Uniroyal MS plus 77 is a winter tyre made in total of 76 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/40 R18 is 100mm wider than the narrowest dimension (145) and 10mm narrower than the widest one (255). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (245mm), which results in 98mm sidewall height. In 245/40 R18, there is only one possible speed index for Uniroyal MS plus 77 - "V", which is good for speeds up to 240 km/h. In 245/40 R18, MS plus 77 usually competes against EuroWinter HS01, which is a tyre from Falken with a rating of 53%, compared to 0% of the Uniroyal in question.