Riken Ultra High Performance is a tyre made in total of 55 sizes, ranging from R17 to R17 - this particular dimension is R17, which means it fits to a 17 inch/431.8mm diameter wheel. 225/45 R17 is 20mm wider than the narrowest dimension (205) and -30mm narrower than the widest one (195). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (225mm), which results in 101.25mm sidewall height. In 225/45 R17, there are 3 possible speed indexes for Riken Ultra High Performance - "Y","V","W", which are good for speeds up to 300, 240, 270 km/h.
