The sensors degrade over time. My two older BMW's both started giving false low warnings. The only way to really know how much oil you have (or had) is a dipstick or to catch the old oil during an oil change and measure it. The system also only has a resolution of 1/4 between MIN and MAX. So, 1/4 above MIN could mean anything from 3/8's to 1/8 above MIN.
At my last oil change, 5.5 years and 55k miles, the system said it was at MIN, but it really only lost about 850cc. I'm not going to add oil until I see the level on screen below MIN. Then, I'm only going to add a half-liter.
Turbochargers, especially old ones, can cause some oil loss.
Last edited by Autoputzer; 09-07-2019 at 04:28 PM.