Semperit Speed-Grip 3 235/40 R18

Semperit Speed-Grip 3 is a winter tyre made in total of 51 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/40 R18 is 50mm wider than the narrowest dimension (185) and -40mm narrower than the widest one (195). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (235mm), which results in 94mm sidewall height.