Pirelli P ZERO Corsa is a summer tyre made in total of 36 sizes, ranging from R19 to R19 - this particular dimension is R22, which means it fits to a 22 inch/558.8mm diameter wheel. 315/30 R22 is 90mm wider than the narrowest dimension (225) and 10mm narrower than the widest one (325). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (315mm), which results in 94.5mm sidewall height. In 315/30 R22, there is only one possible speed index for Pirelli P ZERO Corsa - "Y", which is good for speeds up to 300 km/h.