- A vehicle representing luxury and reason in the difficult post-war period
- An internationally accepted representative car with remarkable effortless superiority
By the end of the Second World War, the benchmarks had changed in Germany and Western Europe. People were suffering greater hardship, their needs were existential, their standards more modest, the newly elected Federal government in West Germany was closer to the people and democratic. The Federal President and the Federal Chancellor initially used cars merely as a mode of transport – the Pullman saloons and cabriolets from the Mercedes-Benz, Horch and Maybach SW 38 brands from pre-war times; the Governing Mayor of Berlin, Luise Schröder, used a Model 170 V as her official car.
At first everyone at Daimler-Benz had other things to worry about than thinking about a remake or new design of the ‘Super Mercedes’. The overall economic situation was gloomy, characterised by the rapid collapse of the ruined Reichsmark. An improvement was only to come about with the currency reform and the introduction of the German Mark, but this did not happen until 20 June 1948. Wilhelm Haspel called a meeting on 22 December 1947 with the aim of discussing plans for a sports and representative car; for a time he was not Chairman of the Board of Management at Daimler AG due to denazification, and it was not until 1 January 1948 that he took on this position again. The aim of the meeting was to decide on a range of vehicles also suitable for export – even in such dark economic times, Haspel recognised the necessity for Mercedes-Benz cars with the appropriate charisma in the luxury segment: ‘But what is missing is a vehicle that gold-plates the name Mercedes-Benz again.’
Another year and a half would pass, however, before Haspel’s ideas took shape on a more modest basis – in the period directly following the war, Central Europe had moved towards vehicles with a much smaller displacement. Initially priority was given to the Model 170 S (W 136 III, later W 136 IV), which Daimler-Benz brought out in 1949. Before the war it had originally been earmarked as the successor to the Model 170 V (W 136), and for two years it now assumed the role of the later S-Class in the Federal Republic of Germany in terms of price and social status. The two-seater Cabriolet A even became the country’s most expensive car. In 1951, the Model 220 (W 187) was launched, and it, too, was one of the S-Class’s forerunners.
Against this background, the Model 300 (W 186 II) which was unveiled at the same time was seen as a superlative-class car back then – something that was reflected in its price and performance as well as its appearance.
But in the meantime the development department took several approaches when it came to creating a vehicle that gold-plated the name Mercedes-Benz again. In order to keep costs and new investments to a minimum in view of the difficulties involved in the procurement of machinery, existing stock was used up. Where the chassis and the bodies were concerned this meant the Model 230 (W 153) with the all-steel body from Daimler-Benz which had come out shortly before the war, plus the corresponding chassis with an X-type pipe with a wheelbase of 3050 millimetres. When it came to the engines the production units for the 2.6 litre M 159 engine had survived the bombings to such an extent that they could be built up again. This resulted in no less than 9004 units of this engine being produced between 1941 and 1944. Although originally intended for passenger cars, they were all installed in the 1.5-tonne L 301 model, which had carved out a career for itself as a small fire-fighting vehicle, and as a bucket-seat car. This engine had a hemispherical combustion chamber with V-shaped overhead valves, which were operated by the low-mounted camshaft via tappets. The first deliberations regarding the construction of a more representative vehicle were made on the basis of this M 159 and the model series W 153. To begin with it was given the model series designation W 182 and was intended to have a displacement of 2.6 litres. In order to take into account the increasing vehicle weight, in 1949/1950 the engine was given a series of higher displacements in rapid succession: firstly 2.8 litres and finally 3.0 litres, with various model variant designations to match.
Tried-and-tested technology as the basis for development
The engine derived from the M 159 was known as the M 182, and whilst it still had a crankshaft with four bearings and a displacement of 2.6 litres, it already boasted a modified cylinder head with larger valves. This was where engine developer Wolf Dieter Bensinger fell back on a design list that had been put together as a stop-gap measure, and this resulted in the characteristic oblique contact surface between the cylinder head and the cylinder block for the engine which was now called the M 186 I and for the variant derived from it. It was in order to take over as many production machines as possible from the manufacturing of the M 159 on the one hand, and also to create room for larger valves in the cylinder head on the other, that Bensinger hit upon the idea of the oblique section, which provided the larger area that was needed.
Along with the increase in displacement the crankshaft was converted over from four to seven main bearings. This engine with the internal designation M 186 I still had overhead valves operated via tappets, but that changed with the advent of the M 186 II, which operated the valves via an overhead camshaft. It was not until a good year before the vehicle presentation at the International Motor Show in Frankfurt am Main (IAA) in 1951 that chief engineer Fritz Nallinger told his colleague Karl C. Müller: ‘The results of work involving the M 186/II engine with an overhead camshaft have now reached such a stage that this design can be described as promising. Therefore I would ask you only to firmly plan in the machines which are used for the 186/II design and to set aside the machines which are additionally needed for 186/I.’
Somewhat confusingly, the engine described at the testing stage as the M 186 II was later given the designation M 186 I or just M 186. Meanwhile the first design of the Model 300 always bore the model series designation W 186 II.
On 27 March 1950, in a report about the Geneva Motor Show, Nallinger also informed his Board of Management colleagues about the development status of what was classified internally as the ‘Group B car’, the Model 300: ‘The cylinder volume has been increased to 3 l, the control shaft moved upwards into the head. This has resulted in the following advantages: better governing of the engine speeds with regard to valve control, so that engine speeds resulting in favourable valve-time cross sections are achieved with the steeply rising cam shape. This means that with the 3 l engine with the normal carburettor engine and intake manifold configurations 115 hp is achieved.’
For reasons of time Nallinger now suggested building the body using stampings from the Models 170 S (W 136 IV) and 230 (W 153) and other new stampings. A solution that the Head of Body Testing in Sindelfingen, Karl Wilfert, who always tended to go his own way, set out in a letter to Wilhelm Haspel himself. But Wilfert had not reckoned on the reaction of his Chairman of the Board of Management. Haspel always had a very determined opinion on vehicles – when it came to both style and technology. He was completely opposed to Wilfert’s proposal and sent him the following reply: ‘Where the matter of shape is concerned, I believe that – even if you have fallen in love with this change – you will not contradict me when I say that this resultant object has become disproportionate and therefore decidedly inelegant. In short, there is no sense in wanting to change and modernise to such an extent an object that was created from a different overall design; the result will be a bastard and one should not do such a thing.’
Hermann Ahrens, who had actually been taken on again after the war by Haspel to work on body design for commercial vehicles, buses and coaches, was commissioned by him to design the body for the model series W 186 II. Ahrens achieved a good compromise between the taste of the predominantly conservatively oriented customers influenced by pre-war Mercedes-Benz design and the expectations of the customers in the initial post-war years, who demanded forms that flowed much more, headlamps integrated into the body and the absence of running boards on a luxury Mercedes-Benz.
In actual fact, the frame of the model series W 153 served as the basis, and its wheelbase – measuring 3050 mm (120 in) – was also retained, but the frame was dimensioned in accordance with the much higher weight of the model series W 186 II. The wheel suspensions corresponded to the latest standard at Daimler-Benz: at the front there were wishbones and coil springs. At the rear a dual-joint swing axle was used, which was designed especially for high levels of ride and suspension comfort. In order to ensure handling safety and comfort with a full load, a torsion-bar suspension which was electrically engageable via the dashboard was installed.
A surprise came in the form of the newly designed three-litre M 186 engine with an overhead camshaft and 115 hp (85 kW) at 4600 rpm. With a maximum speed stopped in tests by specialist journals at 158 km/h/ 98 mph (‘auto motor und sport’), 160 km/h/ 99 mph (‘Automobil Revue’, Bern) and 164 km/h/ 102 mph (‘Motor Rundschau’ and ‘The Autocar’) it is Germany’s fastest car up until the unveiling of the Model 300 S (W 188) in October 1951, the latter being nothing other than the sporty two-door variant of the Model 300.