The Mercedes-Benz 170 S is a luxury car produced by Mercedes-Benz from 1949 to 1955 in various gasoline and diesel guises. It was initially offered with a 1. 8 liter version of the 1. 7 liter inline four-cylinder M136 engine used in the slightly smaller 170 V production type. It was the first Mercedes-Benz to carry the suffix in its name "S" (for Sonder model (Special Model) denoting a superior level of comfort and quality. As such, its target market was successful business owners and business leaders.[1]

The 170 S was released in May 1949, initially sharing the chassis number of the W136 170 V and very similar to it. However, in many ways it was more directly an evolution of the six-cylinder Mercedes-Benz 230 that the company had produced, albeit in small numbers, between 1938 and 1943.[1]

The first upgrade of the 170 S took place in January 1952, being even further removed from the 170 V with its own chassis number W191.[2] Mercedes' introduction a year earlier of the luxury 220 Mercedes-Benz W187 model with the 2. 2-liter M180 six-cylinder engine, positioned between the 170 S and the company's flagship Mercedes-Benz W186 Adenauer tourers of 3. 0 liters, undercut the four-cylinder 170 S. luxury niche.

With the arrival of the all-new 1. 8-litre Mercedes-Benz W120 180 "Ponton" in 1953, the 170 S was discontinued and a 170 S-V using the larger 170 S engine, but slightly smaller bodywork 170 V was introduced. Reverting to chassis code W136, the SV ceased production in 1955.[3]
The Mercedes-Benz 170 S which appeared in May 1949 was 170 mm (7 in) longer, 104 mm (4 in) wider and better equipped than the 170 V. The 170's 1, 697 cc M136 four-cylinder petrol/ petrol engine V was enlarged to 1, 767 cc, offering a maximum power of 52 hp (38 kW), while the smaller engine produced 38 hp (28 kW). Performance has been improved accordingly, with a claimed top speed of 122 km/ h (76 mph). It shared the 170 V's four-speed fully synchronized transmission.

The front wheels were attached using coil springs and double wishbones with a stabilizer bar, as opposed to the simple side leaf spring arrangement on the 170 V.

Since the war, the only version of the Mercedes-Benz 170 V available to the public was fitted with a four-door sedan/ saloon body. With the 170 S, the manufacturer is now recalling some of the wider bodies offered on the pre-war 170 V, adding a two-seater "Cabriolet A" and a four-seater "Cabriolet B".

Although the 170 S was presented as a car aimed at business leaders, the nickname "the first Mercedes-Benz S-Class" began to be applied to it more than twenty years later, following the launch of the W116 from the manufacturer, is not one of those which was used or recognized in the 1950s.

A year after the introduction of the 170 S, its M136 was also installed in the 170 V. However, the compression ratio and the carburetor differed, so that the power advantage of the 170 S was reduced ? by a difference of 14 hp to one of 7 PS ? rather than eliminated.