Barum Polaris 6 is a winter tyre made in total of 78 sizes, ranging from R14 to R14 - this particular dimension is R19, which means it fits to a 19 inch/482.6mm diameter wheel. 235/45 R19 is 80mm wider than the narrowest dimension (155) and 20mm narrower than the widest one (255). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (235mm), which results in 105.75mm sidewall height. In 235/45 R19, there is only one possible speed index for Barum Polaris 6 - "V", which is good for speeds up to 240 km/h. In 235/45 R19, Polaris 6 usually competes against Speed-Grip 5, which is a tyre from Semperit with a rating of 78%, compared to 83% of the Barum in question.