Cooper Discoverer STT PRO 305/60 R18

Cooper Discoverer STT PRO is a tyre made in total of 46 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 305/60 R18 is 274mm wider than the narrowest dimension (31) and 0mm narrower than the widest one (305). This tyre profile of 60 means the sidewall height of the tyre is 60% of the tyre width (305mm), which results in 183mm sidewall height.