Overview
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 $310,000. Learn more, make an offer, or inquire today.
- 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.
Year
2023
Make
Acela
Model
Monterra
Trim/Submodel
GL
Engine
7.2L Turbo Diesel Caterpillar 3126 I6
Transmission
6-Speed Allison Automatic
Drivetrain
6-Wheel Drive
Body Style
Expedition Vehicle
Odometer
~13,500 mi
VIN / Chassis
-
Location
Olympia, WA
Title Status
Clean
Gallery
- All Photos
- Exterior
- Interior
- Habitat
Features & Specifications
This overland expedition vehicle is a mobile stronghold for explorers who want to live beyond the map. With its Caterpillar diesel, 1,000-mile range, 130-gallon water supply, 2,000 watts of solar power, and full off-grid HVAC, this 6×6 is engineered for indefinite overland travel through any climate. Whether your plans involve the Pan-American Highway or the Siberian tundra, it’s built to get you there (and to keep on going).
Powertrain
- 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
Chassis & Dimensions
- Stewart & Stevenson M1088A1 Platform Converted by Acela
- Length: 27 ft | Width: 8.4 ft | Height: 12’8”
- GVW: 28,500 lbs (Fully Loaded)
Habitat Construction
- 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
HVAC & Climate Systems
- 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
Electrical & Solar
- 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)
Water & Plumbing
- 130-Gallon Freshwater Tank
- 40-Gallon Gray Water Tank (Push-Button Dump Valve)
- Isotherm Water Heater (Electric Element)
- External Fill Port & City Connection
Connectivity
- Starlink Mobility Flat High-Performance Dish (IP56 Rated, In-Motion Capable)
Interior – Living Space
- 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
Kitchen
- 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
Bath
- 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
Entry & Exterior Access
- Rear Entry Door with Integrated 7ft Deck (Two Settings)
- Removable Aluminum Steps
Inquire Today.
Use the contact form to inquire now or make an offer on this 2023 Acela Monterra GL 6×6 built by Overland Adventure Truck.
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