275/40 R18 - Best tyres 2025 - market overview, tests, reviews

275/40 R18 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 - 40 is height of the tyre, which is calculated as 40% of the tyre width (275mm), which means the sidewall height has 110 mm. The wheel diameter is R18, which means it fits to a 18 inch/457.2mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 275/55 R17(2306.87 mm), 215/60 R16(2087.27 mm), 285/30 R21(2212.94 mm), 215/75 R16(2289.91 mm), 285/40 R22(2471.81 mm), 225/45 R17(1992.71 mm), 295/30 R18(1992.4 mm).