Falken ZIEX ZE310 Ecorun is a summer tyre made in total of 150 sizes, ranging from R14 to R14 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/45 R18 is 50mm wider than the narrowest dimension (185) and -10mm narrower than the widest one (225). 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 Falken ZIEX ZE310 Ecorun - "W", which is good for speeds up to 270 km/h. In 235/45 R18, ZIEX ZE310 Ecorun usually competes against Ventus Prime3 K125, which is a tyre from Hankook with a rating of 77%, compared to 85% of the Falken in question.