Nokian Seasonproof SUV is a allround tyre made in total of 19 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/55 R18 is 10mm wider than the narrowest dimension (215) and 30mm narrower than the widest one (255). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (225mm), which results in 123.75mm sidewall height. In 225/55 R18, there is only one possible speed index for Nokian Seasonproof SUV - "V", which is good for speeds up to 240 km/h. In 225/55 R18, Seasonproof SUV usually competes against AllSeasonContact, which is a tyre from Continental with a rating of 83%, compared to 56% of the Nokian in question.