Cars with history: Mercedes-Benz W125

Shortly before the Second World War, Germany under Adolf Hitler wanted its country to be a power that dominated not only all sports but also racing. To that end, in 1934 it granted a subsidy to Mercedes-Benz and to Auto Union, which allowed both brands to throw themselves fully into the world of international competition and dominate it almost at will.

In 1937, although the Mercedes W25 and the Auto Union Type C had won many of the races of the 1935 international season, the year 1936 had not been very favourable for the Star’s cars; the German engineers began to envisage the successor to the W25. Helped by the extreme freedom that existed in those years regarding the regulations (the requirement was that the cars weigh less than 750 kilos), there was no limit on power. For 1937, Mercedes presented a new car powered by a 5.7-litre, eight-cylinder in-line engine supercharged by a compressor.

Keeping the maximum weight of these Mercedes cars down was a considerable technological challenge that demonstrated Germany’s advance in engineering over its fierce rivals, the Italians, or over Auto Union itself (the brand that preceded Audi). Thanks to the use of aluminium and nickel-chromium-molybdenum steel, the W125s turned out to be light, even counting the weight of the brutal engine, yet with enviable rigidity. With independent front suspension and generally softer settings than in the 1935 season, the W125 presented itself in 1937, ready to dominate the season.

With Rudolf Caracciola, Manfred von Brauchitsch, Hermann Lang, Richard Seaman and Christian Kautz, the German cars won almost all the races of the year, plus the races that did not award points. The only victory that escaped them was in Belgium. On fast circuits such as AVUS, a special version with bodywork was used that allowed it to reach a top speed of 380 km/h. There is no doubt that such speeds and such power were not achieved until many years later, in Formula 1.

With the limitation on engine size for the following years, the W125 was withdrawn from competition, although there was still one more record the W125 was going to claim: the world land speed record. In 1938, a special version of the W125, streamlined and with a V12 engine of nearly 750 horsepower, was going to set a top speed of 433 km/h, a record that still stands today.

Source | Ultimate Car Page, Supercars