255/70 R18 - Best summer tyres 2025 - market overview, tests, reviews

255/70 R18 doesn't belong to the most popular dimensions for summer tyres - there are 7 tyre models available, which can be compared to 155/60 R15, 160/60 R18, 165/60 R14. Let's break down the sizing - 70 is height of the tyre, which is calculated as 70% of the tyre width (255mm), which means the sidewall height has 178.5 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 2557.88 mm, which is very similar to 275/65 R18(2559.46 mm), 235/85 R16(2531.81 mm), 265/75 R16(2525.53 mm), 265/70 R17(2522.07 mm), 285/65 R17(2520.5 mm), 265/65 R18(2518.61 mm), 285/60 R18(2510.76 mm). There are multiple speed indexes available for summer tyres in 255/70 R18: H(210km/h), Q(160km/h), S(180km/h), T(190km/h), V(240km/h). The same goes for weight indexes: 113, 116, 117.