Is it 205 50 16", I'm not sure? I'm pretty sure that it's not a 40 series or greater than 205. I always had 15's on my GTS, other than the other wheel. The 15" was I think a 195 55 15". So the 16" should be 205 50? Whatever you do, don't go bigger like that. Go with the stock readings. If you have aftermarket wider wheels, then by all means get a wider tire. You want shorter/wider (too a point), not taller. Get the 50.