For the 1934 season, Grand Prix racing's governing body
AIACR introduced a
formula limited mainly by a maximum weight of 750 kg, which was considerably less than the weight of Daimler's previous car used in racing, the outdated seven litre
Mercedes-Benz SSK. That range of cars had been developed in the 1920s by
Ferdinand Porsche, who was by now independent, and proposed his
P-Wagen project racing car concept to the chancellor in office since
January 1933:
Adolf Hitler. He decided to support both the new company
Auto Union, who took over Porsche's concept, and
Mercedes-Benz, who had more than a quarter century of experience in major international racing. Despite reducing weight and engine size to roughly half, Daimler engineers soon managed to get more power from the supercharged
Straight-8 M25 engine than the maximum 300 hp of the SSK. While the W25 was developed in 1933, the first appearance was scheduled to be at the 1934
Avusrennen in Berlin, held on May 27. Mercedes showed up, but after encountering carburetor or fuel pump problems in practice, withdrew from the race. The next entry a week later, again on home soil, at the Nürburgring
Eifelrennen, was successful, with
Manfred von Brauchitsch winning. It is often claimed that this race was the beginning of the
Silver Arrows, but it since has been proven that already in 1932 at the AVUS, v. Brauchitsch had raced an SSKL covered with streamline aluminium sheets, which had been described as a silver arrow by the media. Besides, both German rounds were run to Formula libre rules to attract more entries. In
1934, the W25 won four major races (Eifelrennen,
Coppa Acerbo, Spanish and Italian GP) compared to three for
Auto Union (
German, Swiss and Czechoslovak GP), plus the
Klausenpass hillclimbing event. These popular uphill races were usually dominated by the superior traction of the mid engine Auto Union of
Hans Stuck, who won at ,
Kesselberg, Freiburg
Schauinsland and
Mont Ventoux. The German cars also took two wins in Italy, where the major competitors came from. On the other hand, two events on the soil of
World War I adversaries ended rather embarrassingly. The
1934 French Grand Prix held near Paris had been a disaster for both German teams, as none of their cars finished. The
1934 Belgian Grand Prix was held on the
Circuit de Spa-Francorchamps which then had a tight corner named after the nearby
Ancienne Douane, the old customs station at the former border with Germany. The border had been moved after the war, but the Belgians set up an even tighter chicane for the Germans: Custom officials demanded a hefty sum of duty for the special race fuel containing alcohol which was consumed by the supercharged German engines. Both teams withdrew with short notice. In
1935, was well over 400 hp. As the M25 engines became unreliable when enlarged to 4.7 litre and 490 hp, a V12 engine was tested, but it proved too heavy. To accommodate it, the chassis was lightened and shortened (thus
K for
kurz), but this worsened handling. Thus, in
1936, the W25K was often beaten by Auto Union's
Bernd Rosemeyer. Only Caracciola could take two wins, one at the twisty circuit of the very wet
1936 Monaco Grand Prix. Mercedes decided to skip the rest of the season to concentrate on development. By driving the race car himself, young engineer
Rudolf Uhlenhaut determined that the W25 had a too stiff suspension in a too soft chassis, which made handling difficult. Even though new rules would come in effect in
1938, he set out to develop a new car for
1937, the
Mercedes-Benz W125, which was very successful in the season it was made for. For the
1937 Avusrennen, two Streamline V12-powered W25K were entered, as weight and handling was of low importance at the AVUS which had been fitted with a banked north turn. Streamline variants were also used for records attempts. As part of a partnership between Mercedes-Benz and
Nintendo, the
Wii U game
Mario Kart 8 and its
Nintendo Switch port
Mario Kart 8 Deluxe feature a W25 Silver Arrow as a playable in-game vehicle, added as part of a post-launch
downloadable game update on August 27, 2014. == Specifications ==