Warning: My mechanic uncle told me to check my oil at every gas stop and I ignored him for 3 months
He said it at a barbecue in July, just a passing comment about how he has seen engines seize at 60k miles from a slow leak nobody caught. I blew it off until my Corolla started ticking last month and I was down 2 quarts with no puddle in my driveway. Anyone else had a leak that only shows up when the engine is running?
Those slow leaks are sneaky because the oil burns off on the hot manifold or gets flung around while you drive, so nothing ever hits your driveway. Check the back of the engine and around the valve cover for dark greasy buildup, that's usually where it hides. Also pull your spark plugs, if one looks oily you found your leak.