Dude, an auto NA zetec isn't gonna be fast no matter what. It doesn't matter if you put a 175 or a 245 tire on there. So you might as well do what you can with the part of the car's performance that is alright. 225 works great (and anyways 10mm isn't that much, so not even that different from a 215).
Basically, what I'm trying to say is. It doesn't matter. But 225 equals a tiny little bit more traction and IMO a little better look. Noone is gonna autox an auto zetec competively, so who cares about gearing. Though best thing to do with a contour is nothing. No 17"s, no wide tires, no nothing.
