Mercedes-Benz 540 K Special Cabriolet

The spiritual descendent of the legendary Mercedes-Benz SS/SSK, the 540K was introduced in October of 1936 as the successor to the remarkable 500K. With more than 180 hp available, they were advertised as the fastest regular production automobiles in the world. Highly advanced for the time, they also benefited from some of the most striking coachwork of the prewar era.

No other automobile company has so consistently lead the field, literally from the very beginning of the industry. Credited with the first production automobile, no company has been in production longer. Steady improvements meant that by the first decade of the 20th century, Mercedes’ racecars were dominant worldwide. On the street, the massive cars had no equal for sheer elegance, power and speed.

By 1922, a supercharged six-liter engine was married to a shortened wheelbase. The result was considered the fastest touring car of its day, producing an outstanding 160 horsepower with the supercharger engaged. The S-Series followed, soon developed into the SS and SSK models. More than any other, it was this series of supercharged six-cylinder cars that established Mercedes-Benz’s international reputation.

In its fully developed form, the supercharged 7.1-liter engine of the SSK could reach a staggering 300 hp, powering its lightweight streamlined coachwork to an unheard-of 147 mph. The overwhelming performance of the SSK resulted in many victories for Mercedes-Benz, and perhaps the most important of these were Rudolf Caracciola’s wins at the 1931 Mille Miglia and German Grand Prix.

By the late 1920s, the S, SS, and ultimately the SSK chassis were proving to be the engineering masterpieces of the time. Few today remember that it was the legendary Dr. Ferdinand Porsche who developed the dominant characteristic of the engines – their superchargers. Responsible for all engineering for Daimler from 1924 until 1929, he laid the foundation upon which the eight-cylinder cars would be built.

Following the merger between Daimler and Benz in 1926, a brilliant young engineer named Hans Nibel joined the company. He was named joint Chief Engineer, along with Dr. Porsche, before being named Technical Director of Daimler-Benz AG in 1929 after Dr. Porsche’s resignation.

It was under Nibel’s direction that the eight-cylinder cars were designed. Although it is difficult today to guess at the motivation at the time, it seems fair to suggest that the SS had been successful not only on the track but in the coachbuilder’s galleries. The factory coachworks at Sindelfingen had already earned a reputation for top-quality workmanship – perhaps the best in Europe. Luxurious, well trimmed, and smartly designed, they were well suited to a top caliber chassis.

Clearly, there was more money to be made in catering to the carriage trade, and that probably triggered the desire for a more refined chassis, albeit one that would preserve Mercedes-Benz’s reputation for engineering excellence.

The first result, introduced in 1933, was the 380, a supercharged overhead-valve inline eight-cylinder engine. Power output was modest at 90 bhp naturally aspirated or 120 bhp with blower engaged, but its refinement and smoothness revealed its potential. With its attractive Sindelfingen-built coachwork, 157 chassis were built. Performance was acceptable, if not outstanding, particularly with the heavier and more-luxurious coachbuilding that customers demanded.

Recognizing the need for more power, in 1934 Mercedes-Benz introduced the 500K (“K” for Kompressor, which is German for supercharger). With power increased to 100 bhp or 160 bhp with the supercharger engaged, the cars were finally among the fastest grand touring cars of the time. Even though the 380 had been supercharged, the K designation and new external exhaust left no doubt about the car’s very special chassis.

A total of 342 cars were built before the introduction of the 5.4-liter 540K in 1936. Although similar in many respects to the 500K, the new 540K offered even more power: 115 bhp naturally aspirated or an impressive 180 bhp with the blower engaged. A 12-inch increase in wheelbase to 128 inches improved ride quality and gave the master coachbuilders at Sindelfingen the freedom to create even longer and more elegant bodylines.

According to Jan Melin in Supercharged Mercedes-Benz 8, just 419 540K chassis were built before production ended in 1940. Eleven cataloged body styles were created for the 540K and carried out by Sindelfingen, with each one a masterpiece of the coachbuilder’s art. The new longer wheelbase allowed the hood to be extended, and this, combined with the raked V-shaped radiator and external exhaust pipes, gave the car its undeniable visual presence. Long sweeping fenders, gently skirted, added to the visual impression of length, while chrome accents highlighted the lines and add a sparkling elegance.

This car was auctioned off by RM Auctions in August of 2010 at the Portola Hotel & Spa and Monterey Conference Center, Monterey, California and will be auctioned off by Gooding & Company in August of 2012 at Pebble Beach Concours d’Elegance. 

180 bhp, 5,401 cc overhead-valve, inline eight-cylinder engine with driver-activated and gear-driven supercharger, twin updraft pressurized carburetors, four-speed manual transmission, independent wishbone and coil-spring front suspension, independent swing-arm rear suspension, and four-wheel hydraulic drum brakes. Wheelbase: 128"

Sources: RM Auctions and Gooding & Company
Photo Credit: Copyright Darin Schnabel and Peter Harholdt and Mathieu Heurtault

Mercedes-Benz 540 K Special Cabriolet