Pirelli P ZERO Nero GT 285/25 R20

Pirelli P ZERO Nero GT is a summer tyre made in total of 46 sizes, ranging from R16 to R16 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 285/25 R20 is 90mm wider than the narrowest dimension (195) and 20mm narrower than the widest one (305). This tyre profile of 25 means the sidewall height of the tyre is 25% of the tyre width (285mm), which results in 71.25mm sidewall height.