255/40 R18 Square Winters E92

Anyone know if 255/40/R18 works on the E92 M3?
I am planning to go square size for this winter.

Please let me know if anyone has any experience with this.
My car is not lowered. Just factory suspension for now.

Depends on the wheels. I've run this setup on OEM 219's without a single issue.

I run 255/40/18 and 235/40/18 on stock wheels for winter. Just one step down from stock. My thought was that thinner cuts through snow better and that the tires should be staggered since the wheels are staggered.

Times Like This wrote

Depends on the wheels. I've run this setup on OEM 219's without a single issue.

The wheels are not aggressive one bit. I'm not sure of the offset but I'm sure they are roughly in the 35s.

gordon@ wrote

Anyone know if 255/40/R18 works on the E92 M3?
I am planning to go square size for this winter.

Please let me know if anyone has any experience with this.
My car is not lowered. Just factory suspension for now.

Yup, I don't see why it would be an issue.
I run 225 front and 245 rear on the oem 18's for winter. Works great!

SYT_Shadow wrote

Yup, I don't see why it would be an issue.
I run 225 front and 245 rear on the oem 18's for winter. Works great!

My biggest concern is 255 being too wide for the front and won't clear the liners.

Not too wide for sure, but perhaps too tall. 275/35 fits without much rubbing.

You can't do 255/35 all around?

SYT_Shadow wrote

Not too wide for sure, but perhaps too tall. 275/35 fits without much rubbing.

You can't do 255/35 all around?

Found a deal on 255/40, it was previously installed on a F80. Should be fine no?

gordon@ wrote

Found a deal on 255/40, it was previously installed on a F80. Should be fine no?

the only possible issue you'll have is the total diameter of the tire

Likely is ok though

SYT_Shadow wrote

the only possible issue you'll have is the total diameter of the tire

Likely is ok though

Thanks, SYT. I have a related question:

I plan to run 18x9.5 23mm front wheels on stock ZCP suspension. Do you believe a 255/40/18 tire will fit without issue? TIA.

buddalun wrote

Thanks, SYT. I have a related question:

I plan to run 18x9.5 23mm front wheels on stock ZCP suspension. Do you believe a 255/40/18 tire will fit without issue? TIA.

Not sure but check here too.

http://www.m3post.com/forums/showthread.php?t=1423450

buddalun wrote

Thanks, SYT. I have a related question:

I plan to run 18x9.5 23mm front wheels on stock ZCP suspension. Do you believe a 255/40/18 tire will fit without issue? TIA.

I believe so, yeah. The ET is not that aggressive (may need some camber) but you'll be fine

Does anyone know what the recommended tire pressure for 255/40/18 Square is?

gordon@ wrote

Does anyone know what the recommended tire pressure for 255/40/18 Square is?

The OE Pressure for the factory 245/40/18 is 33 PSI and the OE Pressure for the 265/40/18 is 35 PSI as seen on the door jamb picture, below. I imagine running 35 PSI would be perfectly fine.

SYT_Shadow wrote

I believe so, yeah. The ET is not that aggressive (may need some camber) but you'll be fine

Thanks SYT.

Since I am on sock suspension and cannot dial in much more negative camber, do you think it would work? Planning on using Michelin PSS in 255/40. TIA!

gordon@ wrote

Does anyone know what the recommended tire pressure for 255/40/18 Square is?

I run a good old 35 on all my street cars, front and rear. May not be ideal but it's close to correct and very easy to remember

buddalun wrote

Thanks SYT.

Since I am on sock suspension and cannot dial in much more negative camber, do you think it would work? Planning on using Michelin PSS in 255/40. TIA!

I compared your 255 to the oem tire size for the E92. You're only 1.2% bigger, so you are *perfectly* fine.

Sorry, for some reason I guess I remembered the 19" wheels which have a lower profile than the 18"

I also checked the ET and you're good there as well. OEM has ET29 and you're a tiny bit more aggressive, but OEM also has space for like a 20mm spacer (effectively ET09) so you have tons of room everywhere

SYT_Shadow wrote

I run a good old 35 on all my street cars, front and rear. May not be ideal but it's close to correct and very easy to remember

That's my rule of thumb also. I do 34psi square.

buddalun wrote

The OE Pressure for the factory 245/40/18 is 33 PSI and the OE Pressure for the 265/40/18 is 35 PSI as seen on the door jamb picture, below. I imagine running 35 PSI would be perfectly fine.

Thanks, my doorjam only showed 19" PSI that's why I didn't know what the 18" pressures were.

SYT_Shadow wrote

I compared your 255 to the oem tire size for the E92. You're only 1.2% bigger, so you are *perfectly* fine.

Sorry, for some reason I guess I remembered the 19" wheels which have a lower profile than the 18"

I also checked the ET and you're good there as well. OEM has ET29 and you're a tiny bit more aggressive, but OEM also has space for like a 20mm spacer (effectively ET09) so you have tons of room everywhere

Thank you!

255/40/18 does not work!! It rubs the liner and maybe the cooler too!
When I turn I hear rubbing noises..

Why did you run 45 series?