Firestone Multiseason 2 is a winter tyre made in total of 60 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/45 R18 is 70mm wider than the narrowest dimension (155) and 10mm narrower than the widest one (235). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (225mm), which results in 101.25mm sidewall height. In 225/45 R18, there is only one possible speed index for Firestone Multiseason 2 - "V", which is good for speeds up to 240 km/h. In 225/45 R18, Multiseason 2 usually competes against Seasonproof, which is a tyre from Nokian with a rating of 58%, compared to 58% of the Firestone in question.