Goodyear Eagle F1 Asymmetric 6 is a summer tyre made in total of 57 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/45 R18 is 50mm wider than the narrowest dimension (205) and 10mm narrower than the widest one (265). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (255mm), which results in 114.75mm sidewall height. In 255/45 R18, there is only one possible speed index for Goodyear Eagle F1 Asymmetric 6 - "Y", which is good for speeds up to 300 km/h. In 255/45 R18, Eagle F1 Asymmetric 6 usually competes against Pilot Sport 5, which is a tyre from Michelin with a rating of 97%, compared to 100% of the Goodyear in question.