Blog & Talk


The Mercedes-Benz 300 SL "Gullwing"

and Rudolf Uhlenhaut

This car is certainly one of the sports-car-icons of automobile history. U.S. Americans called this car “Gullwing” (German: “Flügeltürer”) to refer to the elegant swinging movements of a seagull. It is fascinating under which conditions, this car has turned into an automotive masterpiece.

We go back to the year 1947 – Germany and its infrastructure were lying in ruins after Second World War. People were starving and many died as a consequence of malnutrition or froze to death in one of the coldest winters of the 20th century. “White death” and “black hunger” were phrases associated with that time. However, not only Germany suffered under these conditions. The situation of the population all over Europe was dramatic. As historians estimate, the hunger years between 1946 and 1948, caused the loss of nearly two million lives. 

However, the situation had to improve again! The board of Daimler-Benz AG determined in a memorable meeting in June 1947 to develop and construct again a luxury limousine. They wanted to continue their tradition as a premium manufacturer in respect of an era of reconstruction. They also discussed building a sports car. At the same time, in the Austrian Gmünd, decisions were made about the already complete plans of a sports vehicle having the construction number 365. Compelling visions amidst the rubble and ruins! 

Rudolf Uhlenhaut, technical director of the racing department as of 1936, was responsible for major successes of the “Mercedes-Benz Grand-Prix” racing cars. In 1947, he returned to his former employer as a test engineer and put his ideas of a luxury vehicle on paper. The centrepiece – so his dream went – was a newly developed 4.5-litre 12-cylinder engine with a compressor! However, reality proved to be otherwise after a catastrophic, lost war. 

“You had to take what you could get …. And we did all that was humanly possible,” Rudolf Uhlenhaut said in an interview with the former chief editor of the Motor-Klassik. This was just three years before his death in 1989. Therefore, they found a suitable engine for the representational limousine. Internally, the engine was called M 159 and came from the thirties. The engine was actually considered for power transmission of a new 2.6-litre carriages series. Due to the war conflict, this engine was used as power transmission for light trucks and light and fire engines. Then, the engine was carefully modified and received a new name: M 182. The first version had a power rating of 100 HP. Compared to the initial product, which had 60 HP, this makes an impressive increase of 67 %! 

However, performance proved insufficient in relation to the weight of the vehicle, which was currently in the development phase. Therefore, Uhlenhaut modified the engine again. The low camshaft was replaced by an overhead one. In doing so, issues that occurred at a higher revolution speed, were solved. After a further fine-tuning, performance was around 115 HP. In 1951, the new Mercedes-Benz 300 (later on, it was called “Adenauer”) with the newly called engine M 188 was shown at the IAA in Frankfurt. The vehicle was a full success and the audience and public were thrilled! 

Der 300 SL Becomes Reality 

Two months later in June 1951, the board came to the decision to build a new “sports version” of the 300 SL. They had already discussed and settled plans for this version four years earlier. According to the statement of the CEO, Fritz Nallinger, this version should open a small window for the company to become an actual player in the motor sport competition. These were truly humble words if one considers the dominant position of the company within the international Grand-Prix racing sector. 

Then, the new engine M 194 was further developed in order to be used in sports vehicles. Power rating soon raised to 140 HP since they integrated three carburettors, greater air funnels and a sport exhaust manifold. Furthermore, the engine got a dry sump lubrication.   

Finally, they focused on the general concept of the new sports vehicle. After his visit at the Le Mans 24 hour race, Wilhelm Fürst von Urach, who was chief engineer and likewise in charge as a scout, described his ideas with regards to car body and coverage as follows: “A car body that has a good drag coefficient can save a lot of energy. Therefore, for us, the performance of the Jaguar (C-type / 220 HP) will not be the determining factor. The Jaguar is an open vehicle. We should use a closed one. The Jaguar and the Aston Martin have a coverage construction following the principle of lattice chassis. Having a low weight, they reach a high stiffness, which is crucial for the road holding.” 

The new 300 SL was constructed and built on precisely this principle. 

They completely redeveloped the famous tubular frame (Uhlenhaut built the first model out of solder wire). The frame was equipped with an exceptionally aerodynamic, hand-made aluminium body. The engine was installed with a slope of 50 % in order to form the body as flat as possible. All chassis elements and also the lightly modified brakes as well as the four-speed gearbox were – apart from minor changes – almost completely adopted from the 300 limousine. 

After the completion of the prototype (the new 300 SL), which had his first test drive on the solitude-racetrack in November 1951, it almost came to an uproar: racing manager Alfred Neubauer, who prepared the upcoming race participations influenced by his own meticulousness, was not convinced of the engine’s power! He demanded the board to have an engine with at least 200 HP and five-speed gearbox instead of a four-speed one in order to be not only competitive, but also capable of winning! 

Nevertheless, Rudolf Uhlenhaut, who was much more aware of the financially accessible possibilities, brought Neubauer down to earth. He confronted him with an astonishing self-confidence. “Either you accept the M 194 engine (with 170 HP) and the four-speed gearbox, or there won’t be any race participation,” he said to Neubauer. Each construction idea, which did not contribute to the 300 SL, had no chance. This was the board’s command, which Uhlenhaut did not only unavoidably accept, but he also continued to insist on this command. 

First Mercedes-Benz Race Participation Since 1939 

After the short, but troublesome conflict with Alfred Neubauer, the race team concentrated on the preparation for the first race with the same thoroughness as in September 1939. In total, five races were on the schedule in 1952. After the season, the new 300 SL had won four of the races. In the fifth race, they ranked 2nd and 4th! 

At the Mille Miglia, Giovanno Bracco (Ferrari 250 SL) defeated Karl Kling. However, later in Bern, Karl Kling won the race; in Le Mans, the winners were Hermann Lang and Fritz Riess. And Hermann Lang won again the race not only at the Nürburgring, but also at the spectacular and famous Carrera Panamericana (with his passenger Hans Klenk), even though a vulture had destroyed the windscreen and had also hurt the passenger. 

The sensation was excellent! The 300 SL, which was developed under the pressure of extreme thrift, had delivered a great debut in the international racing sector, which people had not thought to be possible. The vehicle presented a gold mine for Mercedes-Benz’ reputation in the era of reconstruction. 

The SL was upgraded for the race participation in 1953. The engine was carefully modified again and a mechanic fuel injection system was installed. In doing so, the vehicle was the world’s first four-stroke engine with fuel injection! The power was now at 225 HP. This is a power increase of 32 % compared to the old version! However, they had only built one model of the second year 300 SL. This vehicle still fascinates enthusiasts today due to its racing qualities! Eventually, the board decided to step in the Grand Prix racing sector again: the premium class among all the motorsport classes. Based on the newly defined 2.5-litre formula (1954), building a completely new Grand Prix or rather Formula 1 racing car was scheduled. Certainly also due to budget reasons, they ceased the project 300 SL. A remodelled “civilized” series version of the SL was not intended around that time. 

What led to the construction of wing doors? 

Already at the Mille Maglia in 1952, Charles Farroux, racing manager of the Le Mans 24 hour race, suggested in a conversation with Alfred Neubauer that the 300 SL’s small access hatches would not match the criteria of the Le Mans Regulations. Shortly after, also the president of the automobile club de l’Ouest, Monsieur Act, demanded in a letter to extend the doors. He attached a sketch. Indeed, the company was forced to take action. The tubular frame was changed at the edges and the famous wing doors were mounted. To this date, these doors are the exceptional feature of an automotive icon of the century! 

The 300 SL enter series production. 

The 300 SL of 1952, which would be nowadays labelled as “EVO1”, was mothballed and the team intensively prepared for the Formula 1 season of 1954. And now, Max Hoffman entered the stage. Since the forties, the Austrian immigrant had been successful with his car trading company (on New York’s Park Avenue) that sold solely exclusive European luxury brands. After the presentation of the Mercedes-Benz 220 and 330 at the IAA in Frankfurt in 1951, CEO Wilhelm Haspel met Hoffman because the New Yorker was one of the most important automotive importers of the USA. Therefore, he intended to close a promising deal. 

Arthur Bechtel Classic Motors Mercedes-Benz 300 SL Gullwing

Since Max Hoffman’s opinion was so highly appreciated by the Daimler board, he was invited to one of the most memorable board meetings two years later. There, he criticised Daimler’s product programme, which he found truly unattractive. Furthermore, he demanded a top-class sports vehicle based on the properties of the 300 SL! Additionally, he requested a Roadster suited for the Boulevard, which would be less expensive and could be built and sold in large quantities. 

The board responded positively to this suggestion. Within the extremely short time of only five months (!), in February 1954, Mercedes-Benz presented one prototype of the 300 SL Gullwing (road version) and one of the 190 SL at the “International Motor-Show” in New York. The audience and the trade press were thrilled and consequently, the progress of implementation was decided. Already a few months later from August 1954, the 300 SL “Gullwing” was placed into the dealers’ showrooms. One year later in May, the 190 SL entered production. Both vehicles achieved great and legendary success. Apart from the Porsche 356-types and the BMW 507, they became a synonym for the creative and self-confident fresh start in war-damaged Germany. They were cars, which actually no one needed. Today, the 300 SL presents one of the most famous automobile design icons. In 1999, readers of the Motor Klassik chose the vehicle as the sports car of the century. Furthermore, the 190 SL (similar to the “great” SL) also ranks as one of the most popular classic cars. 

What did Rudolf Uhlenhaut say about the starting postion? 

“You had to take what you could get …. And we did all that was humanly possible.”