Pirelli P Zero Winter 2 is a winter tyre made in total of 15 sizes, ranging from R18 to R18 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 255/45 R20 is 10mm wider than the narrowest dimension (245) and 50mm narrower than the widest one (305). 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 is only one possible speed index for Pirelli P Zero Winter 2 - "V", which is good for speeds up to 240 km/h. In 255/45 R20, P Zero Winter 2 usually competes against Eurowinter Hs02 Pro, which is a tyre from Falken with a rating of 54%, compared to 0% of the Pirelli in question.