Hey all, I thought I would comment on my setup as alot of you seem to be asking.
There is alot more to setting up a car then just w/a. Tire width, Track, Wheel Width, Offset, Hight.
In saying that, my car is running 265/35/18 Semis on 18*9.5" +35 wheels. This setup gives me a significantly larger contact patch then most, but also more track, which helps with stability and basically more grip to some extent.
I am running such an agressive (grippy) rear setup for a number of reasons;
-MY car makes are rediculious about of midrange torque, so it likes to step out on corner exit, so to keep some of that in check, I need to run more camber to try and get more grip.
-The front of my car has 15mm spacers which reduces the cars tendency to understeer and the track is sooo much wider. It also helps with turn in. Thus, actually giving me ALOT more front grip then it looks.
Apon initial turn in, I use a bit of trail braking to keep the car pitched on the front end, the car then settles mid corner, and I can plant my foot and not have my car being spastic drift spec commig out of a corner.
At the end of the day, it really comes down to power, driver preferance and aerodynamics (which Im not running any).