Pirelli Scorpion Winter 315/45 R21

Pirelli Scorpion Winter is a winter tyre made in total of 251 sizes, ranging from R16 to R16 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 315/45 R21 is 100mm wider than the narrowest dimension (215) and 10mm narrower than the widest one (325). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (315mm), which results in 141.75mm sidewall height.