I have a similar problem with my truck and it appears to be using a quart a week. It has around 93,500 miles on the truck and as you said seems kind of strange to be burning oil with lower miles. Have you found a fix to the problem with your truck?

 

When we bought our new V-10 Gas burner ambulances, we were losing about 2 quarts a week through an engine that had 1000 miles on it. Took it in under warranty and they replaced the PCV valve. A year later they are reaching the 80000 mile mark and they use around half a quart to a quart a week. You have to think though that they also use 5w20 oil and the drivetrains are abused with the hard braking and accelerating and speeds up to 85mph (govererned). I do not use synthetic , but I always use motorcraft filters. Try replacing your PCV Valve and see if that help with the oil loss.

 

2008 4.6 with 23,000. Occasionally I get the blue puff. Seems to happen when the engine was cold, I ran the truck for a minute and then shut it down. Then engine cools totally until I start it again, Then sometimes I get "the puff".
The truck uses no oil. I got "the puff" with semi synthetic and full synthetic.