Barum Bravuris 5 HM is a summer tyre made in total of 159 sizes, ranging from R14 to R14 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 255/45 R20 is 90mm wider than the narrowest dimension (165) and 10mm narrower than the widest one (265). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (255mm), which results in 114.75mm sidewall height. In 255/45 R20, there is only one possible speed index for Barum Bravuris 5 HM - "Y", which is good for speeds up to 300 km/h.