205/45 R18 doesn't belong to the most popular dimensions for summer tyres - there are 2 tyre models available, which can be compared to
155/60 R15,
170/60 R17,
160/60 R14. Let's break down the sizing - 45 is height of the tyre, which is calculated as 45% of the tyre width (205mm), which means the sidewall height has 92.25 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 2015.96 mm, which is very similar to 265/30 R19
(2015.65 mm), 190/55 R17
(2013.13 mm), 265/35 R18
(2019.1 mm), 215/55 R16
(2019.73 mm), 195/60 R16
(2011.88 mm), 180/65 R16
(2011.88 mm), 225/35 R19
(2010.93 mm). There are multiple speed indexes available for summer tyres in 205/45 R18: H
(210km/h), V
(240km/h), Y
(300km/h). The same goes for weight indexes: 86, 90.
