GMC Sierra 3500 Towing Guide: The Professional Grade Heavyweight

Know Your Power: Gas vs. Duramax

For the 2024+ model years, GMC made a massive upgrade: Both engines now come with the legendary Allison 10-Speed Transmission.

• 6.6L Duramax Turbo Diesel (The Towing King):

  • The Stats: 470 hp / 975 lb-ft torque.

  • Max Towing: Up to 36,000 lbs.

  • The Advantage: This engine is built for the mountains. With nearly 1,000 lb-ft of torque and a powerful exhaust brake, it pulls 20,000 lb trailers up (and down) steep grades with zero drama.

  • Best Match: Luxe Fifth Wheels, Riverstone, or 44-foot Toy Haulers.

• 6.6L Gas V8 (The Payload King):

  • The Stats: 401 hp / 464 lb-ft torque.

  • Max Towing: ~18,700 – 19,000 lbs.

  • The Secret Weapon: The gas engine is much lighter than the diesel. This gives a properly equipped Sierra 3500 Gas Dually a massive Payload Capacity (over 7,200 lbs). If you are hauling a heavy Truck Camper in the bed, the gas model is often the superior choice.

Single Rear Wheel (SRW) vs. Dual Rear Wheel (DRW)

• SRW (Single Rear Wheel): Excellent for daily driving and parking. Max towing usually tops out around 20,000 lbs. However, with big fifth wheels, you will often run out of payload capacity (pin weight limits) before you hit your max towing weight.

• DRW (Dually): The "Dually" is the stability king. The four rear tires eliminate the "wiggle" caused by high winds or passing semi-trucks. If your trailer weighs over 16,000 lbs, we highly recommend a Dually for safety and comfort.

The "MultiPro Tailgate" Warning

This is the most critical advice we can give GMC owners.

• The Feature: The MultiPro tailgate folds down into a step, which is incredibly useful.

• The Trap: If you have a ball hitch in your receiver and you deploy the inner step, it will crash into your hitch ball, denting your tailgate instantly.

• The Fix: You must buy a specific hitch that provides clearance, or install a "Tailgate Saver" sensor that prevents the step from opening when a hitch is present.

GMC’s "Transparent Trailer" Tech

GMC offers one of the best camera systems in the industry: the ProGrade Trailering System.

• Transparent Trailer View: By mounting an accessory camera (available at our Parts Counter) on the back of your RV, the truck stitches the video feed to make your trailer look "invisible" on the screen. This allows you to see cars following directly behind your massive camper.

• Jackknife Alert: The truck tracks the position of the trailer and warns you if you are turning too sharp, saving your cab from being crunched by the trailer cap.

What Can I Tow With a Sierra 3500?

• Full-Time Luxury 5th Wheels: The Sierra 3500 is the standard prime mover for "Full-Timers" living in units like the DRV Mobile Suites or Grand Design Solitude. The Allison transmission handles the constant heavy hauling without overheating.

• Mammoth Toy Haulers: With a Dually Duramax, you can pull a 45-foot Forest River XLR loaded with a side-by-side, 100 gallons of water, and a fuel station.

• Heavy Truck Campers: With the massive payload of the Gas Dually, you can carry a Northern Lite or Host Mammoth camper with slide-outs and still tow a boat behind you.

Ready to Go Big?

Your Sierra 3500 is a commercial-grade tool—let's find the job it was built for.

• Shop Heavy Duty: Browse our inventory of Fifth Wheels and Toy Haulers—your truck can handle the biggest ones we have.

• Protect Your Tailgate: Do you have the MultiPro tailgate? Visit our Parts Department to get a hitch that won't destroy it.

• Get Hitched: Need a B&W Companion or Curt hitch installed in your factory puck system? Our Service Team stocks the heavy-duty hardware you need.