Will It Tow?
2025 GMC Sierra 3500HD (6.6L Duramax V8, dually) with the 2026 Puma Grand Mesa 394RKL at its full GVWR of 18,575 lb, two adults and a dog aboard and a weight-distribution hitch.
To know for sure, enter the payload from your door sticker (the yellow Tire and Loading one).
- Tow rating: 1,425 lb to spare (18,575 lb camper, rating 20,000 lb)
- Payload: Not sure yet (4,164 to 5,464 lb used, payload ? lb)
- Truck and trailer together: Not sure yet (, GCWR not listed)
To settle it for your own truck: enter the payload from your door sticker (the yellow Tire and Loading one); measure your pin weight.
Check it with your own numbers- Fifth wheel hitch (needed): Rated for at least your camper's weight (18,575 lb) and about 4,700 lb of pin weight. That points to a 20K-class hitch or bigger. It mounts in the bed over the rear axle.
- Weight distribution and sway control (not needed): Fifth wheels ride on a hitch over the truck's rear axle, which makes them much more stable than a bumper-pull. These are for travel trailers.
- Short bed? (check): With a bed under 8 ft, use a slider hitch or a pin box made for short beds so the camper clears your cab on tight turns.
- Brake controller (needed): Your camper has electric brakes, and the controller in your cab runs them. Many newer trucks have one built in.
- Measure your pin weight (tip): We're estimating 3,344 to 4,644 lb. A CAT scale weigh, hitched and unhitched, gives you the real number. Enter it in step 2.
Hitches make towing steadier, but none of them raise your tow rating or payload. The hitch itself counts against payload.
Ratings come from manufacturer towing guides and spec sheets. These are planning estimates, not a safety guarantee. Your truck and camper stickers, your owner's manual and a scale always win.