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Grand Design Momentum 397TH

Fifth wheelbuilt 2018–25Mixed build tierFindable on the used market
WHAT ONE COSTS
$117,100est. used (2025, 1 yr old)

Sticker was $162,669 in 2025. Out of production since 2025, so the used market is the only way to buy one. Estimate assumes a 2025 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~17,568 lbestimated as towed, for 2 people

dry weight 15,600 lb + fresh water (140 gal, full) 1,168 lb + propane + battery 200 lb + gear for 2 600 lb. Brochure dry weight omits water, propane, batteries and your gear; this estimate doesn't.

You want a tow rating around19,520 lb (10% margin)
GVWR (the sticker maximum)22,500 lb
Tongue weight, loaded~3,801 lb (22%)
WHICH TOW VEHICLES IT FITS: 14 OF 95

Judged the way the app judges: estimated loaded weight against each vehicle's rating less a 10% margin, per model year, because the 397TH's published weights changed mid-run. Fifth wheels also need a pickup bed and are held to the fifth-wheel rating where published.

VEHICLETOW RATINGVERDICT
Chevrolet Silverado / GMC Sierra 2500HD (Duramax, max tow) '24-2622,500 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '20-2636,000 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '11-1923,300 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, gooseneck) '20-2222,800 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 HO diesel, gooseneck) '23-2623,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '17-1932,500 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '20-2237,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '11-1621,600 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2638,000 lbfits, loaded, with 10% margin
Ford F-450 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2640,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins HO) '19-2620,000 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins DRW, gooseneck) '13-1831,210 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '25-2636,610 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '19-2437,090 lbfits, loaded, with 10% margin
The 81it doesn't fit

These verdicts assume 2 people aboard with typical gear. See the margin for your truck and your crew →

THE SPECS
Length44.2 ft
Height (incl. A/C)13.5 ft
Width8.4 ft
Interior height8.4 ft
GVWR22,500 lb
Dry weight15,600 lb
Dry tongue weight3,375 lb
Sleeps5
Slide-outs3
Axles3
Fresh water140 gal
Grey water104 gal
Black water104 gal

A missing row means the maker never published that figure: unknown, not zero.

WHERE PEOPLE SLEEP
  • 1× Front queen bed with under-bed storage (king upgrade offered)(Permanent)60×80
  • 1× Electric drop-down Happi-Jac bunk over the garage(Stow-away)—
  • 1× Garage folding sofa / recliner sofa(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameAluminum
RoofWalk-on
UnderbellyEnclosed

Grand Design (Mixed tier): Grand Design's toy hauler family, spanning four sub-series: the flagship M-Class fifth wheels (the plain M/MS/TH codes), the lighter G-Class fifth wheels (3xxG), G-Class travel trailers (2xG/3xG), and the entry MAV travel trailers. The premium fifth wheels are laminated aluminum-cage coaches on par with Solitude; MAV is a lighter traditional build, which is why the line as a whole reads mixed rather than uniformly better.

YEAR BY YEAR: WHAT CHANGED
YEARSGVWRDRYMSRP
2018–2020,000 lb15,500 lb$162,669
2021–2522,500 lb15,600 lb$162,669
  • 2018Introduced as the 397TH: 43' 3", 20,000 lb GVWR, 15,500 lb dry, sleeps 7
  • 2021Renamed 397THS
  • 2025Final year at 44' 2", 22,500 lb GVWR and 6,900 lb cargo capacity, sleeps 5; MSRP $162,669
  • 2026Dropped when the Momentum fifth-wheel range was reorganised into M-Class and G-Class
FINDING ONE

Findable: a few listed nationwide most weeks. Why: 8-year production run. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Grand Design's long-running big toy hauler; the 397 badge ran eight model years before the 2026 reshuffle retired it. If you actually load the garage, hold out for a 2021-or-later 22,500 lb build.

OTHER MOMENTUM FLOORPLANS
17MAV · 9,950 lb · sleeps 221G · 11,000 lb · sleeps 622MAV · 9,950 lb · sleeps 523G · 13,000 lb · sleeps 624MAV · 11,000 lb · sleeps 325G · 13,000 lb · sleeps 627G · 13,000 lb · sleeps 627MAV · 11,000 lb · sleeps 628G · 13,000 lb · sleeps 628MAV · 11,000 lb · sleeps 629GS · 13,000 lb · sleeps 630G · 13,000 lb · sleeps 731G · 13,000 lb · sleeps 6320G · 16,400 lb · sleeps 6the whole line →
Find one for sale

Live listings for the 397TH on the big marketplaces. Each search opens pre-filled with this exact floorplan:

RV Trader ↗Camping World ↗FB Marketplace ↗Google ↗

Inventory varies by site and day. Slim pickings? search the whole Momentum line ↗

Is the 397TH your #1, or just a spec sheet?

These are the facts. Whether it beats the other six thousand rigs for you depends on what you care about. Set your priorities as sliders, switch on your hard limits, and watch the whole market re-rank around them. Every exclusion explained, every margin shown.

See where it ranks for you →

Data compiled from dealer and aggregator listings, retrieved 2026-07.