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      11-04-2024, 07:28 AM   #1
Syfres
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Running a smaller sidewall up front vs rear

So I’m new to all this so don’t be too harsh on me, but I was wondering if I could run a 245/35/18 up front with 265/40/18 in the rears?
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      11-04-2024, 08:42 AM   #2
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Quote:
Originally Posted by Syfres View Post
So I’m new to all this so don’t be too harsh on me, but I was wondering if I could run a 245/35/18 up front with 265/40/18 in the rears?

RWD? Sure.

AWD? Nope.

Why would you want to, though?
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      11-04-2024, 08:46 AM   #3
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Originally Posted by hooligan_G01 View Post
RWD? Sure.

AWD? Nope.

Why would you want to, though?
It’s RWD and I figured going with a smaller sidewalk and overall diameter would help with the bit of wheel poke I currently have. I’m 255/40/18 currently in the front and 265/40/18 in the rear
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      11-04-2024, 08:57 AM   #4
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Quote:
Originally Posted by Syfres View Post
It’s RWD and I figured going with a smaller sidewalk and overall diameter would help with the bit of wheel poke I currently have. I’m 255/40/18 currently in the front and 265/40/18 in the rear
Well, smaller sidewalls aren't going to help with poke, but narrower section width - 245 v. your current 255 - might.

What are your wheel specs?
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      11-04-2024, 09:00 AM   #5
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Quote:
Originally Posted by hooligan_G01 View Post
Well, smaller sidewalls aren't going to help with poke, but narrower section width - 245 v. your current 255 - might.

What are your wheel specs?
18x9 and 18x10 they’re 513M wheels
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      11-04-2024, 09:45 AM   #6
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Quote:
Originally Posted by Syfres View Post
18x9 and 18x10 they’re 513M wheels
The narrower section might help some - what is poking, the shoulder of the tire or the outer edge of the rim? Both? Maybe think about running 245/40/18?

Narrower tires obviously don't make the wheels narrower or increase their offset, but 18x9, +29mm isn't SUPER aggressive.

Last edited by hooligan_G01; 11-04-2024 at 09:51 AM..
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      11-04-2024, 09:49 AM   #7
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Quote:
Originally Posted by hooligan_G01 View Post
The narrower section might help some - what is poking, the shoulder of the tire or the outer edge of the rim? Both?

Narrower tires obviously don't make the wheels narrower or increase their offset.
More so the shoulder of the tire which I assume would be the diameter and not so much the sidewall. This is all new to me lol normally I just run a stock set up, so I appreciate your input and advice!
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      11-04-2024, 09:57 AM   #8
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Quote:
Originally Posted by Syfres View Post
More so the shoulder of the tire which I assume would be the diameter and not so much the sidewall. This is all new to me lol normally I just run a stock set up, so I appreciate your input and advice!
Well, no, diameter is the total measure of distance across the "face" of the tire - from the point where it contacts the ground to the point closest to your fender. Aspect ratio (sidewall height) definitely impacts, that.

So does tread width, though, because aspect ratio is expressed as a percentage of tread width. So, a 245/40/18 tire will have a sidewall height of 98mm (40% of 245mm) - while a 255/40/18 tire will have a sidewall height of 102mm.

Make sense?



https://www.tirerack.com/upgrade-gar...on-my-sidewall
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      11-04-2024, 09:59 AM   #9
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Quote:
Originally Posted by hooligan_G01 View Post
Well, no, diameter is the total measure of distance across the "face" of the tire - from the point where it contacts the ground to the point closest to your fender. Aspect ratio (sidewall height) definitely impacts, that.

So does tread width, though, because aspect ratio is expressed as a percentage of tread width. So, a 245/40/18 tire will have a sidewall height of 98mm (40% of 245mm) - while a 255/40/18 tire will have a sidewall height of 102mm.

Make sense?



https://www.tirerack.com/upgrade-garage/how-do-i-read-my-tire-size-on-my-sidewall
That makes total sense! Thank you! I should’ve definitely sought advice before getting the tires but I’m due for rears soon so I’ll go either 265/35 or 265/30
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      11-04-2024, 10:49 AM   #10
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flush/minimal poke tire size combos for 513M should be

245/40/18(25.7"dia)+275/35/18(25.6") if lowered, or
235/45/18(26.3")+265/40/18(26.3") if stock height or mildly lowered

245/40+275/35 in link below
https://f30.bimmerpost.com/forums/sh...php?p=22495320

235/45+265/40 shoulders will poke the least but are somewhat stretched up front and mildly stretched in rear.
.

Last edited by alohasurftoad; 11-04-2024 at 11:04 AM..
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      11-04-2024, 10:52 AM   #11
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Quote:
Originally Posted by alohasurftoad View Post
flush/minimal poke tire size combos for 513M should be

245/40/18(25.7"dia)+275/35/18925.6") if lowered, or
235/45/18(26.3")+265/40/18(26.3") if stock height or mildly lowered

245/40+275/35 in link below
https://f30.bimmerpost.com/forums/showthread.php?p=22495320

235/45+265/40 shoulders will poke the least but are somewhat stretched up front and mildly stretched in rear.
Thank you!! I appreciate that! I really wish I would’ve used the forum instead of jumping the gun and ordering my tires
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