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. 225/55 R18 is 80mm wider than the narrowest dimension (145) and 30mm narrower than the widest one (255). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (225mm), which results in 123.75mm sidewall height. In 225/55 R18, there is only one possible speed index for Michelin CrossClimate+ - "V", which is good for speeds up to 240 km/h. In 225/55 R18, CrossClimate+ usually competes against Weather Control A005 EVO, which is a tyre from Bridgestone with a rating of 85%, compared to 87% of the Michelin in question.