2026 Grand Design Momentum M-Class 399M

New Toy Hauler in Corinth, Texas, 76210

Show All 1 Photos

New 2026 Grand Design Momentum M-Class 399M available in Corinth, Texas

Unit Specs

Coming Soon

Stock #15732
Year2026
ManufacturerGrand Design RV
Make Grand Design
ModelMomentum M-Class
Floorplan399M
Floorplan LayoutFront Bedroom
Mid Kitchen
Mid Living Area
Two Entry/Exit Doors
Type Toy Hauler
ConditionNew
Length44' 10"
Width8' 5"
Height13' 6"
VIN573FM473XTBB04988
Price Get Price
Need to know your payment? Use our RV Loan Calculator!
Chassis101" Wide Body Super Chassis w/Drop-Frame Storage
Sleeps6
Water Capacity (Fresh)140 gal
Water Capacity (Black)52 gal
Water Capacity (Grey)104 gal
Air Conditioners1
A/C Spec30,000 BTU
Refrigerator Capacity20 ft³
Slideouts3
Payload Capacity4500 lbs
Dry Weight18,000 lbs
Tow/Hitch Weight3464 lbs
# Axles3

Looking to buy a 2026 Grand Design Momentum M-Class Toy Hauler RV?

This 2026 Grand Design Momentum M-Class 399M is jam-packed with features to make RVing better than ever. Ready to be a proud Grand Design owner? This 2026 Grand Design Momentum M-Class 399M is the perfect fit. This rig sleeps 6, so it makes the perfect family RV. With three slides, this rig feels roomy and spacious inside. The fridge, stove make the perfect combo for eating well on the road. Kick back and relax in the living area with the theater seating and , or TV. With the free standing dinette w/chairs, you’ve got the perfect place for family meal times. Keep a comfortable temperature inside your rig with the heating option. Go longer without filling up thanks to the 140 gallon fresh water tanks. The exterior features make camping a breeze, such as awning, black tank flush, detachable power cord, enclosed underbelly, exterior speakers, heated underbelly, leveling jacks, pass thru storage, ramp, roof vent, screen door, slideout and tinted windows. Never run out of room for your belongings thanks to the pass-through storage underneath.

2026 Grand Design Momentum M-Class 399M Features

Appliances
Furnace, Microwave, Refrigerator, Stove Top Burner, Water Heater
Electrical
Air Conditioning, Batteries, Solar Prep
Equipment
CO Detector, Fire Extinguisher, LED Lights, LP Detector, Propane, Smoke Detector, TV, TV Antenna
Exterior
Awning, Black Tank Flush, Detachable Power Cord, Enclosed Underbelly, Exterior Speakers, Heated Underbelly, Leveling Jacks, Pass Thru Storage, Ramp, Roof Vent, Screen Door, Slideout, Tinted Windows
Interior/Furnishings
Central Vacuum, Day/Night Shades, Fireplace, Free Standing Dinette w/Chairs, Island Kitchen, Kitchen Sink, Medicine Cabinet, Overhead Cabinetry, Pantry, Roof Vents, Shower, Table and Chairs, Theater Seating, Toilet, Wardrobe(s)

2026 Grand Design Momentum M-Class 399M Specifications

General

MSRP

$174,278

Dimensions

Height

13' 6"

Height (interior)

8' 5"

Length

44' 10"

Width

8' 5"

Weights

Dry Weight

18,000 lbs

GVWR

22,500 lbs

Hitch Weight

3,464 lbs

Payload Capacity

4,500 lbs

Capacities

Refrigerator Capacity

20 cu ft

Sleep Capacity

Water Capacity - Black

52 gal

Water Capacity - Fresh

140 gal

Water Capacity - Grey

104 gal

Exterior

# Awnings

# Axles

# Doors

# Slides

Chassis

101" Wide Body Super Chassis w/Drop-Frame Storage

Hitch

Fifth Wheel

Rear Opening

Ramp

Electrical

# A/C

A/C Spec

30,000 BTU

*MFG Specs are for base unit. Certain options may change specifications listed. Please consult dealer for more details. Data is provided by a 3rd party. RVUSA.com cannot guarantee the accuracy of the data presented.