At the start of 1933, Grand Prix racing was dominated by French and Italian marques. Nothing could win against Bugatti, Alpha Romero and Maserati. Adolph Hitler had just risen to the position Chancellor of Germany, and one of his first directives was that the Germans should dominate world auto racing. To be beaten by the French was intolerable to the German people. (When Germany invaded France in 1940, the first industrial complex that was bombed was the Bugatti factory) In March 1933, 250,000 Reichmarks per year were given as a subsidy to Mercedes and Auto Union to build the fastest cars in the world.
For decades each country had its traditional color in auto racing. Italian race cars are still famous for their “Rosso Corso” red color, British ones are British Racing Green(BRG), French blue, and Germany was white.
The international governing body of motor sport prescribed for 1934 onwards a maximum weight limit of 750 Kilograms(1650 pounds) for Grand Prix racing cars, excluding tires and fuel. In spring of 1934 the Mercedes-Benz team placed its new Mercedes-Benz W-25 on the scrutineering scales prior to the Nürburgring race, it recorded 751 kg (1,656 lb). Racing manager Alfred Neubauer had the car taken back to the pit where all the white paint was scraped off. The next day the highly polished, shining silver aluminum beneath was exposed and scrutineering was passed. After the car won the race, the nickname Silver Arrow was born.
From 1934 until the Second World War broke out in 1939, there were very few events in which the Auto Union and Mercedes-Benz drivers, at the wheel of cars with power outputs of up to 500 horsepower, failed to triumph. These silver cars with their futuristic looks always finished far ahead of their rivals.
Many of the stories and legends associated with these cars and drivers tell of their courage, daring and bravado. These race-cars had top speeds equal to those reached in today’s Formula One events, but on ordinary roads and racetracks with no safety measures.
By 1937, the supercharged engine of a Mercedes Benz W125 attained an output of 646 Hp, a figure not exceeded in Grand Prix Racing until the early 1980s, when turbo-charged engines were common in Formula One.
The Silver Arrows of Mercedes and Auto Union cars reached speeds of well over 300 kilometers per hour (186 mph) in 1937, and well over 400 km/h (249 mph) during land speed record runs. Some of these records held for three decades or more.
The Auto Union Grand Prix racing cars types A to D, were developed and built by the specialist racing department of Horch works by Dr. Ferdinand Porsche between 1933 and 1939. They were called P-Wagens after their designer. The layout of the car was unusual for the time, being mid-engined. Hence, the layout of the car front to rear was: radiator; driver; fuel tank; engine.
The cars used supercharged engines that eventually produced almost 550 horsepower (which also contributed toward the handling difficulties, as it promoted oversteer which the cars already had in abundance). The engine was originally the V-16 engine that Porsche had started designing earlier; when, starting in 1938, the maximum engine displacement for Grand Prix cars was limited to 3 liters for blown engines; it became a V-12.
The body was subjected to strenuous testing in the wind tunnel of the German Institute for Aerodynamics, a scientific organization that still exists. The fuel tank was located in the center of the car, directly behind the driver, so that the car's front-rear weight distribution would remain unchanged as the fuel was used: exactly the same location used in modern open-wheel racing cars, and for the same reason. The chassis tubes were initially used as water carriers from the radiator to the engine, but this was eventually abandoned after they often sprung small leaks.
Between 1935 and 1937 Auto Union cars won 25 races, driven by Ernst von Delius, Tazio Nuvolari, Bernd Rosemeyer, Hans Stuck and Achille Varzi. Much has been written about the difficult handling characteristics of this car, but its tremendous power and acceleration provided by the V-16 engine were undeniable. Due to the high power/weight ratio, it was not uncommon to be able to spin the rear tires at 100 mph.
No other cars exhibited the advanced technology, abundant power, purist design and elegance in quite the same form as Germany's Silver Arrows. This was the era of the heroic racing driver clad in cotton overalls and with a leather helmet, who risked his life during every minute of the race and, tragically, sometimes lost it.