Pirelli SCORPION is a tyre made in total of 14 sizes, ranging from R18 to R18 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (225mm), which results in 123.75mm sidewall height. In 225/55 R18, there is only one possible speed index for Pirelli SCORPION - "", which is good for speeds up to km/h.