Max Tire size on stock e90 Sport rims

azeemtn · 03-29-2012, 05:11 PM

Hi Guys,

I'm running my stock setup with
225/40/18 Up Front
255/35/18 In Back.

I am thinking of upgrading all around to Michelin Super Sport's.

I'd like to increase the tire width in the rear if possible, but keep the same overall ratios.

I was thinking of doing

235/40/18 Up Front
265/35/18 In Back.

I have no idea if this is safe or possible. Can someone shed some light on if going up a little on the width is possible?

I am also open to just expanding width in the rear, and leaving the front as is if that helps with front/rear ratios.

I am imagining the wheel speed sensors need to be within a certain spec, but I dont' know what that is..

Thanks!

Timmayy · 03-29-2012, 08:21 PM

If you plug those numbers into the calculator at the top of the page you can answer your questions.

Running tires wider than intended is generally not a desirable condition because you load the sidewalls differently than designed, but in this case it's not too severe due to the aspect ratio.

That said, the aspect ratio might make it very difficult, or impossible, to seat the beads. Someone with more practical experience will have to answer that.

If you don't get an answer here I would just call Tire Rack. All of their support staff are very knowledgeable. You might even be able to get in touch with Gary.

danno_e90 · 03-29-2012, 08:34 PM

i tried goin one size wider on tires with the same wheels on my older wheels and had no issues. It kind of felt a better traction in snow. I assume you can go a one size wider on any wheel but anything bigger might get risky.

Gimmethecash · 03-29-2012, 08:41 PM

If you get the stock size PSS, it's already like going up a size - I did, and even 225/255 PSS looked pudgy on my stock wheels. I kept the tires and installed them on some 8.5f/9.5r wheels - fit perfectly.

I think 235/265 PSS on 8/8.5 wheels is going to look weird, not to mention 225/255 is the recommended max tire width for the stock wheel size.

azeemtn · 03-29-2012, 11:32 PM

thanks Gimmethe cash.

Danno e90, Aren't you supposed to go skinnier in snow for better traction?

03-29-2012, 05:11 PM	#1
azeemtn Second Lieutenant 33 Rep 231 Posts Drives: '14 m5, Space Gray Join Date: Sep 2007 Location: San Jose iTrader: (0) Garage List 2015 m5 [0.00]	Max Tire size on stock e90 Sport rims Hi Guys, I'm running my stock setup with 225/40/18 Up Front 255/35/18 In Back. I am thinking of upgrading all around to Michelin Super Sport's. I'd like to increase the tire width in the rear if possible, but keep the same overall ratios. I was thinking of doing 235/40/18 Up Front 265/35/18 In Back. I have no idea if this is safe or possible. Can someone shed some light on if going up a little on the width is possible? I am also open to just expanding width in the rear, and leaving the front as is if that helps with front/rear ratios. I am imagining the wheel speed sensors need to be within a certain spec, but I dont' know what that is.. Thanks! __________________ ------------ Everything is just for fun, and may or may not constitue real characters in actual life... ------------ Last edited by azeemtn; 03-29-2012 at 05:12 PM.. Reason: type
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03-29-2012, 08:21 PM	#2
Timmayy Private 0 Rep 50 Posts Drives: 09 E92 335i Blk/Blk xDrive 6MT Join Date: Mar 2012 Location: Seattle iTrader: (0)	If you plug those numbers into the calculator at the top of the page you can answer your questions. Running tires wider than intended is generally not a desirable condition because you load the sidewalls differently than designed, but in this case it's not too severe due to the aspect ratio. That said, the aspect ratio might make it very difficult, or impossible, to seat the beads. Someone with more practical experience will have to answer that. If you don't get an answer here I would just call Tire Rack. All of their support staff are very knowledgeable. You might even be able to get in touch with Gary.
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03-29-2012, 08:34 PM	#3
danno_e90 Private 4 Rep 80 Posts Drives: R53 Join Date: Feb 2012 Location: Troy, Michigan iTrader: (1)	i tried goin one size wider on tires with the same wheels on my older wheels and had no issues. It kind of felt a better traction in snow. I assume you can go a one size wider on any wheel but anything bigger might get risky.
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03-29-2012, 08:41 PM	#4
Gimmethecash Lieutenant 152 Rep 485 Posts Drives: F90 M5 Comp Join Date: Mar 2011 Location: Pasadena iTrader: (1)	If you get the stock size PSS, it's already like going up a size - I did, and even 225/255 PSS looked pudgy on my stock wheels. I kept the tires and installed them on some 8.5f/9.5r wheels - fit perfectly. I think 235/265 PSS on 8/8.5 wheels is going to look weird, not to mention 225/255 is the recommended max tire width for the stock wheel size.
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03-29-2012, 11:32 PM	#5
azeemtn Second Lieutenant 33 Rep 231 Posts Drives: '14 m5, Space Gray Join Date: Sep 2007 Location: San Jose iTrader: (0) Garage List 2015 m5 [0.00]	thanks Gimmethe cash. Danno e90, Aren't you supposed to go skinnier in snow for better traction? __________________ ------------ Everything is just for fun, and may or may not constitue real characters in actual life... ------------
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