What are the common problems associated with the Audi 80's engine oil?

I have an Audi 80 and I noticed that it consumes more engine oil than usual. I checked for any leaks but there doesn't seem to be any. What could be causing this issue?

The most common reason for increased engine oil consumption is worn out piston rings. This can result in oil passing through them and burning in the combustion chamber.

Another possibility is a faulty PCV valve. This valve is responsible for regulating the pressure in the crankcase and a malfunctioning one can cause oil to be drawn into the engine and burned.