I did my first oil change at 5400km, i'm living in Rimouski, Quebec, it's very cold and windy city in here! We often have -20c here!
And to go to work, I do a lot of stop and go, idling at traffic lights and stops, so it doesn't help fuel economy.
I live at about 2km from my work, and my wife does about 5km to her work when she takes the Journey.
So my 18,4l/100km si 100% winter city driving as of now, I did a few trips on the highway before reseting my EVIC, and I averaged about 9l/100km which is not bad at all.