Couple things come to mind:
1) Do you make a lot o short trips?
2) Are there any leaks (they can add up)
3) Does is smoke even a little when you start it up in the morning ...or after it sits a couple days. Have someone start it up and watch the tailpipe yourself.
4) Disco Mike was right about watching it going down a long hill. But I would add that you should follow in a car behind. Sometimes it's hard to see smoke inside the vehicle.
5) If you had a little of each issue listed above they could each contribute and you might not really know it. Oil seals are not too hard to do. If it's valve stem guides, it would be the right time to take the heads off and do the gaskets.
6) I wouldn't consider 1 qt per 3000 miles anything to worry about.

Mark G

 

I check the oil every Sat morning after it has sat over night. It is crazy that it uses so much in the first 1/3 of the fresh oil change and then not at all in the last 2/3's. It just blows my mind.
It doesnt smoke and leaks very little around the valve covers.
I use Mobil 1 15w50 Extended Life and change it every 5000 miles. Oh, and 170000 smiles on the clock.