the 2026 GMC Sierra 2500 AT4X that just feels different in person. Especially when you're the one siting behind the wheel of a heavy-duty truck capable of climbing through rough terrain with 470 HP and 975 lb-ft of torque. If you’re looking for a truck that balances the Multimatic DSSV dampers with a 18,500 lbs max towing capacity, this is the benchmark. The Obsidian Rush interior is the quietest cabin in the segment. #GMCSierra #AT4X #DieselTrucks #2500HD #Duramax