XSeries-forum

Can I mix a different run flat brand on different axles?

Currently I have Bridgestone on the fronts and rears but the rears need replacing due to the usual inner wear and was thinking of trying the pirelli.

Yes. You only need to stick to the same type (not even brand) on an axle. It used to mean Radial or Cross-ply but may apply to RFT or non-RFT too.

Personally no I wouldn’t. I had one tyre with a bulge a year ago and that meant a full set as all were well worn (3mm) and new tyres were 7mm depth or slightly more. That put them out of tolerance (<1.5mm difference) so all 4 needed doing at just under £900 - 20” wheels.

As long as they are all runflats yes no issue the only snag is if there would be a big difference in tread depth say front to rear which can upset the 4wd system.

Thanks guys.

I got 5.6 on the fronts......should be okay.

What's the max difference between the sets

As above, no issues as long as replacing in a pair across that axle. As for tread depth even if you buy the same brand they'd be different (so again should be fine).

There doesn't seem to be any clear answers for max tread difference some say 1 % but BMW fit 21's and they are 0.7 % difference even when new, plus the space saver is 1 % bigger if you have one.
An american forum I read seem to suggest 3mm is the max.

All that I have is 1.5% (or 1.5mm), and I have had both answers from a Dealership. Not that helpful I know. ‘’*’ marked we’re supposed to be shaved to ensure a match - allegedly.

Double post oops

Probably some comfusion on the rules 1.5% is by my dodgy calcs about 11mm divided by 2
to allow loss on either side of a wheel is 5.5mm which would be the difference from new to just legal so maximum on any set of wheels.
1.5mm is possibly a cautious figure BMW suggest knowing people will exceed it.
I have 6mm all round except front outer edges now almost bald due to worn front arms and too low pressures and don't like the idea of removing 2 good tyres even though they are not expensive brands