The reveal of Mercedes-Benz’s first full redesign for its iconic G-Class is almost here. The new SUV debuts on January 15 at the 2018 North American International Auto Show in Detroit but Mercedes has already let slip some of the details.

The redesign is the most significant change to the G-Class line since the original civilian model was launched in 1979. We’re talking a new ladder frame chassis, steel and aluminum body, and plush interior with S-Class levels of luxury.

But don’t worry, the new G-Class, which is due in showrooms later this year, as a 2019 model, will be as tough as ever. Mercedes is still testing the vehicle on the Schöckl mountain near the G-Class factory in Graz, Austria. The 3.5-mile track includes gradients of up to 60 percent and lateral inclinations of up to 40 percent. Prototypes for the new G-Class have covered more than 1,200 miles on the gruelling track, and according to Mercedes they are doing it with noticeably more control and comfort than ever before.

2019 Mercedes-Benz G-Class

2019 Mercedes-Benz G-Class

That’s because Mercedes has installed an independent suspension with double wishbones on the front axle, which the automaker boasts is much better than the setup on previous generations. The new front suspension works in conjunction with a live rear axle with four longitudinal control arms on each side and a Panhard rod. There’s also a permanent 4-wheel-drive system with low-range; reduction transfer case; and three full differential locks.

As before, high ground clearance and long suspension travel form the basis for the further improved off-road performance. The ground clearance is actually increased 0.23 inches to 9.49 inches. Despite this, the new G-Class is shorter than its predecessor which, together with a wider track, further aids stability. Other numbers we know of include a 27.5-inch wading depth (up 3.93 inches), 26-degree breakover angle (up 1 degree), 30-degree departure angle and 31-degree approach angle (up degree). Mercedes also quotes spring/rebound travel of 85/100 millimeters for the front axle and 82/142 millimeters for the rear axle.

The new G-Class also benefits from a 9-speed automatic. Mercedes says the wide transmission ratio makes driving quieter and more comfortable especially at low engine speeds. The unit also reduces fuel consumption. The 4WD system’s transfer case is flange-mounted directly to the transmission and splits torque 40/60 front to rear in normal conditions. The low-range ratio can be engaged at speeds of up to 25 mph. The gear ratio of the transfer case is then changed from 1.00 in normal mode to 2.93 low mode. It is possible to switch from low to high at speeds of up to 43 mph. Note, the transfer case’s 2.93 ratio is significantly shorter than the previous generation’s 2.1, which Mercedes says becomes noticeable particularly when pulling away on an extreme gradient.

2019 Mercedes-Benz G-Class

2019 Mercedes-Benz G-Class

New electronic aids have also been fitted to further improve off-road performance. One of these is a G-Mode driving mode that adapts the suspension damping, steering, accelerator and transmission. The new G-Class will automatically select this mode as soon as one of the three differential locks has been activated or low range has been engaged. On top of this, a 360-degree camera  has been added to aid visibility. Buyers can also opt for all-terrain tires.

Wrapping up all the off-road prowess is a luxurious interior design akin to the current E- and S-Classes, albeit with some more rugged touches. There is also some retro touches. For example, on the passenger side sits the familiar dash-mounted grab handle that dates back to the original 1979 G-Class. The position of the air vents is also the same as in the original G.

That’s all the info we have from Mercedes but stay tuned for the reveal of the new G-Class at the North American International Auto Show. To learn about some of the other vehicles appearing at the show, head to our dedicated hub.