2005 4.4 Sport (driven like I stole it)
15 City
21 Highway

From what I'm seeing the 3.0 doesn't get any better mileage yet gives up significantly in the power dept.

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2005 X5 4.4 (Sterling on Truffle) w/sport everything
2011 Audi S4 (Prestige, DSG)
2012 Audi Q7 (Sport, S-Line)