- Positioned as an upper-tier vehicle
- Superior performance and high-level comfort
- A great diversity of vehicle body versions
The Mercedes-Benz Type 320 (W 142 series) celebrated its premiere at the International Automobile and Motorcycle Exhibition (IAMA) in Berlin in February 1937. With it, the brand closed a gap in the market between medium-sized vehicles and vehicles of the largest format. At least, this is what the renowned “Allgemeine Automobil-Zeitung” (AAZ or “General Automotive Magazine”) felt upon the presentation of the new 3.2-litre motor car. With this model Mercedes-Benz broke new ground in this particular vehicle class, which in those days was characterised by extreme competitiveness. Its traditional strong rivals were Horch with its 930 V and 830 BL models, Opel with the newly presented Admiral model and Ford with its 3.6-litre V8.
Initially, Mercedes-Benz offered two wheelbases. For the short-wheelbase versions – 2880 mm (113 in) – the following bodies were available:
|Cabriolet A||Cabriolet A|
|Combination coupé with removable roof||12,300.00 RM|
However, the version with a regular chassis and a wheelbase of 3300 mm (130 in) was the one that found the greater acceptance with customers. The following bodies were available for this variant:
|Saloon with 4 doors & 4 windows||8,950.00 RM|
|Cabriolet B with 2 doors & 4 windows||9,800.00 RM|
|Cabriolet D with 4 doors & 4 windows||10,400.00 RM|
|Pullman saloon with 4 doors & 6 windows||9,800.00 RM|
|Cabriolet F with 4 doors & 6 windows||12,500.00 RM|
|Open touring car with 4 doors & 6 windows||9,900.00 RM|
|Cabriolet A with 2 doors & 2 windows||13,500.00 RM|
|Roadster with 2 doors & 2 windows (only 1937)||13,500.00 RM|
|Streamline saloon (until 1938)||14,500.00 RM|
The Mercedes-Benz 320 was a further development of the 290 model (W 18), which was offered from 1933 to 1936. Its M 18 engine delivered a modest output of 68 bhp (50 kW), which only permitted a moderate driving performance. When the engine was re-worked for the car’s successor, the focus was on achieving a high level of handling comfort and a significantly greater engine output, without however abandoning the concept of the vertical valve, 6-cylinder pushrod engine.
In order to boost the engine’s output, the Untertürkheim engine designers under the direction of Albert Heeß made use of well-known methods. By increasing the cylinder bore from 78 to 82.5 millimetres, the engine’s displacement was increased from 2.9 to 3.2 litres. Its smooth running characteristics were further enhanced by adding 12 counterweights to the crankshaft – a measure that was resoundingly successful. Another step taken towards increasing output was the change from a simple updraught carburettor to a dual downdraught carburettor. Thanks to all these modifications, the engine’s output was raised to 78 bhp (57 kW). The downdraught carburettor additionally led to a more spontaneous throttle response when accelerating.
With the transition from model series W 18 to model series W 142 the four-speed transmissions used until then were also abandoned. These were in actual fact three-speed transmission systems with overdrive, and were replaced by fully-synchronised four-speed transmission systems with a direct-ratio fourth gear – a transmission that found general acceptance and praise in contemporary opinion because of its gearshifting comfort.
The suspension was taken from the W 18 and re-adapted. The front axle featured special independent wheel suspension, with a transversal leaf spring underneath. At top the wheel was attached to a suspension arm that rested on a helical spring on the inside. The rear dual-joint swing axle had two helical springs on each side, one behind the other. The two compensating springs under the differential in model 290 were no longer featured by the 320 model. Dual-action hydraulic lever-type shock absorbers were installed on both front and rear axles. Both the driving comfort and the handling safety were highly praised by contemporary testers, at a time when many competitors were still using rigid front and rear axles. The box-type frame with cross-beams was in line with the standard designs of the time.