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Tyre brand mix

Discuss your latest mods or ideas, and anything to do with the BMW X5 (E70).
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pcdee
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Tyre brand mix

Post by pcdee » Thu Sep 24, 2020 3:27 pm

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.

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X5Sport
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Re: Tyre brand mix

Post by X5Sport » Thu Sep 24, 2020 6:49 pm

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. :( :cry:
Last edited by X5Sport on Thu Sep 24, 2020 8:20 pm, edited 1 time in total.
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Re: Tyre brand mix

Post by Leslie » Thu Sep 24, 2020 8:13 pm

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. :D

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Re: Tyre brand mix

Post by pcdee » Fri Sep 25, 2020 6:12 am

Thanks guys.

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

What's the max difference between the sets

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Re: Tyre brand mix

Post by Raj » Fri Sep 25, 2020 8:56 am

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).

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Re: Tyre brand mix

Post by Leslie » Fri Sep 25, 2020 9:14 am

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.

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Re: Tyre brand mix

Post by X5Sport » Fri Sep 25, 2020 11:10 am

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.
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Re: Tyre brand mix

Post by Leslie » Fri Sep 25, 2020 6:15 pm

Double post oops
Last edited by Leslie on Fri Sep 25, 2020 6:20 pm, edited 1 time in total.

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Re: Tyre brand mix

Post by Leslie » Fri Sep 25, 2020 6:19 pm

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

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