[Pentland]

Originally Posted by jayritchie

I have 3 x PS4S* and 1 x PS4S as I got a puncture day 3 of ownership and no * tyres were available!

The non matching sidewall really gets to me 😂

Let’s hope the non matching compound doesn’t have an effect. (Refer to my linked thread on the subject)

[nype]

I've read varying opinions ranging from "must be * rated" to "it's a money making scheme".

Apparently the xDrive system has a very low tolerance for varying specs amongst a staggered set of tires. A lead tech at my local BMW dealership said that I would risk destroying the transfer case if I installed same size all season tires (not * rated of course). Sounded harsh...

But how does that work if, for example, you have a 25% worn set of * tires and one needs to be replaced? Does BMW suggest replacing all four?

[Pentland]

Originally Posted by nype

I've read varying opinions ranging from "must be * rated" to "it's a money making scheme".

Apparently the xDrive system has a very low tolerance for varying specs amongst a staggered set of tires. A lead tech at my local BMW dealership said that I would risk destroying the transfer case if I installed same size all season tires (not * rated of course). Sounded harsh...

But how does that work if, for example, you have a 25% worn set of * tires and one needs to be replaced? Does BMW suggest replacing all four?

There is a tolerance between tyre diameter on the same axel of (and don’t quote me) something like 2mm or 2% or something.

I replaced a punctured tyre with a new one just to get home on my 4 series once and the pull to the old side (worn tyre side) was pronounced. I’d imagine running like that for any length of time would cause damage or wear somewhere.


I think same tyres same size same axel is critical, front to rear not so much but why would you mix and match.

[German1967]

Originally Posted by nype

I've read varying opinions ranging from "must be * rated" to "it's a money making scheme".

Apparently the xDrive system has a very low tolerance for varying specs amongst a staggered set of tires. A lead tech at my local BMW dealership said that I would risk destroying the transfer case if I installed same size all season tires (not * rated of course). Sounded harsh...

But how does that work if, for example, you have a 25% worn set of * tires and one needs to be replaced? Does BMW suggest replacing all four?

Running 4 same size tires on all wheels is a non-issue. Hence, why you can both run a staggered and non-staggered set-up. If you run staggered you need to stay within 2% variation in circumference (read up in manual). That becomes a potential issues, if you go aftermarket and choose a different size set-up than recommended or in the rare case that you replace your rears while your fronts are almost done.

[Pentland]

Here you go….

https://f30.bimmerpost.com/forums/sh...5&postcount=37

Tyre tread depth difference on the same axel is the important bit so one puncture = max 2 new tyres not 4!