Introduced in 1957 as a counterpart to the West German VW Beetle, the East German Trabant was powered by a 600cc 2-cylinder ... air-cooled horizontally-opposed twin with 9 horsepower. The engine ...

In 1985, Maserati almost made a twin-turbo 2.0L V6 with ... development started on a modular air-cooled horizontally opposed engine family with varying cylinder counts. Two-, four-, six-, and ...