General E21 Details

The BMW E21 was available from 1977 to 1982, with both 4 and 6 cylinder engines. There were approximately one million cars built in that period. Only cars equipped with 4 cylinder engines were commercially available in the US, because the 6 cylinder engines did not comply with US emission regulations. There are a few 6-bangers in the US though, but they were imported from Germany by individuals.
The 4 cylinder versions were built around the M10 engine, and included the following versions: 315, 316, 318, 318i, 320/4 and 320i. The latter is most common in the US. There were only two 6 cylinder versions, namely the 320/6 and the 323i, both built with the M20 engine (the BMW 'small-six'). Some tuners also offered revised versions of the E21, namely Alpina, Hartge and Baur.