Nankang Sportnex AS-2+ is a summer tyre made in total of 76 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/45 R18 is 70mm wider than the narrowest dimension (175) and 40mm narrower than the widest one (285). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (245mm), which results in 110.25mm sidewall height. In 245/45 R18, there is only one possible speed index for Nankang Sportnex AS-2+ - "Y", which is good for speeds up to 300 km/h. In 245/45 R18, Sportnex AS-2+ usually competes against Ultrac Vorti, which is a tyre from Vredestein with a rating of 0%, compared to 20% of the Nankang in question.