Cooper Discoverer All Season is a allround tyre made in total of 48 sizes, ranging from R14 to R14 - this particular dimension is R15, which means it fits to a 15 inch/381mm diameter wheel. 185/60 R15 is 10mm wider than the narrowest dimension (175) and 70mm narrower than the widest one (255). This tyre profile of 60 means the sidewall height of the tyre is 60% of the tyre width (185mm), which results in 111mm sidewall height. In 185/60 R15, there are 2 possible speed indexes for Cooper Discoverer All Season - "H","V", which are good for speeds up to 210, 240 km/h.