With the introduction of the E30 3-series, Alpina phased out the previously popular four cylinder engines and focused their efforts on the small-block six-cylinder models. All of these cars were based on the same platform with different versions of the same basic engine.

In 1985, BMW replaced the 150hp 323i with the 170hp 325i. The C2 2.5 had more power but was significantly more expensive. Alpina responded by introducing the C1 2.5.

The C1 2.5 had 190hp.

Between 1986 and 1987, 50 examples of the C1 2.5 were produced.