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**BigRussia** · 03-22-2026, 10:49 AM

Thoughts on running a 18x10.5 et30 wheel?

I’ve been considering going down to a 10” width wheel but higher offset (et33) from my current 18x10.5 et22 square track setup to bring down the positive scrub radius a bit and hopefully alleviate some of the braking instability issue I pointed out in my above posts; but a square set of 18x10.5 et30 wheels popped up for sale locally about an hour away. Im tempted to see if they fit and if the 8mm offset gain will see any felt benefits.

From my pics above with the VS-5RS I got about 9-10mm of inner clearance to the front strut, so cutting it really close but thinking should clear just barely with no spacer needed. I’m planning to make the drive with the M3 to go test fit them first, but wanted to get thoughts if worth the trouble before driving 1hr in Miami traffic with tools and jack in my still street-able but not comfortable and very tramline-y track setup car?

**Bry5on** · 03-22-2026, 11:21 AM

Originally posted by BigRussia View Post

Thoughts on running a 18x10.5 et30 wheel?

I’ve been considering going down to a 10” width wheel but higher offset (et33) from my current 18x10.5 et22 square track setup to bring down the positive scrub radius a bit and hopefully alleviate some of the braking instability issue I pointed out in my above posts; but a square set of 18x10.5 et30 wheels popped up for sale locally about an hour away. Im tempted to see if they fit and if the 8mm offset gain will see any felt benefits.

From my pics above with the VS-5RS I got about 9-10mm of inner clearance to the front strut, so cutting it really close but thinking should clear just barely with no spacer needed. I’m planning to make the drive with the M3 to go test fit them first, but wanted to get thoughts if worth the trouble before driving 1hr in Miami traffic with tools and jack in my still street-able but not comfortable and very tramline-y track setup car?

That’ll be super close and may ultimately depend on tire fitment. My 17x9 at et47 with 245 tire clears dynamically, so an 18x10.5 et30 with a 275 tire should be 1-2mm closer to the strut tube. With aero the strut tube would likely bend enough to contact the tire with that setup, but on a street car you might be okay.

**BigRussia** · 03-22-2026, 05:03 PM

Originally posted by Bry5on View Post

That’ll be super close and may ultimately depend on tire fitment. My 17x9 at et47 with 245 tire clears dynamically, so an 18x10.5 et30 with a 275 tire should be 1-2mm closer to the strut tube. With aero the strut tube would likely bend enough to contact the tire with that setup, but on a street car you might be okay.

Whoops, should’ve mentioned I’m planning on sticking with my current 265/35 square setup

(Non aero car as well)
Besides the main fitment reason, I dont notice much difference in grip gained from the 10mm slightly wider width, but like the idea of better feedback/sidewall support of the slightly stretched 265 width tire.

I also like the smaller diameter of the 265/35 vs 275/35 for a little better gearing and not needing to go down to 2nd in the slower hairpins. But on the other hand, I realize yeah this wheel spec would limit me to only 265, as the 275 sidewall will likely rub against the spring perch under load and heavy cornering.