Vredestein Quatrac is a allround tyre made in total of 85 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/45 R18 is 80mm wider than the narrowest dimension (165) 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 Vredestein Quatrac - "Y", which is good for speeds up to 300 km/h. In 245/45 R18, Quatrac usually competes against Quadraxer 3, which is a tyre from Kleber with a rating of 84%, compared to 92% of the Vredestein in question.