2019 Mercedes-Benz G-class

Schöckl is a scenic, 4741-foot mountain peak that stands proud of the landscape surrounding Graz, Austria, not far from the Magna Steyr assembly plant where the Mercedes-Benz G-class SUV is still largely hand-built under contract for the three-pointed star. That will remain the case after the first all-new G-class in almost 40 years debuts at the 2018 Detroit auto show.

A hotspot for hikers and mountain bikers, the Schöckl’s significance to the auto world lies in the 3.5 miles of steep, rock-strewn goat paths that cut down its flanks and across the switchback tarmac road that leads to its summit. This is the spiritual home of the Geländewagen, which, despite its advanced age and ritzy price tag, remains one of the world’s foremost production off-roaders. And to assuage any concerns that its engineers have grown soft from decades of upgrading the same old military rig for use by well-heeled civilians, Mercedes invited us to strap in for a preview ride down the Schöckl in the first G-wagen designed for the 21st century.

While greater refinement and on-road drivability were the primary goals for the new 2019 G-class, individual test mules also had to survive more than 1200 development miles on this Austrian Rubicon before getting the green light. Sadly, we weren’t allowed behind the wheel, and the length of pavement we covered while riding in lightly camouflaged G550 prototypes could be measured in feet. But this is still important stuff, with the G-class’s prowess here bolstering its X-factor as a refreshingly absurd diversion from the SUV norm.

Mercedes has yet to release full details and specs, but we know that virtually the entire G-class package is new, down to its stiffer, fully boxed ladder frame fabricated from steel. Yet so closely do the new truck’s proportions adhere to the original’s that only up close do you notice that it has grown 2.1 inches longer and 2.5 inches wider, with an additional 1.6 inches between the axles—small numbers that result in a notably roomier and more usable cabin, particularly for rear-seat riders. Larger disc brakes front and rear necessitate that entry-level G550s wear at least 18-inch wheels (19s and 20s also will be available), with the high-performance Mercedes-AMG G63 version expected to roll on 22-inchers and gain the vertically slatted Panamericana grille that’s spreading across the sub-brand’s lineup. Thanks to smarter engineering and the use of lightweight materials, such as aluminum for the hood and doors, Mercedes says that curb weights should come down by about 300 pounds versus existing models, which in our testing have weighed nearly 6000 pounds.

Dropping into the Schöckl with Benz’s test pilots is a puckering dive into vehicular sadism. With marginally increased approach and breakover angles (31 and 26 degrees; the departure angle remains at 30 degrees), as well as slightly more ground clearance than the current G550’s 8.1 inches, the new G cleanly navigates steep ledges and big rocks that would tear the bumpers off most SUVs. It also sticks to steeper side slopes than the old truck, thanks in part to a 4.8-inch-wider track, and it can ford 27.6 inches of water, nearly four inches more than before. Other tweaks to the G’s foundation include moving the drivetrain above the lowest part of the frame for increased underbody protection and mounting the fuel tank ahead of the rear axle for improved crash performance.

The G-wagen’s most significant update—an independent front suspension in place of a live axle—was immediately apparent on the move, where the old truck’s bouncy, stiff-legged motions are replaced by a greater composure that appeared to be far easier to manage. Front wheel articulation was much better controlled as the G traversed sharp rocks and deep ruts, while its honest-to-goodness, variable-ratio, electrically assisted rack-and-pinion steering never forced the driver to saw at the wheel the way one had to do with the recirculating-ball setup in the old truck. A live rear axle still resides under the back end, although the former trailing-arm setup has been replaced by a more precise arrangement employing a Panhard rod. Steel coil springs and adaptive dampers support each corner; performance-oriented AMG models will use a more street-friendly setup, including a rear anti-roll bar that the G550 lacks.

Thanks in part to the big front control arms mounted high in the new G-class’s chassis, with a curving strut-tower brace tying their mounts together for extra strength, Mercedes says overall suspension travel has increased slightly to 7.3 inches up front and 8.8 inches in back. That’s not a lot for a dedicated off-roader, and the 265/60R-18 Falken Wildtrack all-terrain tires on the preproduction prototypes were modestly sized. Yet our G exhibited impressive shock absorption and attitude control even when it was careening downhill at near reckless speeds.

The G550’s largely carryover twin-turbo 4.0-liter V-8 allowed for climbing up the Schöckl’s slopes with a wonderful excess of power and noise. Mercedes won’t yet quote specific outputs, but it felt like the prototypes made at least the 416 horsepower of the current G550; we expect roughly 600 horses in the new G63 as an AMG-tuned 4.0-liter supplants the existing model’s 5.5-liter mill. The previous seven-speed automatic transmission makes way for a new quick-shifting nine-speed unit shared with other modern Benzes yet featuring a unique casing that incorporates the two-speed transfer case with a default 40/60 percent front/rear torque split. Here, too, the AMG should have its own specific tweaks. The switches for the G’s standard front, center, and rear locking differentials remain prominently placed in the center of the dashboard. Along with side-exit exhaust pipes that filled the woods with a burly V-8 roar, other essential G-wagen traits that make the jump to the new model include doors that close with a vaultlike kachunk and unlock with the satisfying clack of a bolt-action rifle.

While in some markets the G’s locking diffs will be capable of being activated independently of its all-wheel-drive mode, safety concerns in the U.S. dictate that our models will do so only when in low range, which in the new G550 employs an even greater gear reduction than before (2.93:1 versus 2.10:1). Toggling the low-range button on the center console also engages a new G-Mode off-road setting that maximizes traction and maneuverability by softening the dampers, adjusting the programming of the engine and transmission, and deactivating the electronic stability control. (There remain Comfort, Eco, Sport, and Individual setups for the street.) No amount of technology makes ascending Schöckl mountain as riveting as the express trip down. But the G’s extra gearing and selectable lockers kept it chugging forward when only a couple of its tires were touching the ground—which a new 360-degree off-road camera system makes easier to do without a spotter outside the vehicle.

It was clear even from our brief ride in the passenger seat that Mercedes-Benz’s domestication of the Geländewagen has had little effect on its hard-core character. We’ll still have much to learn about the 2019 G-class once we finally get behind the wheel, including how it behaves in the pampered and pampering real world of six-figure luxury SUVs. But if its road manners are even close to as composed and responsive as it felt on the Schöckl’s tortuous trails, this icon’s transformation should be revelatory.