Continental UltraContact NXT is a summer tyre made in total of 22 sizes, ranging from R16 to R16 - this particular dimension is R19, which means it fits to a 19 inch/482.6mm diameter wheel. 255/45 R19 is 50mm wider than the narrowest dimension (205) and 0mm narrower than the widest one (255). This tyre profile of 45 means the sidewall height of the tyre is 45% of the tyre width (255mm), which results in 114.75mm sidewall height. In 255/45 R19, there is only one possible speed index for Continental UltraContact NXT - "Y", which is good for speeds up to 300 km/h. In 255/45 R19, UltraContact NXT usually competes against Quatrac Pro+, which is a tyre from Vredestein with a rating of 52%, compared to 0% of the Continental in question.