GoodYear Vector 4Seasons Gen-3 is a allround tyre made in total of 75 sizes, ranging from R14 to R14 - this particular dimension is R18, which means it fits to a 18 inch/457.2mm diameter wheel. 245/40 R18 is 70mm wider than the narrowest dimension (175) and 10mm narrower than the widest one (255). This tyre profile of 40 means the sidewall height of the tyre is 40% of the tyre width (245mm), which results in 98mm sidewall height. In 245/40 R18, there is only one possible speed index for GoodYear Vector 4Seasons Gen-3 - "W", which is good for speeds up to 270 km/h. In 245/40 R18, Vector 4Seasons Gen-3 usually competes against AllSeasonContact, which is a tyre from Continental with a rating of 81%, compared to 91% of the GoodYear in question.