First: I searched, but couldn't find anything similar-enough to my post to answer my questions.
b/g: I think I'm fairly observant about cars, for example when tires are low, engines don't run properly, etc. And I am very sensitive to "highway odors" as when a semi ahead of us has a cooked brake lining, or somebody is running a rich mix, etc.
My wife has a '12 Forester 2.5 NA with ~28500 miles on it. Per the windshield sticker the dealer put on at the last change, her next change is due at 31000.
Friday night we drove ~220 miles for a holiday visit. When we stopped at the halfway point to refuel, I smelled hot oil, strongly, while close to the car. I have never smelled hot/burned oil near her car; until that moment, her car has done nothing I consider out of the ordinary.
Saturday morning I checked the oil. It was almost a quart low, and the oil on the stick was very black and had an acrid scent. I couldn't see any trace of leak/etc. under the hood, but there was quite a bit of nasty, black sludge at the tip of the exhaust, around the bottom third of the circumference; the rest of the inside of the pipe was clean. The stuff was not oily-water, but a thick oily sludge. It didn't smell of gas, but it had the acrid smell that the dipstick had, and there was enough that it ran/dripped off my finger. Again, this is something I've NEVER noticed about her car before.
I added 0W-20 until the stick showed 1/8" from full, because the engine was still cold and I didn't want to overfill it. My wife called the dealer and they told her the standard "it's normal for engines to burn some oil" blah-blah. I told her to tell them that this engine has NOT used/lost oil before, and there has never been any crud in the exhaust like the engine is just dumping oil straight through into the exhaust.
We drove home today, and at the halfway point I checked the oil and the stick still showed 1/8" from full, so I added a little more, waited a few minutes for the oil I'd added to run down through the engine, and the stick showed completely full. Then I checked the exhaust tip, and the entire circumference, as far inside as I could see, was coated with a solid layer of black, dry soot; I could scratch/scrape some off, and it smelled of oil.
It's going to the dealer Tuesday night, so I'd like to take the pulse of the community and be forewarned/fore-armed when they report to us Wednesday.