• Race-winners.

The racing cars and racing sports cars of the W 196 series.

In 1954, Mercedes-Benz returned to Grand Prix racing with a completely newly developed racing car. The W 196 R – the “R” stood for Racing – complied with all the conditions of the new Grand Prix formula of the CSI (Commission Sportive Internationale): a displacement of 750 cubic centimetres with supercharger or 2,500 cubic centimetres without, no restrictions on fuel composition. The 300 SLR racing sports car (W 196 S – the “S” standing for Sport) was developed in parallel with this model, and was first used in the 1955 season which it proceeded to dominate.

Shared technical concept.

The two cars shared a technical concept consisting of the following components: a spaceframe (introduced in the 300 SL racing sports car in 1952), a transaxle configuration with the five-speed transmission positioned behind the differential, a single-link swing axle with a low pivot point at the rear and – with two exceptions – inboard drum brakes plus the use of torsion bar springs and telescopic shock absorbers. In both, the racing car and the racing sports car, the frame and suspension excelled with forgiving handling characteristics which proved particularly outstanding on demanding, difficult and wet road surfaces. The frame structure impressed with its great torsional rigidity and robustness, contributing to driver safety in accidents or when leaving the road unintentionally.

Especially in difficult driving conditions, the newly developed single-link swing axle produced superior handling characteristics. As an overall package, these technical innovations were almost a guarantee of victory. In the 1955 season, from the British Grand Prix in Aintree, Lancashire, on 16 July onwards, the Formula racing cars were equipped with engageable auxiliary springs designed to keep the wheel camber and suspension at a constant level as the contents of the full fuel tank decreased.

New Technologies.

For the M 196 engine the designers opted for new technologies that had not been used in previous Mercedes-Benz racing cars. These included desmodromic valve control, which reliably allowed high engine speeds – this was not achievable with the previous spring-controlled valves. Another innovation was direct petrol injection, which Mercedes-Benz was introducing into series production with the 300 SL “Gullwing” (W 198) at the same time. This allowed more efficient metering of the fuel to suit the load and performance requirements, while at the same time lowering fuel consumption compared with previous designs.

Ongoing improvements.

The eight-cylinder in-line engine consisted of two adjoined four-cylinder steel blocks with a central power take-off. The variant used for Formula 1 with a displacement of 2,496 cc initially developed 188 kW (256 hp) at 8260 rpm in 1954, increasing to 213 kW (290 hp) at 8,500 rpm in 1955. A major part of the power increase was due to ongoing improvements and the straight intake manifolds introduced for the 1955 season. The higher position of the pressure pipe caused by the straight intake manifolds made a cowl necessary on the right-hand side of the bonnet – a distinguishing feature of the 1955 racing cars. The engine had a compression ratio of 1:11, and could only be operated on special methanol-based racing fuel.

The eight-cylinder engine.

The eight-cylinder engine of the 300 SLR racing sports car distinguished itself from the Formula 1 engine by a displacement increased to 2,982 cc, two cylinder housings of cast aluminium rather than cast steel, and the reversed camshaft rotation. It generated up to 228 kW (310 hp) at 7,500 rpm. The compression ratio was only 1:9, so that normal premium petrol could be used in accordance with the rules for the world sports car championship. Mercedes-Benz also tested this engine in the W 196 R for a racing event, namely the non-formula race on 30 January 1955 in Buenos Aires, Argentina. In contrast to its later use in the 300 SLR, the compression ratio was increased to 1:11 on this occasion.

Streamlined body or exposed wheels.

The concept for the new W 196 R Formula 1 racing car also included the use of two different light-alloy bodies, which had already been planned for the pre-war racing cars and which were selected according to the racetrack. The chassis was given a streamlined body for high-speed circuits. A body with exposed wheels was used for circuits with numerous bends – a configuration that Juan Manuel Fangio for example particularly liked because he could exactly determine the position of the front wheels.

For the racing debut of the W 196 R, the French Grand Prix in Reims on 4 July 1954 in Reims (France), streamlined racing cars were provided for all three drivers because the circuit allowed very high speeds. Juan Manuel Fangio and Karl Kling drove to an epoch-making double victory – on the same day when the German national football team achieved the “wonder in Berne” and won the World Cup. The young Hans Herrmann was the third in this perfect trio for a long time, and even achieved a lap record, but was later forced to retire with engine damage.

W 196 R with exposed wheels.

The classic monoposto with exposed wheels was used for most of the Formula 1 races of 1954 and 1955. This variant had its debut at the Nürburgring on 1 August 1954, where it won the European Grand Prix. Once again the winner was Juan Manuel Fangio. The W 196 R with exposed wheels was available in three different wheelbases for the 1955 season, so as to have the ideal car for any racetrack. This was accompanied by different brake configurations. In the case of the racing cars with a medium and long wheelbase, the engine was moved rearwards and allowed space for large drum brakes located inboard next to the wheels. This space was not available in the version with a short wheelbase, as the engine was positioned further forward, and the front wheel brakes were accommodated outboard within the wheels.

All in all there were therefore four variants of the W 196 R, which were used to suit the relevant race circuit. The result of all this technical effort and excellent race organisation was this: the Mercedes-Benz racing car was the most successful car in the 1954 and 1955 seasons by a wide margin – and it was in this Silver Arrow that Juan Manuel Fangio won the Formula 1 world championship in both years.

300 SLR – the dominant racing sports car of the 1955 season.

From the very start Mercedes-Benz dominated the world sports car championship races of the 1955 season with the 300 SLR (W 196 S), and secured the hotly contested title – the car was far superior to all its competitors. This success by the 300 SLR was due to the outstanding technical basis it shared with the Formula 1 racing cars. This close relationship gave the racing sports car superior roadholding, a highly reliable engine and – not least owing to the strong spaceframe – a robustness that was unusual for a sports car.

One special feature was the so-called air-brake, which was used in the Le Mans 24-hour race and in the Swedish Grand Prix. This enabled the driver to manually extend a metal plate into the airstream. This ensured much improved deceleration compared with using the drum brakes alone – and not only thanks to the significantly higher air resistance, but also owing to the additional downforce at the rear axle. The plate normally lay flat against the bodywork, and was hinged at the rear edge. The driver deployed it hydraulically by operating a hand lever.

The results achieved by the Mercedes-Benz 300 SLR remain unsurpassed to this day.

It won every race in which it competed and finished. It demonstrated its absolute superiority with double victories in the Mille Miglia, the Eifel Race, the Swedish Grand Prix and the Targa Florio – and the 300 SLRs even brought off a triple victory in the International Tourist Trophy. An eternal record was also established by Stirling Moss and his co-driver Denis Jenkinson with their victory in the 1955 Mille Miglia: they won the race at a still unbeaten average speed of 157.65 km/h.

Mercedes-Benz 300 SL “Gullwing” (W 198), 1954 to 1957.

In February 1954 the 300 SL (W 198) “Gullwing” celebrated its world premiere at the International Motor Sport Show in New York. The new high-performance sports car was based on the legendary 300 SL racing car (W 194) from the 1952 season – and the worldwide attention the 300 SL attracted was correspondingly huge. It was the first series production passenger car with a four-stroke engine and petrol injection. What is expected as a matter of course today was an absolute sensation at the time. The striking gullwing doors – an innovative solution made necessary by the high spaceframe – emphasised an appearance that was uncompromisingly sporty for a regular production Mercedes-Benz, and this was further confirmed by corresponding performance figures.

With an engine output of 158 kW (215 hp) – a good 20 per cent more than that of the carburettor-equipped racing version of 1952 – the W 198 was in the top echelon of the production sports cars of its time, and ideal for sporting competition. To be ready for this, a number of different suspension set-ups and final drive ratios were optionally available to allow top speeds between around 225 km/h and 250 km/h.

Icon in automotive engineering

To this day, this sports car with its well-balanced mix of technical innovation, performance and design counts as an icon in automotive engineering. In 1955, its outstanding performance already led to much-noted successes on the international racing and rally scene in Europe and the USA: for example, Werner Engel driving the 300 SL (and the 220 a) won the European rally championship, and Paul O’Shea won the US sports car championship in Class D. It is not least thanks to these trailblazing victories that the 300 SL projected a new, dynamic image of the Mercedes-Benz brand.

Mercedes-Benz 220 a (W 180), 1954 to 1956.

Spring of 1954 saw the launch of the 220 model, also designated 220 a (W 180) internally, the first Mercedes-Benz six-cylinder model with a unibody design. Its modern, roomy “Ponton” body, presented by Mercedes-Benz half a year earlier in the form of the medium-class 180 model, offered previously unheard-of sense of spaciousness and comfort. Safe handling was ensured by the single-joint swing axle, which was introduced into regular automobile production with the 220 a model. In 1955, it was driven by Werner Engel in the European rally championship, alternating with a 300 SL.

In the following year, the sports department under Karl Kling specially prepared three vehicles for use in the 1956 Mille Miglia. These already featured the twin carburettor system that would be fitted to the succeeding model, the 220 S, taking engine power to around 85 kW (115 hp). To ensure sporty handling, shorter, harder springs, and modified shock absorbers were fitted. In addition to this, drivers changed gear using a floor shift of the type found in the 190 SL (W 121), instead of the steering wheel gearshift provided as standard.

Mercedes-Benz 180 D (W 120), 1954 to 1959.

The first diesel engine version of the Mercedes-Benz 180 “Ponton” (W 120) had its debut in January 1954. The Stuttgart-based manufacturer thereby also offered its modern “Ponton” saloon with a compression-ignition engine, which delivered 29 kW (40 hp) from a displacement of 1,767 cc. Up to the model facelift in autumn 1959, a total of 114,046 examples of the model 180 D Saloon were produced. These diesel saloons, which were capable of speeds up to 110 km/h, cannot however be compared with the racing and sports cars that sped to overall victory in the Mille Miglia.

But in its time, the 180 D was an ultra-modern vehicle with a self-supporting body and a “unibody construction subframe” on which the front wheels guided by a double wishbone axle were suspended. It proceeded to demonstrate its strengths and reliability in the Italian road race: Mercedes-Benz entered several 180 D models with the start numbers 04, 09, and 010A, and they won a triple victory in the diesel class.