Bosch K-Jetronic mechanical fuel injection on the 512 BBi replaced the outgoing model’s four, triple-choke Weber 40 IF 3C carburettors. Otherwise mechanically identical, the flat-12 featured lower maximum revs (6,600 rpm compared to the 512 BB’s 6,800 rpm) and the engine developed 20 bhp less, although top speed remained within a whisker of the 512 BB’s 283 km/h.