Falken ZIEX ZE914 EcoRun is a summer tyre made in total of 117 sizes, ranging from R13 to R13 - this particular dimension is R17, which means it fits to a 17 inch/431.8mm diameter wheel. 215/40 R17 is 50mm wider than the narrowest dimension (165) and 0mm narrower than the widest one (215). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (215mm), which results in 86mm sidewall height. In 215/40 R17, there is only one possible speed index for Falken ZIEX ZE914 EcoRun - "W", which is good for speeds up to 270 km/h. In 215/40 R17, ZIEX ZE914 EcoRun usually competes against Ventus Prime3 K125, which is a tyre from Hankook with a rating of 52%, compared to 0% of the Falken in question.