Imperial Snowdragon HP is a winter tyre made in total of 65 sizes, ranging from R13 to R13 - this particular dimension is R15, which means it fits to a 15 inch/381mm diameter wheel. 185/55 R15 is 40mm wider than the narrowest dimension (145) and 10mm narrower than the widest one (195). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (185mm), which results in 101.75mm sidewall height. In 185/55 R15, there are 2 possible speed indexes for Imperial Snowdragon HP - "H","V", which are good for speeds up to 210, 240 km/h. In 185/55 R15, Snowdragon HP usually competes against Cinturato Winter, which is a tyre from Pirelli with a rating of 63%, compared to 5% of the Imperial in question.