Sporty, elegant, modern and above all autonomous: When the new Mercedes-Benz mid-range W 115 and W 114 models were unveiled to the media for the first time in January 1968, they appealed to industry experts and public alike.

Before long, the family of vehicles known internally from their inception by the suffix “/8” was affectionately christened the Stroke Eight.With this car Mercedes-Benz finally abandoned the concept of the cross-range box-type body that had been in vogue since the post-war years, in particular for the three-box “ponton” and fintail designs. The technical highlights of the new model included a diagonal swing axle and the five-cylinder diesel engine in the 240 D 3.0.

Following the introduction of the new premium class in 1965 (W 108 and W 109 series) the Stuttgart company now presented a first ever design for mid-range cars that was both formally and technologically autonomous. The ideal of clean lines represented by the predecessor of the S-Class, the W 108/109 series, was applied even more rigorously in the Stroke Eight models. The sedan was a byword for solidity and love of technical innovation, and it reflected the awareness of its developers of the newly defined role of a mid-range series.

As early as the first press launch in Sindelfingen in January 1968 the media response was outstanding. The equally successful official debut followed in March at the Geneva Motor Show. To begin with the model range included six sedans: The four-cylinder 200, 220, 200 D and 220 D models formed the W 115 series, the two six-cylinder variants 230 and 250 were given the series designation W 114. The top-of-the-range Mercedes-Benz 250 was distinguished from the other models by its double front bumper.

After garnering such praise as a debutant it was just a short step to becoming a bestseller. Demand was high from the outset and soon gave rise to lengthy delivery times. In total almost two million units of the Stroke Eight series were built between 1968 and 1976. That figure roughly equaled the entire number of Mercedes-Benz passenger cars produced between the end of the Second World War and 1968. The Stroke Eight established itself as a versatile and successful model which appealed to sophisticated drivers.

The broad model range doubtless played an important part in this development. The engines available in the Stroke Eight family at the end of the production period ranged from entry-level models to the top-of-the-range 280 E (1972) and 240 D 3.0 (1974). Moreover, in addition to the classic sedan there was also a long-wheelbase sedan and – a first for Mercedes-Benz in this market segment – a Stroke Eight coupe. There were also plans for a station wagon – these were brought almost to production maturity. But in the end it was decided not to introduce this body variant until the successor 123 series. Instead a number of independent coachbuilders offered a variety of customized bodies.

The creation of the Stroke Eight in 1968 was the start of a design revolution in Stuttgart that laid the foundations and set standards for future generations of Mercedes-Benz mid-range series, what is known today as the E-Class. Over its nine years in production, the Stroke Eight became an icon of the automotive culture of the 1960s and 70s. Nowadays vehicles from the 115 and 114 series have long since become highly prized classics and sought-after models on the classic car scene.

1947: Mid-series pre-history begins with the 170 V
After years of box-body construction, the Stroke Eight was the first upper mid-range sedan built by the Stuttgart brand to feature autonomous form and technology when it was launched in 1968. Nevertheless, this new development was based on a long tradition in this market segment for cars with the three-pointed star. Mercedes-Benz had launched vehicles aimed at the upper middle-classes as early as the first half of the twentieth century. One example of this was the Stuttgart 200 model of 1928 based on the 3/38 hp Mercedes-Benz: “The first reasonably-priced mid-range car with the three-pointed star” is how the automotive writers Michael Rohde and Jens-Peter Sirup described this model, developed by Ferdinand Porsche. In his monography on the Stroke Eight, however, Heribert Hofner saw the Mercedes-Benz 170 (W 15) of 1931 as the direct ancestor of the mid-range series. The car’s key features were its state-of-the-art technology, six-cylinder engine – unusual in this class of car – and elegant appearance.

Tracing the family ancestry of the later E-Class becomes less ambiguous in the post-war period. The Mercedes-Benz 170 V of 1947 (W 136 series) marked the new era of passenger car production at Mercedes-Benz after the end of the Second World War. In the months and years that followed further models were brought onto the market as part of the 136 and 191 series, which were also positioned below the premium class. In design terms, however, these models were still based on pre-war developments.

The self-supporting body and contemporary “three-box body” (front end – passenger cell – trunk) of the 180 and 190 models in the W 120 and W 121 series – which came to be known as the “ponton Mercedes” – established a historic milestone in Mercedes-Benz passenger car history in 1953. Together with this ultra advanced design concept, the Stuttgart company also introduced a common body for these models from the upper mid-range and premium class vehicles of the 180 and 128 series. The large “ponton” sedans with six-cylinder in-line engines differed from the four-cylinder W 120 and W 121 series in that they had a longer wheelbase and a larger engine compartment, giving them a more generous silhouette.

Similar differences existed between the four- and six-cylinder versions of the fintail series introduced in 1961. As compared with the premium-class sedans, the 190 and 190 D models (later 200, 200 D and 230) of the W 110 series had a shorter engine hood and also circular rather than rectangular, vertically arranged headlamps. For the first time Mercedes-Benz also offered station wagon variants of the fintail as standard, which were built by IMA in Belgium under the “Universal” designation.

1961: Start of development of the new-generation Mercedes-Benz
Under the leadership of Dr. Fritz Nallinger – Mercedes-Benz Chief Engineer, Member of the Board of Management and Technical Director of Daimler-Benz AG – work on the new upper mid-range series began in 1961. The technical structure of the new car was determined by Karl Wilfert, Head of Body Development. Paul Bracq was responsible for the design, supported by Bruno Sacco. From the start of development it was clear this new mid-range class was to be an autonomous model of success. The standard box-type body was therefore no longer an option. The result of this realization was that as early as 1965 Mercedes-Benz presented the W 108, an entirely autonomous premium-class vehicle. The equivalent for the upper mid-range series, a new generation of Mercedes-Benz, was to be launched in 1968.

Chief Engineer Nallinger had already established the major cornerstones for this new vehicle as early as 1960. Compared with the premium-class model, it would have a significantly more compact design, making the size difference much more appreciable than had hitherto been possible with the standard box-type bodies of the four- and six-cylinder variants. Great importance was attached to minimizing exterior dimensions, while at the same time maximizing space in the passenger compartment. The car’s form, too, would aspire to an ideal of simple elegance rather than reflect changing fashions.

By 1964 the models were already displaying the lines of the later sedans. But at this time discussions were still ongoing regarding alternative designs for the vehicle’s front end. Reflecting earlier differences between the four- and six-cylinder variants, the smaller-engined versions of the new model family were originally to get a simplified front end with horizontally arranged rectangular headlamps. But in early 1965 it was finally decided to abandon this differentiation, as evidenced later in the 115 and 114 series. That year, leadership of the project was handed to Professor Dr. Hans Scherenberg on the retirement of Nallinger.

In addition to the sedan, three other body variants were developed: A coupe, a long-wheelbase sedan and a station wagon. But whereas the sportier two-door design and the longer sedan variant actually went into production, it was ultimately decided not to take the station wagon to the production phase. Nevertheless, with few modifications the basic design of the rear end was harmoniously transferred to the next series, the W 123.

As extensive testing progressed, so camouflaging of the prototypes was gradually reduced, and in 1967 work commenced on setting up production facilities at the Sindelfingen plant. Initially limited to six models across the model series, a total of 1,100 pre-production vehicles were built prior to market launch.

1968: Premieres in Sindelfingen and Geneva
Mercedes-Benz presented the Stroke Eight in 1968. The new series was shown to journalists in January in Sindelfingen; the wider public had to wait until March to assess the new sedan at the International Motor Show in Geneva. The six available models met with broad approval from both motoring experts and public alike. However, the early comment published in an article in the trade journal auto motor und sport, that with this model Mercedes-Benz had ventured to commit a “stylistic shift to the left”, may have had more to do with the underlying socio-political circumstances of 1968.

Praise for the Stroke Eight’s clean, classically progressive lines and fresh, sporty appearance was therefore all the more deserved. And all this was achieved without compromising the identity-giving “Mercedes touch”, as Heribert Hofner emphasized in his series biography published in 2004. It was true, designers and engineers had done a great job, calling for the courage to be innovative and sensitive. On the one hand, there was now a clearer distinction than ever before between the premium class and the upper mid-range series in the Mercedes-Benz product range. And on the other, one could still see the family resemblance between the two autonomous models, as well as their roots in the fintail generation.

Source: Daimler AG