It’s a beautiful day. One that the technical project manager at Mercedes-Benz Classic has been looking forward to for a long time: now the matt silver surface finish of the fully restored 540 K Streamliner can shimmer in the sun. Parked out on the test track, the vehicle looks surprisingly less anachronistic than one might expect of a vehicle built in 1938.
In just a few moments its engine will start up – and we will see whether the unstinting efforts of the past three years can put this aerodynamic trailblazer back on the road.
A very special special model.
The introduction of the motorways in Germany in the 1930s brought new challenges for the automotive design engineers. Aerodynamic styling was becoming a more and more important factor in automotive design. It was during this period that the “special vehicle production unit” in Sindelfingen under Hermann Ahrens created the 540 K Streamliner – initially with the objective of winning the Berlin-Rome long-distance race.
As no other vehicle before, or since, this imposing car combines outstanding aerodynamic efficiency with perfect aesthetics – setting new standards in the process.
Initially merely a test vehicle.
The 540 K was originally conceived as an efficient competition vehicle for the important Berlin-Rome long-distance race. But in fact the Streamliner was initially used as a test vehicle for high-speed tyre testing by the Dunlop company in Germany. A fast, comfortable and safe car was urgently needed for testing the new generations of tyres at very high cruising speeds on the motorway. Following the turmoil of the Second World War, some of the important components from this vehicle found their way into the collection of the Mercedes-Benz Museum.
Complex process of reconstruction.
The reconstruction was not a straightforward endeavour, even though the original line drawing had been made available by the Mercedes-Benz Archives. Some important components of the original vehicle were also tracked down in Mercedes-Benz's own company collection. But of the most important component of this unique vehicle, its aluminium bodyshell, only a few traces remained on the frame: the bodyshell had to be completely reconstructed.
Premiere in the wind tunnel.
All in all, more than 4,800 hours of work went into this extremely demanding restoration and reconstruction project. People who had been around at that time were questioned, documents consulted and individual parts rebuilt until, in 2014, the 540 K Streamliner was ready for testing in the wind tunnel. Here it revealed a drag coefficient of 0.36.
All that was still missing was the road test on the high-speed course at Papenburg – until that sunny day when the project manager was able to take the wheel for himself… and find out as he accelerated away whether the years of work had truly been worthwhile.
On the road again.
Even without the supercharger, the 76-year-old Streamliner was able to hit an impressive 167.97 km/h. Then it was time to measure its performance with the supercharger. The Roots-type supercharger could only be activated for a minute at a time, but it was enough: with a top speed of 185.57 km/h, the 540 K Streamliner achieved the speed its design engineers had envisaged back in 1938.
The 540 K Streamliner is finally back where it belongs: on the road! Find out more about the complex restoration project and watch the extended version.