Firestone TZ300a 195/55 R15

Firestone TZ300a is a summer tyre made in total of 13 sizes, ranging from R15 to R15 - this particular dimension is R15, which means it fits to a 15 inch/381mm diameter wheel. 195/55 R15 is 20mm wider than the narrowest dimension (175) and 0mm narrower than the widest one (195). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (195mm), which results in 107.25mm sidewall height.