Dunlop SP Sport MAXX RT2 is a summer tyre made in total of 101 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 30mm wider than the narrowest dimension (205) and 50mm narrower than the widest one (285). 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 RT2 - "Y", which is good for speeds up to 300 km/h. In 235/40 R18, SP Sport MAXX RT2 usually competes against P ZERO, which is a tyre from Pirelli with a rating of 66%, compared to 79% of the Dunlop in question. Latest test in 235/40 R18 was held by Automotorsport in 2016, where SP Sport MAXX RT2 received rating "Highly recommended" and finished on the 2. place. It was tested on a .