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Mercedes-Benz History: Rear-Engine Mercedes-Benz Vehicles

Words Jim Davis | April 26, 2010
A look back at the Mercedes-Benz Rear-Engine 130, 150 Sports Saloon, 150 Sports Roadster and the 170 H from the 1930’s
Words Jim Davis April 26, 2010

The rear-positioned engine was the driving force behind the earliest pioneering vehicles. Created independently of one another in 1886, the world’s first two automobiles, the Patent Motor Car of Carl Benz and the Motor Carriage of Gottlieb Daimler, both had rear engines. The construction principle of the four-wheeled rear-engine car was widely used up to the turn of the twentieth century, above all in two-seater sports vehicles. Thereafter it became the exception, and the great majority of cars had engines positioned in front of the passengers.

The concept was revived in 1934, when Mercedes-Benz presented the 130 model. This was the first fully-developed mass-produced rear-engine car both in brand history and indeed in the entire history of the automobile – a tradition that now spanned almost half a century.

The starting point for the development of the 130 model was the difficult economic situation of the early 1930s and, in particular, the hoped-for mass motorisation, in which all automotive manufacturers were keen to have a slice of the action. This forced all of them to develop smaller and more affordable vehicles – the Mercedes-Benz brand, in particular, was reputed for producing mainly elegant and expensive models. Germany increasingly focused on the concept of the Volkswagen or ‘people’s car’, a designation which at the time denoted a category and general orientation rather than a specific vehicle.

Daimler-Benz AG did not blind itself to the requirements of the day, however, producing instead a fundamentally new concept, the rear-engine car. The principle reasons, viewed from its own perspective, were documented in the original sales brochures of the 1930s: a rear-mounted engine permitted better use of space. In cars with a relatively short wheelbase, this not only afforded passengers more leg room, it also improved comfort by creating optimum springing between the axles. In addition, the entire drive unit could be focused in a single unit and required no propshaft, giving vehicles the additional benefit of reduced weight and transmission losses.

It was perhaps to be anticipated that although the concept underwent continual refinements over the years, finally reaching maturity in the shape of the Mercedes-Benz 170 H of 1936, ultimately the rear-engine car never really caught on. What follows on these pages, therefore, is a fine example of the consistent application of progressive vehicle concepts throughout the long history of Daimler AG.

Launched by the then DaimlerChrysler AG in 1998, the smart city-coupé, known from 2004 onwards as the fortwo, was also based on the basic idea of a rear-engine vehicle, with optimum use of space and rigorously advancing the concept in the form of a two-seater city vehicle.

The 130 model has the honour of being the concept that took rear-engine design to a new level and made it more widely known, following its earlier implementation in a few individual mini cars – even before the car that would later achieve fame as the “VW Beetle”. The first Beetle prototype did not get under way until October 1935. In 1937 Daimler AG was commissioned to build a further 30 prototypes at the Sindelfingen plant for the purpose of more intensive testing. Volkswagenwerk GmbH was founded in 1938, although with the outbreak of war, series production of the Beetle did not begin until 1945. The rear-engine vehicle finally went on sale to the public in 1946, around twelve years after the Mercedes-Benz 130.

A successor to the 130 model appeared in 1936. As the only rear-engine model available, the Mercedes-Benz 170 H was unique in carrying the letter “H” (for “Heckmotor”) in its model designation, in order to distinguish it from the front-engine Mercedes-Benz 170 V presented at the same time. The 170 H, which remained a part of the model range until 1939, put an end to many of the disadvantages of its predecessor, and offered much improved handling characteristics.

The two-seater Mercedes-Benz 150 with coupé body was also entered for the “2000 km through Germany” event of 1934. This car was based on a mid-engine concept, but nevertheless ranked alongside these distinctive vehicles. Designed specifically for sports events, it played a special role, since the 130 and 170 H models were passenger cars for everyday use. The open-top variant of the competition car, the Mercedes-Benz 150 Sport Roadster, subsequently made its debut at the IAMA in Berlin in 1935. It became part of the official sales range and was offered until 1936 – although built only in extremely small unit numbers.

The rear-engine models were the rigorous realisation of a technical vision. Part of this rigour also involved body design, for with a front radiator no longer required the entire vehicle could now take on a different shape. The models therefore differed fundamentally in appearance from the traditional front-engine vehicles, which – particularly in the case of Mercedes-Benz – had traditionally been heavily determined by the classical, almost iconographic radiator grille. Now, the front end of all rear-engine vehicles appeared rounded, some with three-pointed star mounted inside a circle (130 model), others with a three-pointed star without circle (170 H model), and yet others with the free-standing Mercedes star (150 model) still familiar today.

Without doubt, these divergences from traditional design concepts played a significant part in the failure of rear-engine vehicles to gain the expected foothold in the market. But when one looks at these cars today, particularly the 170 H model, it is impossible to deny their progressive nature – all the more apparent when they stand alongside other cars of their generation.

As a result of their weight distribution, rear-engine cars are often criticised for poor handling characteristics. If corners are taken too quickly, there is a tendency for the vehicle to oversteer – in other words, for the rear end to slide towards the outside of the turn. Since the laws of physics are at the root of the phenomenon, it is a tendency that exists in rear-engine vehicles of all manufacturers. Contemporary driving reports on Mercedes-Benz vehicles tested this tendency and were not sparing in their criticism. But they also said that drivers could – and indeed had to – adjust to this phenomenon in order to drive safely at all times. It was also noted that in the 170 H, a late evolutionary stage of the rear-engine vehicle, handling characteristics were more balanced thanks to a comprehensive range of design measures. And compared with its counterpart with front-mounted engine, the 170 V, the 170 H even came off better in terms of suspension comfort, noise, drag and performance.

In the sum of their qualities, the rear-engine vehicles were also in line with the traditional Mercedes-Benz claim of giving customers the best whatever the vehicle model. As such, these vehicles offered active proof of the technological leadership of Daimler-Benz AG.

The call for a smaller Mercedes-Benz

The second half of the 1920s was a period of innovation in automobile technology. Many engineers began freeing themselves from the still popular designs based on the model of the horse-drawn carriage, with box frame, rigid axles and leaf springs. Instead, they strove towards new solutions such as independent suspension and high-rigidity frames.

The plans of Daimler-Benz AG fitted into this period of technological progress, for shortly after the merger of Benz & Cie. and Daimler-Motoren-Gesellschaft in 1926, the new company returned once again to a latent topic – development of the bottom end of the model range. Several designs for smaller vehicles with displacements of 1.3 litres and 1.4 litres were created under Ferdinand Porsche’s leadership as chief engineer; some of these were also built for testing purposes. In 1926 these included eight prototypes (W 01 series) with a 1.4-litre six-cylinder engine and an output of 18 kW, and in 1928 a total of around 30 test vehicles (W 14) with a 1.3-litre four-cylinder engine, which also developed an output of 18 kW. However, both cars toed the conventional line with side-valve engines and rigid axle chassis. They never reached the series production stage for economic reasons.

In 1931 Daimler-Benz AG then brought to market the Mercedes-Benz 170 (W 15) developed by Porsche’s successor Hans Nibel. Although this car proved a great success, there was still a long way to go. Europe did not escape the impact of the global economic crisis during the early 1930s, and realising the pressing need for an even more affordable vehicle, the company once again opened up a serious internal debate on extending the model range further downwards. Chairman of the Board of Management Wilhelm Kissel and chief engineer Hans Nibel, in particular, warmed to the challenge of this issue, since before the merger at Benz & Cie. the two had enjoyed success with smaller vehicles, including the 6/18 hp Benz of 1911. They were also supported by Max Wagner, Head of the Design Office, and his designer Josef Müller.

Smaller vehicles already in the family for some time

In his memoirs, published in 1990, Müller wrote: “Questions had been raised within the company for some time [about the possibility of a smaller car], since the days when we could sell only large and prestigious vehicles seemed to be gone for good; we were on the brink of a new type of popular motoring. The four passengers deserved to be given the best suspension possible between the axles.”

The young Josef Müller was one of the avant-garde of automotive engineers striving for fundamentally new technological innovations. After completing his diploma at the Technical University in Munich, he joined the “CB”, as Max Wagner’s construction office (Construktionsbüro) was known, and set about tackling new challenges with creativity. In 1932, for example, he pressed ahead with the advance development of a design for cars with a 1.2-litre engine.

Between late 1931 and 1934 the department also came up with numerous designs for small four-seater rear-engine cars with air-cooled boxer engines and liquid-cooled three- and four-cylinder engines, some of which were transverse-mounted above the rear axle. At the same time, however, vehicles were also produced in the same size category with front-mounted engines and front-wheel drive – a pioneering combination at the time. Kissel authorised the front-engine designs in order to have a replacement for the rear-engine car if required.

Lofty claim of technological leadership

Kissel’s lofty claim of technological leadership applied to his company as a whole; but if a smaller Mercedes-Benz was to live up to the claim, it had to provide actual proof of the technological leadership of Daimler-Benz. This became plain in fundamental comments made by Kissel on another occasion: “Although we have to be prudent with our money in these critical years, it is necessary, now more so than ever, to show the world that the spirit of Gottlieb Daimler and Carl Benz lives on in us, and to prove that Daimler-Benz AG is determined to defend its inheritance.”

The level of urgency accorded the project is today evident from discussions that Kissel had with the Board of Management and other key figures during the International Automobile and Motorcycle Exhibition (IAMA) in Berlin in 1933. He said: “We are facing the situation that our position this year [1933], as well as our plans for a 1.3-litre car, would be considerably enhanced, particularly if the general outlook does not significantly improve and instead the trend towards smaller, more economical and cheaper cars sooner or later becomes more marked than hitherto. The benchmark remains the position that our sharp focus must be on developing technological progress, because otherwise another company may succeed in producing a car with driving qualities at a price that could thwart our intentions in respect of the 1.3-litre car.”

So the decision to build the Mercedes-Benz 130 had already been taken some time earlier. It made its debut in 1934 and was based on what was for the time a revolutionary concept. As a rear-engine car, it almost literally turned back to front most of what until then had been considered conventional basic car design.

In June 1933 Kissel predicted a change in the market situation. The minutes of a meeting of the Board of Management noted: “On the issue of whether the larger models will suffer as a result of the 1.3-litre model, Mr. Kissel observed that model orientation was moving downwards and that customer numbers for cars priced over 4,400 Reichsmarks were becoming increasingly smaller. Larger cars, including the six-seaters, would therefore inevitably become less important.” Another of Kissel’s remarks is also particularly striking set against the historical context: “As a further aspect for present considerations, it should not be forgotten that a price code is to be introduced. Dealing will disappear, just as haggling will be eliminated. But with fixed prices our share in the RM 4,400 car class will probably drop from 10 % to 6 % without the 1.3-litre. Therefore, if we are to maintain and consolidate our current market share, the 1.3-litre car must be produced.”

Kissel also justified the decision in favour of the new model on a different occasion, saying that: “in view of the rapidly sinking market, there were two possibilities: Either to so cheapen the 170 model that the sales price could be set much lower, or to reach out at the bottom end of the sales range by creating a new model. The second solution – to introduce the 1.3-litre car – was the only logical option.”

But voices calling for practical small automobiles could also be heard in the public arena. One of the untiring advocates – along with the designers Edmund Rumpler, Hans Ledwinka, Béla Barényi and Carl Slevogt – was the journalist and editor-in-chief of the trade magazine Motor Kritik, Joseph Ganz, who had himself designed and built a number of mini cars with rear-mounted engines and independent suspension, such as the Standard Superior. Ganz, who maintained close contact with Kissel, but also with Nibel and Jakob Krauß, the head of the test workshop, wrote in an earlier observation: “In Untertürkheim, where I have been pressing for the design of a larger rear-engine car since 1930, the matter was taken in hand in earnest. In order to overcome the most recent preconceptions, in winter 1931 the Maikäfer [Ganz’s rear-engine mini car design] was brought by truck to Untertürkheim and given a thorough workout for a day by the Board of Management. At the same time, following completion of the uprated Maikäfer, the Standard Superior, at the Standard-Fahrzeugfabrik in Ludwigsburg, the Mercedes rear-engine car, the current 130 model, was developed along basically the same principles by designers at the plant.”

In 1930s Germany there was also another project that was the talk of the automotive industry – the Volkswagen or People’s Car. This term was used at the time to denote a category and desired orientation rather than a specific model. Volkswagenwerk GmbH only started series production of the vehicle that would later become famous as the “Beetle” in 1939.

Kissel pushed for involvement in the Volkswagen project and demanded that “[…] in spite the 1.3-litre car, design of the so-called Volkswagen and the necessary preliminary studies should be pursued with all due despatch.” The project was still exerting a grip on the Board of Management nine months later, when it was observed: “During discussions concerning the creation of a cheaper and smaller car, it transpired that Daimler-Benz AG was indeed in a position to perhaps bring out a vehicle in the 2,000 – 2,200 Mark price range, but that it would be inconceivable that our company could produce an even cheaper car. The question of whether we should concern ourselves with the development of such a car was thus for the time being decided, to the effect that it must first commit itself to the Volkswagen problem. Since, in relation to the Volkswagen problem, Daimler-Benz AG had certain employment obligations and declarations concerning these from the Führer, our company must maintain its role at the centre of this matter. As experience to date has shown us unable to create something positive ourselves, the decision was made to bring together all German passenger car manufacturers in order to see whether, by pooling all resources, a solution to the Volkswagen problem might be found.”

At the core of this statement by Kissel is the recognition that it was impossible for a single company to manufacture and produce for sale a vehicle with a price tag of 990 RM (Reichsmark), as demanded by Adolf Hitler, by going down the private sector route. At the same time, it should not be forgotten that vehicle sales also involved the manufacture, stocking and distribution of replacement parts and the provision of a service network. This was particularly true in view of the imminent rationing of raw materials and the segmenting and assignation of specific vehicle categories, in which individual companies would be required to operate.

These were difficult times. But Daimler-Benz confronted them by going on the offensive. The new small Mercedes-Benz with rear-mounted engine was a courageous step forwards. Based on a fundamentally innovative concept, it injected important new ideas into the automotive world of the 1930s.