Staggered Rear Wheel Fitment Question

barnsdale · 03-05-2013, 04:28 PM

I just picked up a set of CS7's for my 128i and I have a question about rear tire fitment.

Everyone says for a staggered go 225/40/18 and 255/35/18 however doesn't that mean that the front tires will actually have a bigger diameter around and in turn look larger then the rear wheel? Is 40 bigger diameter vs 35? or is it the other way around?

I'm kind of confused because I actually want the reverse so the rear sits higher for an aggressive stance.

Maybe I'm not understanding this correctly, hoping someone can clarify!

MightyMouseTech · 03-05-2013, 04:39 PM

The 40 or 35 series refers to the percentage of the width. So, 40% of 225 is less than 35% of 255. When in doubt, check the overall diameter as list in the specs, like on the Tirerack website.

fe1rx · 03-05-2013, 05:38 PM

Quote:

Originally Posted by barnsdale

I just picked up a set of CS7's for my 128i and I have a question about rear tire fitment.

Everyone says for a staggered go 225/40/18 and 255/35/18 however doesn't that mean that the front tires will actually have a bigger diameter around and in turn look larger then the rear wheel? Is 40 bigger diameter vs 35? or is it the other way around?

I'm kind of confused because I actually want the reverse so the rear sits higher for an aggressive stance.

Maybe I'm not understanding this correctly, hoping someone can clarify!

"Everyone" is right. 225/40R18 and 255/35R18 have the same revs per mile within a hair. There are subtle differences between brands and models though so MightyMouseTech's advice is good. Check for yourself with the tire you plan to buy.

By the way, if you intentionally mismatch your tire diameters what you will get is a "pose", not a "stance".

ptack · 03-05-2013, 07:08 PM

You will never notice the difference so don't sweat it. Those are the recommended +1 sizes.

barnsdale · 03-06-2013, 09:01 AM

Quote:

Originally Posted by MightyMouseTech

The 40 or 35 series refers to the percentage of the width. So, 40% of 225 is less than 35% of 255. When in doubt, check the overall diameter as list in the specs, like on the Tirerack website.

Awesome - Thanks! This is exactly what I was looking for.

Pyrat 2 · 03-06-2013, 08:09 PM

Need to think about what you are trying to achieve. Same handling with more grip equals the 225/255 option. More grip and less under steer equals 225/245 or 235/245 or 235/255. I'm running 235/245.

03-05-2013, 04:28 PM	#1
barnsdale Lieutenant 65 Rep 475 Posts Drives: 2015 M4 6MT AY Join Date: Feb 2013 Location: Toronto, ON iTrader: (1)	Staggered Rear Wheel Fitment Question I just picked up a set of CS7's for my 128i and I have a question about rear tire fitment. Everyone says for a staggered go 225/40/18 and 255/35/18 however doesn't that mean that the front tires will actually have a bigger diameter around and in turn look larger then the rear wheel? Is 40 bigger diameter vs 35? or is it the other way around? I'm kind of confused because I actually want the reverse so the rear sits higher for an aggressive stance. Maybe I'm not understanding this correctly, hoping someone can clarify! Last edited by barnsdale; 03-05-2013 at 04:29 PM.. Reason: Title Change
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03-05-2013, 04:39 PM	#2
MightyMouseTech Major General 4338 Rep 6,196 Posts Drives: 13 135i 6MT LeMans Blue MSport Join Date: Feb 2013 Location: Ottawa, Canada iTrader: (0)	The 40 or 35 series refers to the percentage of the width. So, 40% of 225 is less than 35% of 255. When in doubt, check the overall diameter as list in the specs, like on the Tirerack website.
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03-05-2013, 07:08 PM	#4
ptack Brigadier General 266 Rep 4,469 Posts Drives: 135i Join Date: May 2008 Location: NJ iTrader: (0) Garage List 2008 135i [6.50]	You will never notice the difference so don't sweat it. Those are the recommended +1 sizes. __________________ 135i, SGM, Coral, Sport Package, Auto, Premium Hifi, USB/ipod, Apex EC-7s, PPK Stage II
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03-06-2013, 08:09 PM	#6
Pyrat 2 Colonel 1418 Rep 2,560 Posts Drives: Rapidly from A to B Join Date: Jun 2005 Location: Chicago 'burbs or TN Smokies iTrader: (3) Garage List 2022 Porsche GT4 [9.64] 2018 Porsche GT3 [9.33] 2007 Z4 M Roadster [8.33] 2020 BMW X1 [0.00]	Need to think about what you are trying to achieve. Same handling with more grip equals the 225/255 option. More grip and less under steer equals 225/245 or 235/245 or 235/255. I'm running 235/245. __________________ '07 Z4MR '22 GT4 '18 GT3 '16 GT4, '16 M2, '14 X1, '13 135is, '06 330i, '03 323 Ci, '01 330i, '99 M3 (RIP), '96 318is, some non-BMWs
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