235/40 R18 - Best tyres 2025 - 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 160/60 R18(2039.52 mm), 245/40 R21(2291.48 mm), 165/70 R14(1842.86 mm), 245/55 R17(2203.2 mm), 175/65 R14(1831.86 mm), 255/35 R18(1997.11 mm), 180/65 R16(2011.88 mm). You can find 235/40 R18 on 34 car models - mainly Mercedes-Benz, Maserati, Volkswagen, Audi, Porsche.