Michelin Pilot Sport EV is a summer tyre made in total of 50 sizes, ranging from R19 to R19 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. This tyre profile of 50 means the sidewall height of the tyre is 50% of the tyre width (235mm), which results in 117.5mm sidewall height. In 235/50 R20, there is only one possible speed index for Michelin Pilot Sport EV - "Y", which is good for speeds up to 300 km/h.