Honestly if you getting at least the new revised numbers from the EPA...you really can't complain. This is a 4300# SUV. Th top numbers are for the CRD.
http://www.fueleconomy.gov/feg/findacar.htm
If you really try (100% of the time), you can get better mileage than this also...but you have to control speed, acceleration rates, idiling time, ect. I even put the auto in Neutral or Park when sitting at a light or turn it off if I know I am going to be there for 30 seconds or more.
Some others (all 2006 models):
Toyota RAV AWD 3.5L V6 Auto(5).....................................19/26
Honda CR-V AWD 2.4L I4 Auto(5).....................................20/25
Subaru Forrester AWD 2.5L Flat 4 Auto(4)........................20/25
Jeep CRD 4x4 2.8L I4 Diesel Auto(5)...........................19/23
Suzuki Grand Vitara AWD 2.7L V6 Auto(5)........................17/21
Ford Escape 4WD 3.0L V6 Auto(4)....................................17/21
Jeep Liberty 4x4 3.7L V6 Auto(4)......................................15/20
Ford Escape Hybrid 4WD..................................................28/26
None of the "other" SUVs above are true 4x4s and I don't believe any of them can tow near 5,000 pounds. I routinely get 20+ city/27+ highway.
2007 Diesel SUV choices:
Mercedes ML320 CDI 4MATIC.................................19/24
Mercedes GL320 CDI 4MATIC.................................18/23
Jeep GC CDI Auto.................................................17/22
VW Touareg 10CYL Diesel......................................15/20
Not very many choices and all are $40,000+