[Rosen85]

I have a 2022 G30 M550i xDrive.
The tires are Pirelli P Zeros.
The front ones are compromised and can't be fixed. I do want to replace them with brand new.
They will be new but from another brand, not Pirellis.
Will there be a problem, hence I will be changing only the brand and hence the thread. They will be the same size, speed and load indexes as the old ones.

[tjbuggy2b]

Depends on a couple things.

1. If the wheelset/tires are square (all 4 tires are the same size) it's probably not advisable. I've heard of traction control systems getting antsy if the tire traction tendencies differ front to back.

2. If they are staggered, you probably won't have a problem since the small size difference between front and back would likely have a bigger impact on TC than the tread/compound of the new tires.

3. Now that I've said that, even if they're square it probably won't hurt anything, since the TC system surely has some measure of tolerance built into it. JUST BE SURE TO NEVER HAVE THE DIFFERENT TIRES ON ONE SIDE OF THE CAR, ONLY DIFFERENT FRON TO BACK. That's some baaad juju.

[Rosen85]

The front and rear tires are different sizes right from the factory.
The front tires are 245/35ZR20 95Y and the rear ones are 275/30ZR20 97Y.
The front rims are 8Jx20 ET30, and the rear ones are 9Jx20 ET44.
I will be buying the same size, load and speed index as the ones the car has now, but not the same brand and model as the rear ones.
My main concern is the tire thread (or one might call it a tire pattern, I am not sure about the word in English) and nothing more.
After all the total circumference will be the same on the old and on the new tires. I do not think that a different brand will have a different overall ride height.

[dscabra]

Every tire has slightly different handling characteristics, so different brands may feel/handle differently and mixing them may exacerbate the difference. If you buy from a place that will let you drive on them for a few days and bring them back if they don't feel right, that might be the best way to see what your thoughts are and if necessary, buy the full set of matched tires.

[BMW012]

yes, for a performance vehicle, or for any car - would recommend uniform tires. Its one of the most important aspect/part of the vehicle.

[zinner]

I think you will be ok, but it's far from an ideal situation. I would make sure they are all factory size and like characteristics, IE all 4 tires are ~500 tw all seasons or summer tires. You won't be at optimal performance, but if the tires are bad, two good new tires are better than two old bad ones.

[BMW012]

also, your front tires will have much more depth considering your back ones now. depending how worn out the back is. might possibly matter for x drive

[Chappers 71]

As long as the tread patterns are similar it’ll be fine. I currently have Michelin Primacy 3 on the front with Pirelli P7’s on the rear. Was like this when I bought my G31 from supplying dealer.
I also ran Michelin PS3’s on the front of my e92 35i with GoodYear F1 ASY3’s on the rears when I couldn’t get the PS3’s all with no issues at all.

[Mike 540]

Having different thread on each axle is not ideal, but probably ok as long as the wheel circumference is equal. BMW told me the difference in the thread depth must be smaller than 1,5 mm otherwise the x-drive may be damaged.