Michelin CrossClimate is a allround tyre made in total of 36 sizes, ranging from R14 to R14 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/45 R18 is 80mm wider than the narrowest dimension (165) and -243mm narrower than the widest one (2). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (245mm), which results in 110.25mm sidewall height. In 245/45 R18, there is only one possible speed index for Michelin CrossClimate - "Y", which is good for speeds up to 300 km/h. In 245/45 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.