The 2002 Audi S6 runs on premium unleaded (required).
The 2002 Audi S4 runs on premium unleaded (required).
The 2002 Audi S8 runs on premium unleaded (required).
The 2002 Audi A4 runs on premium unleaded (required).
The 2002 Audi A8 runs on premium unleaded (required).
The 2002 Audi A6 runs on premium unleaded (required).
The 2002 Audi TT runs on premium unleaded (required).
No it doesn't, unless their is a problem.
Use Exactly what Audi recommends as written in your owners manual. You listed no year so I would only be guessing.
An Audi A4 1997 R reg will use 5 W 30 oil. This oil can be purchased at any auto parts store such as NAPA.
castrol full synthitic 5W-40.... ONLY ...........PER AUDI DEALSHIP
Change the oil/filter every 5,000 miles if you use conventional oil, and every 8,000 miles if you use synthetic.