Having now complete 6 track days, I have a question about the amount of wear front to back pads? My car is the 1998 F with origonal brake calipers. The first 3 track days were with GreenStuff pads and the 2nd 3 with RedStuff fitted. The wear for both sets were roughly the same. The front are about 50% gone while the rears are 75% gone. Is this normal as I would have expect the fronts to wear more than the rears?