[Adrian E]

Originally Posted by IT

The tyres are proper crap

Worth noting that the requirements for a sports diff equipped car wrt to evenness of tyre tread wear on the rear axle are much more stringent than the 'take average depth tread across each axle and make sure there's no more than 2mm difference in the average depth across the axle, or front to back'

ElsaWin states:

Permissible differences in tread depth

t Tyres of the same construction and tread pattern should always be used on all four wheels.

t The tyres with the deeper tread should always be fitted on the front wheels.

t It is basically possible to replace tyres individually. However, Audi recommends replacing at least both tyres on an axle at the same time.

t On vehicles with rear sport differential, Audi recommends that you always replace both rear tyres at the same time.

and also links to this which may not come out formatted correctly

Models with longitudinally installed engine

Difference in tread depth on models with longitudinally installed engines, e.g. A4, A5, A6, A7, A8, Q5, Q7, etc:

On these models, the difference between the front and rear axle must not be more than 2 mm.

Left tyre (front axle) Right tyre (front axle) Average Difference
3.0 mm 3.0 mm 3.0 mm (left to right)
Left tyre (rear axle) Right tyre (rear axle)
3.0 mm 7.0 mm (new tyre) 5.0 mm (left to right) 2.0 mm (front to rear)
within permissible tolerance range


Left tyre (front axle) Right tyre (front axle) Average Difference
2.0 mm 2.0 mm 2.0 mm (left to right)
Left tyre (rear axle) Right tyre (rear axle)
4.0 mm 4.0 mm 4.0 mm (left to right) 2.0 mm (front to rear)
within permissible tolerance range