Nokian WeatherProof is a allround tyre made in total of 49 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 90mm wider than the narrowest dimension (155) 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 Nokian WeatherProof - "V", which is good for speeds up to 240 km/h. In 245/40 R18, WeatherProof usually competes against EuroALL Season AS210, which is a tyre from Falken with a rating of 77%, compared to 59% of the Nokian in question.