Nexen N fera Sport is a summer tyre made in total of 20 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/35 R18 is 30mm wider than the narrowest dimension (225) and -10mm narrower than the widest one (245). This tyre profile of 35 means the sidewall height of the tyre is 35% of the tyre width (255mm), which results in 89.25mm sidewall height. In 255/35 R18, there is only one possible speed index for Nexen N fera Sport - "Y", which is good for speeds up to 300 km/h. In 255/35 R18, N fera Sport usually competes against Aspire XP, which is a tyre from Apollo with a rating of 53%, compared to 76% of the Nexen in question.