Some of you are truly amazing. You can diagnose long distance, not even knowing if there is a problem.
The 8.1 using as much as a quart in 1000 miles is not all that unusual, qspecially if it only has 6000 miles total.
He did not state how much is being added, nor at what interval. He also has not stated what lubricant is being used, nor how hard the engine is being worked.
Either some have ESP or must be using PRECISSION GUESSWORK.
Throwing out possible scenarios only serves to confuse the issue without any fedback from the OP.