Standard piston rings for Bmw E9 : Bmw E9 : - 3.0 cs 6cyl 180hp from 04/1971 to 11/1975 (engine code m30) - 3.0 csi 6cyl 200hp from 02/1972 to 11/1975 (engine code m30) - 3.0 csl 6cyl 206hp from 09/1972 to 06/1973 (engine code m30) Please note! Not compatible with other Bmw E9 engine code m30 versions.