Replacing tyres

[Isleaiw]

Hi all, looking for the collective wisdom for some advice..... my RS4 was subject of a recall when it was serviced last Oct (late) - didnt really ask much about it, these things happen. Anyway, a couple of weekends back the tyre pressure monitor came on but all tyres were reasonable pressure. made sure all as per spec, reset and did another decent drive, when it came on again. Checked again, all tyres fine. Then received a letter to say that the last recall had caused another recall - apparently first one was something to do with bolts in back axle and they hadnt appreciated that wheel alignment could be out after.... which could lead to bad tyre wear. Checked my rear tyres and guess what, outer edges scrubbed really badly so not much tread left....

Booked back in with Audi, alignment done and they agree rear tyres need replacing..... so the questions:

1. Its pretty clear it was tyre wear causing the tyre pressure monitor to ping, which means the rolling circumference must have been affected. Coming from prior AWD cars, I was led to believe that too much difference between rolling circ was bad for the running gear?

2. Audi want to replace the rear tyres but should I be insisting on all four? Car has done 9000 miles, fairly sedately to be honest so I'd imagine front tyres not beyond half worn yet.... but if they have more than 3mm of tread depth difference I was led to believe all 4 should be done?

To add to the joy, tyres are on back order so have to go back next week (hopefully) for them. So that will be three visits (35 mile round trip each visit!) when one would have done.....

[Isleaiw]

So just to close this one off, Audi fitted the two rear tyres, rechecked the alignment, and checked the wear on fronts. Rears with new tread 7mm, fronts between 5.1 and 4.9 so I'm happy only two needed. I'll try to just drive and forget about it now, starting with 900 miles in a week via the Cotswolds and Derbyshire

Might be time for a change after that, thinking that I can sell my runaround Mini and get an EV for the short journeys that will also cart the dog around and have a proper weekend car for weekends....

[RS Owner]

I find my fronts wear faster than my rears and will reach a point where I switch the tyres front to rear.
I think would have the 7mm on the front and 5mm at the rear and I think the cornering on my local roads would tend to level them out.