2026 Grand Design Momentum 399M

Vehicle Photo
  • MSRP: $195,915
  • Dealer Discount: $50,926
  • Finance Incentive: $5,000
  • Sale Price: $139,989
  • As Low As: $936 /mo (Edit)
Stock #: 21175561
Tucson, AZ
  • Available
  • New
  • Class: Fifth Wheel
  • Length: 44 ft 10in
  • Slides: 3
  • Dry Weight: 19,170
  • Sleeps: 4

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  • Front Bedroom
  • Kitchen Island
  • Toy Hauler
  • Two Entry/Exit Doors
Floorplan
  • Available Beds Queen
  • Exterior Height 13 ft 6in
  • Exterior Width 8 ft 5in
  • Interior Height 8 ft 5in
  • Garage Size 12 ft 6in
  • Pin Weight 3,406 lbs
  • Gross Weight 23,500 lbs
  • Dry Weight 19,170 lbs
  • Fuel Capacity 60 gal
  • Tire Size 17.5
  • Axle Count 3
  • Fresh Water Capacity 140 gal
  • Grey Water Capacity 104 gal
  • Black Water Capacity 52 gal
  • Furnace BTU 35,000
  • Refrigerator Type 12V Stainless Steel
  • Refrigerator Size 20
  • Cooktop Burners 3
  • Shower Type Shower w/Seat
  • Number of Awnings 3
  • Electrical Service 50 amps
  • Washer/Dryer Available Yes
  • TV Info LR 50"" LED TV, Garage 32"" LED TV, Patio 65"" TV

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.

 

†Airstream of Tucson strives to ensure the accuracy of the information provided on this website. However, actual products, programs and services may differ materially from those on this site. Airstream of Tucson is not responsible for errors made in stated pricing or specifications. Specifications and availability subject to change without notice. Price, length, weight, or any other specifications cannot be relied upon. Buyers should verify and confirm all claims made on the website. Sale price includes all manufacturer discounts and rebates. All prices listed on this site exclude tax, tags and title fees. Applicable government fees, state taxes, dealer fees and emissions testing charges will be added to comply with state vehicle codes. Freight and prep costs are additional and vary by state. Contact Airstream of Tucson for complete details.

*90 Days – Payments can be deferred for 90 days with approved credit. Interest accrues from contract date. Financing terms subject to lender approval. Not valid with other offers. Actual products, programs and services may differ materially from those on this site. Airstream of Tucson is not responsible for errors made in stated pricing. Specifications and availability subject to change without notice. Document fees vary by location. See dealership for complete details.

**Airstream of Tucson believes the specifications on this site supplied by the manufacturer to be correct at the time posted. However, specifications, standard equipment, model availability, options, fabrics, and colors are subject to change without notice. Some equipment may be unavailable when a vehicle is built. Some vehicles are pictured with options, which may be available at extra cost or may not be available on some models. You should verify the equipment that is on all vehicles. If a new vehicle shown on this website is subject to an open safety recall, Airstream of Tucson cannot deliver the vehicle to you until the recall repair is completed. This is a requirement of federal law.

***The advertised discount contains a $5,000 finance incentive. Finance Incentive applies if financing for your RV purchase is obtained with assistance by Airstream of Tucson and placed with a third party lender. Terms and Conditions may apply. Contact our finance department for further details.