Not surprised. It's significantly heavier than the others. The MPG leaders in this category are the new ML and Cayenne now. Before it was the Touareg or X5.
Originally Posted by Emission
For those keeping score. I had the 2012 Audi Q7 TDI in my driveway for a week (they just took it away). I put about 300 miles on it, of which 120 miles was pure highway travel to/from the airport. My average economy was 18.2 MPG (for comparison, my X5 35d would average about 22 mpg over the same route).
2011 X5 xDrive 35d Red/Black: ZCW, ZPP, ZRC, ZTP, 300, 386, 496, 4AB, 6FL, Combox, LED Coronas. 04/11 Production