I feel my current car's tendency to plow even at relatively low speeds if I have a little fun on a freeway onramp or a tight turn on a twisty road -- no track work involved. Much of it is probably attributable to the overall weight of my current car and the somewhat sloppy suspension which allows too much body movement during quick maneuvers, but others have suggested a square setup will be more neutral overall which has always been my preference.
When I had a MazdaSpeed 6 a while back, the grip was sometimes limited given the width of the tire (215s stock) vs. the weight of the car, but the breakaway was almost completely neutral under all circumstances, and that also describes the feeling in my E30 M3 back in the day. That's more what I'm after.
Given the relatively light power of the N52 down low, I figure 225s are enough rear tire. Stock, a 128i comes with 205 rear and BMW only moves to 225 rears when M-Sport is added, so that's telling -- the ZED package changes the tires to 215 front/245 rear like an M-Sport 135i. Maybe not the best setup for a 128i.
My original plan was to go with 18 x 8 Aero 7s and 225/40-18 all around, and I still may go that route, but now I'm aiming for the ZED package and I like the rims that come with it. They're just wider than expected, hence my original question.