01 What makes it unique
The Momentum 351MS is a fifth-wheel toy hauler 39 ft 11 in long with an 11 ft garage, on two axles with three slide-outs and a 60-gallon fuel station. It is on Grand Design’s Momentum roster for 2027.
Grand Design’s page lists an unloaded vehicle weight of 15,760 lb, a GVWR of 19,000 lb and a pin weight of 3,000 lb. It publishes no cargo carrying capacity, so none is printed or computed here. Tanks are 140 gal fresh, 52 gal grey and 104 gal black, and it sleeps 6.
Grand Design’s page names the 381MS and 320G as comparison floorplans.
How the 351MS differs from the other eleven Momentum fifth wheels. Most distinctive first. Each rank counts only the siblings that publish that field, and a figure most of them share is left out.
- Pin weight as a share of dry weight, 19%: third-smallest of twelve, between the 399M (17.8%) and the 350G (19.4%).
- Pin weight, 3,000 lb: fourth-lightest of twelve, between the 325G (2,638 lb) and the 363G (3,100 lb).
- Dry weight, 15,760 lb: fifth-lightest of twelve, between the 363G (14,250 lb) and the 344M (15,910 lb).
- Grey tank, 52 gal: smallest of twelve, level with the 320G, 350G and 381MS; next is the 395MT (78 gal).
- Black tank, 104 gal: largest of twelve, level with the 320G, 350G and 381MS; next is the 395MT (78 gal).
- Length, 39 ft 11 in: shared with the 344M; of twelve, three shorter and seven longer, nearest the 350G (39 ft 9 in) and the 363G (41 ft 7 in).
- GVWR, 19,000 lb: shared with the 344M and 363G; of twelve, three lower and six higher, nearest the 325G and 350G (18,000 lb) and the 394G (22,500 lb).
- Sleeping capacity, 6: shared with the 320G, 325G and two others; of twelve, two smaller and five larger, nearest the 350G and 399M (5) and the 394G, 395MT and 396DB (7).
Next to the 363G, the nearest lighter floorplan by dry weight, the 351MS is 1,510 lb heavier by dry weight, has a pin weight 100 lb lighter, is 1 ft 8 in shorter, has a fresh tank 42 gal larger, has a grey tank 50 gal smaller, has a black tank 52 gal larger, sleeps three fewer and has one more slide-out; the two publish the same GVWR and exterior height.
Next to the 344M, the nearest heavier floorplan by dry weight, the 351MS is 150 lb lighter by dry weight, has a pin weight 500 lb lighter, has a grey tank 52 gal smaller and has a black tank 52 gal larger; the two publish the same GVWR, length, exterior height, fresh tank, sleeping capacity and slide-out count.
02 Full specifications
Dimensions
- Exterior length
- 39 ft 11 in
- Exterior width
- 8 ft 5 in
- Width, slides out
- 14 ft 3 in
- Exterior height
- 13 ft 6 in
- Chassis
- 101″ wide body · 5-side aluminum cage
- Garage / flex length
- 11 ft
Weights
- Dry / unit base weight (UVW)
- 15,760 lbs
- GVWR (max loaded)
- 19,000 lbs
- Net cargo / payload
- Not published by Grand Design
- Hitch / pin weight
- 3,000 lbs
Capacities
- Fresh water
- 140 gal
- Grey water
- 52 gal
- Black water
- 104 gal
- LP gas
- 60 lbs · 2 tanks
- Refrigerator
- 20 cu. ft.
Construction
- Chassis
- 101″ Wide Body Super Chassis w/ drop-frame storage
- Body
- 5-side aluminum cage · 101″ wide body
- Sidewalls
- High-gloss gel coat · frameless tinted windows
- Roof
- Worry-Free composite w/ lifetime warranty · walk-on
- Underbelly
- Fully enclosed and heated underbelly and storage area
Running gear
- Hitch
- Fifth-wheel (in-bed) · MORryde® pin box
- Suspension
- MORryde® Independent Suspension 2.0 w/ disc brakes
- Leveling
- 6-point hydraulic
- Tires
- Heavy-duty H-rated · 17.5″ H-rated aluminum wheels
- Spare
- 17.5″ undermount
- Tire size
- ST215/75R17.5 LRH
- GAWR, as Grand Design lists it
- 14,000 lbs
Garage
- Garage / flex length
- 11 ft
- Ramp
- Ramp door w/ Keyed Alike™ latches
- Tie-downs
- 2,500 lb rated flush-mount tie-downs
- Fuel station
- 60 gal · dual tank
Galley & systems
- Refrigerator
- 20 cu. ft. 12-volt
- Air conditioning
- 30,000 BTU
- Furnace
- 35,000 BTU
- Water heater
- On-Demand
- Solar
- 330W roof-mounted panel · 50 AMP controller w/ Bluetooth · inverter prep · 2 USB dock ports
- Shower
- 48 X 30
Sleeping & layout
- Sleeps
- 6
- Slides
- 3
- Awnings
- 2
- Hitch type
- Fifth-wheel (in-bed)
- Primary bed
- 60 X 80 Queen Bed (King Opt.)
How these published figures sit against the rest of the catalogue: fifth wheel pin weight and payload; fresh, grey and black tank sizes; camper trailer size chart.
Drawn to scale
Size, with end view
Holding tanks
Axles, wheels and nose shape are schematic; not a floorplan. Data: dataset.
Towing it
Check your vehicle. Enter the ratings from your owner’s manual and the door-pillar placard.
Compares your figures with this page’s published GVWR (19,000 lb) and the upper loaded pin estimate (4,750 lb, a rule of thumb). Your vehicle’s placard and the trailer’s own weight label govern.
Loaded range: 15–25% of GVWR on the pin, a rule of thumb, not a measurement of this unit. No truck ratings or hitch classes (why; NHTSA, DOT HS 809 433). The range starts at the published figure, because loaded is never lighter than that.
03 The Momentum floorplan family
Momentum is Grand Design's toy-hauler family, and it spans four rosters across both tow types. The full-size Momentum fifth wheel is the flagship — a 101-inch wide-body coach on MORryde independent suspension with disc brakes, carrying a 60-gallon dual fuel station. The Momentum G-Class fifth wheel sits below it on MORryde CRE3000 suspension and a Rotoflex pin box with a 30-gallon fuel station, and the G-Class travel trailer puts that same garage behind a bumper pull. The Momentum MAV is the compact end — the lightest and cheapest way into a Momentum garage, and the one roster with no fuel station at all. The 351MS on this page is highlighted; each other profiled plan links to its own page. The full MY2027 catalogue runs to 28 floorplans across the four rosters; eight are profiled in depth here and the rest are catalogued on the line hub with their weights.
| Floorplan | Roster | Type | Length | Garage | Sleeps | Notable |
|---|---|---|---|---|---|---|
| 351MS | Momentum | 5W | 39′ 11″ | 11 ft | 6 | 11 ft garage, sleeps 6, 3 slides |
| 344M | Momentum | 5W | 39′ 11″ | 11 ft | 6 | Entry Momentum — lowest GVWR of the ten, tightest payload |
| 381MS | Momentum | 5W | 43′ 11″ | 15 ft | 6 | 15 ft garage, sleeps 6, 3 slides |
| 392M | Momentum | 5W | 45′ 11″ | 17 ft | 9 | Sleeps nine, longest fifth-wheel garage in the family |
| 395MT | Momentum | 5W | 46′ 4″ | 14 ft* | 7 | 14 ft* garage, sleeps 7, 3 slides |
| 396DB | Momentum | 5W | 46′ 4″ | 10 ft 10 in | 7 | 10 ft 10 in garage, sleeps 7, 3 slides |
| 399M | Momentum | 5W | 44′ 10″ | 12 ft 6 in | 5 | 12 ft 6 in garage, sleeps 5, 3 slides |
The full-size Momentum is Grand Design's luxury fifth-wheel toy hauler and the top of the family — a 101-inch wide-body coach on MORryde independent suspension with disc brakes, a 60-gallon dual fuel station and a 20-cubic-foot refrigerator. Pin weights here are factory dry figures and a toy hauler's real loaded pin climbs hard once the garage is full — weigh the loaded coach against your truck's payload and rear-axle rating. The other Momentum fifth-wheel floorplans are catalogued on the line hub.
04 Notes on this floorplan
11 ft garage, 60-gallon fuel station
Garage / flex length and fuel station as printed on the 351MS page.
Pin 3,000 lb on 15,760 lb UVW
Grand Design’s pin weight is 19.0% of its unloaded weight; the loaded figure is higher.
30,000 BTU A/C, 35,000 BTU furnace
Climate equipment as Grand Design lists it for the 351MS.
140 fresh / 52 grey / 104 black
Tank capacities in gallons, from the 351MS page.
05 How it compares
Named by Grand Design’s 351MS page as a comparison floorplan: UVW 17,722 lb, GVWR 23,500 lb, 43 ft 11 in.
Named by Grand Design’s 351MS page as a comparison floorplan: UVW 13,100 lb, GVWR 16,400 lb, 36 ft 3 in.
Every current Momentum floorplan, all four rosters, side by side.
07 Where this floorplan sits
Closest sibling: the Momentum 381MS, nearest on the published figures. It differs on 4 of the 8 fields both publish (this plan first): length 39 ft 11 in vs 43 ft 11 in; dry weight 15,760 lb vs 17,722 lb; GVWR 19,000 lb vs 23,500 lb; hitch weight 3,000 lb vs 3,726 lb. They match on sleeps, fresh tank, grey tank and black tank.
| Momentum fifth-wheel plans | This plan | Position, low to high | Range |
|---|---|---|---|
| GVWR (lb) | 19,000 | 4–6 of 12 | 16,400–23,500 |
| Dry weight (lb) | 15,760 | 5 of 12 | 12,603–19,170 |
| Hitch weight (lb) | 3,000 | 4 of 12 | 2,300–3,760 |
| Length | 39 ft 11 in | 4–5 of 12 | 35 ft 6 in–46 ft 4 in |
| Fresh tank (gal) | 140 | 5–12 of 12 | 98–140 |
| Grey tank (gal) | 52 | 1–4 of 12 | 52–104 |
| Black tank (gal) | 104 | 9–12 of 12 | 52–104 |
| Sleeps | 6 | 3–7 of 12 | 5–9 |
Either side of it by GVWR: Momentum 344M matches it at 19,000 lb GVWR; Momentum 363G matches it at 19,000 lb GVWR.
| Nearest Momentum fifth-wheel siblings | Length | Sleeps | Dry (lb) | GVWR (lb) | CCC (lb) | Hitch (lb) | Fresh (gal) |
|---|---|---|---|---|---|---|---|
| Momentum 351MS | 39 ft 11 in | 6 | 15,760 | 19,000 | — | 3,000 | 140 |
| Momentum 381MS | 43 ft 11 in | 6 | 17,722 | 23,500 | — | 3,726 | 140 |
| Momentum 350G | 39 ft 9 in | 5 | 13,400 | 18,000 | — | 2,600 | 98 |
| Momentum 320G | 36 ft 3 in | 6 | 13,100 | 16,400 | 3,300 | 2,300 | 98 |
| Momentum 344M | 39 ft 11 in | 6 | 15,910 | 19,000 | 3,090 | 3,500 | 140 |
| Momentum 395MT | 46 ft 4 in | 7 | 19,100 | 23,500 | — | 3,760 | 140 |
All 24 Momentum floorplans: Momentum line hub.
| Other lines, nearest by GVWR | GVWR (lb) | Dry (lb) | Sleeps | Length |
|---|---|---|---|---|
| 351MS | 19,000 | 15,760 | 6 | 39 ft 11 in |
| Influence 3804DS | 19,000 | 14,603 | 6 | 42 ft 6 in |
| North Point 375TBDB | 19,000 | 15,735 | 9 | 42 ft 1 in |
| Paradigm 385FL | 19,000 | 15,487 | 6 | 41 ft 4 in |
| Solitude 310GK | 19,000 | 12,100 | 4 | 34 ft 4 in |
| Seismic 3512 | 18,995 | 14,285 | 7 | 41 ft 7 in |
| Riverstone 39RKFB | 18,975 | 16,511 | 4 | 42 ft 1 in |
Against the 351MS: the Influence 3804DS is 3 ft longer; the North Point 375TBDB is 2 ft longer and sleeps 3 more; the Paradigm 385FL is 1 ft longer.
08 Common questions about the 351MS
How much does the 351MS weigh?
15,760 lb dry; 19,000 lb GVWR, the most it may weigh loaded.
What is the pin weight of the 351MS?
3,000 lb as published, 19% of the dry weight (median across 411 fifth wheels here: 19%).
What size tow vehicle does the 351MS need?
A tow rating of at least 19,000 lb, plus payload for the loaded pin weight, passengers and cargo.
How many people does the 351MS sleep?
It is rated to sleep 6. 5 of the 12 Momentum fifth-wheel floorplans that publish a count sleep more.
What are the tank capacities on the 351MS?
Fresh 140, grey 52, black 104 gallons. Off hookups, fresh water runs out first.
How long is the 351MS?
39 ft 11 in overall, tongue or pin box included.
From the figures above.
09 What this page publishes, and what it does not
14 of the 18 fields this catalogue tracks are published for the 351MS. Not published: cargo capacity (CCC), interior height, axle count, tire size (a description is published, a size is not).
Sourcing rules: methodology.
10 Manuals & documents
Sources: granddesignrv.com (linked below); the full source note is at the foot of the page.
11 NHTSA safety record
NHTSA holds 19 recall campaigns and 201 owner complaints (model years 2005 on) against the Momentum line. They are counted separately: a recall is a confirmed defect with a remedy, a complaint one owner’s unverified account.
What to look at on a used one. Across the 201 complaints filed on this line the most-reported components are structure (41%), unknown or other (19%) and suspension (10%).
Reports that name the 351MS
1 of those record name this floorplan specifically rather than the line as a whole.
| Type | Date | Reference | What it says |
|---|---|---|---|
| Recall | 6 May 2025 | 25V281000 | Steps that detach while in use increase the risk of injury. |
Recall coverage here is not complete, and complaints are owners’ unverified reports (how this record is built). Check a specific VIN at NHTSA before you buy. Full tables are on the Momentum line page.