[Nguyen2fold]

Will these tires be ok on xdrive. I know stock height is 26 these will be 26.8 will that mess with rolling diameter too much??? It will be square set up

[.BMW.]

No issues with square setups and xDrive!

[unixpro]

The issue is more the change in overall diameter. Check on tyresize.com with stock measurements vs your plan. The overall change in diameter needs to be within 1% I believe. Also bare in mind 20" tyres cost a fair bit more.

I have an F32 xdrive on 20" 624m's that I am looking to change for smaller wheels so have the same question in the opposite direction. If it helps my current staggered setup is F:225/35/R20 R:255/30/R20

[alohasurftoad]

tire diameter deviations greater or less than oem diameter of 26" do not matter. the difference between the front and rear diameters of staggered setups matter and should not exceed 1.2%, 1% to be conservative.

although your butt dyno may not sensitive enough to feel it, 245/35/20 will worsen your acceleration and braking because it's taller(pavement gearing) and heavier. although, it fills the hideous x-drive gap nicely, it's also raising the total height of the vehicle 0.4". if the wheel offset is too low, there is a possibility of front tires outer shoulder rubbing fenderwell liner while turning.

personally, i don't care to deviate more than 0.5" diameter greater than oem, 26.8" is approaching F34 oem diameter of 27".

here is a thread with square 245/35/20...https://f30.bimmerpost.com/forums/sh...d.php?t=849595

[rjd_F30]

Car will be fine the rolling diameter thing only applies to having different rolling diameters front and back. The only downside will be what the above post specifies and your speedo will be inaccurate.

[.BMW.]

The speedo will be spot on, since it reads high with OEM tire sizes.

[rjd_F30]

Originally Posted by .BMW.

The speedo will be spot on, since it reads high with OEM tire sizes.

I don't that the math would work out that the speedo is now spot on but fair point. Should say that the speedo won't read the same as it does with the OE whelels/tires.

[.BMW.]

My winter tires are 26.8", exactly the same diameter as 245/35-20, 3% tallar than OEM 26".

The speedo reads perfect now, checked with GPS.

[jseeleybmw]

Here in the US my local dealer invalidated my factory warranty for having a staggered setup and my front vs rear diameter was only a 0.4% difference

225/40R19 front
255/35R19 rear

I would suggest if you do run staggered, never take it into the dealer that way and you should be ok.

My dealer seemed to make a big deal over the tire sizes on my car not matching what is printed in my door jam... I think you'll be 100% ok with running a square setup of the slightly larger size... I just wouldn't give a dealer any reason to question anything if your car starts showing a problem, I would try to take it in with the stock size or if you're not under warranty, then don't worry about it.

[F30.TRMBBIMMER]

You would probably want to change the profile to 30, but depends on the width of the wheel