Vredestein Ultrac Satin is a summer tyre made in total of 69 sizes, ranging from R16 to R16 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 255/55 R18 is 50mm wider than the narrowest dimension (205) and -20mm narrower than the widest one (235). This tyre profile of 55 means the sidewall height of the tyre is 55% of the tyre width (255mm), which results in 140.25mm sidewall height. In 255/55 R18, there is only one possible speed index for Vredestein Ultrac Satin - "Y", which is good for speeds up to 300 km/h. Latest test in 255/55 R18 was held by Autobild in 2020, where Ultrac Satin received rating "Exemplary" and finished on the 3. place. It was tested on a BMW X5.