Originally Posted by nospam
Along with straight line traction comes increased stability and friction when braking.
I believe BMW makes staggered setups standard on all vehicles with increased top-speed limiter. Square setups get limited top speed. IMO, only true M-cars are ready for the track without modification. 3-series and X1s should not be tracked. I'm pretty sure everyone here is buying the X1 for the street only.
I'm not arguing that. I've also owned a number of M and non M cars with staggered tires and find it to be purely cosmetic. I'd greatly prefer a 235 or 245 square setup to the staggered setup offered. I also think just about every BMW sold in the US (not the smaller engines for the ROW) has been speed limited for a good while, but I know what you're getting at, the difference in a 130 and a 155 mph governor.
Again, you could put 335's on back and you wouldn't noticeably alter stopping distanced, I'd predict that the added weight would help more than the actual additional traction, which as stated, is extremely low in a stopping situation when the vast majority of the dynamic weight is transferred to the front brakes. One common fallacy to BMW's silly marketing of the benefits of a 50/50 weight balance is that cars with a rearward biased balance get better traction and braking than cars that are so called "balanced".