Michelin Pilot Alpin PA4 is a winter tyre made in total of 116 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/45 R18 is 30mm wider than the narrowest dimension (225) and 90mm narrower than the widest one (345). 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 R18, Pilot Alpin PA4 usually competes against
Winter i*cept evo3 W330, which is a tyre from
Hankook with a rating of 86%, compared to 0% of the
Michelin in question.