For me running all stock, you are limited to 255's Square. This car needs more traction in the rear than that. I will keep my 255's for the front and get a pair of FL-5's in 10.5" for the rear to put 275's, or 285's, which will give me the ability to go between square and staggered. If you have camber plates or modified suspension then you have the ability to run wider tires for a square set-up. My Square set-up was still a big improvement over my stock wheels (Contis). It's just that coming out of corners and putting down power , the rear loses traction too easily so you have to feather the gas or start to slide with 255's. Enjoy your upcoming track day, it;s all good.
