remix919

I have owned my 2017 GLS450 since new and it currently has about 60k miles, I do all the maintenance myself and recently when doing an oil change, I noticed I only drained 3.5 quarts out, but I always put in 7.5-8 quarts w/ filter, so that means I lost over 4 quarts between oil changes. I'm quite surprised the car didn't give me any low oil warning. I know that turbocharged engines typically will eat some oil but 4 quarts seems like a lot. I looked under the car and don't see any oil leaks or drips and then looked in the engine bay and saw a small amount of buildup around the valve cover and timing inspection cover but nothing to justify losing 4 quarts of oil. I also searched on this forum and didn't see any oil related posts. Hoping someone could give me some more information on potential leak areas or if this amount of consumption is normal for this biturbo engine.

chassis

M276 does not consume large amount of oil between changes.

Leading candidate is underfill at the most recent oil change.

You report no drips under the car, slight weeping on the valve cover (normal for all MB engines), and no low oil warning light.

Do you have smoke from the tailpipe?

If no smoke, then you underfilled it last time. It happens.