Rear Discs worn out quicker than pads????

Just got my A6 back from its MOT that it passed with no issues.

It's a Bi Turbo 3.0 one with the oversized front brakes.

It also had its end of warranty check at the original dealer and what was strange was the rear discs were noted as 80% worn, pads at 50% and recommendation of replacement. The car has done just under 22k miles.

It had a service done at a different dealer in March at just over 19k miles and the front and rear pads were noted as 25% worn with nothing for the discs. I have checked to see if they have a record of the disc thickness and am awaiting to hear back.

Is this normal? No mention of warping but it seems very odd? They are not seized either?

Could they have got the wrong thickness of the discs and worked it out wrongly?

Any ideas?

The wear figures do seem strange but it is quite possible to "wear out" the disks before the pads simply through a lack of use. The rears do very little work at the best of times and gentle driving will lead to disk degradation through lack of use that will cause them to need to be replaced. I had to have my rear disks on my RS6 replaced at 30,000 miles as the disks were deemed to be worn out even though the pads were - like yours only - only partially worn (they were the original disks and pads from new). Of course, they then had to replace the pads at the same time.

Yep it just seems a little bit odd, that in 3000k miles my pads jump from 25% to 50% when in 19k miles they have gone from 0 - 25% and the rear discs are 80% worn.

Although it doesn't say on the invoice, it did on the service sheet the front discs are only 35% worn. :(

At £520 to swap I am wanting to make that it is necessary and they haven't got the wrong starting thickness for example.

If these are your original disks from new (which I assume they are), then it doesn't surprise me they are shot. the % wear may be a reflection of the Tech's opinion of the service life left in the disks rather than their thickness, which is the major but not the only factor in considering their service life. Trouble is, these cars need to be driven hard to make the disks last longer! I needed all four disks changed whilst still on my original pads. Still recovering from the 2.5K bill but my fault for failing to drive the car harder. If I had, I expect I could have got more life out of the rears and probably the fronts, too.

Yes original disks but it was based on a measurement. I asked them to remeasure when I picked up and a different mechanic came back at 83% based on the job sheet. Hence me wondering if they had the right original thickness.

They also reported a fault with the key fob that it would not lock the door. However it worked fine at the end of the day so am just wondering .....

I do drive it relatively hard, not that many miles but you should see my average MPG ....

I am going to get a second opinion on them and just trying to work out where from. A local independent is normally pretty reliable so might give them a shout.

I am also likely to swap the car in the 6 months so hadn't planned on spending any more money than was necessary on it.

Discs can wear quicker in the rear as they do like 10% of the braking so don’t heat up so always have surface corrosion all the time and get cleared off as you pull away.
My first A6 had problems with the electronic calliper not winding off properly when handbrake was released. Needed a good clean and that sorted it.
Check you Pr numbers, I got rear discs and pads relative cheap and better quality than the Audi oe ones. The TRW stuff is miles better and the hub is well coated so doesn’t look like a rusty mess like the Audi one gets.
I have a set for sale but think yours have the bigger ones.

I get 45,000 miles all round on my A6 brake pads and that's towing a 1,800 kg braked horsebox

I got 85,000 miles out of my front discs , but it was ok on the outside and totally rusted in the inside and more age of car at 12 year old

I had to replace the discs in the rear at 45,000 miles due to a sticky EPB

You could feel the wheel nuts after driving, the rears should feel the same either side and be slightly warmer than the front, but not too much

I just stuck on Euro's Pagid stuff as OEM and its not too bad a DIY job

An independent Audi specialist had a look and thinks that Audi are being a bit too cautious with their estimate....