OM615

When the W114/W115 saloons — the Stroke Eight — arrived in 1968, the 200 D's two-liter four was very nearly the OM621 carried over from the outgoing fintails, changed mainly by a relocated oil filter and a lower, shorter intake manifold to clear the new car's flatter nose. The variant that mattered was the other one. Keeping the 87 mm bore and stretching the stroke to 92.4 mm gave 2.2 liters and 60 PS, and the 220 D built on it became the best-selling diesel of the entire Stroke Eight range.

Both versions crossed into the W123 in 1976, and in February 1979 the smaller one was lifted to 60 PS as well. Outside Stuttgart the OM615 turned up in places Mercedes-Benz never sold cars: SEAT fitted it to the 132 in Spain from 1973, and it worked in the N1300 and MB100 vans and in the Unimog. Boring it out to 2.4 liters in 1973 created the OM616, which promptly displaced the 2.2 altogether. By the time the OM601 replaced it, this modest four had been in production for seventeen years.