[2] In the 1970s BMW decided to develop an engine, which would both be powerful and have a good fuel economy.

It started as a joint venture with Steyr-Daimler Puch in 1978, but in February 1982 BMW took over the reins.

Beginning in 1983, Ford was planning to buy 190,000 BMW turbodiesels over a period of several years.

[3] With the American diesel market imploding in the early 1980s, Ford only built a small number of Lincolns thus equipped and only for two model years.

In 1985, BMW introduced a naturally aspirated version of the M21, which was popular in countries with a high motor vehicle tax.