Graz, Austria - When you’re trying to build the ultimate off-roader, it helps to have one Europe’s toughest routes in your backyard.
Near Graz, where G-Wagens are made, there’s a 1445 metre high mountain called the Schöckl, with a 5.6 kilometre off-road track up its slopes that includes gradients of up to 60 percent and side slopes of up to 40 percent.
Mercedes G-Class test drivers have been using the Schöckl as a test track for years; each new model has to survive more than 2000km on this very demanding course - including the 2019 version, due to debut at the Detroit motor show in less than two weeks.
The basic building blocks remain the same as its predecessor - first introduced four decades ago in 1978 - a sturdy ladder type frame, three 100-percent differential locks and a low-range transfer case.
But this G-Wagen’s all-new suspension is the result of collaboration between the G guys in Graz and AMG in Affalterbach. The front end has double wishbones (usually found on supercars) with a strut brace, mounted directly onto the chassis without a subframe, and as high as possible for maximum ground clearance.
The rear suspension is more conventional, with a live rear axle located by four longitudinal control arms on each side and a Panhard rod.
To judge by the numbers, the results are impressive; given sufficient grip, the new G-Class will go straight up a one-in-one slope, across a 35 degree side slope without toppling over (that’s seven degrees better than its predecessor could handle), and through water or mud 700mm deep - 100mm deeper than before.
It has 241mm of ground clearance between the axles (an improvement of six millimetres) an approach angle of 31 degrees (one degree improvement) a departure angle of 30 degrees, and a breakover angle of 26 degrees.
The iron fist may have a sumptuous new velvet glove - but that doesn’t mean it’s gone soft.
As soon as any one of the three differentials is locked or low range is engaged, the chassis defaults to G Mode - independently of drive mode - which adapts the suspension damping, the steering and accelerator response, and avoids unnecessary gearshifts, for the smoothest possible progress on rough terrain, while a small ‘G’ icon discreetly lights up in the instrument cluster.
The 2019 G-Class has a newly-developed version of Mercedes’ nine-speed 9G-Tronic automatic transmission with torque converter, controlled by special software that reduces shift and response times while using the wide spread of transmission ratios to makes driving quieter and more comfortable, as well as reducing fuel consumption.
The new permanent four-wheel drive transfer case is flange-mounted directly on to the gearbox, sending 40 percent of the drive torque to the front axle and 60 percent to the rear axle. The permanent all-wheel drive ensures maximum traction.
Low range (and it is really low at 2.93:1, as opposed to 2:1 in the previous model) can be engaged at up to 40km/h by shifting the transmission into neutral and hitting the low range switch; you can go back to high range the same way at up to 70km/h.
And finally, all-round visibility is provided by a 360° camera, the reversing camera and three further cameras, so that you can see obstacles located below the window line or in front of the car, in a choice of different views on the multimedia display, with dynamic guide lines showing the road and the width of the car, along with height, gradient, angle, compass, steering angle and which differentials are locked.