Explore our GMC Sierra HD hub (2000–present) for in-depth specs, dimensions, towing and payload ratings, real-world performance, safety features, and ownership insights across every 2500HD and 3500HD variant—gas and Duramax diesel, 2WD and 4WD, all trims and model years. Find reliability patterns, common issues, recalls, maintenance schedules, fluid specs, and buyer guides to help you choose the right configuration for work, trailering, and daily use.