A good quality summer 285 tire on a nice 10” wheel is plenty of tire for almost all purposes. I’ve never really telt they look thin. Sure 305 look meatier from the back but the grip linear doesn’t really improve much at all going from a 285 to a 305 IMHO. Thats my 2c from road and track use with square 285s on 10s and square 305s on 11s. Conventional wisdom that wider is better isn’t as dramatic in practice. 285 is still wider than most GT Mustangs get from the factory.