Keystone Montana 3900RK
Fifth wheelbuilt 2026– (in production)Mixed build tierFindable on the used market
WHAT ONE COSTS
$175,800MSRP today
Still in production. A used 2023 would run roughly $103,700.
WHAT IT WEIGHS BEHIND YOUR TRUCK
~18,527 lbestimated as towed, for 2 people
dry weight 17,085 lb + fresh water (77 gal, full) 642 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 around20,590 lb (10% margin)
GVWR (the sticker maximum)19,405 lb
Tongue weight, loaded~3,692 lb (20%)
Cargo capacity2,320 lb
WHICH TOW VEHICLES IT FITS: 13 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 3900RK's published weights held steady. Fifth wheels also need a pickup bed and are held to the fifth-wheel rating where published.
The 82it doesn't fit
- Chevrolet Colorado / GMC Canyon (2.7 Turbo HO, tow pkg) '23-26: over by ~11,597 lb loaded
- Chevrolet Colorado / GMC Canyon (2.8 Duramax) '15-22: over by ~11,597 lb loaded
- Chevrolet Silverado / GMC Sierra 1500 (6.2 V8, max tow) '19-26: over by ~9,257 lb loaded
- Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '20-23: over by ~1,867 lb loaded
- Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '11-19: over by ~2,237 lb loaded
- Chevrolet Silverado 1500 (max tow) '14-18: over by ~8,087 lb loaded
- Chevrolet Silverado EV (4WT) '24-26: over by ~7,277 lb loaded
- Chevrolet Suburban (5.3 V8, max tow) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Chevrolet Tahoe (5.3 V8, max tow) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Chevrolet Traverse (tow pkg) '18-26: no pickup bed (cannot hitch a fifth wheel)
- Chrysler Pacifica '17-26: no pickup bed (cannot hitch a fifth wheel)
- Dodge Durango (5.7 / 6.4 Hemi, tow pkg) '14-26: no pickup bed (cannot hitch a fifth wheel)
- Ford Bronco 4-dr (2.7 EcoBoost, tow pkg) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Ford Expedition (3.5 EcoBoost, tow pkg) '25-26: no pickup bed (cannot hitch a fifth wheel)
- Ford Expedition (3.5 EcoBoost, tow pkg) '18-24: no pickup bed (cannot hitch a fifth wheel)
- Ford Explorer (3.0 EcoBoost, tow pkg) '20-26: no pickup bed (cannot hitch a fifth wheel)
- Ford F-150 (3.5 EcoBoost, max tow) '24-26: over by ~8,807 lb loaded
- Ford F-150 (3.5 EcoBoost, max tow) '15-20: over by ~7,817 lb loaded
- Ford F-150 (3.5 EcoBoost, max tow) '21-23: over by ~5,927 lb loaded
- Ford F-150 (3.5 EcoBoost, max tow) '11-14: over by ~8,357 lb loaded
- Ford F-150 Lightning (max trailer tow) '22-26: over by ~9,527 lb loaded
- Ford F-250 Super Duty (6.7 diesel, tow pkg) '17-19: over by ~2,327 lb loaded
- Ford F-250 Super Duty (6.7 diesel) '11-16: over by ~3,587 lb loaded
- Ford Maverick (2.0 EcoBoost, 4K tow pkg) '22-26: over by ~14,927 lb loaded
- Ford Ranger (2.3 EcoBoost, tow pkg) '19-23: over by ~11,777 lb loaded
- Ford Ranger (2.7 EcoBoost, tow pkg) '24-26: over by ~11,777 lb loaded
- Ford Transit (HD tow pkg) '15-26: no pickup bed (cannot hitch a fifth wheel)
- GMC Acadia (tow pkg) '20-26: no pickup bed (cannot hitch a fifth wheel)
- GMC Hummer EV Pickup '22-26: over by ~11,777 lb loaded
- GMC Sierra EV '24-26: over by ~7,727 lb loaded
- GMC Yukon / Yukon XL (5.3 V8, max tow) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Honda Odyssey '18-26: no pickup bed (cannot hitch a fifth wheel)
- Honda Passport (AWD) '19-26: no pickup bed (cannot hitch a fifth wheel)
- Honda Pilot (AWD, tow pkg) '16-26: no pickup bed (cannot hitch a fifth wheel)
- Honda Ridgeline (AWD) '17-26: over by ~14,027 lb loaded
- Hyundai Palisade (tow pkg) '20-26: no pickup bed (cannot hitch a fifth wheel)
- Hyundai Santa Cruz (2.5T AWD) '22-26: over by ~14,027 lb loaded
- Jeep Gladiator (3.6 V6, max tow) '20-26: over by ~11,597 lb loaded
- Jeep Grand Cherokee (5.7 Hemi) '11-21: no pickup bed (cannot hitch a fifth wheel)
- Jeep Grand Cherokee (WL, tow pkg) '22-26: no pickup bed (cannot hitch a fifth wheel)
- Jeep Grand Cherokee L (5.7 Hemi) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Jeep Grand Wagoneer (Hurricane, max tow) '22-26: no pickup bed (cannot hitch a fifth wheel)
- Jeep Wagoneer (Hurricane, max tow) '22-26: no pickup bed (cannot hitch a fifth wheel)
- Jeep Wrangler Unlimited 4-dr (tow pkg) '18-26: no pickup bed (cannot hitch a fifth wheel)
- Kia Telluride (tow pkg) '20-26: no pickup bed (cannot hitch a fifth wheel)
- Land Rover Defender '20-26: no pickup bed (cannot hitch a fifth wheel)
- Land Rover Discovery '17-26: no pickup bed (cannot hitch a fifth wheel)
- Lexus GX 550 (tow pkg) '24-26: no pickup bed (cannot hitch a fifth wheel)
- Lexus LX 600 '22-26: no pickup bed (cannot hitch a fifth wheel)
- Mazda CX-90 (3.3 turbo, tow pkg) '24-26: no pickup bed (cannot hitch a fifth wheel)
- Mercedes-Benz Sprinter '19-26: no pickup bed (cannot hitch a fifth wheel)
- Nissan Armada (3.5 twin-turbo, tow pkg) '25-26: no pickup bed (cannot hitch a fifth wheel)
- Nissan Armada (tow pkg) '17-24: no pickup bed (cannot hitch a fifth wheel)
- Nissan Frontier (3.8 V6, tow pkg) '22-26: over by ~12,092 lb loaded
- Nissan Pathfinder (tow pkg) '22-26: no pickup bed (cannot hitch a fifth wheel)
- Nissan Titan (5.6 V8, tow pkg) '17-24: over by ~9,742 lb loaded
- Nissan Titan XD (Cummins diesel) '16-19: over by ~7,087 lb loaded
- Ram 1500 (3.0 Hurricane, max tow) '25-26: over by ~8,077 lb loaded
- Ram 1500 (5.7 Hemi eTorque, max tow) '19-24: over by ~7,052 lb loaded
- Ram 1500 (5.7 Hemi, max tow) '11-18: over by ~8,967 lb loaded
- Ram 2500 (6.7 Cummins HO) '19-26: over by ~527 lb loaded
- Ram 2500 (6.7 Cummins) '11-18: over by ~2,347 lb loaded
- Ram ProMaster '14-26: no pickup bed (cannot hitch a fifth wheel)
- Rivian R1S '22-26: no pickup bed (cannot hitch a fifth wheel)
- Rivian R1T '22-26: over by ~8,627 lb loaded
- Subaru Ascent '19-26: no pickup bed (cannot hitch a fifth wheel)
- Subaru Outback (XT / Wilderness) '20-26: no pickup bed (cannot hitch a fifth wheel)
- Tesla Cybertruck '24-26: over by ~8,627 lb loaded
- Tesla Model X (tow pkg) '16-26: no pickup bed (cannot hitch a fifth wheel)
- Tesla Model Y (tow pkg) '21-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota 4Runner (4.0 V6) '11-24: no pickup bed (cannot hitch a fifth wheel)
- Toyota 4Runner (i-Force Max) '25-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Grand Highlander (i-Force Max) '24-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Highlander (tow pkg) '20-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Land Cruiser (i-Force Max) '24-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Sequoia (i-Force Max, tow pkg) '23-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Sienna '21-26: no pickup bed (cannot hitch a fifth wheel)
- Toyota Tacoma (i-Force Max, tow pkg) '24-26: over by ~12,677 lb loaded
- Toyota Tacoma (V6, tow pkg) '16-23: over by ~12,407 lb loaded
- Toyota Tundra (5.7 V8, tow pkg) '11-21: over by ~9,347 lb loaded
- Toyota Tundra (i-Force Max, tow pkg) '22-26: over by ~7,727 lb loaded
- Volkswagen Atlas (tow pkg) '18-26: no pickup bed (cannot hitch a fifth wheel)
These verdicts assume 2 people aboard with typical gear. See the margin for your truck and your crew →
THE SPECS
Length43.8 ft
Height (incl. A/C)13.3 ft
GVWR19,405 lb
Dry weight17,085 lb
Dry tongue weight3,405 lb
Cargo capacity2,320 lb
Sleeps6
Slide-outs4
Fresh water77 gal
Grey water150 gal
Black water100 gal
Air conditioning18,000 BTU
Solar (standard)220 W
A missing row means the maker never published that figure: unknown, not zero.
WHERE PEOPLE SLEEP
- 1× front bedroom king (60×80 queen available)(Permanent)60×80
- 2× theater seating and dinette(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameAluminum
RoofWalk-on
UnderbellyEnclosed
Keystone (Mixed tier): Keystone's flagship — the best construction in the Keystone stable (laminated walls, aluminum frame, long structural warranty), but Thor-era QC inconsistency keeps the line at mixed.
YEAR BY YEAR: WHAT CHANGED
- 2026Introduced with the redesigned Montana
FINDING ONE
Findable: a few listed nationwide most weeks. Why: Keystone is a volume manufacturer; only one model year; still in production. Estimated from build volume and production span, not a count of live listings.
OUR TAKE
Longest Montana at 43ft 10in - rear kitchen full-timer on the 19,405 lb chassis.
OTHER MONTANA FLOORPLANS
3100RL · 19,000 lb · sleeps 43120RL · 16,000 lb · sleeps 43121RL · 16,350 lb · sleeps 43123RL · 16,350 lb · sleeps 43230CK · 16,680 lb · sleeps 43231CK · 16,680 lb · sleeps 43531RE · 16,480 lb · sleeps 43532SP · 16,500 lb · sleeps 43700LK · 16,400 lb · sleeps 63740FK · 16,500 lb · sleeps 63760FL · 16,800 lb · sleeps 63761FL · 18,000 lb · sleeps 63762BP · 16,980 lb · sleeps 63763BP · 16,980 lb · sleeps 6the whole line →
Find one for sale
Live listings for the 3900RK on the big marketplaces. Each search opens pre-filled with this exact floorplan:
Inventory varies by site and day. Slim pickings? search the whole Montana line ↗
Is the 3900RK 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.