The 175 tire may be closer to the original width of our OEM tires...of 180. But....the sidewall ratio of 60 on the 175 tire makes it much shorter of a tire than the OEM tire.
180/60-16 tire has a sidewall height of 108
195/55-16 tire has a sidewall height of 107.5
175/60-16 tire has a sidewall height of 105
That sidewall height has a direct affect on the overall diameter of the tire, which in turn affects the speedometer and odometer.
Remember, a difference of 3mm in sidewall height, multiplied by 2, equals an overall difference of 6mm in change.
With a 195/55-16 tire, the total overall change is only 1mm.
Given the choice, I would prefer to run a slightly wider tire, as long as it fits in there, than a slightly narrower tire.