Nokian WR SUV 4 is a winter tyre made in total of 69 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/60 R18 is 10mm wider than the narrowest dimension (215) and 90mm narrower than the widest one (315). This tyre profile of 60 means the sidewall height of the tyre is 60% of the tyre width (225mm), which results in 135mm sidewall height. In 225/60 R18, there are 2 possible speed indexes for Nokian WR SUV 4 - "H","V", which are good for speeds up to 210, 240 km/h. In 225/60 R18, WR SUV 4 usually competes against WR SUV 3, which is a tyre from Nokian with a rating of 0%, compared to 26% of the Nokian in question.