[Ehodg66]

Hello All,

I've just purchased a 2014 335i GT M Sport and loving the upgrade from a VW .
Bimmerpost has been a great help so far in answering my questions.

I currently have 20" rims with Pirelli Run flats - 255/30 R20 92y on the rear and 225/35 R20 90y on the front. The fronts are not far away from needing replacement and I'm trying to educate my self on what I can replace with.

1. I will be losing the run flats. I've purchased a spare and just not a fan of run flats.
2. I would actually like a little more side wall because a bump on these low profiles feels like the rim bottoms out.
3. Lastly, I was thinking about lowering the car a little but not sure if that works with a 20" rim and a larger sidewall tire.

Any help would be appreciated.

thank you
Eric

[Billfitz]

The only way to get more sidewall is with a larger diameter tire. Tirerack for one lists the diameters of tires by size. That probably takes lowering off the table.

[alohasurftoad]

F3/4 series cars tire diameters are 26" with the exception of F34 (GT) which is 27". that is why your wheel gaps are so big. is your car an x-drive also?

at minimum you should be using the OEM staggered tire sizes for a F34 GT. 225/40/20, 255/35/20, 27.1"/27.0" a profile size up in aspect ratio from what you currently have.

if you are not x-drive you there's a few other tire size combinations you can consider but i'd go with what's above to keep it simple.

[Ehodg66]

Yes, My GT is an X drive

[alohasurftoad]

use 225/40/20, 255/35/20 for x-drive...damn, i just noticed there are no tires in this size combination on tirerack.

you might have to do a square tire set up on staggered wheels. either 235/40/20(27.4") if you want more sidewall but a tiny bit less rear curb protection and great wheel gap fill, unfortunately only michelin pilot sport a/s 3+(all season) in this size.

OR 245/35/20 square 26.8", less sidewall but more curb protection in front, less gap fill but better overall handling. lots of choices in this size. i'd recommend this size for you.

you could possibly do 245/35/20, 255/35/20 but the diameter difference is right at 1%, generally thought of as the working limit for x-drive. more risk on the transfer case with this combo.

[Billfitz]

I wouldn't go staggered, there's not much point to it with xDrive. 235-45 would get an extra half inch of side wall and reduction in gap.

[Ehodg66]

Thank you Alohasurftoad and Bill for your help.
I'll look into all of your suggestions.