Bridgestone Potenza RE050A 265/40 R18

Bridgestone Potenza RE050A is a summer tyre made in total of 109 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 265/40 R18 is 90mm wider than the narrowest dimension (175) and 40mm narrower than the widest one (305). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (265mm), which results in 106mm sidewall height.