Mercedes S 500 4matic: Confident Even On Ice

2023 Author: Eric Donovan | [email protected]. Last modified: 2023-08-25 09:36

Mercedes is sending the S-Class with all-wheel drive into the race in autumn. The developers caused a surprise with the distribution of power. We have already tested the S 500 4matic on a mountain tour.

By Stefan Grundhoff

The Audi A8 quattro opened the new segment in the mid-1990s. Luxury class and 4x4 drive - that makes sense because of the generous horsepower and weight dimensions of over two tons. The Ingolstadt debut was followed by the brands VW, Bentley, Chrysler and Mercedes. Even if it hardly makes sense, one model - the all-wheel drive S-Class - is very popular in the USA.

Good image

The reason is not to be found in driving dynamics or winter suitability. Rather, this class is more about the important image. In Europe, people are more practical. For the ski weekend in St. Moritz, you don't always want to have to pull the sluggish Range Rover out of the garage, you want to shine with the new S-Class.

While the additional front-wheel drive on the predecessor W 220, first presented in 1998, had to be laboriously tinkered with on the drive train during the ongoing production process (from 2002), the new S-Class (W 221) had been chosen as a rear-wheel and all-wheel drive version since the first technical drawings. The development time of five years was unusually long for a drive concept.

Noticeable even on icy ground

The result is impressive. The two-tonne S-Class does a remarkable job even on ice-slippery and snow-covered roads in the Swiss Alps. Undeterred, it goes up and down the winding roads and paths. In addition to driving in all locations, another development goal was achieved. The permanent all-wheel drive with its open central differential loads the luxury body with an additional weight of just 70 kilograms.

The 4x4 concept comes as a surprise on closer inspection. While the competition from Audi, BMW or VW is increasingly moving in the direction of a variable power distribution, the Stuttgart-based company is relying on a fixed balance of power. 45 percent of the power goes to the front axle, the remaining 55 percent work at the rear.

"So that the desired propulsion is achieved right from the start on slippery ground, both axles have a rigid throughput up to a torque of 50 Nm," explains Dr. Andreas Faulhaber, responsible for the control systems of the S-Class. This is particularly helpful when starting up on the mountain. The 4matic all-wheel drive was coupled to the housing of the seven-speed automatic which has been extended by 20 centimeters. The gear set itself was not changed.

Tight vote

From the end of the gearbox housing the cardan shaft goes at a seven-degree angle to the right side of the front axle. The pinion is not lubricated by its own system, as with the predecessor, but by the closed high-pressure circuit of the automatic.

The spring-damper coordination of the S 500 4matic seems a bit tighter than that of the rear-wheel drive. Especially in the Gz range, you would like a steering with a little better feedback. The driver and passengers only feel the differences in propulsion when it becomes slippery due to ice, water, snow or unpaved ground. If a drive wheel loses traction, the power is not transferred to another wheel, but is braked in a fraction of a second by the engine electronics. The chassis developers have remained true to their line and have also designed the all-wheel drive version of the flagship understeer. You have to perform tricks to get the stern to break away easily. In the snow, switching off the electronic stability program can bring the desired success. If the snow is a little higher, the S 500 can be raised using the standard air suspension.

0.5 liter additional consumption

The engineers had to work through a full specification sheet in the five years of development. In addition to low weight and the desired propulsion, the list also included the low additional consumption. "That also worked," says development manager Gunter Fischer, "the W 221 4matic uses just half a liter more fuel per 100 kilometers than the rear-wheel drive version."

The 4matic versions of the Mercedes S-Class will hit the German market in autumn. Initially as the S 450 and S 500 with outputs of 340 and 388 hp. The new 4matic models should cost around 3000 euros more than the comparable standard versions. The diesel versions S 320 CDI and S 420 CDI with 4matic are to follow in the medium term. Overall, an all-wheel drive share of between 10 and 15 percent is expected in the S-Class. A third of the 4matic versions are planned in North America.