2023 Acela Monterra GL 6×6 Expedition Vehicle

This 2023 Acela Monterra GL 6×6 started life as a Stewart & Stevenson M1088A1 military tractor before being transformed into a self-contained, global expedition rig by the expert team at Overland Adventure Truck. With only 13,500 miles, this 330-horsepower, full-time six-wheel-drive machine combines battlefield toughness with modern off-grid comfort. Offered in Olympia, WA for $279,000.

• Powertrain & Capability: A Caterpillar 3126 turbo-diesel delivers 330 horsepower through an Allison 3000-series automatic transmission and full-time 6×6 drivetrain. With a 150-gallon diesel tank, 47-inch tires, and a central tire inflation system, this truck boasts a 1,000-mile range and serious traction across sand, snow, or shale.

• Overland Adventure Truck Expertise: Built by the Washington-based specialists at Overland Adventure Truck, this rig reflects a mastery of expedition design. Their builds are known for combining industrial reliability with yacht-grade craftsmanship, using custom torsion-isolated subframes and marine-spec electrical systems designed to survive the harshest conditions on Earth.

• Interior & Living Space: Inside, comfort rivals high-end RVs. The 19'9" habitat features closed-cell foam insulation, FRP composite walls, and a full suite of amenities: a U-shaped dinette, queen bed, wet bath with composting toilet and bidet, and a fully equipped kitchen with diesel cooktop, farmhouse sink, microwave, and 12V fridge/freezer. Every inch is built for function and durability, from Chemetal aluminum cabinetry to soft-close drawers.

• Exterior & Systems: Outside, the Acela's steel chassis carries two aluminum storage boxes, branch guards, and an electrical spare-tire winch for easy deployment. Power comes from 2,040W of solar panels feeding 10 Battle Born lithium batteries (1,000Ah) through a Victron Energy inverter system, while onboard Starlink Mobility helps keep you connected anywhere on the planet.

• Ownership & Condition: Showing only 13,500 miles, this Acela Monterra 6×6 is ready for global travel without the wait or complexity of a new build. It's been meticulously engineered and outfitted by a team that specializes in world-expedition rigs, making it a rare opportunity to buy a fully tested, turnkey platform built for true long-haul independence.

• Caterpillar 3126 7.2L Turbo Diesel (330 HP)

• Allison 3000 Series Automatic Transmission

• Full-Time 6×6 Drivetrain

• Central Tire Inflation System (Highway, Cross-Country, Sand, Emergency, Run-Flat modes)

• 150-Gallon Diesel Capacity (~1,000-Mile Range)

• 47" Tires ×6 + Spare

• 4 Wireless Cameras with In-Cab Monitor

• Electrical Spare Tire Winch

• Cab-to-Habitat Access

• Stewart & Stevenson M1088A1 Platform Converted by Acela

• Length: 27 ft | Width: 8.4 ft | Height: 12'8"

• GVW: 28,500 lbs (Fully Loaded)

• Length: 19'9" | Width: 8.4 ft

• 3.25" High-Density FRP Roof/Floor | 2" Reinforced Sidewalls

• Closed-Cell Foam Insulation

• 4-Point Torsion-Isolating Subframe Mounting System

• Two Aluminum Storage Boxes (53"L × 23"D × 28"H)

• Full Branch Guards

• Webasto Thermo Pro 90 Heater with Circulation Pump (Cabin & Water Heat + Engine Preheat)

• Cruise N Comfort 12V Marine-Grade A/C (10,000 BTU)

• Day/Night Solar Roof Vent Fan

• Victron 3000W Pure Sine Inverter & MPPT Controller

• 2,040W Panasonic Solar Array (6 Panels)

• 10× Battle Born 12V 100Ah Lithium Batteries (1,000Ah total)

• Energy Management System with Bluetooth, Wi-Fi, and Internet Access

• 120V Shore Power (30A)

• 130-Gallon Freshwater Tank

• 40-Gallon Gray Water Tank (Push-Button Dump Valve)

• Isotherm Water Heater (Electric Element)

• External Fill Port & City Connection

• Starlink Mobility Flat High-Performance Dish (IP56 Rated, In-Motion Capable)

• U-Shaped Dinette (Converts to Bed) with Memory Foam Upholstery

• Queen Bed (72" × 72") with Under-Bed Storage and Exterior Hatch

• Multiple Outbound Windows with Day/Night Shades

• LED Ceiling & Toe-Kick Lighting (Color-Selectable)

• Abundant 12V and 110V Outlets

• Chemetal Aluminum Veneer Cabinetry on Europly

• Farmhouse Stainless Sink with Accessories

• Webasto X100 Diesel Double-Burner Cooktop

• Furrion Arctic 12V Refrigerator (10 cu.ft)

• Panasonic HomeChef 4-in-1 Microwave

• Full Pantry and Soft-Close Drawers

• Fiberglass Wet Bath with Rain Shower and Handheld Spray

• Sunmar GTG Compost Toilet with Porcelain Bidet

• Wall-Mounted Soap/Shampoo Dispenser

• Outbound Window with Day/Night Shade

• Rear Entry Door with Integrated 7ft Deck (Two Settings)

• Removable Aluminum Steps