Michelin Pilot Sport Cup vs. Michelin Pilot Sport Cup+
BMW and Michelin had developed the Michelin Pilot Sport Cup tyre for the M3 CSL.
A few years later a more user-friendly version of this tyre had been created and was named Pilot Sport Cup+
The Cup+ version had different rubber and bigger grooves (it had less rubber which meant better performance in wet conditions).
Original cup pattern
Photos comparing the 2 tyres