Used 2023 Grand Design Momentum 399TH
Lakewood, COWindish RV Center
Questions about this 2023 Grand Design Momentum 399TH
What does it cost?
Windish RV Center lists it at $96,980.
Is it new or used?
Used. It is a 2023 model.
Is it still for sale?
Windish RV Center’s website listed it for sale on October 31, 2026. RV Shift checks dealers’ websites about once a day, so ask the dealer to be sure.
Where is it?
At Windish RV Center in Lakewood, CO. See all 50 RVs Windish RV Center lists on RV Shift.
How many people does it sleep?
The dealer lists it as sleeping 5.
How long is it?
43' 1", with 3 slide-outs, as the dealer lists it.
How much does it weigh?
The dealer lists a dry weight (empty) of 15,900 lb, a GVWR (the most it is allowed to weigh loaded) of 20,000 lb and a hitch weight of 3,400 lb.
What does it take to tow it?
RV Finder’s estimate: it needs a vehicle rated to tow about 17,100 lb, with a fifth-wheel hitch. That is its 15,900 lb dry weight plus 1,200 lb for water and gear, rounded up to the next 100 lb. The listing doesn’t say whether it’s a fifth wheel or a bumper-pull. RV Finder judged it as a fifth wheel from its weights: ask the dealer. RV Finder shows whether it is within your vehicle’s published rating, from the maker’s own towing guide, and checks tongue weight and payload too. Confirm your numbers in your owner’s manual and on the sticker in the driver’s door jamb. Check it in RV Finder
How do I ask the dealer about it?
Use the Check availability form on this page. Your message comes to RV Shift and we pass it to Windish RV Center.
About this RV
Grand Design Momentum fifth wheel toy hauler 399TH highlights: • Fold-Down Side Patio • 13' Garage • Bath and a Half • Dual Entry • Island with Bar Stools • 60 Gallon Fuel Tank Get ready for a lot of fun when you head out to the off-road park, a special event, or a long trip with your toys! You will love the garage with the Fast Ramp rear ramp door, the Ram-Air garage vents on both sides, the 2,500 lb. rated flush-mount tie-downs and the protective diamond plate on the garage sidewalls. This area can become a bedroom or an extra living area if you want to add Happi-Jac rollover sofas/table with a top bed option, plus you will already have a half bath for convenience, an LED TV and storage for your gear. The living and kitchen area is spacious with dual slides and a kitchen island with bar stools, a free standing table and theatre seating or choose the super sofa option, and everything you need to feed everyone. The fold-down side patio offers an LED TV, storage and a great place to relax outdoors above ground. There are many more features to enjoy, and several options to customize your fifth wheel.
Specifications as listed by the dealer
- Type
- Toy hauler
- Condition
- Used
- Year
- 2023
- Make
- Grand Design
- Model
- Momentum 399TH
- Stock number
- 26C1071
- VIN
- 573FM4531P1123988
- Sleeps
- 5
- Slides
- 3
- Length
- 43 ft 1 in
- Ext Width
- 8 ft
- Ext Height
- 13 ft 5 in
- Hitch Weight
- 3,400 lbs
- GVWR
- 20,000 lbs
- Dry Weight
- 15,900 lbs
- Fresh Water Capacity
- 155 gals
- Grey Water Capacity
- 104 gals
- Black Water Capacity
- 104 gals
- Tire Size
- 17.5"
- Furnace BTU
- 40,000 btu
- Fuel Capacity
- 60 gals
- Available Beds
- Queen
- Refrigerator Type
- 12V Stainless Steel
- Refrigerator Size
- 20 cu ft
- Cooktop Burners
- 3
- Number of Awnings
- 2
- Axle Weight
- 7,000 lbs
- Garage Size
- 13 ft
- LP Tank Capacity
- 30 lbs
- AC BTU
- 30,000 btu
- TV Info
- LR 49" LED TV, BR LED TV, Garage 32" LED TV, Ext. LED TV
- Awning Info
- 14' & 16' Power w/LED Lights
- Axle Count
- 3
- Washer/Dryer Available
- Yes
- Number of LP Tanks
- 2
- Shower Type
- Sunken Tub/Shower
- Electrical Service
- 50 amp
Features
- Keyed Alike™ Ramp Door Latches
- 2nd Patio Awning w/ LED Lights
- 3rd Awning w/ LED Lights (Main Slide - 397THS & 410TH)
- Interior Color Changing LED Accent Lighting
- High-Gloss Gel Coat Exterior Sidewalls
- Door Side Exterior Spray Port
- Frameless Tinted Windows
- Walk-On Roof
- 17.5" Spare Tire (Undermount)
- Solid Step Quad Entry Step
- Slam-Latch Baggage Doors
- Mo-Secure
- 101" Wide Body Construction
- 5-Side Aluminum Cage Construction
- Fully Enclosed and Heated, Underbelly and Storage Area
- Upgraded Axle Hangers
- Heavy Duty H-Rated Tires w/NitroFill™
- Heavy Duty 7,000 lb. Axles with ABS Brakes
- 17.5" H-Rated Aluminum Wheels
- MORryde® CRE3000 Suspension System
- Anti-Lock Brake System
- 6-Point Hydraulic Leveling System
- MORryde® Pin Box
- 101" Wide Body Super Chassis w/Drop-Frame Storage
- Hardwood Cabinet Doors w/Hidden Hinges
- Sofa w/Headrest (Includes Heat, Massage & LED Lighting Package
- Central Vacuum System w/ Tools and Dust Pan
- Plywood Drawer Bottoms
- Microwave
- Residential Kitchen Faucet
- Professional Grade Stainless Steel Cooktop
- 12-Volt High Power MaxxAir w/Rain Sensor
- Window Behind Range
- Kitchen Barstools w/ Extended Countertops (397THS, 399TH, 410TH only)
- Solar Prep (10 gauge wiring with universal MC4 connectors)
- 75 Amp Converter
- 12V Battery Disconnect
- 12V High Power Fan (Kitchen)
- 35k BTU High Capacity Furnace
- Fireplace w/ 5,000 BTU Electric Heater
Listing and photos: Windish RV Center. Details come from the dealership and can change; confirm them before you buy.