Firestone Roadhawk 235/40 R18

Firestone Roadhawk is a summer tyre made in total of 174 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/40 R18 is 70mm wider than the narrowest dimension (165) and 60mm narrower than the widest one (295). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (235mm), which results in 94mm sidewall height. In 235/40 R18, Roadhawk usually competes against Summer, which is a tyre from Cooper with a rating of 76%, compared to 60% of the Firestone in question.