Audi S3 - Tread depths - Billsboy

I understand the need to keep tyre tread depths more or less the same on all four wheels on vehicles with 4wd, but how much leeway is there without causing transmission problems?

A front wheel puncture on a car with Quattro transmission has recently meant a new tyre where all others have about 5mm of tread.

The Audi dealer stated that they do not recommend more than a 2mm difference across the axles and no more than 3mm front to back.

The Tyre Dealer, who would obviously gain the sale of at least two more tyres and probably three if we stuck to the dealer's recommendations, said that the differences should be OK.

Has anyone any views on this? I'm not sure it is relevant but the annual mileage is only about 8k miles.

Audi S3 - Tread depths - Miniman777
I had a Kuga 4x4 and swapped tyres front to back every 10k. Sold it at 31000 miles still with original tyres but with the Haldex system (same as Audi?) there are known problems on widely different depths. But I find punctures rare these days.

I guess it's a trade off for running a car that costs £35k plus new but annoying even so.
Audi S3 - Tread depths - madf

The Audi dealer stated that they do not recommend more than a 2mm difference across the axles and no more than 3mm front to back.

The Tyre Dealer, who would obviously gain the sale of at least two more tyres and probably three if we stuck to the dealer's recommendations, said that the differences should be OK.

Has anyone any views on this? I'm not sure it is relevant but the annual mileage is only about 8k miles.

Uneven diameters means wear of the 4wd system...£1000s.

I would listen to a dealer. They should be an expert on their cars..

Tyre dealers? Not their field of expertise or problem when it goes wrong..

Audi S3 - Tread depths - Billsboy

Even the dealers differ. I asked another dealer out of interest and they said a 3mm difference was acceptable both across the axles and back to front.

The question is to spend £300 on three more tyres that have 5mm of tread or take the risk as suggested by the second dealer and have 8mm on one wheel and 5mm on the rest.

Audi S3 - Tread depths - HopLane

There's a question on Ask Honest John from the last couple of days from someone who has trashed his Vauxhall Antara's transfer case by running tyres with different tread depths.