i HAVE 225/45-17's on a 17x7" wheel. they fit just fine. as a matter of fact, they fit more like a factory fit than a 215. ever notice how those really ricey guys put something like a 205/40-17 on a 17x8 and the sidewalls are angled in so much you can almost use them as tread surface? i HATE that! lol. my sidewalls have a nice rounded shape to them similar to the way my stock wheels and tires looked.

don't get me wrong, 215's will also fit fine. we're only talking about a centimeter difference in section width so it's not a big deal either way. your choice.