Bridgestone Turanza T001 is a summer tyre made in total of 69 sizes, ranging from R15 to R15 - this particular dimension is R17, which means it fits to a 17 inch/431.8mm diameter wheel. 245/55 R17 is 60mm wider than the narrowest dimension (185) and -20mm narrower than the widest one (225). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (245mm), which results in 134.75mm sidewall height. In 245/55 R17, there is only one possible speed index for Bridgestone Turanza T001 - "W", which is good for speeds up to 270 km/h.