New 2026 Grand Design Momentum 399M Toy Hauler Fifth Wheel

Relax on the L-shaped sofa with recliners while watching the 50" TV and enjoying the fireplace.
12ft Garage Video Tour Bed Queen
2026 399M Features and Options

"This is the manufacturer's minimum allowed advertised price, contact us today for your unbeatable personalized quote."

 

NEW 2026 Grand Design Momentum 399M Fifth Wheel Toy Hauler Highlights:

  • Front Private Bedroom

  • Kitchen Island

  • Hybrid Desk/Dinette

  • Unobstructed Pass-Thru Storage

  • Side Patio

Adventure meets comfort in the 2026 Grand Design Momentum 399M, a fifth wheel toy hauler designed for off-road enthusiasts who want all the conveniences of home. The 12' 6" separate garage provides ample space for your ATVs, motorcycles, or other toys, and you can entertain outdoors with the side patio, complete with a 65" TV, 1.7 cu. ft. refrigerator, and exterior griddle. Optional Liftsuite system and underside lighting allow extra sleeping space or ambiance in the garage.

Inside, the fully equipped kitchen features a kitchen island, pantry, pull-out countertop extension, and plenty of prep space. Relax on the L-shaped sofa with recliners while watching the 50" TV and enjoying the fireplace. Need to get some work done on the road? The hybrid desk/dinette with windows makes it easy to stay connected. The full bathroom is conveniently located near the front private bedroom, which offers a queen bed slide (optional king), large closet with washer/dryer prep, dresser with TV prep, and comfortable space to unwind after a day of adventure.

Built for four-season travel, the Momentum toy haulers include a fully enclosed and heated underbelly, 5-sided aluminum cage construction, and triple insulated garage floor for extreme weather protection. The MORryde CRE3000 suspension system and upgraded axle hangers provide smooth towing, while interior luxuries include color-changing LED accent lighting, hardwood cabinet doors with hidden hinges, and a central vacuum system. Four included packages—Garage Package with Tuff-Ply flooring, Weather-Tek Package with Stealth AC, and Interior Luxury Package with solid surface countertops—ensure your travels are comfortable, stylish, and functional.

Why Buy from Campers Inn RV Tucson? Campers Inn RV Tucson offers the largest selection of Momentum toy haulers, transparent pricing, and a team of experts ready to help you find the perfect RV for your adventures. From your first step on the lot to years of service, your experience will be seamless, fun, and worry-free.

Inventory/Stock Images may be shown. Colors and specifications may vary. Call our AMAZING TEAM for details.

 

What Our Customers Are Saying

Great Experience

They went above and beyond to make a wonderful experience buying our camper. From sales to the guys doing the walk through to finance. I would highly recommend them to anyone. Very easy transaction. A+ rating in our book. Thank you for everything. - Jason
Price: $191,444
Campers Inn
Location: Tucson AZ
Stock# 21175561
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2026 399M Specifications
Sleeps 4
Slides 3
Length 44 ft 10 in
Ext Width 8 ft 5 in
Ext Height 13 ft 6 in
Int Height 8 ft 5 in
Hitch Weight 3406 lbs
GVWR 23500 lbs
Dry Weight 19170 lbs
Fresh Water Capacity 140 gals
Grey Water Capacity 104 gals
Black Water Capacity 52 gals
Tire Size 17.5"
Furnace BTU 35000 btu
Fuel Capacity 60 gals
Available Beds Queen
Refrigerator Type 12V Stainless Steel
Refrigerator Size 20 cu ft
Cooktop Burners 3
Number of Awnings 3
Axle Weight 7000 lbs
Garage Size 12 ft 6 in
LP Tank Capacity 30 lbs
Water Heater Type On Demand
AC BTU 30000 btu
TV Info LR 50" LED TV, Garage 32" LED TV, Patio 65" TV
Awning Info 9', 12', 14' Power w/LED Lights
Axle Count 3
Washer/Dryer Available Yes
Number of LP Tanks 2
Shower Type Shower w/Seat
Electrical Service 50 amp
VIN 573FM4731TBB04622
For more information Contact Us

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Manufacturer and/or stock photographs may be used and may not be representative of the particular unit being viewed. Where an image has a stock image indicator, please confirm specific unit details with your dealer representative.