Behind the Wheel of America's New Baja-Tuned, Duramax-Powered Humvee Replacement
Over the past 30 years, multiple wars, and dozens of conflicts, the AM General Humvee has cemented its legacy in American culture. Officially the High Mobility Multipurpose Wheeled Vehicle, or HMMWV, the Humvee went into service with all five branches of the United States Military beginning in 1985, but it wasn’t until Americans back home watched the Humvee barrel into battle during the Gulf War that it captured the hearts and minds of civilians. The Humvee has served valiantly since then, but there’s no escaping Father Time or the unconventional nature of modern warfare. With Humvees proving vulnerable to roadside bombs and small-arms fire, the U.S. Army and Marine Corps began looking for a successor in 2008. The replacement is now ready: the faster, stronger, and deadlier Oshkosh L-ATV. Likely to be better known as the Oshkosh JLTV, we got behind the wheel of the new Baja-bred and Duramax-powered armored truck before it officially goes into service late next year.
The Oshkosh JLTV, or Joint Light Tactical Vehicle, is currently in low-rate initial production and is designed to replace all Army and Marine Humvees in front-line service. But before we get too far into the JLTV, it’s important to understand why the tried-and-true Humvee is being replaced.
The Humvee, like the M151 MUTT and Willys M38 and MB Jeeps before it, was designed to support troops in a conventional conflict like World War II. It was intended to get troops and cargo anywhere, thanks to a drivetrain tucked up into the cabin and portal axles that helped to give the Humvee tidy dimensions and impressive clearances. Designed in a different era, the Humvee wasn’t intended for the types of wars the U.S. has fought in Afghanistan and Iraq. With both conflicts devolving into unconventional warfare, Humvees quickly proved vulnerable to enemy roadside mines and Improvised Explosive Devices (IEDs). The military’s initial response of sending “up-armored” Humvees into battle was insufficient. With curb weight jumping from 6,000 pounds (2,721 kg) to over 13,000 pounds (5,897 kg), the Humvee’s 190-hp 6.5-liter turbodiesel V-8, four-speed automatic and independent suspension was quickly overwhelmed by the extra weight. The last M1116 up-armored Humvee we tested weighed 13,200 pounds (5,987 kg) and did 0-60 mph in 36.5 seconds (we’ve also tested a 2004 H1 hitting 60 mph in 15.6 seconds). There’s slow, and then there’s Humvee-slow.
Up-armored Humvees can’t accelerate, can’t haul, and were so overtaxed that they broke down all the time—not to mention that they were still vulnerable to IEDs. The “Iron Triangle,” as Oshkosh puts it, of payload, performance, and protection was broken.
Enter the MRAP, or Mine-Resistant Ambush Protected vehicle. These were basically big 30,000-plus-pound (13,600-plus-kg) trucks with built-in armor and V-shaped hulls designed to deflect blasts from roadside bombs. The first wave of MRAPs was far more survivable in Iraq, but the vehicles were too heavy for the treacherous and rugged conditions in Afghanistan. The military issued a request in December 2008 for an all-terrain MRAP, called the M-ATV. By January 2009, Oshkosh had designed what would ultimately become the winning entrant. By December of that year, it was producing 1000 M-ATVs per month.
The Oshkosh M-ATV was ultimately a stop-gap measure for the military’s real prize—the Joint Light Tactical Vehicle program.
The JLTV program started in 2006 but began in earnest in October of 2008 when the military selected BAE Systems, General Tactical Vehicles (a team consisting of AM General and General Dynamics), and Lockheed Martin for the Technology Development testing phase. Oshkosh’s entrant, the diesel-electric LCTV didn’t make the cut, but Oshkosh kept at it, utilizing lessons learned on its LCTV to develop the M-ATV for the military. By the time the army was ready for the JLTV program’s Engineering and Manufacturing Development testing phase in 2012, Oshkosh, hot off its M-ATV win, was ready to give it another go with its new L-ATV.
The Army accepted Oshkosh’s bid, also accepting AM General’s BRV-O, and Lockheed Martin’s JLTV in the JLTV competition.
The military’s requirements for the JLTV were demanding. It had to be a family of two vehicles: the JLTV Combat Tactical Vehicle and the JLTV Combat Support Vehicle. The former is to seat four, have a 3,500-pound (1,588 kg) payload, and have three distinct mission packages: General Purpose, Heavy Guns Carrier, and Close Combat Weapons Carrier. The latter is a two-seat pickup with a 15-inch wheelbase stretch and a 5,100-pound (2,313-kg) payload.
Both JLTV variants also need to offer their occupants more protection than the Humvees they’re slated to replace. The base A-Kit, or factory armor, is designed for use in low-threat environments to ease wear and tear on vehicles, while the add-on B-Kit armor has to meet or exceed full-size MRAP-levels of protection. Given that JLTVs are supposed to be light (for a military vehicle, at least), they also have to weigh less than 15,000 pounds (6,804 kg) in A-Kit form so that they can be transportable by air, sea, and land. They’ve also got to be quick, offer up at least 300 miles (483 km) of range on a tank of JP-8 jet fuel, be as mobile as the original Humvee off-road, and be net-ready, among other things.
After nearly three years of testing, the Army and Marine Corps selected the Oshkosh L-ATV, now redesignated as the JLTV, as the winner of the competition.
The reason Oshkosh earned the contract is simple, says Oshkosh vice president and and general manager of defense programs, Dave Diersen. “We don’t make pianos,” he said. “We know what it takes to make a severe duty, tactical wheeled vehicle and make it last.”
The military’s testing would seem to agree. One of the most telling publicly released stats from the JLTV competition are the entrant’s mean miles between operational mission failure stats—or in other words, the average reliability for the 22 test vehicles over the 33 months of testing. The requirement was 2,400 miles (3,862 km) between operational mission failure. The AM General BRV-O averaged 526 miles (846 km) between failures, the Lockheed JLTV 1,271 miles (2.045 km) between failures, the up-armored Humvee 2,968 miles (4,776 km) between failures, and the Oshkosh JLTV an astounding 7,051 miles (11,347 km) between failures.
The key to the Oshkosh JLTV’s reliability—and ultimately its selection as the military’s Humvee replacement—are in the pieces that make it up. Built on the same Oshkosh, Wisconsin, assembly line that builds all of Oshkosh’s tactical wheeled vehicles (as well as a handful of civilian trucks), the JLTV combines two key Oshkosh technologies with modern automotive advancement to make the ultimate military off-roader. Each JLTV features the company’s TAK-4i suspension system and Core 1080 armor system to help the JLTV go anywhere and to help protect its occupants while doing so.
Many Oshkosh JLTV details remain classified, but the JLTV’s chief engineer, Kent Schulte, let us in a little on TAK-4i and Core 1080. Core 1080 is basically Oshkosh’s method for mounting what it calls the capsule, or the body, of the JLTV to the truck’s modular medium-duty frame. The capsule consists of a blast-deflecting hull, heavy armored-locking suicide doors, energy absorbing floors and seats, an automatic fire-suppression system, and much more. The armored capsule is designed to absorb blast damage from the bottom, sides, or top, and it can even support 100 percent of the JLTV’s gross vehicle weight on its roof. The capsule is modular to be easily up-fitted with the heavy-duty B-Kit armor, and it is designed to be easily repaired in the field, with pieces removable and replaceable with just a few bolts.
TAK-4i is Oshkosh’s newest and most advanced version of its high-pressure gas-adjustable heavy-duty double-wishbone independent suspension. More than anything, TAK-4i is what makes the JLTV tick. Fine-tuned on the Baja 1000, TAK-4i is designed to give the JLTV Ford F-150 SVT Raptor levels of comfort and speed off-road while also retaining the ability to haul a meaningful payload, fit inside military transports, and ford rivers and other water crossings. With the JLTV’s Central Tire Inflation System working together with the suspension’s 20-inches of wheel travel and high-pressure gas shocks, the JLTV’s suspension is designed to absorb all the punishment from the road allowing the four passengers (five, if you include the gunner on the optional turret) to arrive into battle comfortably and well-rested.
Although ride comfort was likely at the bottom of the priority list when it came to the Humvee, it’s become especially important over the past two decades because typical missions now last longer. For example, when Diersen joined the Marine Corps in the mid-‘80s, he says typical missions in the then-new Humvee lasted for a couple of hours at a time; nowadays it’s not uncommon for American soldiers and Marines to be cooped up in their Humvees for 10 to 12 hours at a time on a mission. “If you’ve got a really poor ride quality, you’re getting thrown around in those vehicles,” he said. “With full body armor, you’re basically worn out wherever you get. One of the benefits of the JLTV’s suspension is with that better ride quality, you’re not getting thrown around, so you’re much more refreshed by the time you’re getting to where you’re going. Plus with the suspension taking all the abuse from the road and whatever else is out there, it makes the vehicle more reliable and it lasts longer.”
Ride comfort isn’t all the JLTV’s suspension is good for, though. Thanks to the gas system, the JLTV can raise itself up to ford up to 60 inches of water (more with the optional snorkel kit), lower itself to match the Humvee’s 74-inch roof height so it can squeeze into cargo planes and amphibious transports, and it can even level itself out if parked on uneven terrain—all this via a center-console mounted tablet that controls most all of the JLTV’s functions. The latter suspension setting, dubbed the Suspension Aided Egress System, or SAES, is basically made necessary by the weight of the JLTV’s armored doors. When parked on an incline, one side of the JLTV’s suspension will raise and the other will lower, making the cabin of the vehicle level with the horizon. This makes sure the doors are easy to open, and it also has the added benefit of ensuring the turret is level and ready to fire.
The other piece to the JLTV puzzle is its powerplant. Even though its initial LCTV prototype used Oshkosh’s ProPulse diesel series hybrid system, the company instead decided to power the L-ATV JLTV by a tried-and-true powertrain that GM Heavy Duty truck owners swear by: a Duramax 6.6-liter turbodiesel V-8 paired with an Allison six-speed automatic transmission. Chosen because of its reliability (fun fact: an Oshkosh JLTV ingested water during testing and still went another 2,000 miles (3,219 km) before having the engine rebuilt) and power density, the JLTV’s engine is essentially a militarized version of the new 2017 Chevrolet Silverado HD and GMC Sierra HD’s L5P Duramax diesel. GM ships each engine to Banks, which modifies the L5P with severe duty components and tunes the engine to run on jet fuel, or in a pinch, diesel, kerosene, or alcohol—any combustible liquid, basically. After its militarization, the Duramax engine is redesignated the Banks 886T and shipped to Oshkosh for installation. Horsepower and torque of the militarized Duramax are currently classified, but Diersen says the JLTV doesn’t actually need the 445 hp and 910 lb-ft of torque the engine makes in the latest Silverado and Sierra HD. Best guess is that this under-stressed Duramax is making around 400 hp and 850 lb-ft of torque.
After watching some of the first production-spec JLTVs roll off Oshkosh’s production line alongside various other military and civilian trucks, I went over to Oshkosh’s Test and Development Facility to get some seat time in the military’s new toy. Parked alongside a Humvee and an M-ATV on Oshkosh’s muddy off-road proving ground, the JLTV is an imposing sight in its desert tan paint. In pictures it’s a bit difficult to differentiate the JLTV from its M-ATV cousin, but in person the JLTV splits the difference between the more SUV-like Humvee, and trucklike M-ATV.
Before hopping behind the wheel of the JLTV, I took a quick spin around Oshkosh’s off-road course behind the wheel of an unarmored Humvee just to put the new JLTV into context.
The Humvee might look timeless, but there’s no denying they’re ancient from an automotive engineering standpoint. Hop inside the cramped cabin, sit down in the low-backed canvas seats, and strap on the two-point seatbelt—you’re going to need it. I fired up the old turbodiesel V-8, dropped the four-speed auto into gear, and set off toward the first set of obstacles: a group of offset moguls designed to test wheel articulation. At 8 mph (13 km/h) and despite that old-school seatbelt, I was literally thrown from my seat and jammed my back into the exposed steel seat frame as the Humvee bounced over the moguls.
I’d always heard Humvees were uncomfortable, but this was a whole different level.
After clearing the moguls, my poor minder pointed me toward a steep rocky hill to climb up. The Humvee slowly but capably made its way up the hill at little faster than a walking pace. It feels a lot like an older Jeep Wrangler in a lot of ways—choose your line, be consistent with your throttle inputs, and take it slow. You can probably go faster, but you might break something—likely your body before the Humvee.
Once clear of the rocks, we hung a right and set up a hill caked with thick, fresh mud. With the gas pedal essentially a glorified suggestion box, I kept my foot planted and hoped that the Humvee had enough mechanical grip to keep itself in motion. We bounced our way up the hill, and at the crest I realized that the only way down was through a waist-deep pond. With only one way to go, I dipped into the throttle, and the Humvee bounced down the hill towards the pond. We hit the water, and I kept my foot in it. Water started coming in from the door seams and through the HVAC vents as we slowly cleared the pond.
After about 10 minutes of bouncing around in the Humvee, I was ready to get out of the loud, cramped cabin. As iconic as the Humvee is, there’s no hiding its age or the fact that it replaced open-air jeeps when it went into service in 1985.
Let’s see what 30 years of automotive development feels like.
Swing open the armored doors, pull yourself up, and into the SUV-like driving position, and the differences between the JLTV and Humvee couldn’t be clearer. Although no images of the JLTV’s interior publically exist yet, the crew capsule will feel immediately familiar to any young serviceman or woman who has driven a modern car or truck. The all of the seats are comfortable and spacious. They’re well padded, too, with a slot down the middle for a soldier’s CamelBak hydration backpack and a quick-release five-point harness. Behind the wheel there’s a large tachometer and speedometer and a variety of auxiliary gauges monitoring battery, radiator temperature, oil temperature, and transmission temperature. To the left of the wheel are your light buttons, varying from driving lights to tactical and blackout lights. Windshield wipers, indicators, flashers, and high beams are on a stalk on the left side of the column. To the right of the wheel are switches for the central tire inflation system, locking front and rear differentials, and fording mode. There’s also an emergency trailer air brake switch and an air parking brake operated by a big red pull lever directly below the Windows-based touchscreen on the center console. Beneath the touchscreen are two cupholders (how luxurious!) and the automatic transmission shifter, which is arranged RND21. Neutral and the airbrake serve as park.
I fired up the JLTV’s Duramax V-8, shifted into Drive, and motored out of the staging area into the off-road course. The first thing that surprised me was how easy the JLTV was to drive in low-speed, tight areas. The turning circle is pretty tight, and visibility out the front and side windows is surprisingly good, considering its size. You’ve got a good sense of where the front bumper is from behind the wheel, and even though there’s no rear window, a standard backup camera that displays on the center screen makes reversing easy.
I lined the Oshkosh truck up with the moguls and put my foot into the throttle. The JLTV hunkered down on its rear haunches and was off.
Wow. This is no Humvee.
I hit the moguls the first time at a bit over 20 mph (32 km/h). I mean, I think I hit them—I could see we were driving over them, but I could hardly feel them in the cabin. The JLTV’s TAK-4i suspension simply erases the moguls from existence. It’s downright Raptor-like. Throughout the rest of the course, the suspension continued to perform well. It allowed the JLTV to power up the rocky hill at speeds far beyond possible in a Humvee and at comfort levels rivaling some of the best luxury cars on the road today. Seriously. It’s amazing to experience the type of abuse the suspension can withstand without imparting any undue harshness into the cabin. The time the Oshkosh team spent testing at the Baja 1000 really shines through in the finished product.
The JLTV’s Duramax V-8 and Allison transmission are equally impressive. With no need to worry about emissions or easing Joe Schmo’s monthly diesel bill, Oshkosh tuned the engine and transmission to be far more responsive than GM’s tune in its HD trucks. Throttle response is linear and near instantaneous, with no noticeable lag from the diesel’s big turbocharger. Thanks to a ton of torque and close gearing, the JLTV leaps forward off the line quicker than anything weighing damn-near 14,000 pounds (6,350 kg) has any right to. The Allison transmission shifts quickly and without hesitation, and it isn’t ever afraid to hold a lower gear when necessary.
Oshkosh won’t comment on a 0-60 time, but my best guess would be somewhere around 10 seconds to 60 mph. Top speed is electronically limited to 70 mph (113 km/h), mostly because the military is justifiably nervous about letting 17-year-old privates go any quicker in a 7 ton armored truck on public highways.
The most amazing thing to me about the JLTV I noticed during my afternoon of driving is that it can go anywhere the lighter unarmored Humvee can go with three times the speed and comfort and with much less training. Although there aren’t any terrain modes in the JLTV like you see in some modern off-roaders such as the Toyota Land Cruiser or Jeep Grand Cherokee, the JLTV does have a few tricks buried in its computer system. Everything from tire pressure to suspension hydraulic pressure to the angle the vehicle can be accessed there. For the soldier who grew up with computers, it’s incredibly intuitive. For example, rather than manually setting a tire PSI, simply select Highway for a higher asphalt-ready tire pressure, Overland for a lower general off-road setting, Mud/Snow for an even lower pressure, and then Sand for even more contact patch than Mud/Snow.
The adjustable suspension works the same way. The JLTV will squat down to the Humvees height within approximately one minute so that it can fit on trailers, and it’ll quickly rise up even higher with the push of a button to set the JLTV up in its fording mode. The locking differentials work similarly. Rather than selecting which differential you want locked, just press up on the differential switches to lock the rear, and press up again and then front diff. Soldiers don’t need to necessarily think “first lock the rear, then the front, and unlock in that order or you’ll break it,” because the JLTV essentially just gives them increasing levels of mechanical grip, allowing the occupants to focus on the tasks at hand—you know, like fighting a war.
The computerized systems Oshkosh baked in essentially make driving the JTLV off-road idiot proof, or perhaps more accurately, private proof. Just point it at an obstacle, and it’ll go. At one point after driving through the pond that swamped the Humvee for the seventh time in a row, my Oshkosh minder suggested I hang off the track we’d been on for a more challenging trail that hadn’t been driven on since winter due to the amount of mud that accumulated in it. We hung a left off the trail, went through a stream, and quickly found ourselves in a thick mud pit 50 yards across and 20 yards wide. With the JLTV in its overland setting, I just kept my foot in the throttle, kept the wheels spinning, and kept going. Easy.
Actually, that’s probably the best word to describe what it’s like driving the Oshkosh JLTV—easy. It makes just about every conceivable task easy to accomplish. Need to haul four troops and 3,500 pounds (1,588 kg) of cargo into battle? Need to blast quickly across the desert? Need to patrol a dangerous urban area? The JLTV makes it easier and, more importantly, safer for our troops than it’s ever been before. My ‘military experience’ might be limited to three years of U.S. Army J.R.O.T.C. in high school, but even cadet sergeant first class Seabaugh can clearly see the benefit the JLTV brings to our troops.
Although initially slated to replace all of the Army’s and Marine Corps’ nearly 200,000 Humvees, the two branches have instead decided to replace Humvees with JLTVs in front-line units, while refurbishing Humvees to serve through 2050 in the role they were originally intended—behind front lines. The Marine Corps have currently ordered 5,500 JLTVs, with deliveries slated to be complete by the early 2020s, and the Army has ordered 49,099 JLTVs, with deliveries slated through 2040.
Oshkosh says each JLTV is designed for 20 years of service without needing any major retrofits or upgrades.
There’s also possibly more to come because the Army is considering ordering a new version of the JLTV to replace Humvees in the recon role, and the U.S. Air Force is considering ordering JLTVs to patrol America’s Intercontinental Ballistic Missile sites. There are also reports of interest from American allies, including the United Kingdom, which might use JLTVs to replace numerous different vehicles, including a Land Rover Defender variant for the Multi Role Vehicle-Protected program.
Compared to the up-armored Humvee, which costs around $220,000 USD fully-equipped and the M-ATV, which costs around $470,000 USD, the Oshkosh JLTV’s price is a downright bargain. Military pricing structures don’t necessarily translate to the real world, but the average unit manufacturing cost for the JLTV, which is roughly equivalent to a base price in the civilian world, is no more than $250,000 USD, with some sources reporting real costs to the government at around $220,000 USD. The JLTV’s average procurement unit cost, which would roughly be the cost of a loaded field-equipped model, is less than $399,000 USD each, with some reports of the cost being closer to $370,000 USD.
Ultimately the most disappointing thing about the Oshkosh JLTV is that most civilians will never be able to experience how nice they are to drive. Humvees and jeeps ultimately made their way into the civilian world, but Oshkosh says it can’t sell the JLTV to the public. Despite alleged requests from a certain Austrian-born movie star and politician with a penchant for ex-military hardware, Oshkosh says the level of armor baked into even the base JLTV exceeds current allowable civilian levels. That’s probably for the best—not only can the military genuinely use every one it can get its hands on, but this Baja-bred Wisconsin-built rig will also make an exceptional recruiting tool once the public sees what the Oshkosh JLTV is truly capable of.