Despite all the engineers' efforts, it is ultimately the drivers themselves who determine how safe they are out on the road. They should always adapt their driving style in accordance with the wintry conditions and ensure that their vehicle is suitably equipped; winter tyres are absolutely essential.
An engineering genius: Professor Wunibald Kamm
Professor Wunibald Kamm (born 26 April 1893, died 11 October 1966), after whom the "Kamm's Circle" is named, worked under Paul Daimler and Ferdinand Porsche in the racing engines department of the Daimler-Motoren-Gesellschaft (DMG) from 1922 until 1925. He then moved to the German Experimental Institute for Aviation in Berlin-Adlershof where he gained valuable experience. In 1930, Professor Kamm founded and became head of the Research Institute for Motor Transport and Vehicle Engines at the Stuttgart College of Technology. During this time, Professor Kamm developed a pioneering testing ground for motor vehicles including a 1:1 wind tunnel, as well as researching and describing dynamic driving processes. This led him to devise the "Kamm's Circle". In 1952 he was appointed head of the Battelle Institute's Mechanical Engineering faculty, specialising in automotive engineering. Professor Kamm's induction into the "Automotive Hall of Fame" on 6 October 2009 recognises his status as one of the world greats of the automotive industry who have made "major contributions to the advancement of the automobile through their ingenious creations, unerring dedication and valuable inventions". Other famous figures who have received this honour and have close links to Daimler AG include Gottlieb Daimler, Carl Benz, Béla Barényi, Wilhelm Maybach, Ferdinand Porsche and Rudolf Diesel. The work of Professor Kamm, who maintained close ties to Daimler AG throughout his lifetime, earned him further accolades too: on 1 August 1958 he was awarded the Federal Cross of Merit, First Class, while the University of Stuttgart conferred an honorary doctorate on him on 26 April 1966.
Pulling away with ease on ice and snow
When starting off in wintry conditions, certain road surface conditions are automatically detected and the interventions of the 4ETS electronic traction control system adjusted so as to achieve the greatest possible acceleration while minimising wheel slip, ensuring optimum directional stability in the process. This strategy also allows the vehicle to pull away under the most adverse conditions, such as when one side of the vehicle is on an icy slope (µ-split) or both wheels on the front or rear axle have limited grip (µ-jump).
When starting off on µ-split, one side of the E-Class 4MATIC is on snow or ice and the other on asphalt. This means there are major differences in the coefficient of friction between the left and right-hand side of the vehicle. On all vehicles with open axle differentials, the wheel with the smallest friction coefficient limits the maximum transferable drive power. If the drive power exceeds the maximum transferable power, the wheels on snow or ice will start to spin and the E-Class 4MATIC would be unable to start off. 4ETS instantly detects this situation and prevents the wheels from spinning by building up exactly the right amount of pressure in the wheel brakes. As the wheel with the higher friction coefficient is now braced by the brake force at the wheel with the smaller friction coefficient, the E-Class 4MATIC starts to move. After pulling away, the wheel characteristics are closely observed and the brake pressure regulated in such a way that, as far as possible, there is no difference in speed between the individual wheels. The braking force applied by 4ETS effectively simulates a higher coefficient of friction on the side of the road covered with ice or snow; ideally, this will match the coefficient of friction on the asphalt side. This produces an optimal inter-wheel locking effect at the axle differentials, resulting in the maximum possible acceleration on µ-split surfaces.
An engineering genius: Professor Wunibald Kamm
Professor Wunibald Kamm (born 26 April 1893, died 11 October 1966), after whom the "Kamm's Circle" is named, worked under Paul Daimler and Ferdinand Porsche in the racing engines department of the Daimler-Motoren-Gesellschaft (DMG) from 1922 until 1925. He then moved to the German Experimental Institute for Aviation in Berlin-Adlershof where he gained valuable experience. In 1930, Professor Kamm founded and became head of the Research Institute for Motor Transport and Vehicle Engines at the Stuttgart College of Technology. During this time, Professor Kamm developed a pioneering testing ground for motor vehicles including a 1:1 wind tunnel, as well as researching and describing dynamic driving processes. This led him to devise the "Kamm's Circle". In 1952 he was appointed head of the Battelle Institute's Mechanical Engineering faculty, specialising in automotive engineering. Professor Kamm's induction into the "Automotive Hall of Fame" on 6 October 2009 recognises his status as one of the world greats of the automotive industry who have made "major contributions to the advancement of the automobile through their ingenious creations, unerring dedication and valuable inventions". Other famous figures who have received this honour and have close links to Daimler AG include Gottlieb Daimler, Carl Benz, Béla Barényi, Wilhelm Maybach, Ferdinand Porsche and Rudolf Diesel. The work of Professor Kamm, who maintained close ties to Daimler AG throughout his lifetime, earned him further accolades too: on 1 August 1958 he was awarded the Federal Cross of Merit, First Class, while the University of Stuttgart conferred an honorary doctorate on him on 26 April 1966.
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Pulling away with ease on ice and snow
When starting off in wintry conditions, certain road surface conditions are automatically detected and the interventions of the 4ETS electronic traction control system adjusted so as to achieve the greatest possible acceleration while minimising wheel slip, ensuring optimum directional stability in the process. This strategy also allows the vehicle to pull away under the most adverse conditions, such as when one side of the vehicle is on an icy slope (µ-split) or both wheels on the front or rear axle have limited grip (µ-jump).
When starting off on µ-split, one side of the E-Class 4MATIC is on snow or ice and the other on asphalt. This means there are major differences in the coefficient of friction between the left and right-hand side of the vehicle. On all vehicles with open axle differentials, the wheel with the smallest friction coefficient limits the maximum transferable drive power. If the drive power exceeds the maximum transferable power, the wheels on snow or ice will start to spin and the E-Class 4MATIC would be unable to start off. 4ETS instantly detects this situation and prevents the wheels from spinning by building up exactly the right amount of pressure in the wheel brakes. As the wheel with the higher friction coefficient is now braced by the brake force at the wheel with the smaller friction coefficient, the E-Class 4MATIC starts to move. After pulling away, the wheel characteristics are closely observed and the brake pressure regulated in such a way that, as far as possible, there is no difference in speed between the individual wheels. The braking force applied by 4ETS effectively simulates a higher coefficient of friction on the side of the road covered with ice or snow; ideally, this will match the coefficient of friction on the asphalt side. This produces an optimal inter-wheel locking effect at the axle differentials, resulting in the maximum possible acceleration on µ-split surfaces.