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    1. Home
    2. Fifth wheel trailers
    3. Grand Design
    4. Solitude
    Grand Design Solitude 378MBS exterior

    Grand Design Solitude 378MBS

    Front bedroom, rear living area, bunk beds, mid bunk

    • Mid bunk
    • Front bedroom
    • Rear living area
    • Mid den
    • Desk
    MSRP

    $127,405

    Browse inventory (19)

    Videos

    Find a Grand Design Solitude 378MBS

    See it in person or find a great deal nationwide.
    Browse inventory (19)

    Similar floor plans

    Fifth wheel trailers that share features with the Solitude 378MBS, like front bedroom, washer dryer prep and fireplace.

    Keystone Montana High Country 281CK exterior

    Keystone Montana High Country 281CK

    MSRP$85,471

    5 units available

    Keystone Montana High Country 281CK floor plan
    Max weight

    14,250 lbs

    Length

    32 ft 2 in

    Sleeps

    4

    Grand Design Reflection 150 Series 280RS exterior

    Grand Design Reflection 150 Series 280RS

    MSRP$72,799

    13 units available

    Grand Design Reflection 150 Series 280RS floor plan
    Max weight

    10,995 lbs

    Length

    32 ft

    Sleeps

    6

    Keystone Cougar 260MLE exterior

    Keystone Cougar 260MLE

    Front bedroom, rear kitchen

    MSRP$76,763

    57 units available

    Keystone Cougar 260MLE floor plan
    Max weight

    12,000 lbs

    Length

    30 ft 11 in

    Sleeps

    4

    Forest River Impression 238RLVIEW exterior

    Forest River Impression 238RLVIEW

    Rear window, l-couch, bar seating, bunk beds

    MSRP$69,164

    2 units available

    Forest River Impression 238RLVIEW floor plan
    Length

    31 ft 3 in

    Sleeps

    5

    Grand Design Reflection 100 Series 28RL exterior

    Grand Design Reflection 100 Series 28RL

    Front bedroom, rear living area

    MSRP$68,605

    154 units available

    Grand Design Reflection 100 Series 28RL floor plan
    Max weight

    10,995 lbs

    Length

    31 ft

    Sleeps

    4

    Forest River Cherokee Black Label 265GDKBL exterior

    Forest River Cherokee Black Label 265GDKBL

    MSRP$65,130

    3 units available

    Forest River Cherokee Black Label 265GDKBL floor plan
    Max weight

    10,000 lbs

    Length

    30 ft 6 in

    Sleeps

    6

    Forest River Impression 242RD exterior

    Forest River Impression 242RD

    MSRP$59,021

    12 units available

    Forest River Impression 242RD floor plan
    Max weight

    9,995 lbs

    Length

    30 ft 5 in

    Sleeps

    3

    CrossRoads Volante 269RK exterior

    CrossRoads Volante 269RK

    MSRPTBD

    2 units available

    CrossRoads Volante 269RK floor plan
    Max weight

    10,270 lbs

    Length

    30 ft 11 in

    Sleeps

    4

    Other Solitude floor plans

    Grand Design Solitude 280RK

    Rear kitchen, walk-thru bath, rear window

    MSRP$116,786

    15 units available

    Grand Design Solitude 280RK floor plan

    RV Envy's expert take

    We like: Coffee bar, Bedroom TV faces bed

    Consider: No washer/dryer, Limited bedroom storage

    Max weight

    15,000 lbs

    Length

    32 ft 7 in

    Sleeps

    4

    Grand Design Solitude 280RK-R

    MSRP$116,786

    3 units available

    Grand Design Solitude 280RK-R floor plan
    Max weight

    15,000 lbs

    Length

    32 ft 7 in

    Sleeps

    4

    Grand Design Solitude 2930RL

    MSRP$107,647

    5 units available

    Grand Design Solitude 2930RL floor plan

    RV Envy's expert take

    We like: Fridge accessible w/ slides in, Bedroom closet in slideout, Large nightstands

    Consider: Washer/dryer replaces pantry, Limited bedroom storage, Limited kitchen storage

    Max weight

    15,000 lbs

    Length

    34 ft 4 in

    Sleeps

    6

    Grand Design Solitude 2930RL-R

    MSRP$107,647

    1 unit available

    Grand Design Solitude 2930RL-R floor plan
    Max weight

    15,000 lbs

    Length

    34 ft 4 in

    Sleeps

    6

    Grand Design Solitude 300GK

    MSRPTBD

    5 units available

    Grand Design Solitude 300GK floor plan
    Max weight

    15,000 lbs

    Length

    34 ft 11 in

    Sleeps

    4

    Grand Design Solitude 300GK-R

    MSRPTBD
    Grand Design Solitude 300GK-R floor plan
    Max weight

    15,000 lbs

    Length

    34 ft 11 in

    Sleeps

    4

    Grand Design Solitude 305RE

    MSRPTBD

    2 units available

    Grand Design Solitude 305RE floor plan
    Max weight

    16,000 lbs

    Length

    35 ft 11 in

    Sleeps

    4

    Grand Design Solitude 310GK

    Front bedroom, rear living area

    MSRP$141,620

    253 units available

    Grand Design Solitude 310GK floor plan

    RV Envy's expert take

    We like: Large bedroom window, Pull-out trash cans, Large bedroom closet

    Consider: Limited pantry space, Fragile pendant lights, Limited bathroon storage

    Max weight

    19,000 lbs

    Length

    34 ft 4 in

    Sleeps

    4

    Grand Design Solitude 310GK-R

    MSRP$120,083
    Grand Design Solitude 310GK-R floor plan
    Max weight

    15,000 lbs

    Length

    34 ft 11 in

    Sleeps

    4

    Grand Design Solitude 321RL

    MSRPTBD

    1 unit available

    Grand Design Solitude 321RL floor plan
    Max weight

    15,000 lbs

    Length

    34 ft 11 in

    Sleeps

    4

    View all Solitude floor plans →
    Grand Design Solitude 378MBS overview
    • Mid bunk
    • Front bedroom
    • Rear living area
    • Mid den
    • Desk
    Grand Design Solitude 378MBS exterior

    Key facts

    MSRP
    $127,405
    Length
    40 ft 2 in
    Max weight
    18,000 lbs
    Sleeps
    7

    Specs

    Dimensions

    Length
    40 ft 2 in
    Height
    13 ft 5 in
    Width
    8 ft 5 in
    Slideouts
    Grand Design Solitude 378MBS floor plan
    Grand Design Solitude 378MBS floor plan

    Key facts

    MSRP
    $127,405
    Length
    40 ft 2 in
    Max weight
    18,000 lbs
    Sleeps
    7

    AI summary

    What makes the 378MBS interesting is its layout logic: the living room lives in the rear slide, giving it a true room-like feel, while the east/west bed up front stays well away from the noise. The mid-bunk section is legitimately versatile — owners have used it as an office, guest space, or actual bunk room depending on the trip. Grand Design builds the Solitude line with thicker walls and more insulation than most competitors, and the 378MBS adds CRE 3000 suspension and auto-leveling to help manage what is a substantial rig to tow. A kitchen island, desk, fireplace, and washer/dryer prep mean this one is set up for extended stays, not just weekends.

    4

    Tanks & capacities

    Fresh water
    81 gal
    Gray water
    106 gal
    Black water
    53 gal

    Weight & towing

    Dry weight
    14,344 lbs
    GVWR
    18,000 lbs
    Hitch weight
    2,686 lbs
    3/4 ton truck required
    New Ford F-250, RAM 2500, Sierra 2500, or bigger

    Based on overall weight and weight directly on tow vehicle's hitch and a new model tow vehicle. Please consult with a professional.

    Accommodations

    Sleeps
    7
    Download brochure

    Available years

    20252024202320222021
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