Thats what the instant thingy says on the trip computer, was a coolish morning though, if it is hotter I have seen about 8 or 9 usaully :0), it is really effecient on the highway, sucks around town though, oh well
Hard to give a generalisation, varies from car to car. Often better at around 80-90 kays but with that long a trip you're better off sticking to the speed limit otherwise it will take forever. Judge it by how far you have to put your foot down on the accelerator. Don't try higher speeds as a ticket will cost more than any fuel you might save!