Questions about the "shift" mode switch

[Telecaster]

Whether the switch only change the "shift mode" or it would also change the air/fuel parameters when I switch from "E" to "S"? I usually drive in "E" mode (To save fuel, the fuel price in here is so expensive), but when I switch it to "S" mode for a while today, it performs totally different, it become much powerful.)
Mine is a 92 325i Cabrio (A/T).