Hankook Winter i*cept X RW10 is a winter tyre made in total of 49 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (215mm), which results in 118.25mm sidewall height. In 215/55 R18, there is only one possible speed index for Hankook Winter i*cept X RW10 - "T", which is good for speeds up to 190 km/h.