Hankook Kinergy 4S2 X H750A is a allround tyre made in total of 28 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/60 R18 is 40mm wider than the narrowest dimension (215) and 30mm narrower than the widest one (285). This tyre profile of 60 means the sidewall height of the tyre is 60% of the tyre width (255mm), which results in 153mm sidewall height. In 255/60 R18, there is only one possible speed index for Hankook Kinergy 4S2 X H750A - "V", which is good for speeds up to 240 km/h.