305/35 R23 doesn't belong to the most popular dimensions for winter 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 - 35 is height of the tyre, which is calculated as 35% of the tyre width (305mm), which means the sidewall height has 106.75 mm. The wheel diameter is R23, which means it fits to a 23 inch/584.2mm diameter wheel. The total circumference of the tyre is 2506.05 mm, which is very similar to 285/60 R18(2510.76 mm), 265/65 R18(2518.61 mm), 285/65 R17(2520.5 mm), 285/50 R20(2491.28 mm), 265/70 R17(2522.07 mm), 265/75 R16(2525.53 mm), 275/70 R16(2486.26 mm). There are multiple speed indexes available for winter tyres in 305/35 R23: V(240km/h). The same goes for weight indexes: 111.