I ran into a Cayenne TDI owner at my local gas station filling up his tank in front of me. Had a quick chat.
He's averaging around 30mpg mixed driving according to his trip computer. I'm jealous.
2011 X5 xDrive 35d Red/Black: ZCW, ZPP, ZRC, ZTP, 300, 386, 496, 4AB, 6FL, Combox, LED Coronas. 04/11 Production