Maxxis Premitra HP5 is a summer tyre made in total of 56 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/40 R18 is 50mm wider than the narrowest dimension (195) and 10mm narrower than the widest one (255). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (245mm), which results in 98mm sidewall height. In 245/40 R18, there is only one possible speed index for Maxxis Premitra HP5 - "W", which is good for speeds up to 270 km/h. In 245/40 R18, Premitra HP5 usually competes against ZIEX ZE310 ECORUN, which is a tyre from Falken with a rating of 85%, compared to 76% of the Maxxis in question.