Mixing Tyre tread depths on a cayenne

[jen155]

Hope someone can help.
Three of my cayenne tyres have approx 4mm of tread left but one is down to 2.5mm which I woud ideally like to replace.
I'm told I can't just replace one tyre as the difference in tyre diameters due to differing tread depths will confuse the four wheel drive system and cause drivetrain issues.
Anyone know if I can just renew 2 x tyres on the same axle rather than all four?
I don't really want to shell out for a whole new set of tyres just yet.

Cheers
Jenno

[Callughan]

Will be ok some treads are not much more, only really see an affect or damage to 4x4 system if you really push the car on a regular basis.

Edited by Callughan on Saturday 2nd June 00:18

[jen155]

Will I need to replace two together on the same axle or can I mix a new tyre with a 4mm one?

[Callughan]

If exact same tyre as the other axel should be ok. Do not mix

[TTX50]

You could look around for a part worn one of the same type with 4mm left?

[rog007]

It's not a huge problem I'm led to believe; same effect when anyone has an unrepairable puncture. They replace the tyre with a new one, only replacing both on the axle if the other is already way down. If however money, or your company car account, is no limit, then of course do both.

[anonymous-user]

Mixing tyres - even with very small tread differences - is well know for causing issues in BMW 4*4 transmissions but not heard of same issue in Porsche.