Michelin Pilot Alpin PA4 is a winter tyre made in total of 115 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 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 R18, there is only one possible speed index for Michelin Pilot Alpin PA4 - "V", which is good for speeds up to 240 km/h. In 225/45 R18, Pilot Alpin PA4 usually competes against Blizzak LM-005, which is a tyre from Bridgestone with a rating of 87%, compared to 0% of the Michelin in question. Latest test in 225/45 R18 was held by Sportscars in 2015, where Pilot Alpin PA4 received rating "Recommended" and finished on the 4. place. It was tested on a .