XSeries-forum

I picked up some non runflats the other day to try out , The fronts are Pirellis but the rears are Accelera.

The garage I use said I should get rid as they cause problems with the Xdrive system, has anyone heard this before?

Yes,  not just this make, but non star marked tyres, especially different makes  can wreck your transmission.
Loads and loads of posts on here relating to this problem
I bought mine with different tyres fitted and could feel it winding up the transmission.
Problems went away once I replaced the tyres .
I measured the rolling circumference of the tyres I removed and was shocked to see a 30 mm difference.
That's 30 mm for every revolution . Which is about 25 mts per mile.

Blimey, found some older posts on the subject and it looks like im going have to bite the bullet and get some new rubber.

Now you know why BMW means Breaks My Wallet........whoever designed the xDrive system to be so intolerant of tyres should be hanging their head in shame.  >:(

Well you learn something every day!  Ordered a set of Toyos, my tyre place said I would be fine with those. About £600 fitted

Any tyre other than those with a ‘*’ mark run the risk of breaking the transmission.  Not guaranteed to do so, but.....