185/75 R16 doesn't belong to the most popular dimensions for winter tyres - there are 19 tyre models available, which can be compared to 255/35 R20, 175/80 R14, 235/45 R19. Let's break down the sizing - 75 is height of the tyre, which is calculated as 75% of the tyre width (185mm), which means the sidewall height has 138.75 mm. The wheel diameter is R16, which means it fits to a 16 inch/406.4mm diameter wheel. The total circumference of the tyre is 2148.54 mm, which is very similar to 295/30 R20(2151.99 mm), 225/45 R19(2152.31 mm), 225/50 R18(2143.19 mm), 285/35 R19(2142.88 mm), 215/70 R15(2142.57 mm), 215/65 R16(2154.82 mm), 255/35 R20(2156.7 mm). There are multiple speed indexes available for winter tyres in 185/75 R16: R(170km/h), S(180km/h). The same goes for weight indexes: 104.