Bridgestone Turanza T005 is a summer tyre made in total of 350 sizes, ranging from R14 to R14 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 315/35 R20 is 160mm wider than the narrowest dimension (155) and -30mm narrower than the widest one (285). This tyre profile of 35 means the sidewall height of the tyre is 35% of the tyre width (315mm), which results in 110.25mm sidewall height. In 315/35 R20, there is only one possible speed index for Bridgestone Turanza T005 - "Y", which is good for speeds up to 300 km/h.