Despite all the power and modern technology available in modern supercars, it is almost impossible to reach a speed of 269 mph in an automobile on public roads today. And nearly ninety years ago, it was an engineering feat of astonishing proportions.
In 1938, Mercedes-Benz built an enclosed streamlined version of its Grand Prix racing car, the W125, for champion racing driver Rudolf Caracciola, so that he could complete the race. That W125 had already won half the races of the 1936 Grand Prix season, but the closed-wheel bodywork and bubble cockpit made it more slippery. Mercedes used early wind tunnels developed for Zeppelins to shape the car for maximum speed. A massive twin-supercharged V12 replaced the racing car’s inline eight-cylinder engine and made it even faster.
This effort of Mercedes and Caracciola was inspired by Germany’s Chancellor Adolf Hitler. The head of the Nazi Party pushed his sportswashing propaganda wing to prove the country’s strength and technical prowess under his watch. Hitler and his right-hand man, Joseph Goebbels, conceived the idea of German Record Week, a top speed competition to show how great the country’s newly-developed Autobahn network was. The competition was scheduled during the Grand Prix off-season, allowing the leading world championship contenders Mercedes and Auto Union to compete for high-speed glory. The government-sponsored event took place on the newly-built section of the Autobahn between Frankfurt and Darnstadt.
While the 1937 Rekordwoche competition had been taken by Auto Union and its celebrity driver Bernd Rosemeyer, Mercedes entered the battle in 1938 with a new contender and even more speed. Heavy modifications were made to the W125, and the world land speed record was in sight. Mercedes was so confident that it requested to move the event from autumn to January so that it could win on the stand of that year’s International Automobile and Motorcycle Exhibition.
setting the record straight
The backbone of this record attempt was the car’s 5.6-liter V12 engine, which featured a pair of Roots-style superchargers. The engine was the heaviest part of the car ever built, being made from steel cylinders with welded-on steel cooling fins. According to Mercedes, the engine was capable of an incredibly impressive 765 horsepower and could spin at over 5,800 rpm.
To find extra speed for short top-speed runs, Mercedes thought it best to eliminate the cooling ducts for the engine. Where the engine was traditionally air-cooled, Mercedes instead enclosed the cylinders in jackets and directed water across the wings. Without a conventional radiator system, Mercedes filled the water tank with ice to prevent the engine from overheating during short high-speed runs.
Not only did Mercedes bring out its A-game for the record run of 1938, but Auto Union also brought a highly updated and streamlined V16-powered Type C. In early practice for the event, Rosemeyer stepped behind the wheel of the Type C and reportedly clocked an impressive 267 MPH ahead of the official time. When the official event began, Caracciola responded immediately with a run of 268.9 mph, a new world record. Rosemeyer was confident that his auto union would win in motion. However, the world will never know if he could have done so, as Rosemeyer lost control and his car went flying and crashed into a bridge embankment, where he was thrown from the car and died instantly.
Some argue that Rosemeyer’s fatal race was so fast that it took the record back, but officials could not confirm this, as the race would always remain incomplete. Rudolph and his Mercedes will remain the fastest thing ever driven on a public road.
finally broke the record
These smooth-moving machines were the product of an evil propaganda machine. Despite the talent of the drivers involved, the incredible efforts of these automakers and their associated engineers, and the usefulness of Germany’s high-speed Autobahn system, these achievements only served to publicize the claimed superiority of the Nazi regime. That these records stood for decades after Hitler’s death made their fall all the more impressive.
The Koenigsegg Agera RS driven by factory driver Niklas Lilja recorded a 2-way average speed of 444.6 km/h (277.9 mph). A new world record! pic.twitter.com/FXUjKpTW1q
– Koenigsegg (@koenigsegg) 4 November 2017
In late 2017, when Koenigsegg took the 1,200-horsepower Agera RS down a long straight stretch of highway in Nevada in an attempt to break multiple speed and acceleration records, the Swedish hypercar maker finally outclassed the older Mercedes. Caracciola’s old record ultimately fell to test driver Niklas Lilja, with a two-way average of 277.87 mph from a street-legal production car. On the 11-mile Nevada highway return trip, Lilja hit a top speed of 284.6 mph.
Like the Autobahn run, this Nevada highway was chosen because it was long, straight, and flat. This car didn’t need a dedicated race course or a wide open salt flat to set its record, just a regular normal stretch of US interstate. And the only publicity machine Koenigsegg was promoting with its world record speed run was that Koenigsegg is good.
