Metzeler ME 880 Marathon is a winter tyre made in total of 30 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 210/40 R18 is 70mm wider than the narrowest dimension (140) and -90mm narrower than the widest one (120). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (210mm), which results in 84mm sidewall height. In 210/40 R18, there is only one possible speed index for Metzeler ME 880 Marathon - "H", which is good for speeds up to 210 km/h.