[Cap'n]

Hey all--

Longtime M3Forum member recently upgraded to E90, who seem to hang out here (weird, but I'm in). Couple questions...

I'm considering 20" BBS CH-R in black, but TireRack's automated system is suggesting they'll rub. I've seen quite a few here with 20's and thought I would get some empirical feedback. Any reason 245/30 up front and 305/25 in back wouldn't work? (24mm offsets front and back).

I actually only considered 305 as that's what Tirerack online suggested out of the box for a 20x10.5 Rear. So could I just go with the same rim but 295 instead?

Does the answer change if I wanted to lower with either Eibach or H&R sport springs?

I also seem to hear a lot of what I think is flywheel chatter when idling the car out of gear. If I push in the clutch, the noise largely goes away. Is this normal? The E46 had noisy chatter on shutdown when the clutch was out. Wasn't sure if this simply happened all the time in clutch out idle on these cars.

Thanks!!