besides the Extra 15bhp and the jump of about 4 insurance groups and the obvious fact the two extra doors. what is the difference in the engine?? dont the both run on the same FP3 engine? Im sure ive heared somthing metioned about the RSI being an 8 valve and the RT not but surely it would be in the haynes manual? is it running on the same engine or is it different?? thanks colin