255/40 R18 Royal Black Royal Performance variants
Royal Black Royal Performance is a tyre made in total of 68 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/40 R18 is 60mm wider than the narrowest dimension (195) and 30mm narrower than the widest one (285). 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. In 255/40 R18, there is only one possible speed index for Royal Black Royal Performance - "W", which is good for speeds up to 270 km/h.
Royal Black Royal Performance is made in 68 sizes, starting from 195/45 R15 up to 285/50 R20.
