Continental SportContact 7 is a summer tyre made in total of 66 sizes, ranging from R18 to R18 - this particular dimension is R21, which means it fits to a 21 inch/533.4mm diameter wheel. 265/40 R21 is 40mm wider than the narrowest dimension (225) and 70mm narrower than the widest one (335). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (265mm), which results in 106mm sidewall height. In 265/40 R21, there is only one possible speed index for Continental SportContact 7 - "Y", which is good for speeds up to 300 km/h. In 265/40 R21, SportContact 7 usually competes against Ultrac Vorti, which is a tyre from Vredestein with a rating of 87%, compared to 100% of the Continental in question.