Collectors Corner - Mercedes-Benz 540K (W29 / W24)

1938 Mercedes-Benz 540K Cabriolet A  s/n  154076

1938 Mercedes-Benz 540K Cabriolet A s/n  154076


For the updated model series introduced in the fall of 1936 at the Parisian “Mondial de l’Automobile”, the supercharged straight-eight engine of Mercedes-Benz’s roadster was bored up to 5.4 liters, leading to the 540K model name. Further performance potential resulted from the reduced weight of a tubular chassis.

... Mercedes-Benz 540 K Register >>>

The innovative independent suspension and servo-assisted hydraulic braking inherited from its predecessor had left enough head-room for the even more powerful engine. Developing 115 hp when naturally aspirated, power leaped to 180 hp once the Roots-type supercharger was engaged by pushing the accelerator pedal to full throttle. With top speeds around 170 km/h (110 mph) it was among the fastest road cars of its era, earning praise for its steering and handling.

Although a few chassis were sent to outside coach-builders, most were completed at Mercedes’ own “Karosserie Sindelfingen”. The Sport-Roadster and Sport-Cabriolets rest on a short (“kurz”) wheelbase chassis, twelve armored 6 seater convertible “Spezial Limousine” for official use were built on top of an extended wheelbase chassis (W24), while most cars were delivered with standard wheelbase: The powertrain layout for the Saloons, Open Tourers and the Cabriolets B and C had the radiator directly above the front axle, while the Roadster and fastback Autobahn-Kurier had the radiator, engine and cockpit set back 185 mm from the front axle. Either layout could be ordered for the Coupé, Cabriolet A and Spezial-Roadster.

The history of the 540 was cut short by the start of World-War II, with chassis production winding down in 1940, and the intended 5.8 l successor having to be abandoned. However, it saw a limited revival after the 1942 assassination of the SS governor of Czechoslovakia, Reinhard Heydrich, when the Reich Chancellery commissioned twenty armored 2-door limousines under their “Aktion P”.


540 K, 540 K kurz

Production Period

1936-1940, 1943/44


8 cyl. supercharged overhead valve inline


5,401 cm³


115 hp / 180 hp

Top Speed

170 km/h, armored 80 km/h


3,290 mm (standard)
2,980 mm (“Kurz”)
3,880 mm (“Spezial”)


Four or five-speed synchromesh


Coil spring four-wheel independent suspension,
parallel wishbones at the front, swing axles at the rear


Four-wheel vacuum-assisted hydraulic drum brakes

Principal Developers

Max Sailer, Gustav Rohr, Hermann Ahrens

Related Material
... Mercedes-Benz 540 K Auction Results 

Mercedes-Benz 540 K Register created by Peter Singhof