Mercedes-Benz W 125 "AVUS" racing car with streamlined body, 1937

The traditional AVUS race scheduled for the end of May 1937 was to be the scene of another demonstration of Nazi Germany's strength. Following the construction of the high-banked north curve, those responsible hoped to achieve average speeds beyond the spectacular 300 km/h mark on what was already a very fast circuit, and thus be able to boast about the fastest race track in the world in Berlin.

Since this goal could not be achieved with the 750 kg Formula racing cars available at the time, the race was declared formula-free without further ado, thus enabling the dominant German protagonists of Grand Prix racing to bring custom-specified racing vehicles to the starting line for the AVUS race. Although there were no sporting prizes to be won beyond the exhibition of German grandeur, of course neither Daimler-Benz AG nor Auto Union AG shunned this event. Instead, they went to great lengths to meet the requirements.

In order to be able to reach the very highest speed ranges as required, aerodynamically optimised bodies had to be used. Only fully enclosed bodies offered better wind resistance, which naturally turned out to be considerably heavier than the sleek bodywork of the regular Grand Prix racing cars with their free-standing wheels. In addition to a W 25 from the previous season, two brand-new W 125 cars from the new racing season were also fitted with streamlined bodies and received larger wheels (22-inch front, 24-inch rear), whose tyres with their larger rolling circumference were able to withstand the extreme loads caused by higher speeds, the more than 200 kg higher vehicle weight and the effects of the new banked curve more reliably.

While Manfred von Brauchitsch took the start in the streamlined car based on the W 25, Rudolf Caracciola and Hermann Lang drove the two fully-clad W 125 cars. Caracciola and von Brauchitsch won the two qualifying heats of the race; however, they had less luck in the final after their gearbox became so hot under the streamlined bodywork that the soldered connection of a gearbox oil line melted and the gearbox was without lubrication. Hermann Lang was luckier in that the critical connection in his car was not soldered but screwed, and so he finished the race with an average speed of 261.7 km/h as the winner ahead of the Auto Union drivers Ernst von Delius, Rudolf Hasse and Bernd Rosemeyer.