Mercedes 260 D

Although there are already predecessors, the pictured Mercedes 260 D applies as the first car in the world with diesel engine. Three years of development is needed to teach the engine the necessary manners. It has - then still correct according to thetype designation - a displacement of 2545 cc and reaches a top speed of about 95 km/h. It is on the motor show presented in Berlin 1936, about 12 years after the first diesel truck.

The body is designed as a Pullman limousine with six to seven seats. The car is also sold in a special series almost exclusively as a taxi. It has, despite its size, a low consumption, moderate carbon-particulate emission and very high oil consumption. For one tankful, it requires at least one liter of oil. Actually, the taxi owners been waiting for this car, but it needs about 30 percent less than a about equally powerful gasoline engine. Actually, the taxi owner been waiting for this car, but it needs about 30 percent less than a approximately equally powerful gasoline engine. With the appropriate license the diesel fuel costs due to the favorable customs tariff only half compared to petrol. In addition, the engine will last longer with the many cold starts.

There have been many prior attempts to tame the diesel engine for passenger cars. Many of them are failed due to the enormousdisturbance of the engine. Thus a planned three-and four-cylinder does not meet the expectations. The final version is created from a six-cylinder petrol engine. But first the pre-chamber method, a different engine mounting, a newly developed Bosch injection pump and much fine work lead to a somewhat expected result. It succeeds to give the engine through special dimensioning some running smoothness and an acceptable durability. 250,000 km should be quite possible for frequent riders. Problems are the high purchase price of the car and the thin network of filling stations for diesel fuel.

Obviously, the newly developed Bosch in-line injection pump helps a lot. This is evident by the fact that it is then maintained in principle over 30 years. The engine has contrary the practice at a diesel engine a control valve. It is similar the flap in the gasoline engine, but works quite differently. If one accelerates, it opens and via low pressure the control rack is moved in the injection pump, which will provides for larger injection. The system is particularly protected against leakage at Mercedes. If this happens namely to a greater extent, so the system automatically gives full throttle...