I've got an '06 SE, when I drive it I get about 20mpg in mixed driving. 80 plus on the highway, late braking and fairly rapid acceleration. When my wife drives it she only gets in the low 16's. The longer I've had it the better the milage. 32k now. When I put new tires on it the milage initially went down, but now no complaints.
My Range Rover gets 16.8 to 17.2 no matter how it's driven, which I just dont get.
I have driven both trucks from Denver to Chicago, The LR3 got about 19mpg on the trip and the Rover was at 17.5mpg with the cruise set at 82, I also use a secondary gps to measure the speed and calculate fuel usage, so I know it's pretty accurate.