Offroad Tracks: the G-Class in Kitzbühel.
One of the most demanding courses in the world.
Snow, gravel, sand, ice and crushed rock all in the confines of just six kilometres: here, in a quarry near Kitzbühel, is one of the most demanding off-road courses in the world. Anyone who dares tackle it has to contend with steep 90 percent climbs and descents, fords and inclined breakover angles. It’s all about discovering the vehicle in extreme situations. Without an experienced guide, it’s impossible. Christian Vis is on-board with us. He’s an off-road instructor for Mercedes-Benz Driving Events which regularly take place here in the quarry.
Over 20 years of experience.
Christian Vis has more than 20 years of experience in off-road driving. He has a thing for pushing himself and his vehicle to the limits. “It’s a make or break kind of situation – it’s precisely this challenge with the laws of physics and nature that makes off-roading so special”, explains Christian. “It’s always fascinated me”, But it was only really when he first sat in a G-Class that it hit him fully – the “off-road virus” had well-and-truly taken hold of him.
“Experiencing a car that is so capable in off-road terrain was a truly memorable experience”.
The protagonist: the G-Class.
That’s precisely the thing that also makes the G-Class the undisputed star of the driver training events in Kitzbühel. Its reputation brings it to the forefront, and even its markedly angular lines set it out from the rest of the varied vehicles in the Mercedes-Benz Driving Events fleet. Off-road pro, Christian Vis, will show us shortly exactly what it is that makes the G-Class so unique.
“You can just do so much with it. With the G-Class, the fun starts where other vehicles reach their limits”, he says. Settled in the vehicle, the first thing you ponder upon is the reason for the solid-looking grab handles on the passenger side, just above the glove compartment. And another thing that you immediately notice after climbing aboard is the upright, high seating position which provides an unusually good overview of the vehicle’s surroundings.
Simple warm-up exercise.
As soon as we pull away, Christian presses the button for the central differential lock. The warning lamps for ABS and ESP light up straight away. “To drive off-road with optimal traction, we always need the central differential to be locked. ABS and ESP then turn off automatically. ABS and ESP are made for roads; off-road, their effect is not helpful, especially on loose ground”. We climb a steep slope and despite climbing on loose ground, the vehicle impressively accelerates us forwards. “This is a G 500 with 422 hp and a V8 biturbo engine. Without the central differential, the power would be wasted on spinning wheels with no traction”, explains Vis whilst stepping back on the accelerator. “Now, the same engine speed is delivered to the front and rear axles, irrespective of the torque generated in each case”. The car attacks the slope as if it were flat land; it’s an easy task for the G 500.
Fuel consumption combined: 12.3 l/100 km;
combined CO₂ emissions: 289 g/km.*
Steep descent in front of an amazing backdrop.
The Hartsteinwerk Kitzbühel not only offers an off-road track, it also provides visitors with an amazing backdrop. “We always create the six-kilometre-long off-road course around mid-December with the help of diggers”, says Christian. The route is slightly different this year as the mining work continues to change the face of the terrain. Now we’re approaching a steep descent. Before we start descending, Christian sets the transfer case to low range and engages the central differential lock. “Here we need to descend by edging slowly forward. It works well with low range engaged; we can use the much greater engine braking effect and practically roll down the hill in low first gear” – this is how the off-road expert describes first gear with low range engaged. The vehicle ducks down, the bonnet has already disappeared deep below us and the descent continues, getting steeper by the second. We’re hanging by our now taut seat belts with all our body weight pushing forwards as we look through the windscreen at the quarry pit below us. It feels like we’re about to hit the ground.
But the G-Class doesn’t even slip once, it drives down the descent slowly and smoothly with splendour. Christian is supporting himself with both arms on the steering wheel and we hold tightly onto the grab handles to avoid sliding forward. That explains what the sturdy-looking grab handle is for!
The three magic buttons.
One unique selling point of the G-Class is the presence of the three differential locks, available since its very beginnings. The three switches for operating the differential locks sit proudly in the central row of the dashboard. You notice them immediately. The central differential lock forms the link between the front and rear axle. The two axle differentials, meanwhile, connect both wheels on each of the axles. In this way, all of the wheels can be provided with a constant rotational speed, even if the wheel is hanging in the air or spinning on ice. If one wheel has grip, that suffices to ensure traction. Before every tough obstacle, Christian presses the button for the rear differential lock and, if the going gets really tough, he even activates the front lock. “To keep you moving in the right direction on tough terrain, there’s nothing better than differential locks”, he says. “The G-Class is the only vehicle in the world that features this technology as part of its basic equipment”.
Fighting fear and instinct.
Christian drives us sideways along a steep slope. “The G-Class can handle leaning up to 54 percent, that’s the equivalent of a 29-degree slant which it can drive along without tipping over”. This is a statistical value, but when the ground is uneven or when the vehicle has a higher centre of gravity due to its load, this breakover point can be reached much more quickly. The steeper Christian drives into the hillside, the worse we feel – the belts tighten around us again and the grab handle once more finds itself befriending our palms.
“This position is a very unusual one for the human body to experience. Instinctively, we seek to get out of this position as soon as possible, but accelerating will only increase the risk of the vehicle tipping, so we just have to get on with it and drive our way slowly through to the end”.
Help for extreme terrain.
Suddenly it starts to slip. Only for a fraction of a second though. Christian quickly and briefly removes his foot from the brake pedal and the vehicle soon falls back in line with his commands. The rapid, reflex-like reaction really impressed us. “That’s something you can’t just learn quickly. That’s something that you can only learn with the experience gained from plenty of miles driven off-road. Our job here, of course, is to teach our training participants the basics of driving off-road, i.e. the foundation. They will then need to build the rest up on that foundation”.
More than just a car.
Believe it or not, the G-Class vehicle concept is 37 years old. 1979 saw the model’s introduction and since then, it has been built predominantly by hand in Graz, Austria. With its solid, stable ladder-type frame, it is built to last forever. “I see the G-Class as more than just a car”, says Vis. “And you’re always glad to be seen in one, regardless of the occasion”.