Audi recommends it right in the manual for 20v's (actually Autobahn..same stuff) Right on the advice to use immediately before oil change. Wrong, that using Premium Fuel makes it unnecessary...a number of listers including myself that have only ever used good quality hi-test fuel have noted modest to marked improvements by using Techron. Last advice....WAL-MART $5-$6. Royal 90-90QMolotov20v