245/70 R17 doesn't belong to the most popular dimensions for winter tyres - there are 6 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. Let's break down the sizing - 70 is height of the tyre, which is calculated as 70% of the tyre width (245mm), which means the sidewall height has 171.5 mm. The wheel diameter is R17, which means it fits to a 17 inch/431.8mm diameter wheel. The total circumference of the tyre is 2434.11 mm, which is very similar to 265/60 R18(2435.36 mm), 265/55 R19(2431.91 mm), 245/75 R16(2431.28 mm), 295/45 R20(2430.02 mm), 265/65 R17(2438.82 mm), 265/50 R20(2428.45 mm), 265/70 R16(2442.27 mm). There are multiple speed indexes available for winter tyres in 245/70 R17: L(km/h), Q(160km/h), R(170km/h), S(180km/h), T(190km/h). The same goes for weight indexes: 110, 119, 143.