Dunlop SP Sport MAXX GT is a summer tyre made in total of 118 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 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 Dunlop SP Sport MAXX GT - "Y", which is good for speeds up to 300 km/h. In 235/40 R18, SP Sport MAXX GT usually competes against SportContact 6, which is a tyre from Continental with a rating of 0%, compared to 0% of the Dunlop in question.