Oh, ****. Here we go again.
PERFORMANCE SHIFT, if your car is equipped, allows it to shift where a car WITHOUT this option would shift.
NORMAL shift is a lower RPM shift for efficiency. So Joe, your car shifts where mine does in Performance shift, assuming you don't have the option.
It provides efficiency for the SC models. This was tested and proven between my car (with the option) and Jseabert'* car (without the option). Both are 93'*. His is an SSE (NA).
Adding this option to a car will NOT improve performance, but will improve efficiency.