Michelin Pilot Sport A/S 3 305/40 R20

Michelin Pilot Sport A/S 3 is a summer tyre made in total of 7 sizes, ranging from R19 to R19 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 305/40 R20 is 50mm wider than the narrowest dimension (255) and 10mm narrower than the widest one (315). 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.