Originally Posted by 370z1

I have the stock sport pkg wheels and am running HandKook VENTUS V12 tires on all 4. The front tires are 255/35/19 and the rear tires are 305/30/19 and fit with no issues at all. You could probably go a little wider but taking into consideration side wall height ratio between front and back, and the tire staring to stretch i think a 265/305 combo would be the widest. The staggered setup widths is subjective to your preference but as long as you keep the side wall profile close to the same height it should look proportional. If you put something like a 275 in the front it may start to rub in turns, but have a search around the forum, you will see what others are running.