healthservices

Offsets in the wheels may not allow you to put the rears on the front. The rear wheel may and will most likely hit the spring perch if mounted in front.,

healthservices

Reasons for having smaller tire in front.I personally like large tires in the front and when possible put as large of a tire up there as I can. Reason for larger tire in the rear more traction exiting the corners.

tiato

New member here, having taken delivery of a 2008 CPO 535xi last Wed. Not a stranger to BMW's though. Have owned Z3s, M3s, Z3 M Coupe over the last 12 years. Besides the e60, my other current BMW is a '96 M3 build to BMW Club Race "i" prepared rules. Been racing in BMW Club Racing for the last 4 years and also instruct at BMW HPDE events.

I think I can add to this conversation:

Staggered wheels are primarily specified in higher HP BMW's to further induce undertseer. By design, all manufacturers design in understeer into the chassis. Larger rear wheels only serve to further the understeer. In BMW's eyes, and their attorneys, understeer is safe and manageable. 99% of all drivers do not know how to handle onversteer.

Cool looks is simply a bonus.

Sure, in some applications, larger rear tires aid in rear wheel traction, only after the chassis and suspension was dialed in to induce oversteer.

My '96 M3 originally came with a staggered set up and in most street use worked fine, when the car wasn't pushed. Past a certain point rear traction would overwhelm the rear and cause the car to push.

For track purposes, I went to a non staggered set up to control understeer and make the car feel more neutral. As I developed the car, it received Single adjustable coilovers and got corner balanced thus dialing out more oversteer. Then added a track specific alignment to gain more neutral handling. As the car became a race car, I went to a double adjustable suspension, added aero and a wider non staggered wheel set up. With my race alignment, the cars balance is 50/50. Handling is adjusted by shock adjustments, sway bar settings and aero adjustments. Now with 17x9 wheels shod with 245/40 hoosiers the car is extremely balanced with just a hint of oversteer.

Granted the e60 is not a race car but in stock form, even with a non sports suspension and non staggered wheels the car feels pretty balanced with understeer apparent in high speed turns. There is obvious body roll, mostly in the back and the rear rotates slowly but predictably. Transition from right to left turns is fair. Would my car with a staggered set up handle this well? IMO, not as good and the push would be at an even lower level than it is now. With a staggered set up, the rear would also rotate more slowly as there is more rubber on the road. For a staggered car to rotate as freely as a non staggered car, one would have to install a heavier rear sway bar to decrease traction or if one has coils, a heavier rear spring.

In the end, with chassis performance in mind, balance/neutrality should be priority. To do that mods to minimize undesireable chassis tendencies should be installed. Square wheel set up is a cheap start. Then sway bars, also cheap. Then shocks and springs.

However there is absolutely nothing wrong with having fun making your car looks better either, but when doing so, make sure one understands how the chassis balance is altered toward understeer or oversteer. Always make one change at a time to feel what it does. Keep notes to record what you feel.

Every car owner has different goals. Plan appropriately for yours. Looks. Handling. Combination of both.

Heres a pic of my highly compromised 'e36:

CVTBenhogan

I agree with this and have heard this. BTW. I have a few extra thrill in the winter with a non-staggered setup (18 245 40s all round). Lots of oversteer and no doubt less traction with the winter tire.