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[stilesg57]

Hi all,

Pre-LCI 328i.

Was planning on 235/45R17 square setup on 17x8.5 ET38 wheels, with 15mm spacers in the rear.

Due to supply chain issues the wheels haven't shipped yet. This is dangerous because it's giving me more time to think this over haha.

My question is: how much unsprung weight is an 18" setup or a wider, staggered setup with more rubber on the road "worth"?

Moving up to an 235/40R18 square setup on 18x8.5 ET38 wheels will add 4.50lbs in net unsprung weight, along with 0.2" additional tread width at each corner. They'll look a little better, ride a little worse, and cost more in upfront tire expense.

Going to a staggered 235/40R18 - 18x8.5 ET38 F | 265/35R18 - 18x9.5 ET35 R will add 9.75lbs in net unsprung weight, along with 0.2" additional tread width in the fronts and 1.3" additional tread in the rears. They'll arguably look even little better, still ride a little worse, and cost a lot more due to upfront tire expense and the inability to rotate them. Dialing out understeer will probably take some alignment tweaking.

So what is 4.5lbs or 9.75lbs in unsprung, rotational mass worth in terms of additional grip and better looks? The E90 is generally heavy and more tire width will probably help it in cornering grip, but given I'll just have a 3SIM & 3.73 gears I don't think I'll benefit much from 265s out back.

Thoughts?