Kleber Dynaxer UHP is a summer tyre made in total of 44 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 235/40 R18 is 40mm wider than the narrowest dimension (195) and 20mm narrower than the widest one (255). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (235mm), which results in 94mm sidewall height. In 235/40 R18, there is only one possible speed index for Kleber Dynaxer UHP - "Y", which is good for speeds up to 300 km/h. In 235/40 R18, Dynaxer UHP usually competes against Quatrac Pro+, which is a tyre from Vredestein with a rating of 52%, compared to 48% of the Kleber in question.