Metzeler ME 888 Marathon Ultra is a summer tyre made in total of 85 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 260/40 R18 is 120mm wider than the narrowest dimension (140) and -130mm narrower than the widest one (130). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (260mm), which results in 104mm sidewall height. In 260/40 R18, there is only one possible speed index for Metzeler ME 888 Marathon Ultra - "V", which is good for speeds up to 240 km/h.