The most flabbergasting aspect of the 2014 Mercedes-Benz G63 AMG 6x6 isn't that it exists, but that it's a production vehicle. As in, you can buy one. AMG has already built nearly 60 units so far this year. I just spent a week at the Magna Steyr plant in Graz, Austria -- home of the Geländewagen -- and saw five 6x6s: three customer trucks, one for display, and the slate-colored beast you see here.

Turns out that the gargantuan 6x6 is actually hand-built on the same assembly line that produces every other G-Wagen. A workforce 1500 strong recently added a second shift because G-Wagen sales are through the roof, with 2012 the stout off-roader/military vehicle's best full sales year since production started in 1979. As of November 2013, Mercedes had already sold more of them than in all of 2012, and about half of those are the very pricey G63 AMG models. Get this: In the States, the G63 is now the best-selling AMG product.

Since the G-Wagen is hitting its stride after 34 years, Axel Harries, the "Boss of the G," gave the green light to throw caution, common sense, and any pastiche of restraint to the wind and green-light the 6x6. Why? Aside from massive profits, the automaker had the parts lying around. The majority of the monstrosity is made of standard G-Class parts. Most of the cab, the three-axle frame, and retuned transfer case are both from an Australian military G. The 5.5-liter, twin turbo V-8, seven-speed transmission, and quilted diamond-stitched leather Designo interior are from the G63 AMG. There are, of course, new pieces, including the 18-inch beadlock wheels wrapped with gummy 37-inch tires. These tires can be centrally inflated or fully deflated with the help of four 20-liter air tanks and a giant compressor. Zero pressure to a roadworthy 2 bar happens in 20 seconds.

Then there are the Öhlin gas bypass shocks, stiffer springs, more robust bump stops, and a bunch of custom aluminum pieces, such as the rear bumper. The real money, however, went into the geared-offset "portal axles" required to accommodate central tire inflation. Initially designed for a future armored military G, not only do they give the 6x6 its impressive 18 inches of ground clearance, but they were designed with carlike performance in mind.

All of the above leads us to numbers, and like everything else about the 6x6, they are jaw-dropping. Ready? At current exchange rates, the 6x6 costs a little less than $625,000. Take out the 19 percent European value-added tax and you're still looking at around $525K. (Sadly, Mercedes isn't selling the 6x6 in the States, or the V-12 G65 -- yet.) The 6x6 weighs a touch more than 9000 pounds (up from 5876 for our last standard G63), yet Mercedes claims this monster can hit 60 mph in fewer than 8 seconds. Not only is the ground clearance way up compared to the regular G-Class' 8 inches, but fording depth is up from 24 to 39 inches. In fact, every off-road metric is hugely inflated, from approach/departure angle (36/27 degrees for G63, 50/45 degrees for 6x6) to breakover angle (21 degrees versus 50). It's just over 19 feet long and 7 feet wide, and 7 feet, 9 inches tall. There's an additional 13.2-gallon fuel tank, activated by a toggle switch above the rearview mirror next to the tire pressure controls, that increases the total amount of gas on board to 38.6 gallons. That last bit gives you some idea of the 4.5-ton thug's fuel consumption. (Nicht gut!)

My new favorite driver is a Graz local and master G-Wagen instructor named Erwin Wonisch. Why? Because after about two minutes inside Magna Steyr's off-road proving ground, he began jumping the 6x6. Like for real, jumping a 9000-pound, six-wheeled pickup truck with me grinning like an idiot from the passenger seat. Since we had our usual crew of photo and video people ("Good, but do it once more, please…"), Erwin jumped with the 6x6 again and again and again -- I neglected to actually count, but I'd guess 20 jumps is pretty accurate. Then he drove through four feet of water, and then started bounding up boulders at unbelievable angles. Then he let me drive the 6x6. Which, according to Mercedes, makes me the first journalist to be given the thrill.

Whee! From behind the wheel you get the impression that you're sitting in nothing more than a jacked-up G-Wagen. In a sense, you are. If you're familiar with portal axles, you'll feel just a whiff of the familiar rocking sensation. Then the 536 hp and 561 lb-ft of torque kick in and you're off like a hippopotamus over a waterfall. It's best to get out of the G-Wagen's way. Top speed is limited to 160 km/h (about 100 mph), but getting there is no problem for the AMG motor. The limiting factor is a mix of reluctant sanity and the portal axles. The six drilled Brembo brakes help stop the big bully in what seem like normal distances. It's interesting that you can lock the differentials on the 6x6 while the transfer case is in high. That came in very handy when I found myself suddenly charging through a foot of muddy, rutted grass. Regular G-Wagens only allow any of the three differentials to lock in low range. Once locked, the relatively puny, four-wheeled truck can only achieve 50 mph, half the velocity of fully locked 6x6.

I should probably mention that the 6x6 has five differentials. This gets a little tricky, but it's worth explaining. The transmission on the regular strength G-Wagen feeds torque into the transfer case where, when locked, it's meted out 50/50 to the front and rear solid axles. When the 6x6's first locker button is activated, the center transfer case locks and sends 31 percent of the available torque to the front axle. The remaining 69 percent of the torque is divided further by the 6x6's real party trick, the first rear axle's double-differential. It's complete with a pass-through, chain-driven power takeoff to the aftmost axle that simultaneously locks along with the transfer case to provide a final torque split of 31/42/27 front to rear. I found it eye-opening that the sportiest drive mode was not only engaged by putting the transmission in Sport (or Manual), but by actually pressing the first locker, thereby setting the torque split at a very AMG-like 31/69 front to rear. The new AMG 4Matic systems on the E- and S-Class feature a permanent torque split of 33/67. Surprisingly, with the first locker engaged, the 6x6 gets a little tail-happy. Talk about fun. Pressing the second locker button activates the locking differentials in the two rear axles. The third locker button locks the differential up front, turning the already crazy-capable 6x6 into a real-life -- to coin an obvious phrase -- supertruck. I'd also like to point out that the lockers on the 6x6 engage and disengage much faster than the ones we're used to on the standard G-Wagen.

Anything I didn't like? Sure. The slight lag from the portal axles combined with the slight lag from the twin-turbo V-8 mean that if you find yourself stopped on a pile of boulders and facing uphill, it's a bit tricky and sticky to get moving again. Of course the answer is to simply recklessly charge forward, because the 6x6 will go over (or jump, crush, annihilate, etc.) whatever's in front of it. I had to forget a lifetime's worth of off-road skills and learn to just keep it floored when climbing 45-degree inclines. There's also no radar cruise control. Or even plain old normal cruise control -- they removed the stalk. Inexplicably, there's no backup camera. Now, I realize complaining about a lack of a backup camera is similar to what my predecessors did in the 1970s and '80s when they'd moan about the lack of rear visibility in a Lamborghini Countach. With the Countach, drivers developed the technique of sitting on the doorsill to reverse. I think 6x6 owners will develop the technique of just running over the Lamborghini parked behind them. When I asked Axel Harries why no backup camera, he just put his head down and started laughing. Hey, I'm grabbing at straws here. Like the strange reflection you get from the cab's rear pane of glass that makes it look the car in front of you is in your rearview mirror. Call it a sign of things to come.

I mention the Countach on purpose, because on the automotive scale of practical appliance to wild exotic, the 6x6 gets parked next to the greatest ever Lamborghini. One is a sports car, the other an off-roader, but both are taking their missions to their respective extremes. You just can't stop looking. I remember the first time I saw a Countach on the street I just stood and stared for an hour at Gandini's masterstroke, never once getting bored. The same thing happened during the four days I spent in and around the G63 AMG 6x6. Every time I saw it, I turned into a 12-year-old boy, simply giddy with each glimpse. I think the lucky, wealthy folks who purchase AMG's biggest, most expensive toy will experience the same sense of childlike huzzah and wonderment every time they step into their garage. I've never owned a Countach, yet that wonderful machine has given me a lifetime of thrills simply when sitting still. I predict the awesome G63 6x6 will do the same for a whole new generation of car lovers.


2013 Mercedes-Benz G63 AMG 6x6
BASE PRICE $525,000 (est)
VEHICLE LAYOUT Front-engine, 6WD, 4-pass, 4-door, pickup
ENGINE 5.5L/536-hp/561-lb-ft twin-turbo DOHC 32-valve V-8
TRANSMISSION TRANSMISSIONS 7-speed automatic
CURB WEIGHT 9050 lb (mfr)
WHEELBASE 165.2 in (front axle-rearmost axle)
LENGTH X WIDTH X HEIGHT 228.1 x 86.0 x 93.2 in
0-60 MPH 7.8 sec (mfr est)
EPA CITY/HWY FUEL ECON 9/12 mpg (est)
ENERGY CONSUMPTION, CITY/HWY 374 / 281 kW-hrs/100 miles (est)
CO2 EMISSIONS 1.91 lb/mile (est)
ON SALE IN U.S. On sale now