185/70 R15 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 - 70 is height of the tyre, which is calculated as 70% of the tyre width (185mm), which means the sidewall height has 129.5 mm. The wheel diameter is R15, which means it fits to a 15 inch/381mm diameter wheel. The total circumference of the tyre is 2010.62 mm, which is very similar to 225/35 R19(2010.93 mm), 180/65 R16(2011.88 mm), 195/60 R16(2011.88 mm), 190/55 R17(2013.13 mm), 265/30 R19(2015.65 mm), 265/35 R18(2019.1 mm), 225/40 R18(2001.82 mm).