I'm looking to replace at least two of my tires (front) since they are right at the wear bars. I still have the OEM Goodyear run-flats at 195/55-R16, but I want to be able to compare several different replacement options, one of which is the Yokohama S.Drive which doesn't come in that size. What I need to know is; am I OK to switch to a 205/50-R16 from a performance/MPG/Speedo-Odo Accuracy standpoint?

 

Absolutely. 205/50-R16s will fit with no issues. They are very close to being the same diameter 195/55s, so there is minimal impact on the spedometer.

I'm running this size as my summer tires on my '07, and I've compared the spedometer impact with my Garmin GPS, and the offset is not noticeable when compared to the stock size.

 

I switched from Continental 195/55's to BF Goodrich gForce A/S 205/50-16 several months back. Quite happy with the tires. The MINI speedometer reads about 3 percent faster than my Garmin GPS.