Bridgestone Potenza RE040 275/40 R18

Bridgestone Potenza RE040 is a summer tyre made in total of 9 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 275/40 R18 is 70mm wider than the narrowest dimension (205) and 0mm narrower than the widest one (275). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (275mm), which results in 110mm sidewall height.