The 2009 Audi TTS runs on premium unleaded (required).
The 2009 Audi A6 runs on regular unleaded.
The 2009 Audi S4 runs on premium unleaded (recommended).
The 2009 Audi Q7 runs on premium unleaded (recommended).
The 2009 Audi R8 runs on premium unleaded (required).
The 2009 Audi S8 runs on premium unleaded (required).
The 2009 Audi A8 runs on premium unleaded (required).
The 2009 Audi A3 runs on premium unleaded (recommended).
The 2009 Audi S6 runs on premium unleaded (required).
The 2009 Audi A5 runs on premium unleaded (required).
The 2009 Audi A4 runs on premium unleaded (recommended).
The 2009 Audi S5 runs on premium unleaded (required).
The 2009 Audi Q5 runs on premium unleaded (required).