2025 Grand Design Solitude 345GK vs 2024 Forest River Sierra 321RL

Two noteworthy RVs face off: the 2025 Grand Design Solitude 345GK and the 2024 Forest River Sierra 321RL. From dimensions to amenities, here's the full breakdown.

Specifications Comparison

Specification2025 Grand Design Solitude 345GK2024 Forest River Sierra 321RLAdvantage
CategoryFifth WheelFifth Wheel
Year202520242025 Grand Design Solitude 345GK
Length37 ft28.5 ft
Width8 ft8.5 ft
Height13.5 ft12.5 ft
Dry Weight10,000 lbs10,900 lbs
GVWR13,900 lbs14,600 lbs
Sleeping Capacity492024 Forest River Sierra 321RL
Fresh Water56 gal76 gal2024 Forest River Sierra 321RL
Gray Water61 gal65 gal2024 Forest River Sierra 321RL
Black Water40 gal46 gal2024 Forest River Sierra 321RL
Fuel Capacity
Horsepower
Engine
Slide-Outs11Tie
Solar200 W100 W2025 Grand Design Solitude 345GK
Battery150 Ah150 AhTie
Inverter1,500 W2,000 W2024 Forest River Sierra 321RL
MSRP$162,000$158,0002024 Forest River Sierra 321RL

Detailed Comparison

Two noteworthy RVs face off: the 2025 Grand Design Solitude 345GK and the 2024 Forest River Sierra 321RL. From dimensions to amenities, here's the full breakdown.

Dimensionally, you're looking at 37.0 ft for the Grand Design Solitude 345GK and 28.5 ft for the Forest River Sierra 321RL. The Forest River Sierra 321RL carries an extra 900 lbs, which affects tow vehicle requirements and fuel economy.

Capacity-wise, expect to sleep 4 in the Grand Design Solitude 345GK versus 9 in the Forest River Sierra 321RL. With 1 and 1 slide-outs respectively, the parked floor plans differ significantly.

Tank capacities are a key off-grid consideration. The Grand Design Solitude 345GK carries 56 gal of fresh water, 61 gal gray, and 40 gal black. The Forest River Sierra 321RL offers 76 gal fresh, 65 gal gray, and 46 gal black. The Forest River Sierra 321RL has the edge for extended dry camping.

Budget-wise, the Forest River Sierra 321RL is listed at $158,000 compared to $162,000 for the Grand Design Solitude 345GK.

For family camping trips, the larger floor plan and additional berths make a real difference. For boondocking, the model with superior solar and battery setup will keep you comfortable off the grid longer. If you're going full-time, the larger tanks and more robust build quality matter enormously.

Whichever you choose, you'll be getting a capable rig. Just make sure to inspect one in person before signing.

Individual Overviews

2025 Grand Design Solitude 345GK

  • Category: Fifth Wheel
  • Length: 37 ft
  • Weight: 10,000 lbs
  • Sleeps: 4
  • MSRP: $162,000
View Full Specs

2024 Forest River Sierra 321RL

  • Category: Fifth Wheel
  • Length: 28.5 ft
  • Weight: 10,900 lbs
  • Sleeps: 9
  • MSRP: $158,000
View Full Specs