I cheated, but it answered your ?
In 1993 the 850Ci replaced the 850i.
There were also two new models available: the 840Ci and the 850CSi.
The 840Ci had an eight cylinder engine with 286 HP.
The 850 CSi had a twelve cylinder that had 380 HP.
The 850CSi had a special M package wich included M style wheels and mirrors.
In 1994 the 850Ci received more power. It now had 326 HP.
In 1996 the 840 Ci received a new engine but there were no changes in power or top speed.
The 850CSi went out of production in 1997.