255/35 R20 doesn't belong to the most popular dimensions for tyres - there are tyre models available, which can be compared to 325/30 R21, 155/60 R15, 155/65 R13. Let's break down the sizing - 35 is height of the tyre, which is calculated as 35% of the tyre width (255mm), which means the sidewall height has 89.25 mm. The wheel diameter is R20, which means it fits to a 20 inch/508mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 195/50 R16(1889.35 mm), 265/35 R18(2019.1 mm), 195/65 R15(1993.34 mm), 265/40 R21(2341.74 mm), 200/60 R17(2110.52 mm), 265/65 R17(2438.82 mm), 205/55 R15(1905.38 mm). You can find 255/35 R20 on 17 car models - mainly Jaguar, ALPINA, Aston Martin, Audi, Ferrari.