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Another "fit" question (already wasted 2 hours of my life)...

PLEASE help me. I am purchasing a 2019 2.5 premium and I want to run 18/8.5 x 45mm rims. I believe the OEM are 7" wide? If so, will they fit? The various calculators are too much for me, I've tried. Sorry.
 

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So you are saying the wheel will stick out 1.5" from the fender? Shoot; exactly what I don't want. Is that due to the offset? I thought the oem offset is 55mm? If these are 45mm would that only be 10mm total? Thus 5mm on each side? I really have no idea so likely am wrong, but that is my understanding as of now.
 

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If you aren't lowering the car, it should be okay, the wheel will stick out an extra 1.5" I believe. You'll clear the strut.

The real question is brand and caliper clearance.

My car is lowered and my 18x8.5 wheels fit fine.
 

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So you are saying the wheel will stick out 1.5" from the fender? Shoot; exactly what I don't want. Is that due to the offset? I thought the oem offset is 55mm? If these are 45mm would that only be 10mm total? Thus 5mm on each side? I really have no idea so likely am wrong, but that is my understanding as of now.
That guy is 100% WRONG!
It will not stick out 1.5” there are rim / tire size calculators online. However, I’m running 17x8” with 40mm offset and plenty of room before fender lip.
 

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This is going to be fun. Ya'll have me doing math early in the morning.
I did not say it will be out from the fender. I said the wheel will stick out an extra 1.5".
18x7+55 is the factory wheel size.
I guestimated the wheel setting when I posted, so since you guys want exactitude here you go.

I did the math this way: You have 7" of width and the offset of 55 mm on the OEM wheel. The new wheel is 8.5" and an offset of 45 mm. The offset is measured from the hub mounting surface to the center line of the rim. A 7.5" wheel has a center at 3.75" and an 8.5" wide wheel has a center at 4.25". That's an extra .5" from center for the 8.5" when measured from center to outside edge. 1/2" is about 13mm. Then you take the offset and in mm the 55 is about 2", a little more really at 2.165. So a 7" wide rim has 4.835" of it's width on the interior of the hub mounting surface, the remainder on the outside, 2.164". Or, the 7" rim is 178 mm wide with the center at 89 mm. Plus 55 means that the hub mounting surface is 55 mm off center toward the outer edge which means 144 mm will be inside, and 34 mm to the outside. The 8.5" wheel with +45 mm offset, or 1.77", (216 mm wide and center at 108 mm) makes the offset 10 mm shorter putting the wheel at 6" interior and 2.5" exterior (about 153 mm in and 63 out). The difference is approximately 1.14", or 29 mm, of extra wheel on the outside of the hub surface since an 8.5" wheel may not be exactly 8.5" (it could be 8.4 or 8.7 - wheels are measured rounding it to the nearest 1/2"). In other words the wheel will stick out an extra 1.14" from the original wheel.

So my guestimate was about .4" off.

What you will have to do is make sure the offset in conjunction with the wheel design does not interfere with the caliper. If the spokes of the wheel are designed in a way that arches them inward, they are designed close to the hub mounting surface, or they are manufactured with thick spokes, you could have caliper clearance issues when the wheel is mounted. Most wheel designs will clear it, but some people have run in to issues after the purchase because they didn't do the math. You'd need the exact specs on the wheel design and then compare it to the car.

My Motegi FF7 18x7.5+45 on the VDC clear the calipers by about 1", the strut's spring seat base by about 10 mm with the tires I have on the car (255/45-18). I'm at a 3" drop and I get scrub on turns and severe bumps. Maybe it's time for stiffer strut setup or smaller tire size. Or I just slow it down a little. :grin2:
 

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255-55-18 stock rim. Next up and aftermarket wheel with a little more offset just because I want them flush with the fender. No rub now anywhere but sure couldn't have gone taller without making contact with strut.


Sent from my Pixel 2 XL using Tapatalk
 

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255-55-18 stock rim. Next up and aftermarket wheel with a little more offset just because I want them flush with the fender. No rub now anywhere but sure couldn't have gone taller without making contact with strut.


Sent from my Pixel 2 XL using Tapatalk
Wow what a clean garage you have, I'm jealous..:smile2:
 

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255-55-18 stock rim. Next up and aftermarket wheel with a little more offset just because I want them flush with the fender. No rub now anywhere but sure couldn't have gone taller without making contact with strut.


Sent from my Pixel 2 XL using Tapatalk



Do you have any additional images from the side? Looking to do the same one mine but debating b/t 235/60/18 and 255/55/18
 
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