It’s been just over three weeks and 1,400 miles since we began to call this new rig “home.” Now that we’ve settled in, it’s time for our virtual housewarming, if you will. Here, we break down all the nitty gritty details of our new truck, providing a full spec list and systems breakdown. So when you see us on the road and wonder, “What the heck IS that thing?!,” now you have a place to go to get a sneak peek and answers to all your burning questions. If we left something out, please let us know in the comments below.
First of all, if you haven’t already read our post on why we chose an expedition vehicle as the platform for our new home, you can learn all about our rationale and reasons for going with a truck this beefy.
Don’t feel like reading? Check out this short video.
Our truck is based on the M1083 variant of the FLMTV (which is the family of light medium tactical vehicles for the US military). She’s 29 feet long, with a 6×6 drive train, and is powered by a 3126 Caterpillar engine mated to a commercial Allison C7 transmission.
In her past life, she was a military gun truck set up for heavy cargo, as indicated by the 70,000-pound rear leaf springs. She rides on 395 Series Michelin tires mounted on 20” rims, for an overall tire height of 48 inches. The rims can be split for field-changing tires, and the central tire inflation system (CTIS) allows us to change tire pressure from highway to trail, sand or mud, or even to continually fill one tire in an emergency.
As with most military vehicles, every aspect of her is solid, overbuilt and ready to be field-serviced using simple tools. With the cabin and 254 gallons of fuel, along with 145 gallons of water, plus personal possessions, she weighs right around 11-12 short tons (~23,000 pounds).
According to her specifications, she can climb a 65% grade and traverse four feet of water without any modifications. So far, we have taken her over boulders, across worn washboard gravel roads, through ditches and (more frequently than we care to admit), over curbs and highway exit medians when we’ve missed an exit…Ooops. All without effort and a barely perceptible passenger feel. Our first trip of 1,400 miles, mostly highway and city driving, resulted in an average of 6.88 miles per gallon. As she’s been breaking in, we are now averaging 8 miles per gallon.
The cab was originally designed for a three-person crew, so with the middle seat removed, there’s over 40” between the passenger and driver seats. Where there used to be military gear and ammunition boxes behind the seats, we now have ample storage space for crates of gear and a place to hang jackets. The cab is not luxurious; it’s quite minimalistic, but it does have good AC and heat, as well as air-ride seats (which helps ease the transition between the smooth Mercedes Sprinter ride and this quite nicely).
Between the cab and cabin is a solid, structural, insulated and locking cab-to-cabin access door, allowing easy access while underway. It’s a bit more of a contortionist maneuver than the Sprinter van, but it’s not bad and will certainly keep us limber. The ability to close off the cab from the cabin completely is not only good for temperature regulation, it’s also a lot safer.
The full cabin, manufactured by Global Expedition Vehicles in Nixa, Missouri, measures 20.5 feet long (including 16.5 feet of cabin living space along with a 4.5 foot gear garage). It is 8 feet wide and 6 feet, 7 inches tall. This truck was originally a spec-build by GXV, so the finishes are not of our choosing and some of the layout choices had be modified to accommodate our needs. For instance, the truck was originally only intended to have exterior storage beneath the queen size bed. Cleverly, GXV was able to extend the rails of the chassis to accommodate our much larger gear garage, sandwiching the structural composite to the back of the original cabin for a nearly seamless end result.
Within the cabin itself, a 16.5’ x 8’ x 6’7” rectangle, we have a spacious wet bath with a Thetford cassette toilet, a slate stone sink with small vanity and mirrored medicine cabinet.
An almost 6 foot long galley has plenty of pantry storage, a deep stainless steel sink and quartz countertops. We opted for a Webasto diesel stove because of its energy efficiency. Induction is great, but if you plan on living off-grid as much as possible, you will find the energy-suck astounding. Diesel isn’t without its downside, as it is hot and takes a long time to heat up. Therefore, we also use two plug & play induction burners in the summer months or when we have access to shore power.
On the other side of the cabin, from fore to aft, we have a Vitrifrigo two-drawer refrigerator/freezer, above which sits a combination washer/dryer in its own custom cabinet. For dining, we have a booth-style dinette, seating four, and a high/low table converts to a sleeping berth. Shoes and extra pantry items can be stowed beneath the seat benches.
At the far end, there is an east-west queen-sized bed, elevated 48-inches to allow water tankage, the heating system, inverter and solar controllers, along with a spacious under-bed garage accessed by heavy-duty doors on both sides of the vehicle.
The integrity of the thermal cabin envelope is maintained by three Armor Vision double-paned, steel-framed windows, which are among the strongest and heaviest-duty available. They can be opened fully, screened-in or used in full black-out mode. Also, they can be locked in a cracked-open position to allow air-flow while maintaining security, which is particularly nice when we’re driving and Bethany is making coffee in the back, or when we are using the Fantastic Vent fan to create optimal air circulation. A note on our Fantastic Vent: If given the choice, we would have gone with the non-automated version. The 7350 model seems nice, but when the rain sensors detect condensation at 2am and interpret it as rain, the whole thing shuts down. Plus, you have to locate the remote in order to operate it. Some things are better off left to manual operation.
THE GEAR GARAGE
Aft of the bed, sealed off from the main unit, is our gear garage. The gear garage is full width, full height, and 4.5 feet deep. It accommodates four bicycles held vertically using Thule Sidearm carriers, plus nearly all of our other sports gear from paddles, backpacks, and kite-boarding kit to fitness equipment, outdoor paraphernalia and snow gear. The interior is criss-crossed with seat track so we can easily change the configuration of tie-down points as necessary. We also stow our spare tire in here, as we did not want to add length to the vehicle by storing it outside, and it would have interfered with the way our garage door is operated.
The garage is accessed via a custom full-size lift gate, which can be lowered by winch to 23” above ground, creating an access ramp. When held parallel to the ground, it transforms into what we fondly refer to as “Party Mode,” an 8’ x 6.5’ patio which supports up to 1,500 pounds.
We have a 16,000 BTU air conditioner mounted on the roof.
The heating is hydronic, powered by a Webasto Thermal 90 unit, which supplies hot air as well as hot water. Since our hydronic unit is connected to the engine’s cooling system via a heat exchanger, running the engine creates hot water and cabin heat. In reverse, heating the cabin creates hot water and pre-heats the engine for ease of start-up in extreme conditions. Since we plan to take full advantage of winter in the American and Canadian Rockies, and eventually Patagonia, heat is not only for sheer comfort, but necessity. In temperatures below zero, a loss of heat could create a life or death situation that we wanted to be prepared for with multiple back-up systems. Should our main heating system fail, our diesel stove will easily warm the cabin and, should that too fail, we can run our A/C in reverse, which puts out 5,000 BTUs of heat.
On the roof, we have three 100-watt solar panels mated to an Outback controller. On an average day, the sun provides us with enough power so we do not need to run the 3.6 kW generator, which is mounted in a sound-proof box on the chassis. The solar power is stored in three AGM D8 batteries with a total capacity of 765 amp hours. On our maiden voyage with her, we stayed in Wisconsin for a week in partial shade and never needed to plug in or run the generator.
OTHER EXTERIOR FEATURES
- Manual awning
- Triple backup cameras to provide visibility left, right and behind the truck
- Roof racks for stand-up paddleboards
- Above-the-cab storage box for inflatable boards and other weatherproof gear
- 50” light bar to light up the road
- The original military headlights were replaced with LED headlights
- Locking exterior storage lockers for tools, cords and our ladders
- Slide-out aluminum retractable stairs for cabin entry, along with a custom retractable mini-step GXV built to help Bethany (5’4”) be able to reach the cabin door when the stairs are not deployed.
Have a question or want to know something we missed? Ask us below! We are now headed to Glacier National Park for a few weeks before doing some work in Albuquerque. Follow us on Instagram for all the latest.