It's a 9100 actually and there's a 9100S and a 9100T. The S is the speedier version while the T is the Torque. I've used both versions on both throttle and steering and been very happy. I've also run 9000's and 8800's. Can't go wrong with JR servos. I know people who run T's on both the throttle and steering, while i prefer an S for steering and T for throttle and brake.