The Type , being presented as the successor to the Type 290. The larger engine with 10% more displacement and an increase by 10 hp to 78 hp was a noticeable improvement and matched the model’s positioning as a large, comfortable tourer. The 3.2-litre inline-6 engine was based on the engine of the predecessor, which was drilled out to the new displacement and further refined by fitting a crankshaft with 12 balancing weights. The updraft carburettor was also replaced with a Solex double-downdraft carburettor. The standard gearbox at launch was a regular four-speed manual gearbox with a direct-ratio fourth gear instead of the overdrive gearbox from the Type 290. The frame and suspension were taken from the Type 290 without any relevant changes, meaning the Type 320 was also available in two different wheelbases. This time treated the long wheelbase (3.300 mm) as the standard version and distinctly designated the short version (available until 1939) as the 320 N. This was a reaction to customers increasingly preferring the long wheelbase versions. In addition to a “rolling chassis”, you could choose from various factory bodies. Among them were a five-seater limousine, a -limousine with 7 seats and a futuristic streamlined limousine, along with an open tourer, a 2-3 seat roadster and four convertibles (designated the Cabriolet A, B, D and F) with 2 or 4 doors. The exclusive Cabriolet A, identifiable by the wide and low windshield with three wipers, was built by the bodywork factory in nheim in just 30 examples. This was a low production run even for the time. In 1939 the displacement was increased to 3.4 litres, without redesignating the model as a Type 340, and the gearbox received a separate overdrive in reaction to the spreading tobahn network. The Type 320 was a great success for , selling around 5,000 units, and could have continued to for several more years if the war had not put an end to the production in 1942.
Source: Public ive