Mt 2.7t S4 returned about 21-22 mpg, day-in, day-out. Of course, that car was lighter than a Aa6 2.7t by about 300lbs, and amanual.

My S6 avant (4.2l) returns about 17mpg under the same circumstances.

Keep in mind that fuel economy is mostly related to three things:

1. mass/weight ( f=ma, after all)
2. losses - aero, friction, tranny
3. thermal efficiency of the motor

#3 is where the 2.7t does well. A smaller motor operates at higher compression ( lower vacuum, note i did NOT say lower compression ratio) than a larger motor. Even more so for a turbo, which compresses air TWICE. Compression is the leading variable in efficiency.

Grant

glenahan@fastmail.fm