Michelin Pilot Alpin PA4 is a winter tyre made in total of 115 sizes, ranging from R17 to R17 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. 295/30 R20 is 70mm wider than the narrowest dimension (225) and 50mm narrower than the widest one (345). This tyre profile of 30 means the sidewall height of the tyre is 30% of the tyre width (295mm), which results in 88.5mm sidewall height. In 295/30 R20, there are 2 possible speed indexes for Michelin Pilot Alpin PA4 - "V","W", which are good for speeds up to 240, 270 km/h.