Goodyear UltraGrip Performance Gen-1 305/30 R21

Goodyear UltraGrip Performance Gen-1 is a winter tyre made in total of 102 sizes, ranging from R13 to R13 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 305/30 R21 is 110mm wider than the narrowest dimension (195) and -30mm narrower than the widest one (275). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (305mm), which results in 91.5mm sidewall height.