Viking WinTech is a winter tyre made in total of 53 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/40 R18 is 90mm wider than the narrowest dimension (145) and 40mm narrower than the widest one (275). 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. In 235/40 R18, WinTech usually competes against Radial Champiro WinterPro 2, which is a tyre from GT with a rating of 60%, compared to 58% of the Viking in question.