Continental PremiumContact C is a summer tyre made in total of 9 sizes, ranging from R17 to R17 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 225/50 R18 is 10mm wider than the narrowest dimension (215) and 60mm narrower than the widest one (285). This tyre profile of 50 means the sidewall height of the tyre is 50% of the tyre width (225mm), which results in 112.5mm sidewall height. In 225/50 R18, there is only one possible speed index for Continental PremiumContact C - "V", which is good for speeds up to 240 km/h. In 225/50 R18, PremiumContact C usually competes against Quatrac Pro+, which is a tyre from Vredestein with a rating of 52%, compared to 0% of the Continental in question.