The 2026 GMC Sierra 3500 HD can tow up to 36,000 lbs with fifth-wheel or gooseneck trailer equipment when configured with the Duramax 6.6L Turbo-Diesel, the Dual Rear Wheel (DRW) setup, the Max Trailering Package, and the 2WD drivetrain. SRW diesel models are rated up to 23,000 lbs, and gas SRW models reach approximately 18,700 lbs of towing capacity when properly equipped.

SRW (Single Rear Wheel) is the standard configuration with one tire on each rear corner — easier to maneuver and more practical for everyday driving. DRW (Dual Rear Wheel), commonly called a "dually," adds a second tire on each rear corner, significantly increasing stability under heavy fifth-wheel loads, raising max towing to 36,000 lbs, and boosting max payload to 7,200+ lbs. The DRW is wider and better suited for commercial hauling, horse trailers, large gooseneck loads, and heavy fifth-wheel RVs.

The Sierra 3500 HD offers two engines: the standard 6.6L V8 gasoline engine (401 HP / 464 lb-ft) and the available 6.6L Duramax Turbo-Diesel V8 (470 HP / 975 lb-ft). Both are paired with the Allison 10-speed automatic transmission as standard on every trim. The Duramax diesel is available on all trims and is standard on the Denali Ultimate. For maximum towing (36,000 lbs), the diesel is required.

Both trucks share the same engines, transmissions, cab styles, and trim lineup. The 3500 HD differs in three key ways: it offers a higher towing capacity (up to 36,000 lbs vs. 22,500 lbs), higher max payload (7,200+ lbs DRW vs. 4,049 lbs), and the addition of Dual Rear Wheel (dually) configurations. The 3500 HD also comes standard with a three-stage rear leaf spring suspension across all trims and has greater ground clearance in SRW form (285mm vs. 259mm on the 2500 HD).

GMC offers the Sierra 3500 HD in standard pickup configurations (Regular Cab, Double Cab, and Crew Cab) in both SRW and DRW wheel setups. For commercial chassis cab applications with custom flatbeds, service bodies, or utility beds, our Century Buick GMC sales team can discuss available options and ordering. Contact us directly at CenturyBuickGMC.com or call us for commercial fleet inquiries.

Yes — Century Buick GMC maintains Sierra 3500 HD inventory in multiple trims, cab configurations, engine choices, and wheel setups including DRW (dually). We serve contractors, ranchers, commercial buyers, and serious truck buyers from Tampa, Brandon, Carrollwood, South Tampa, Westchase, St. Petersburg, and all of Tampa Bay. Every Sierra 3500 HD at Century comes with our Exclusive Lifetime Powertrain Warranty — engine, transmission, and drive axles covered for life.