We picked up our 2010 Fit Sport from the first owner a couple months ago. They had put on garbage 205/55r16 tires (on the stock Sport wheels). I have seen people mention that there was no real difference between the 50 and 55 ratio tires other than a cushier ride and the speedo reading a little high.

One more data point, I found that when pushed hard (in this case, rallycross) the 205/55r16 tires rub the fender liners. I was rubbing both sides on hard corners. Once I switched to 205/50r16, no rubbing!

 

I guess it depends on your definition of "real difference." Note that 205 mm width tires are 20 mm wider than the stock size (185/55R16) for your 2010 Fit Sport, so 205/55R16 tires are both taller and wider than what the car came with. Add in suspension compression and turning wheels on hard corners and it's not surprising that you rubbed.

 

Agreed, there is a noticeable difference between a 185 tire and a 205, the post was in reference to others who claimed no noticeable difference between a 205/50r16 and a 205/55r16. Rubbing, to me, is quite a noticeable difference.

 

Yeah that’s a huge tire for a fit. Bad advice gets spread easily when it gets into the hive mind.