Falken Azenis FK520 is a summer tyre made in total of 115 sizes, ranging from R17 to R17 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 325/30 R21 is 120mm wider than the narrowest dimension (205) and 0mm narrower than the widest one (325). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (325mm), which results in 97.5mm sidewall height. In 325/30 R21, there is only one possible speed index for Falken Azenis FK520 - "Y", which is good for speeds up to 300 km/h. In 325/30 R21, Azenis FK520 usually competes against Proxes Sport 2, which is a tyre from Toyo with a rating of 63%, compared to 72% of the Falken in question.