[Whjohnson13]

Hey All, I have a 2014 BMW 435i XDrive, I bought new wheels that are 19x9.5 (square set) I am currently running 19x8 (front) and 19x8.5 (rear). 225/40/19 front and 255/35/19 rear

I am trying to figure out what tire size would match sidewall size and work well with the new wheel size.

[Llarry]

If it was me, since you've gone to a non-staggered wheel size, I'd go to a non-staggered tire size, but buy one size bigger tire: 235/40R-19 front and rear.
You could certainly stick with the original 225/40R-19 size as well.

An even better place to ask this question would be the 3/4 series F30 tire and wheel forum. Click on the 4 series at the top of the page, then look down the page to find the wheel and tire forum.

[pbonsalb]

There can be issues with AWD when changing the stock front to rear tire circumference differential. Usually it is increasing the difference that causes transfer case problems. Going square, I am not sure there is a problem, particularly if BMW has approved a square snow setup.

[Llarry]

Originally Posted by pbonsalb

There can be issues with AWD when changing the stock front to rear tire circumference differential. Usually it is increasing the difference that causes transfer case problems. Going square, I am not sure there is a problem, particularly if BMW has approved a square snow setup.

Yeah, square should not be a problem at all. Square is the BMW-recommended winter setup.

[jnbut]

Modifying the original front-to-rear tire circumference ratio might lead to complications in the all-wheel drive (AWD) system. Often, it's the increase in this difference that triggers challenges with the transfer case. However, when transitioning to a square tire setup, any potential issues remain uncertain. This is especially true if BMW has granted approval for a square snow configuration, indicating that compatibility concerns are likely addressed.

[Bc2005]

In a BMW staggered setup the rear tires are wider/larger, but have a lower profile. The net effect is almost no difference in total tire/wheel circumference. The xDrive system will have no issues.

[pbonsalb]

Originally Posted by jnbut

Modifying the original front-to-rear tire circumference ratio might lead to complications in the all-wheel drive (AWD) system. Often, it's the increase in this difference that triggers challenges with the transfer case. However, when transitioning to a square tire setup, any potential issues remain uncertain. This is especially true if BMW has granted approval for a square snow configuration, indicating that compatibility concerns are likely addressed.

Be wary of this new member — the 2 posts so far just take info from the thread and repackage it with some extra words.