Continental ContiWinterContact TS 810S is a winter tyre made in total of 27 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 265/40 R18 is 90mm wider than the narrowest dimension (175) and -20mm narrower than the widest one (245). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (265mm), which results in 106mm sidewall height. In 265/40 R18, there is only one possible speed index for Continental ContiWinterContact TS 810S - "V", which is good for speeds up to 240 km/h.