Yokohama Advan V61 is a summer tyre made in total of 7 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/55 R18 is 30mm wider than the narrowest dimension (225) and -20mm narrower than the widest one (235). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (255mm), which results in 140.25mm sidewall height. In 255/55 R18, there is only one possible speed index for Yokohama Advan V61 - "V", which is good for speeds up to 240 km/h. In 255/55 R18, Advan V61 usually competes against Turanza All Season 6, which is a tyre from Bridgestone with a rating of 89%, compared to 0% of the Yokohama in question.