Hi guys, just one question.
I have a Mazda Protege5 (2002) with tire size 195/50R16. Could I switch them for 205/55R16? Would be it a problem?
Thank’s a lot,
M
You’d be much better to go to 205/45R16. The increased section width will increase the diameter, dropping the aspect ration down a notch will largely offset the increase from 195 to 205.
I’ve added a link to a good primer on tires. You may find it interesting. I’ve also attached a link to the Tire Rack site. See the “upgrade garage” section. Between the two, you can find out of your stock rime width will accommodate a 10mm increase in section width.
You might also check to see how much clearance exists between the inner edge of the tire and the strut spring or spring pad.
Some years ago I dropped a car off for some tires (stock was 195-60-15). As I pulled away from the store I heard scraping and stopped.
Apparently they were out of stock on the 195s and installed a set of 205-60-15s. That extra 10 MM was causing both front tires to get chewed up on the inside by the spring pad.
So, stuck for more hours while they rounded up more tires and redid their mistake… 
Given that Tire Rack shows 16 different tires available in the original size, I think that’s enough options to reconsider changing size.