i have no problems getting over 500kms on a tank going to and from work. letting it warm up min 3-5mins every time i start it morning and night(home form work). highway can get around 600kms usually. once i got a little over 630 but it started to cut out going up a hill outside of brantford .
easy on the gas, pace your lights if you can. keep your oil changed reuglarly.
i'll give you guys a tip for me, use pioneer gas, i tend to get my best mileage on that so does my wifes escape w/ 3.0l.
happy driving.