195/45 R16 doesn't belong to the most popular dimensions for 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 - 45 is height of the tyre, which is calculated as 45% of the tyre width (195mm), which means the sidewall height has 87.75 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 mm, which is very similar to 275/30 R20(2114.29 mm), 205/70 R15(2098.58 mm), 275/40 R20(2287.08 mm), 215/45 R17(1964.44 mm), 275/55 R17(2306.87 mm), 215/60 R17(2167.07 mm), 285/30 R21(2212.94 mm). You can find 195/45 R16 on 20 car models - mainly Ford, Fiat, Kia, MG, Opel.