305/40 R20 - Best allround tyres 2025 - market overview, tests, reviews

305/40 R20 doesn't belong to the most popular dimensions for allround tyres - there are 0 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. Let's break down the sizing - 40 is height of the tyre, which is calculated as 40% of the tyre width (305mm), which means the sidewall height has 122 mm. The wheel diameter is R20, which means it fits to a 20 inch/508mm diameter wheel. The total circumference of the tyre is 2362.48 mm, which is very similar to 265/70 R15(2362.48 mm), 245/60 R18(2359.96 mm), 245/50 R20(2365.62 mm), 275/40 R21(2366.88 mm), 245/65 R17(2357.14 mm), 245/70 R16(2354.31 mm), 275/45 R20(2373.47 mm). There are multiple speed indexes available for allround tyres in 305/40 R20: V(240km/h). The same goes for weight indexes: 112.