NEW In Stock | Category: Toy Hauler | Brand: Grand Design | Stock No: GR2490
2026 Grand Design Momentum M-Class 399M
$164,495.00
Southaven RV & Marine | RV & Marine | Southaven, Mississippi
2026 Grand Design Momentum M-Class 399M Our top-of-the-line Momentum Fifth Wheel Toy Haulers are — inside and out — our most luxurious Toy Haulers. With the comfort of a master suite and master bath, home’s now a long way from your house. Features may include: Thermal Roof Design (R-40)* Fully Laminated Walls (R-11)* Triple Insulated Main ... [read more]
2026 Grand Design Momentum M-Class 399M
Our top-of-the-line Momentum Fifth Wheel Toy Haulers are — inside and out — our most luxurious Toy Haulers. With the comfort of a master suite and master bath, home’s now a long way from your house.
Features may include:
Thermal Roof Design (R-40)*
Fully Laminated Walls (R-11)*
Triple Insulated Main Floor (R-45)*
Triple Insulated Garage Floor (R-40)*
1.5" Insulated Baggage Doors
Vented Attic
Insulated Gooseneck
Rail-Tite Underbelly Seal
Our top-of-the-line Momentum Fifth Wheel Toy Haulers are — inside and out — our most luxurious Toy Haulers. With the comfort of a master suite and master bath, home’s now a long way from your house.
Features may include:
Thermal Roof Design (R-40)*
Fully Laminated Walls (R-11)*
Triple Insulated Main Floor (R-45)*
Triple Insulated Garage Floor (R-40)*
1.5" Insulated Baggage Doors
Vented Attic
Insulated Gooseneck
Rail-Tite Underbelly Seal
| Condition | NEW | |
| Stock Number | GR2490 | |
| Year | 2026 | |
| Make | Grand Design | |
| Model | Momentum M-Class 399M | |
| Vehicle Type | Trailer | |
| Category | Toy Hauler | |
| Brand | Grand Design Momentum | |
| VIN | 573FM4734TBB04792 | |
| Self-Contained | No |
| Dimensions | |
| Overall Height | 13' 6" | (w/opt. AC): 13' 6" |
| Overall Length | 44' 10" |
| Overall Width | 8' 5" |
| Interior Height | 8' 5" |
| Dimensions | Standard Bed: 60 X 80 Queen Bed | Standard Bunk: 30 X 80 | Shower: 48 X 30 |
| Garage Length | 12' 6" |
| Awning Size | 14' 9' 12' |
| Weights | |
| Hitch Weight Capacity | 3,464 lbs. |
| Unloaded Weight | 18,000 lbs. |
| GVWR | 22,500 lbs. |
| Capacities | |
| Fresh Water Capacity | 140 gal. |
| Gray Water Capacity | 104 gal. |
| Black Water Capacity | 52 gal. |
| LP Tank Capacity | 60 gal |
| Sleeping Capacity | 9 |
| Fuel Capacity | 60 lbs |
| Water Heater | On-Demand |
| Refrigerator | 20 cu. ft. |
| Features | |
| Features | Propane Tanks: 2 | Construction Type: Aluminum Cage | Slide Room R-Value: R-11 | Garage R-Value: R-40 | Slides: 3 | Awnings: 3 |
| R-Value, Floor | R-45 |
| R-Value, Wall | R-11 |
| R-Value, Roof | R-40 |
| Operational | |
| Furnace Output | 35,000 BTU |
| Air Conditioner Output | 30,000 BTU |
| Chassis | |
| Axle Count | 3 |
| Wheels & Tires | |
| Wheels | 17.50 in. |
| Tires, Rear Specification | ST215/75R17.5 LRH |
Estimate Payments
Payment calculations are just estimates. Rates and terms vary day to day. Not an agreement, informational purposes only. Contact dealer for current rates, terms, and payment plans, etc.
Advertised pricing excludes applicable taxes title and licensing and are subject to change without notice. Pricing may exclude any added parts, accessories or installation unless otherwise noted. Sale prices include all applicable offers. Not all options listed available on pre-owned models. Contact dealer for details.