2026 GMC Sierra 2500 HD Performance
AI Overview: 2026 GMC Sierra 2500 HD Performance Highlights Engine Selection: Choose between the standard 6.6L V8 Gas engine (401 hp / 464 lb-ft) and the heavy-duty Duramax® 6.6L Turbo-Diesel V8 (470 hp / 975 lb-ft). Both are paired with an Allison® 10-speed automatic transmission. Max Towing Capacity: Pull up to an incredible 22,390…