The star and the four rings: a marriage which happened 60 years ago…and led to the post-war renaissance of Audi

Prototyp eines kompakten Mercedes-Benz Personenwagens (W 119), 1962. Exterieur, Sicht von rechts vorne. Zu einer Serienfertigung kommt es nicht. 955 Mille Miglia: Mercedes-Benz senior engineer Ludwig Kraus (far left) with Rudolf Uhlenhaut, Denis Jenkinson, Stirling Moss and Dr. Hans Scherenberg (left to right).
Prototype of a compact Mercedes-Benz Passenger car(W 119), 1962. It will not make it into series production. 

In the spring of 1958, decisive motor history was written: In april of that year, the then Daimler-Benz AG acquired a majority in Auto Union GmbH. All the remaining shares followed on 31 December 1959.

By 1960, Auto Union was therefore a wholly-owned subsidiary of Daimler-Benz. This meant that all the brands of Auto Union, which included Audi, now could be revived.

And so Daimler did, to let the public forget the two stroke image of Auto Union and DKW. Of course, they had one small car adventure with the two stroke engined DKW Junior, wich actually proved quite popular.

But Mercedes rather more loved the four cylinder engines and the nobler Audi image, which would fit perfectly. So they made efforts – which we will explain here further – to bring a revolutionary four srtoke engine into the existing Auto Union/DKW  F103, and started work on the development of an all new Audi.

Daimer strategy changed however, and so they sold on 1 January 1965 the majority of the shares of Auto Union to Volkswagen, and offered  them Audi on a plate…in the form of a already extensively developed Audi four dour model, and they even sold the engineer who developed this car with it!

Das Mercedes-Benz Werk Düsseldorf ist das größte Transporterwerk der Daimler AG. Rund 6.600 Mitarbeiter produzieren dort heute den Mercedes-Benz Sprinter. Historisches Foto der Montage des Transporters T1 aus den 1980er-Jahren. The Mercedes-Benz plant in Düsseldorf is the largest van plant of Daimler AG. Around 6,600 employees produce the Mercedes-Benz Sprinter at the plant. Historical photo of T1 van assembly in the 1980s.

The Mercedes-Benz plant in Düsseldorf is the largest van plant of Daimler AG. Around 6,600 employees produce the Mercedes-Benz Sprinter at the plant. Historical photo of T1 van assembly in the 1980s.

In the meantime, from 1961 onwards, the major Mercedes-Benz plant in Düsseldorf was constructed on a site previously operated by Auto Union. With a workforce of some 6600 and an annual output of around 150,000 vans, Düsseldorf is now Daimler AG’s main factory for vans. All the closed variants of the Mercedes-Benz Sprinter – i.e. panel vans and crewbuses – roll off the production line there. Just read further…

Hans Knol ten Bensel

Daimler’s efforts to turn around Auto Union…

On 14 April 1958, the first joint Board of Management meeting between Daimler-Benz AG and Auto Union GmbH was held in Stuttgart-Untertürkheim. At the end of April 1958, the Daimler-Benz Board of Management members Professor Fritz Nallinger and Wilhelm Künkele travelled to Düsseldorf to begin coordinating the activities of the two companies. In August 1958 Hans-Martin Schleyer and senior engineer Arthur Mischke were appointed to manage the liaison between Daimler-Benz AG and Auto Union.

Creating Audi models with Mercedes-Benz genes to be built in Ingolstadt.

Mille Miglia 1955: Mercedes-Benz Oberingenieur Ludwig Kraus (ganz links) mit Rudolf Uhlenhaut, Denis Jenkinson, Stirling Moss und Dr. Hans Scherenberg (von links). 1955 Mille Miglia: Mercedes-Benz senior engineer Ludwig Kraus (far left) with Rudolf Uhlenhaut, Denis Jenkinson, Stirling Moss and Dr. Hans Scherenberg (left to right).
Mille Miglia 1955: Here you see Mercedes-Benz Oberingenieur Ludwig Kraus (far left ) the father of the Audi 100, with from left to right Rudolf Uhlenhaut, Denis Jenkinson, Stirling Moss und Dr. Hans Scherenberg. When Auto Union was sold in ’65 to VW, Ludwig Kraus also went along to VW, to supervise the further development of this Audi 100, to be launched in ’68. Its popularity we believe, suprised many  …

While Düsseldorf was being established as the lead plant for the Mercedes-Benz van division, the aim was also to modernise the production of Auto Union now concentrated in Ingolstadt. The financial resources required for this were considerable: between 1959 and 1964, more than 340 million German marks were invested at Auto Union in addition to the proceeds from the sale of the Düsseldorf plant to Daimler-Benz AG.

Yet development at the company progressed only slowly. This is why Daimler-Benz dispatched one of its most capable engineers to Ingolstadt on 8 October 1963: Ludwig Kraus, head of design in the Mercedes-Benz pre-development department.

Kraus had been designing marine diesel engines since the late 1930s, played a major role in the design of the 1.7-litre OM 636 diesel engine after 1945, and in the early 1950s was head of design for the successful Mercedes-Benz W 196 R Formula 1 racing car and the 300 SLR (W 196 S) racing sports car.

Now his mission was to accelerate changes at Auto Union. Kraus had something of a home advantage, as he had gone to school and obtained his higher school leaving certificate in Ingolstadt.

A stroke of genius: the clever “Mitteldruck Motor” or medium-pressure engine.

„Mitteldruckmotor“ des ersten Audi, 1965. Die Vierzylinder-Konstruktion geht auf die Mercedes-Benz Entwicklung M 118 zurück. “Medium pressure engine” of the first Audi, 1965. The four-cylinder design was based on development of the Mercedes-Benz M 118.
“Medium pressure engine” of the first Audi, 1965. The four-cylinder design was based on development of the Mercedes-Benz M 118.

His arrival was to have far-reaching consequences. This is because Ludwig Kraus not only brought a team of highly motivated young Daimler-Benz technicians with him to Ingolstadt, but also a new, almost fully developed four-cylinder engine with the in-house designation M 118 and the original code name “Mexico”. Its high compression ratio (1:11.2) and the intense swirling effect on the intake mixture of helical intake ducts led to a low fuel consumption. It was also low in vibrations, as all the tests at the time confirmed.

As a so-called medium-pressure engine, this Mercedes-Benz four-cylinder unit had its 1965 debut in the new Auto Union Audi Premiere, also known internally as the F103. This vehicle was the first post-war passenger car by Auto Union to feature a four-stroke engine, and also the first post-war model under the Audi brand.

„Mitteldruckmotor“ des ersten Audi, 1965. Die Vierzylinder-Konstruktion geht auf die Mercedes-Benz Entwicklung M 118 zurück. “Medium pressure engine” of the first Audi, 1965. The four-cylinder design was based on development of the Mercedes-Benz M 118.
“Medium pressure engine” of the first Audi, 1965. The combustion chamber was actually lodged in the piston head., adding additional swirl effect. The long stroke layout of the engine did the rest in making it very fuel efficient under partial load conditions.

Moreover, subsequent vehicle developments at Auto Union and its Audi brand also bore the distinct signature of Mercedes-Benz. This is because Ludwig Kraus remained in Ingolstadt as Technical Director when Daimler-Benz AG sold its majority in Auto Union to the Volkswagen group on 1 January 1965. From 1966 the company was a wholly-owned subsidiary of Volkswagen.

The Audi 100 carried (much) Daimler styling and engineering…

Ludwig Kraus and the other former Mercedes-Benz engineers were familiar with the prototype development work carried out since 1953 for the possible Mercedes-Benz medium-class model series W 122 and W 119. These had a front section reminiscent of the W 113-series SL sports cars, modern body lines with a low beltline and a dynamic rear end design. It is therefore not surprising that the body of the first Audi 100 developed at Auto Union shares features with the W 119.

This model too was equipped with the four-cylinder medium pressure engine. Kraus initially worked on the medium class car in secret, though it finally celebrated its premiere in 1968 – and brought the company its great leap forward into the future. The Audi 80 (1972) and Audi 50 (1974) were also designed under the aegis of Kraus…

We now have asked Mercedes about some additional detailed information about the actual share of Daimler design and engineering in the styling features and technical development of the Audi 100, we will keep you posted…

Hans Knol ten Bensel