a for AUDI !
Depends on model year, driving style and climate but in general 5w30 or 5w40 synthetic.
You need to do an in-depth diagnosis of the problem to determine the cause, and repair it.
The 2010 Audi A8 has 32 valves.
The 2009 Audi A8 has a V8 engine.
The 2014 Audi A8 has 24 valves.
The 2003 Audi A8 has a V8 engine.
The 2006 Audi A8 has 40 valves.
The 2011 Audi A8 has 32 valves.
The 2012 Audi A8 has 32 valves.
The 2005 Audi A8 has 40 valves.
The 2002 Audi A8 has a V8 engine.