Low oil level. ~3k miles since change

Go ahead… got it back from the trip. I checked the oil at each fill and it was the same, no drop. Initially, when the oil light came on, it was a low 1.5 liters. I added 1 liter at that time. It didn’t move from that time until I took it to the dealer. I had checked the cart and it was bone dry. There are no visible leaks under the hood either. The dealer ran it through a series of diagnostics and said everything was fine. I had also checked the tail pipe and there was carbon buildup in there but they assured me that was normal.

The next step. Consumption test. They changed the oil (was only 500 miles from needing to) and said to put it back at 1200 miles to check the level. The service rep said he thought Subaru’s specs allowed for 1/3 of a quart loss in that time period. I then asked if at 3600 miles, according to spec, if the acceptable range would be 1 quart. His answer was yes. I explained to him (as calmly as I could) that a quart of oil gone at 3600 miles was unacceptable if the change frequency is 6k miles. Anyway, I’ll take it back there in two weeks to check it out and go from there.

The rest of the puzzle…I called the place that did the last oil change to see if they had a record of how much oil was in it when I put it in. have put. It may have been low from the last oil change. I hope that’s the case and I’m not burning oil. If I have to add a quart of oil between oil changes, I’ll trade it.