Forest River Sierra 3770FL

Name: Forest River Sierra 3770FL
Brand: Forest River

Fifth wheelbuilt 2022–22Mixed build tierFindable on the used market

WHAT ONE COSTS

$52,000est. used (2022, 4 yr old)

Sticker was $86,752 in 2022. Out of production since 2022, so the used market is the only way to buy one. Estimate assumes a 2022 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK

~12,771 lbestimated as towed, for 2 people

dry weight 11,554 lb + fresh water (50 gal, full) 417 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 around14,190 lb (10% margin)

GVWR (the sticker maximum)14,175 lb

Tongue weight, loaded~2,404 lb (19%)

WHICH TOW VEHICLES IT FITS: 19 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 3770FL's published weights held steady. Fifth wheels also need a pickup bed and are held to the fifth-wheel rating where published.

VEHICLE	TOW RATING	VERDICT
Chevrolet Silverado / GMC Sierra 2500HD (Duramax, max tow) '24-26	22,500 lb	fits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '20-23	18,510 lb	fits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '11-19	18,100 lb	fits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '20-26	36,000 lb	fits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '11-19	23,300 lb	fits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, gooseneck) '20-22	22,800 lb	fits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, tow pkg) '17-19	18,000 lb	fits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel) '11-16	16,600 lb	fits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 HO diesel, gooseneck) '23-26	23,000 lb	fits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '17-19	32,500 lb	fits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '20-22	37,000 lb	fits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '11-16	21,600 lb	fits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 HO diesel DRW, gooseneck) '23-26	38,000 lb	fits, loaded, with 10% margin
Ford F-450 Super Duty (6.7 HO diesel DRW, gooseneck) '23-26	40,000 lb	fits, loaded, with 10% margin
Ram 2500 (6.7 Cummins HO) '19-26	20,000 lb	fits, loaded, with 10% margin
Ram 2500 (6.7 Cummins) '11-18	17,980 lb	fits, loaded, with 10% margin
Ram 3500 (6.7 Cummins DRW, gooseneck) '13-18	31,210 lb	fits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '25-26	36,610 lb	fits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '19-24	37,090 lb	fits, loaded, with 10% margin

The 76it doesn't fit

Chevrolet Colorado / GMC Canyon (2.7 Turbo HO, tow pkg) '23-26: over by ~5,841 lb loaded
Chevrolet Colorado / GMC Canyon (2.8 Duramax) '15-22: over by ~5,841 lb loaded
Chevrolet Silverado / GMC Sierra 1500 (6.2 V8, max tow) '19-26: over by ~3,501 lb loaded
Chevrolet Silverado 1500 (max tow) '14-18: over by ~2,331 lb loaded
Chevrolet Silverado EV (4WT) '24-26: over by ~1,521 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 ~3,051 lb loaded
Ford F-150 (3.5 EcoBoost, max tow) '15-20: over by ~2,061 lb loaded
Ford F-150 (3.5 EcoBoost, max tow) '21-23: over by ~171 lb loaded
Ford F-150 (3.5 EcoBoost, max tow) '11-14: over by ~2,601 lb loaded
Ford F-150 Lightning (max trailer tow) '22-26: over by ~3,771 lb loaded
Ford Maverick (2.0 EcoBoost, 4K tow pkg) '22-26: over by ~9,171 lb loaded
Ford Ranger (2.3 EcoBoost, tow pkg) '19-23: over by ~6,021 lb loaded
Ford Ranger (2.7 EcoBoost, tow pkg) '24-26: over by ~6,021 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 ~6,021 lb loaded
GMC Sierra EV '24-26: over by ~1,971 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 ~8,271 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 ~8,271 lb loaded
Jeep Gladiator (3.6 V6, max tow) '20-26: over by ~5,841 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 ~6,336 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 ~3,986 lb loaded
Nissan Titan XD (Cummins diesel) '16-19: over by ~1,331 lb loaded
Ram 1500 (3.0 Hurricane, max tow) '25-26: over by ~2,321 lb loaded
Ram 1500 (5.7 Hemi eTorque, max tow) '19-24: over by ~1,296 lb loaded
Ram 1500 (5.7 Hemi, max tow) '11-18: over by ~3,211 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 ~2,871 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 ~2,871 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 ~6,921 lb loaded
Toyota Tacoma (V6, tow pkg) '16-23: over by ~6,651 lb loaded
Toyota Tundra (5.7 V8, tow pkg) '11-21: over by ~3,591 lb loaded
Toyota Tundra (i-Force Max, tow pkg) '22-26: over by ~1,971 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

Length40.6 ft

Height (incl. A/C)13.3 ft

Width8.0 ft

GVWR14,175 lb

Dry weight11,554 lb

Dry tongue weight2,175 lb

Sleeps6

Slide-outs4

Axles2

Fresh water50 gal

Grey water82 gal

Black water52 gal

Air conditioning15,000 BTU

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

WHERE PEOPLE SLEEP

1× Rear queen bed(Permanent)60×80
2× Dinette and sofas convert to beds(Convertible)—

HOW IT'S BUILT: 4/5

WallsLaminated fiberglass

FrameAluminum

RoofWalk-on

UnderbellyEnclosed

Forest River (Mixed tier): Sierra is the Sandpiper's badge twin - welded aluminum-framed laminated construction, mid-pack Forest River quality control.

YEAR BY YEAR: WHAT CHANGED

2022Discontinued after a single model year
2022Introduced

FINDING ONE

Findable: a few listed nationwide most weeks. Why: Forest River is a volume manufacturer; only one model year. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Front-living couples plan offered for a single model year.

OTHER SIERRA FLOORPLANS

2850RL · 10,000 lb · sleeps 6 321RL · 13,669 lb · sleeps 4 3250IK · 10,000 lb · sleeps 6 3330BH · 13,769 lb · sleeps 6 3370RLS · 13,560 lb · sleeps 4 3440BH · 14,075 lb · sleeps 6 3550BH · 15,500 lb · sleeps 8 3660MB · 14,115 lb · sleeps 6 368FBDS · 15,500 lb · sleeps 6 3710HBFB · 15,500 lb · sleeps 8 372LOK · 15,500 lb · sleeps 8 373BH · 15,500 lb · sleeps 6 377FLIK · 15,500 lb · sleeps 8 379FLOK · 16,069 lb · sleeps 6 the whole line →

Find one for sale

Live listings for the 3770FL 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 Sierra line ↗

Is the 3770FL 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.