Michelin Pilot Super Sport is a summer tyre made in total of 156 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/45 R18 is 30mm wider than the narrowest dimension (205) and 80mm narrower than the widest one (315). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (235mm), which results in 105.75mm sidewall height. In 235/45 R18, there is only one possible speed index for Michelin Pilot Super Sport - "Y", which is good for speeds up to 300 km/h. In 235/45 R18, Pilot Super Sport usually competes against Ultrac Vorti, which is a tyre from Vredestein with a rating of 55%, compared to 35% of the Michelin in question.