Michelin CrossClimate is a allround tyre made in total of 36 sizes, ranging from R0 to R0 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/45 R18 is 233mm wider than the narrowest dimension (2) and 10mm narrower than the widest one (245). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (235mm), which results in 105.75mm sidewall height. In 235/45 R18, there is only one possible speed index for Michelin CrossClimate - "Y", which is good for speeds up to 300 km/h. In 235/45 R18, CrossClimate usually competes against Vector 4Seasons Gen-2, which is a tyre from GoodYear with a rating of 65%, compared to 56% of the Michelin in question.