Michelin Pilot Sport 4 S 255/40 R21

Michelin Pilot Sport 4 S is a summer tyre made in total of 250 sizes, ranging from R13 to R13 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 255/40 R21 is 30mm wider than the narrowest dimension (225) and 70mm narrower than the widest one (325). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (255mm), which results in 102mm sidewall height. In 255/40 R21, Pilot Sport 4 S usually competes against Ventus Evo, which is a tyre from Hankook with a rating of 99%, compared to 96% of the Michelin in question.