M102

Replacing the M115 in 1980, the M102 was deliberately oversquare — a big bore on a short stroke — and became the entry engine for three model families at once: the last of the W 123, the new W 201 190 and 190 E, and then the W 124. It ran from 1.7 to 2.5 liters, with carburetors at the bottom of the range and Bosch K- and KE-Jetronic injection above, and in 2.3-liter form it also went into the W 460 G-Wagen for markets that wanted a petrol engine.

Then Erich Waxenberger, by that point running motorsport, decided the 190 E should go rallying and commissioned Cosworth to design a 16-valve twin-cam head for it. The rally program never happened. The engine did: in August 1983 three 190 E 2.3-16s ran the Nardò bowl in 40 °C heat and covered 50,000 km in 201 hours, 39 minutes and 43 seconds at an average of 247.9 km/h, taking two further world records and nine class records with it. The car was shown to the public four weeks later at Frankfurt.