Yokohama A008 is a summer tyre made in total of 9 sizes, ranging from R13 to R13 - this particular dimension is R15, which means it fits to a 15 inch/381mm diameter wheel. 225/50 R15 is 60mm wider than the narrowest dimension (165) and 20mm narrower than the widest one (245). This tyre profile of 50 means the sidewall height of the tyre is 50% of the tyre width (225mm), which results in 112.5mm sidewall height. In 225/50 R15, there is only one possible speed index for Yokohama A008 - "V", which is good for speeds up to 240 km/h.