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New 2026 Grand Design Momentum 397THS

Toy Hauler Fifth Wheel|Salt Lake City, UT| Stock# 358314

MSRP: $184,714

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Overview
Specifications

The 2026 Grand Design Momentum 397THS is a flagship luxury toy hauler built for travelers who demand residential comfort, massive cargo capacity, and rugged off‑grid capability. At over 44 feet long with a triple‑axle foundation, the 397THS delivers exceptional stability, storage, and towing confidence.

The 13'6" garage transforms from a high‑capacity cargo bay into a fully functional living space with a half bath, Happi‑Jac queen bed, rollover sofas, and its own entry door. Whether hauling ATVs, motorcycles, kayaks, or a side‑by‑side, the garage is engineered for serious adventure.

Inside, the main living area features opposing slides, a large entertainment center, theater seating, a tri‑fold sofa, and a spacious kitchen with a 20‑cu‑ft 12V refrigerator, convection microwave, and a large island. The panoramic windows and high ceilings create an open, residential feel.

Up front, the master suite includes a king bed, large wardrobe, washer/dryer prep, and direct access to the luxurious full bathroom with a 48" x 30" shower and molded seat. The Stealth 3+ A/C system provides 30,000 BTU of ultra‑quiet cooling, while the 40,000 BTU furnace and tankless water heater ensure year‑round comfort.

With three awnings, a 60‑gallon fuel station and generator, the Momentum 397THS is built for extended stays, remote camping, and high‑end adventure living. It’s a true luxury home on wheels designed for travelers who want capability without compromise.

Overview

The 2026 Grand Design Momentum 397THS is a flagship luxury toy hauler built for travelers who demand residential comfort, massive cargo capacity, and rugged off‑grid capability. At over 44 feet long with a triple‑axle foundation, the 397THS delivers exceptional stability, storage, and towing confidence.

The 13'6" garage transforms from a high‑capacity cargo bay into a fully functional living space with a half bath, Happi‑Jac queen bed, rollover sofas, and its own entry door. Whether hauling ATVs, motorcycles, kayaks, or a side‑by‑side, the garage is engineered for serious adventure.

Inside, the main living area features opposing slides, a large entertainment center, theater seating, a tri‑fold sofa, and a spacious kitchen with a 20‑cu‑ft 12V refrigerator, convection microwave, and a large island. The panoramic windows and high ceilings create an open, residential feel.

Up front, the master suite includes a king bed, large wardrobe, washer/dryer prep, and direct access to the luxurious full bathroom with a 48" x 30" shower and molded seat. The Stealth 3+ A/C system provides 30,000 BTU of ultra‑quiet cooling, while the 40,000 BTU furnace and tankless water heater ensure year‑round comfort.

With three awnings, a 60‑gallon fuel station and generator, the Momentum 397THS is built for extended stays, remote camping, and high‑end adventure living. It’s a true luxury home on wheels designed for travelers who want capability without compromise.

Specifications

Specifications

RV Details

  • Sleeps8
  • Slides3
  • Length44 ft. 2 in.
  • Width8 ft. 5 in.
  • Height13 ft. 5 in.
  • Dry Weight17514 lbs.
  • Hitch Weight3450 lbs.
  • GVWR20000 lbs.
  • VIN573FM4637TBB04772

Tanks & HVAC

  • Fresh Water1 Tank(s) | 140 gal.
  • Black Water2 Tank(s) | 104 gal.
  • Gray Water2 Tank(s) | 104 gal.
  • Propane2 Tank(s) | 60 gal.
  • ACautomatic 30000 BTU
  • Heatpropane 40000 BTU
  • Water Heatertankless
  • GeneratorNPS 6000

Appliances

  • Awnings3 | 14 ft + 12 ft + 10 ft
  • BedsKing bed, Queen Happi Jack
  • Bunks2
  • ShowerResidential fiberglass shower w/ seat 48 x 30 in.
  • Refrigerator20 cu ft
  • Cooktops | Microwave3 | Yes
  • Washer/Dryer PreppedNo

Can you tow this RV?

Understanding your vehicle's towing capacity rating is critical to choosing the right RV for you and your family. Towing your next RV safely down the road will depend on having the right tow vehicle and RV combination. Use our handy towing guide below to help find your vehicle's towing capacity and filter our RV inventory down to RVs you can tow. View Tow Guide >

Attention: Your vehicle's max towing capacity includes passenger weight, added accessories, any current liquids in tanks, and any cargo you've added such as food, clothes, chairs, grills, games, tools, etc.. For purposes of RVs I can Tow, we've allowed 1000 lbs for RVs over 8000 lbs, 750 lbs for RVs under 8000 lbs, and 500 lbs for RVs under 5000 lbs for average Cargo Weight. Always confirm your specific tow vehicles towing capacity directly from your vehicle's manufacturer before purchasing or towing an RV. You are responsible for the decision to operate your vehicle and any RV you may tow. If your specific vehicle is not listed, please contact us for assistance.

General RV works hard to ensure the accuracy of all its listings however we are not responsible for any misprints, typos, or errors found in our website pages. Manufacturer-provided pictures, specifications and features may be used as needed. Inventory shown may be only a partial listing of the entire inventory. Please contact us at 888-436-7578 for availability as our inventory changes rapidly.

*All RV prices exclude tax, title, registration and fees, including documentary service fees. All payments are with approved credit through dealer lending source. Advertised monthly payment is based on 20% cash down, plus tax, title, registration and fees, at 7.99% APR for 96 months on finance amounts under $10K, at 7.99% APR for 144 months on finance amounts from $10K to $25K, at 7.99% APR for 180 months on finance amounts from $25K to $50K, and at 7.99% APR for 240 months on amounts over $50K. $79 monthly payment based on purchase price of $9,999 with 20% down at 8.24% APR for 218 months. $439 monthly payment based on purchase price of $69,995 with 20% down, at 6.49% APR for 240 months. For select models only. Rate and payments are subject to change at any time. Conditions apply. See dealer for details.