Bridgestone Alenza 001 305/40 R20

Bridgestone Alenza 001 is a summer tyre made in total of 96 sizes, ranging from R13 to R13 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 305/40 R20 is 90mm wider than the narrowest dimension (215) and -30mm narrower than the widest one (275). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (305mm), which results in 122mm sidewall height.