What does the “CSi” suffix denote?
The “CSi” suffix was first used in 1971 on the E9 3.0 CSi coupe to denote “Coupe Sport injection”. It was carried over by the 3.0 CSi’s successor, the E24 633CSi (and its successors, the 628CSi, 635CSi and M635CSi). However, in the case of the 8 Series, the CSi suffix is unique to the M-powered version (all other 8 Series models have either an “i” or “Ci” suffix).
