based purely on my recent roundtrip to Adelaide via Melbourne and Dunkeld (edit: that's from Sydney - approx 3800KM in 7 days
)
Model: 2007 Ford Focus Zetec
Generation: LT
Type: 2.0 Petrol Manual
Driving style: 95% freeway / 5% city
Fuel Consumption: Avg 6.7L / 100km (computer reckoned it would get between 750-780 each time I filled up)
normally it's 95% city, 8.7L/100KM and about 600KM/tank