Now in its fifth year, the Ultimate Build program allows Overland Expo’s editorial team and overland gurus to transform proven factory vehicles into their interpretation of the Ultimate Overland Build. The 2025 Ultimate Overland Build features the 2025 GMC Sierra 2500 HD AT4X AEV Edition and the 2024 Suzuki V-Strom 800DE. Hang the bike off the back of the truck, and you will have the very best of both worlds. Very tempting.
2025 GMC Sierra 2500 HD AT4X AEV Edition
The GMC Sierra 2500 HD AT4X is a heavy-duty truck engineered for off-road travel and long-distance expeditions. This vehicle serves as the foundation for Overland Expo’s vision of an expedition-ready platform straight from the factory, ready for some bolt-on overland-specific upgrades. At its core, the Sierra HD AT4X boasts a fully boxed high-strength steel frame designed to handle heavy payloads and demanding conditions.
The first stop on the build journey was American Expedition Vehicles (AEV) in Wixom, Michigan, where the team installed the AT4X AEV Edition upfit package to further enhance the Sierra’s overland capabilities. The package expands on the factory-installed AT4X AEV Edition features, refining both form and function for demanding off-road use.
The truck was fitted with 18×9 AEV Salta XD wheels, which feature a +18mm offset to increase clearance while maintaining compliance with the fender flares. These wheels are rated for 4,100 pounds, offering the strength required for overland travel with heavy payloads. To accommodate larger tires without altering the suspension or adding lift, AEV installed its 37-inch tire clearance kit. This modification made room for 37×13.50R18 BFGoodrich All-Terrain KO2 tires, a proven choice for all-terrain performance with a severe snow rating and a 50,000-mile warranty, balancing trail traction with road comfort.
A ComeUp Solo 12.5rs winch was integrated into the AEV-stamped steel front bumper. Developed in collaboration with General Motors, this winch is a factory-validated component, seamlessly blending into the Sierra HD’s front-end design. AEV equipped the truck with a snorkel based on heavy-duty industrial and military applications to improve engine performance in dusty or wet environments. This snorkel helps deliver cooler, cleaner air to the engine under extreme conditions.
The Sierra HD AT4X AEV Edition offers two engine options: a 6.6-liter V8 gas engine and a 6.6-liter Duramax diesel engine. This build utilizes the Duramax diesel, paired with an Allison 10-speed automatic transmission, delivering smooth shifts and consistent performance under load (be sure to pack extra DEF if you are heading south). This powertrain is well-suited for long-range travel, offering impressive fuel economy for a heavy-duty truck (combined: 14–17 mpg) and an integrated exhaust brake for better control on steep descents. An electronic locking rear differential enhances traction in challenging conditions, essential for those overlanders who like to get there and back with peace of mind. The AT4X trim enhances off-road performance with additional lift height and Multimatic DSSV (dynamic suspensions spool valve) dampers, which offer precise damping across various terrains. These race-proven shocks provide consistent and predictable performance, especially over uneven or rocky terrain.
Towing capacity exceeds 18,000 pounds, with a payload rating of over 3,000 pounds, allowing for substantial hauling capabilities. Inside, the AT4X AEV Edition prioritizes comfort and connectivity, essential for extended overland journeys. The interior supports those living out of their vehicle for prolonged periods, combining durability with modern conveniences.
The team selected a slide-in camper for the 2025 Ultimate Overland Build to provide a self-contained, all-season living solution. After careful consideration, they chose the OEV Back Country, a robust pop-up truck camper engineered for remote travel in challenging environments. This model is known for its durable construction and adaptability. It features a removable four-season cabin, a three-season water system, and R8-rated insulated composite walls that support comfort in various temperatures. The interior is designed to accommodate up to four people, balancing off-grid capability with practical living space.
The camper’s plumbing and climate systems include a Truma Aquago water heater and a Truma Vario cabin air heater, ensuring reliable warmth and on-demand hot water. A 20-gallon freshwater tank, a stainless-steel sink, and an integrated cooktop support daily cooking and cleaning needs during extended stays off-grid.
The electrical system was built with autonomy in mind, featuring a Victron 220-watt solar panel and a Battle Born 270 amp-hour lithium battery for long-lasting energy storage. A Xantrex Freedom X 2000 inverter and dedicated control panel manage power distribution, while an Isotherm Cruise 65 Clean Touch refrigerator offers efficient food storage in a compact form. A Lavabox portable campfire system adds a layer of versatility to outdoor living.
Specifications: 2025 GMC Sierra 2500 HD AT4X
Engine: 6.6-liter Duramax turbo-diesel V8
Transmission: Allison 10-speed automatic
Drivetrain: 4WD with electronic locking rear differential
Shocks: Multimatic DSSV dampers
Wheels: 18×9 AEV Salta XD
Tires: 37×13.50R18 BFGoodrich All-Terrain KO2
Clearance: AEV 37-inch tire clearance kit installed
Bumper: AEV heavy-duty steel with integrated ComeUp Solo 12.5rs winch
Camper Specifications: OEV Back Country Slide-in
Construction: R8-rated insulated composite walls, removable 4-season cabin
Sleeping Capacity: Up to four
Heating: Truma Vario cabin air heater
Hot Water: Truma Aquago on-demand
Battery: Battle Born 270Ah lithium
Solar: Victron 220-watt panel
Inverter: Xantrex Freedom X 2000
Refrigeration: Isotherm Cruise 65 Clean Touch
2024 Suzuki V-Strom 800DE
The 2025 Ultimate Overland Motorcycle is a customized 2024 Suzuki V-Strom 800DE designed to meet the demands of modern adventure riders. This annual build showcases a motorcycle outfitted with premier adventure gear, highlighting the potential of overland travel.
The V-Strom 800DE features a 776cc parallel-twin engine, delivering a balance of power and efficiency suitable for both on-road and off-road conditions. Its chassis is equipped with 8.7 inches of suspension travel and 21/17-inch spoked wheels, enhancing its capability on varied terrains. These specifications position the V-Strom 800DE as a versatile platform for long-distance and rugged adventure riding.
To prepare the V-Strom for overland expeditions, Overland Expo collaborated with industry partners to enhance its functionality and resilience. Outback Motortek provided crash protection components, including skid plates and engine guards, to safeguard the motorcycle in challenging environments. Mosko Moto contributed modular luggage systems, offering flexible storage solutions for extended journeys.
Cyclops Adventure Sports equipped the motorcycle with high-output auxiliary lighting to enhance nighttime visibility. RAM Mounts contributed secure mounting solutions for navigation devices and electronics, ensuring that essential tools remain accessible and protected during travel. Klim supplied rugged riding apparel built to handle various weather conditions, providing both comfort and protection for the rider. Zoleo added a satellite communication device, enabling reliable connectivity in areas without cellular coverage. Dunlop outfitted the build with ADV tires designed for varied terrain, balancing traction and durability. Optima Batteries supported the electrical system with dependable power delivery, while Moto Machines contributed a range of accessories to improve performance and overall functionality.
Specifications : 2024 Suzuki V-Strom 800DE
Engine: 776cc parallel twin
Transmission: 6-speed
Suspension Travel: 8.7 inches
Wheels: 21-inch front / 17-inch rear spoked ADV wheels
Tires: Dunlop ADV tires
Crash Protection: Outback Motortek skid plate, crash bars
Luggage: Mosko Moto modular luggage systems
Lighting: Cyclops Adventure Sports auxiliary lights
The 2025 Ultimate Overland Builds will be showcased at Overland Expo events throughout the year, including Overland Expo West in Flagstaff, Arizona. Attendees can view both vehicles at these events and learn about their features and capabilities. Towards the end of the year, the vehicles will be auctioned, with proceeds benefiting the Overland Expo Foundation, which supports initiatives related to overlanding, public land access, education, and responsible exploration.
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