2021 Momentum 381M Fifth Wheel Toy Hauler by Grand Design RV.

Momentum 381M

The Momentum offers luxury living space, while also providing a mobile garage for dirt bikes, ATV’s,  side by sides, and more! Grand Design has raised the bar for any competing toy hauler, with quality construction, game changing features, and a beautiful living space to relax in after a long day of playing hard.


Insulation, Heat, and A/C

Grand Design cut no corners when it came to insulating their M Series Toy Haulers. These trailers feature a thermal roof design that doesn’t just end with the roof, but extends down around the bottom of the front cap as well.  Fiberglass insulation, a layer of radiant foil, and another similar radiant foil insulation barrier are used as the three layers that insulate the floor and garage. (Yes! The garage is insulated, a detail that most toy haulers lack.)

The sidewalls, ramp door, and slides are welded aluminum framed and laminated with rigid foam insulation, along with the baggage doors and even the gooseneck of the Fifth Wheel!  Additionally the attic is vented to reduce condensation in the roof structure, and there is a Rail-Tite underbelly seal that helps to keep the corrugated barrier up tight against the frame and sealed from the elements.

There is 40,000 BTU of heating power to be delivered through the high performance furnace and fireplace. Dedicated heat ducts run to the underbelly and storage bay, as well as 12 volt heat pads on each holding tank to ensure functional water systems even in the coldest of temperatures.

If you are worried about the heat, no need. Grand Design uses a Stealth A/C System, which is 2x quieter than competition units. Airguide Technology is used to strategically guide and force air out of the vents, and the racetrack ducting ensures 23% more airflow than the average of leading competitors. There are 3 A/C units throughout the 381M to ensure that no matter where you are in the trailer you are never hot.


Exterior Features

  • 6 point hydraulic leveling system
  • Upgraded axle hangers
  • MORryde CRE3000 suspension system
  • Straight frame chassis (12″)
  • Solar prep
  • Door side exterior spray port
  • Enclosed fuel station with dual fuel tank  (60 Gal, 227 lbs)

Kitchen and Living Space

The 381M features a full kitchen to cook anything from leftovers to a 5 course dinner. It comes standard with a 18 Cu. Ft. Refrigerator, microwave, pantry, four burner range stove with cast iron grills, an electronic ignition oven, and 42,500 BTU of cooking power. There is even an island with a residential kitchen faucet, extendable countertops and bar stool seating. There is plenty of storage space inside the overhead cabinets, massive fridge, and pantry.

The living space merges with the kitchen of the 381M, designed to maximize hospitality and family time with its 4 seater sofa, entertainment center with an LED TV, fireplace, and even a loft! Above the cargo doorway there is a hidden overhead bed that can easily sleep an extra person if needed.

Bed and Bath

The 381M series floorplan features a full front bathroom, close to the front master bedroom, with a solid surface countertops, smart sink, toilet, and mirrored medicine cabinet for extra storage.  The bathroom also features a beautiful walk in shower with a glass door, seat and skylight. Best yet, Grand Design has solved the common problem of hunching over inside travel trailer’s tiny showers, by using a “sunken tub” technique, creating 6.5 feet of interior height to stand up inside this shower.

The front master bedroom has a queen sized bed, but there is also an option for a king. The residential headboard, dual 110 volt bedside outlets, and separate reading lights are sure to make you feel right at home in this bedroom. There is plenty of storage inside the wardrobe, and even more beneath the bed.


The 381M has a 15′ cargo area to store all kinds of toys from dirt bikes to side by sides. The rear ramp is easy to put up and down with just one person thanks to Grand Design’s Fast Ramp that features two sided lift assist technology. The cargo floor is triple insulated, and the Tuff-Ply surface is gas and oil resistant, easy to clean once the machines are out and you are ready to move in.

Momentum trailers allow the user to get the most out of the entire space in their trailer, because once the cargo area has been emptied it offers sleeping space for up to 4 more people, a second bathroom, and even a deck!

The 381M includes a Happi-Jac electric bunk system with folding sofas, with just a touch of a button you can easily change the space from a garage, to a bedroom, to a living space. Lowering the folding sofas allows the user to create a dinette to enjoy lunch, or fold the seats to create a bed and easily sleep 2 people. A top bed is optional to create bunk bunks and room to sleep an additional 2 people. There is also a LED TV, washer dryer prep, and a half bath with a sink and toilet.

Check out our Momentum 381M inventory here at Traveland RV on our website, and get in touch with us to set up a viewing!