2026 Forest River Sierra 3990FL

New Fifth Wheel in Mesa, Arizona, 85213

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New 2026 Forest River Sierra 3990FL available in Mesa, Arizona
2026 Forest River Sierra 3990FL - New Fifth Wheel For Sale by General RV Center in Mesa, Arizona
2026 Sierra 3990FL by Forest River from General RV Center in Mesa, Arizona
New 2026 Forest River Sierra 3990FL available in Mesa, Arizona

Unit Specs

**Forest River Sierra fifth wheel 3990FL highlights:** - King Bed - Front Living Area - Two Tri-Fold Hide-A-Beds - Theater Seating The perfect fifth wheel for a larger family! This unit sleeps eight people the loft above the rear master bedroom and bathroom. In the loft area, there are two 44" x 74" bunk mats for comfort as well as wardrobe/storage at the head of each. The master bedroom features a king size bed that slides out to create more space by the bed. A spacious bath features a one-piece fiberglass shower for comfort. A spacious kitchen features two slides, a free-standing dinette in one, and the 12V refrigerator and stove in the other. There is also a center island with large sink for added food prep space. Head up the steps in front to a dual slide front living area with 50" TV and fireplace beneath the window. There is also theater seating opposite the TV, and a tri-fold hide-a-bed in each slide allowing added sleeping space when needed. Each one of these Forest River Sierra fifth wheels are equipped with everything you need to make the most of each adventure! The underbelly armor will protect your unit's vitals from road debris and the painted two-tone aerodynamic fiberglass front cap has an improved turning radius to make them easier to navigate. With an electric leveling system, you can set your unit up quick and easy then get to having fun faster than ever. The cambered powder coated frame with rust prohibitor construction allows for more duration of the fifth wheel. Each model also comes with a TV antenna with booster, 60,000BTU on demand tankless water heater, Goodyear Radial tires with 7,000 lb. axles, and the list goes on. The interior is just as impressive with Beachside Sundance Congoleum linoleum, recessed residential lighting, a memory foam mattress, and hidden hinged, soft close drawers and cabinets!

View a video of this 2026 Forest River Sierra 3990FL RV on YouTube!

2026 Forest River Sierra 3990FL Features


2026 Forest River Sierra 3990FL Specifications

Dimensions

Height

13' 4"

Length

43' 6"

Width

8' 0"

Weights

Dry Weight

12,439 lbs

GVWR

15,375 lbs

Hitch Weight

2,825 lbs

Payload Capacity

2,936 lbs

Capacities

Refrigerator Capacity

16 cu ft

Sleep Capacity

10

Water Capacity - Black

50 gal

Water Capacity - Fresh

50 gal

Water Capacity - Grey

80 gal

Exterior

# Awnings

1

# Axles

2

# Doors

1

# Slides

5

Hitch

Fifth Wheel

Electrical

# A/C

2

A/C Spec

Dual ducted 15k BTU Air Conditioners, prepped for 3rd 15k BTU A/C

*MFG Specs are for base unit. Certain options may change specifications listed. Please consult dealer for more details. Data is provided by a 3rd party. RVUSA.com cannot guarantee the accuracy of the data presented.

2026 Forest River Sierra 3990FL Literature


Seller Info

General RV Center

2260 E Main Street
Mesa, AZ 85213

Member Since 2025

See 20 Reviews

Unit Specs

Estimated Payment-

Interest Rate % *(W.A.C.)
Term Years
Down Payment $
*W.A.C. = With approved credit

Email Seller

Request More Info on this 2026 Forest River Sierra 3990FL Offered for sale by General RV Center
General RV Center
General RV Center

2260 E Main Street
Mesa, AZ 85213

Phone: Click to Call

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New 2026 Forest River Sierra 3990FL available in Mesa, Arizona
2026 Forest River Sierra 3990FL - New Fifth Wheel For Sale by General RV Center in Mesa, Arizona
2026 Sierra 3990FL by Forest River from General RV Center in Mesa, Arizona
New 2026 Forest River Sierra 3990FL available in Mesa, Arizona