[asianbanker]

I recently purchased a set of wheels/tires from another member of a BMW group for my 2022 M240i x-Drive. However, after putting on the wheels and tires, my traction control is kicking-in and cutting power for some reason. Turns out his car is RWD and mine is AWD hence I am guessing that is the issue, but I am not sure. The sizes for the front and rear are as follows:

(i) front wheels and tires 19 x 8.5, 255/35/19
(ii) rear wheels and tires: 19 x 9.5, 276/35/19

The OEM tires were squared 225/40/19

Do I need to change the tire sizing?

Thanks for any advice!

[nype]

What are the wheel offsets?

Those are the same size and diameter of the fsctory ZTK Package staggered, but the factory tires are 245/35/19 front and 255/35/19 rear.

Any pics?

[Ghostrider.1127]

xdrive = bmw star marked tyres

[kaos2774]

Do to the car being AWD your wheels need to be the same height. You can blow out your diff. You need to get the right size tires. Any wheel shop can help you out. Stop driving the car until you get this fixed.

[akumachu]

My 2015 228xi comes with a square setup but I run my summer/autocross wheel from a 235i that is staggered, aka rear being .5 inch wider:
```
Stock Square - 380:
7Jx17 ET40 (7" width 17" diameter), tire 205/50/R17

Stagger - 436M:
Front Wheels: 7.5Jx18 ET45 (7.5" width 18" diameter) (p/n BMW 36117845870), tire 225/40R18
Rear Wheels: 8Jx18 ET52 (8" width 18" diameter) (p/n BMW 36117845871), tire 245/35R18
```

I had no problem with them, or at least I didn't feel any power cut.
One thing you can do is to turn off all the nannies and see if that feels different.

[blue135]

From what I understand, BMW recommends 1% difference in tire diameter front to rear, for XDrive. If the tires are outside that limit, you could damage your diffs as was said. And BMW would not warrant the damage.
The fact that you are getting the responses from the car you are suggests you can subject the car to damage if you turn off the nannies.

[akumachu]

Originally Posted by blue135

From what I understand, BMW recommends 1% difference in tire diameter front to rear, for XDrive. If the tires are outside that limit, you could damage your diffs as was said. And BMW would not warrant the damage.
The fact that you are getting the responses from the car you are suggests you can subject the car to damage if you turn off the nannies.

Just did the quick math my stagger setup is well within the 1% (where did you see that info?).

((225 * .40 ) - (245 * 0.35)) / 457.2 = 0.0093

Note that 457.2 mm is 18 inches of the diameter.

I really doubt if it was the tire setup for the OP having power cut issue. Just using my setup as a reference point.

[blue135]

First, I do not have a 240 with AWD or RWD. Just going by what I have seen in other posts on here. While akumachu's calculation gets .1% diff in width, the concern is the overall diameter.
Second, the 255/35/19 has a diameter of 26" and the 275/35/19 is 26.6". My calculation is slightly over 2% difference in diameter.
So, if Xdrive does require 1% or less difference, how do the control systems react if that specification is exceeded?

[akumachu]

Originally Posted by blue135

First, I do not have a 240 with AWD or RWD. Just going by what I have seen in other posts on here. While akumachu's calculation gets .1% diff in width, the concern is the overall diameter.
Second, the 255/35/19 has a diameter of 26" and the 275/35/19 is 26.6". My calculation is slightly over 2% difference in diameter.
So, if Xdrive does require 1% or less difference, how do the control systems react if that specification is exceeded?

No, my calculation was based on diameters (hence the part for 225 * .40). And with an actual tire size calculator instead of my quick math, turned out the diff is around 1.2%. And my set of wheels was actually an optional for my car with a different wheel package.

I could really find that 1% reference except for this forum link https://f30.bimmerpost.com/forums/sh....php?t=1142647

I believe that forum link was more about tire wear and nothing about power cut or differential wear.

I never seen my stability control light came on because of the ratio difference. Only time it came on was when I went fast over water but even that was only a few times. Also my car has an e-diff not a mechanical one anyway so the wear would be the brakes.

[blue135]

My bad. You are right about your calculation, just curious why use of actual diameters returns a different result.
Good luck with resolving your problem.