Dunlop SP Sport MAXX GT600 is a summer tyre made in total of 15 sizes, ranging from R20 to R20 - this particular dimension is R20, which means it fits to a 20 inch/508mm diameter wheel. This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (255mm), which results in 102mm sidewall height. In 255/40 R20, there is only one possible speed index for Dunlop SP Sport MAXX GT600 - "Y", which is good for speeds up to 300 km/h. In 255/40 R20, SP Sport MAXX GT600 usually competes against Pilot Sport 4 S, which is a tyre from Michelin with a rating of 74%, compared to 0% of the Dunlop in question.