235/40 R18 - Best tyres 2026 - market overview, tests, reviews

235/40 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 (235mm), which means the sidewall height has 94 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 205/60 R15(1969.78 mm), 275/35 R21(2280.48 mm), 215/40 R16(1817.1 mm), 275/45 R20(2373.47 mm), 215/55 R16(2019.73 mm), 285/25 R20(2043.61 mm), 215/70 R15(2142.57 mm). You can find 235/40 R18 on 34 car models - mainly Mercedes-Benz, Maserati, Volkswagen, Audi, Porsche.