I am driving a 2007 Prius in Haifa, Israel. This city is built on a mountain, so all the driving is up or downhill. Since the energy recovery is a lot below the energy needed to drive up the mountain, there is a net loss.
I get about 15 Km/liter (36.6 MPG)in the city and around 48 MPG open road. The A/C is constantly on automatic, as the temperatures here are usually in the high 80 or low 90 deg.F.
I would like to hear from other Prius drivers about their mileages
51 all round.
The best place is to check out GreenHybrid. They have a database of real-world mileage reports from over 5000 Prii driven over 100,000,000 miles. The Average real-world performance is 47.6 MPG.
I get just under 45 MPG in the Desert Southwest of the US, so A/C is pretty much always on too, but no large hills on my daily commute.