BFGoodrich Trail Terrain T/A 275/65 R18

BFGoodrich Trail Terrain T/A is a winter tyre made in total of 48 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 275/65 R18 is 40mm wider than the narrowest dimension (235) and 10mm narrower than the widest one (285). This tyre profile of 65 means the sidewall height of the tyre is 65% of the tyre width (275mm), which results in 178.75mm sidewall height.