Dunlop Grandtrek At5 255/55 R18

Dunlop Grandtrek At5 is a summer tyre made in total of 14 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/55 R18 is 40mm wider than the narrowest dimension (215) and 30mm narrower than the widest one (285). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (255mm), which results in 140.25mm sidewall height.