Bridgestone Exedra Max E-MAX is a summer tyre made in total of 36 sizes, ranging from R15 to R15 - this particular dimension is R15, which means it fits to a 15 inch/381mm diameter wheel. 170/80 R15 is 40mm wider than the narrowest dimension (130) and -50mm narrower than the widest one (120). This tyre profile of 80 means the sidewall height of the tyre is 80% of the tyre width (170mm), which results in 136mm sidewall height. In 170/80 R15, there is only one possible speed index for Bridgestone Exedra Max E-MAX - "H", which is good for speeds up to 210 km/h.