Royal Black Royal Sport 255/70 R18

Royal Black Royal Sport is a tyre made in total of 30 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/70 R18 is 40mm wider than the narrowest dimension (215) and 30mm narrower than the widest one (285). This tyre profile of 70 means the sidewall height of the tyre is 70% of the tyre width (255mm), which results in 178.5mm sidewall height.