Michelin CrossClimate+ is a allround tyre made in total of 81 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/45 R18 is 90mm wider than the narrowest dimension (145) and 20mm narrower than the widest one (255). 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 CrossClimate 2, which is a tyre from Michelin with a rating of 95%, compared to 71% of the Michelin in question.