Kumho Ecsta PS31 225/40 R18

Kumho Ecsta PS31 is a summer tyre made in total of 59 sizes, ranging from R15 to R15 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/40 R18 is 40mm wider than the narrowest dimension (185) and 50mm narrower than the widest one (275). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (225mm), which results in 90mm sidewall height.