The 2007 Audi A6 runs on regular unleaded.
The 2007 Audi S4 runs on premium unleaded (required).
The 2007 Audi S8 runs on premium unleaded (required).
The 2007 Audi S6 runs on premium unleaded (required).
The 2007 Audi A3 runs on premium unleaded (required).
The 2007 Audi A8 runs on premium unleaded (required).
The 2007 Audi Q7 runs on premium unleaded (required).
The 2005 Audi A6 runs on regular unleaded.
The 2009 Audi A6 runs on regular unleaded.
The 2006 Audi A6 runs on regular unleaded.
The 2010 Audi A6 runs on regular unleaded.
The 2008 Audi A6 runs on regular unleaded.