135/80 R13 doesn't belong to the most popular dimensions for winter 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 - 80 is height of the tyre, which is calculated as 80% of the tyre width (135mm), which means the sidewall height has 108 mm. The wheel diameter is R13, which means it fits to a 13 inch/330.2mm diameter wheel. The total circumference of the tyre is mm, which is very similar to 225/70 R15
(2186.55 mm), 315/40 R21
(2467.41 mm), 235/40 R19
(2106.75 mm), 235/55 R17
(2168.64 mm), 235/65 R17
(2316.3 mm), 155/70 R19
(2197.86 mm), 245/35 R20
(2134.71 mm). There are multiple speed indexes available for winter tyres in 135/80 R13: T
(190km/h). The same goes for weight indexes: 70.
