Metzeler ME 888 Marathon Ultra is a summer tyre made in total of 220 sizes, ranging from R14 to R14 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 260/40 R18 is 170mm wider than the narrowest dimension (90) and -80mm narrower than the widest one (180). 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.