On my Journey (R/T with 6cyl & everything except DVD players & only 2 rows of seats) I have been getting the following:
Averaging 21.3 MPG over the first 1000 miles (based on computer)... But calculations from gas purchased shows me getting 21.7 (slightly higher than computer). This is based on driving mostly highway (76 mile round trip commutes 3 days a week with the rest being 'city' driving)...
I found that my 'best' mileage was/is at highway speed of 60mph with it it 6th gear - 25mpg - with same speed in 5th gear it drops to 21mpg for me - quite a difference...
I 'trained' my transmission to shift at lower points (you do so by drinving non-aggressively AND backing off on the accelorator when the RPM's hit about 2500 - so that it shifts then --- keep it up for about 50-100 miles and your transmission will 'learn' to shift at lower RPMs for you - but remember, if you switch driving techniques again, it will change to accomodate) - shifting at lower points helps get better mileage in most cases...
I also found that when it tells me I am 'low' on fuel, and I go to fill up, it usually only takes 17 gallons... Has anyone tried running it to empty yet to see if it in fact goes through 20 gallons? I will try to do so in the future, to find out, but not if someone else already has...