Interesting question. I would have thought ci0 would always produce the slowest speed so even a 200kt tailwind with ci20, the managed speed will still be a nanomach faster than ci0, most likely unnoticeable. Ci0 is max range, ci20 isn't so there must be a tiny difference in speed. Don't forget the ci also affects optimum cruise alt information. Ci100 will offer a lower optimum level, or higher tas.