Pirelli Scorpion Winter is a winter tyre made in total of 212 sizes, ranging from R16 to R16 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 255/45 R20 is 40mm wider than the narrowest dimension (215) and 70mm narrower than the widest one (325). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (255mm), which results in 114.75mm sidewall height. In 255/45 R20, there are 3 possible speed indexes for Pirelli Scorpion Winter - "H","V","W", which are good for speeds up to 210, 240, 270 km/h. In 255/45 R20, Scorpion Winter usually competes against Winter i*cept evo3 X W330A, which is a tyre from Hankook with a rating of 72%, compared to 0% of the Pirelli in question.