Holiday 2009 – 1936 Mercedes-Benz OM138 (260D) diesel engine, the first diesel engine for cars

They used this engine concept until the 1980s.
45 hp, 2600 cc

"1936: The Mercedes-Benz 260 D was the world’s first production passenger car with diesel drive. Its four-cylinder engine was fitted with a Bosch injection pump that allowed high revs and ensured a particularly fast fuel supply. The 2.6-liter engine had a compression ratio of 1:20.5 and output of 33 kW (45 hp) at 3200/min. The world’s first diesel passenger car was the result of intensive research that dated from the merger between DMG and Benz & Cie. in 1926. Among the test engines developed were a 3.8-liter six-cylinder unit with 60 kW (82 hp) and the three-cylinder OM 134 diesel with 22 kW (30 hp) used in the Mercedes-Benz 175 D (W 134) prototype. But the real step in the direction of production was the four-cylinder OM 141 engine with 26 kW (35 hp) used in the 175 DX (W 141) test cars. This ultimately gave rise to the four-cylinder 2.6-liter OM 138 diesel – based on a six-cylinder commercial vehicle diesel engine – for the Mercedes-Benz 260 D. By this time the engineers had perfected soft combustion after the pre-chamber process by using, for example, a Bosch four-plunger injection pump. The state-of-the-art four-cylinder unit already featured overhead valves, and a crankshaft running in five bearings helped ensure effective vibration damping."

Source: www.emercedesbenz.com/Mar08/25_001082_Winning_Foursomes_A...

See also here: www.emercedesbenz.com/Jan06/17FlashBackDieselEnginePassen... for some more history.

A visit to the Automobile and Technical Museum Sinsheim in Germany.