Firestone Fs400 215/75 R17.5

Firestone Fs400 is a tyre made in total of 7 sizes, ranging from R13 to R13 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 215/75 R17.5 is 205mm wider than the narrowest dimension (10) and 50mm narrower than the widest one (265). This tyre profile of 75 means the sidewall height of the tyre is 75% of the tyre width (215mm), which results in 161.25mm sidewall height.