Pirelli Scorpion Winter 2 is a winter tyre made in total of 77 sizes, ranging from R18 to R18 - this particular dimension is R22, which means it fits to a 22 inch/558.8mm diameter wheel. 325/55 R22 is 100mm wider than the narrowest dimension (225) and 0mm narrower than the widest one (325). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (325mm), which results in 178.75mm sidewall height. In 325/55 R22, there is only one possible speed index for Pirelli Scorpion Winter 2 - "H", which is good for speeds up to 210 km/h.