Trip yesterday. Close to 400 miles round trip--average speed, per the readout, was about 72mph. Mileage on first half was 29.6 mpg, return was 28.5.
Car is a 2009 Carrera

 

'08 C4 Automatic - A recent trip from Washington, DC to Manhattan got me 23.2mpg, otherwise I'm averaging 19mpg around town. Mostly commute, with a 30/70 mix of city/highway, in crappy rush hour traffic half the time. I'm usually in manual mode, shifting between 4k and 5k once the oil has warned up.