Wow. That seems pretty poor. I've been underwhelmed by our mileage, but part of it is the fact my wife has a pretty heavy foot compared to me. After a week of driving, I managed to knock our long-term fuel consumption average down by .1 L/100 km.

Anyhow, we're getting 8.1 right now, over a long period (so says the car). We're in an auto as well, so I'm not sure what would be causing your issues. I would say we run a pretty typical ratio of city/highway driving.