GT Radial Champiro HPY 255/40 R17

GT Radial Champiro HPY is a summer tyre made in total of 9 sizes, ranging from R17 to R17 - this particular dimension is R17, which means it fits to a 17 inch/431.8mm diameter wheel. 255/40 R17 is 40mm wider than the narrowest dimension (215) and -20mm narrower than the widest one (235). 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.