Goodyear Eagle F1 Supersport is a summer tyre made in total of 90 sizes, ranging from R18 to R18 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/40 R18 is 40mm wider than the narrowest dimension (205) and 70mm narrower than the widest one (315). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (245mm), which results in 98mm sidewall height. In 245/40 R18, there is only one possible speed index for Goodyear Eagle F1 Supersport - "Y", which is good for speeds up to 300 km/h. In 245/40 R18, Eagle F1 Supersport usually competes against SP Sport MAXX RT2, which is a tyre from Dunlop with a rating of 79%, compared to 78% of the Goodyear in question.