Vredestein Wintrac Xtreme S is a winter tyre made in total of 78 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/50 R18 is 20mm wider than the narrowest dimension (215) and 60mm narrower than the widest one (295). This tyre profile of 50 means the sidewall height of the tyre is 50% of the tyre width (235mm), which results in 117.5mm sidewall height. In 235/50 R18, there is only one possible speed index for Vredestein Wintrac Xtreme S - "V", which is good for speeds up to 240 km/h. In 235/50 R18, Wintrac Xtreme S usually competes against Wintrac Pro, which is a tyre from Vredestein with a rating of 68%, compared to 0% of the Vredestein in question.