Can the complete oil flow out through the oil drain valve?
Is the oil drain valve screwed into the oil pan out higher than the lowest point of the sump and flows from it is not the complete oil?
Not every oil pan is the same. The thread of the oil drain bolt into the oil pan is not standardized, so there is no uniform length. That is why we have chosen a compromise, which in most cases no difference in terms of the amount of residual oil, compared to the conventional drain plug.
The threaded length of the stahlbus-oil drain valve is 12mm. The engagement in the oil pan is attached through the use of copper gasket around 10mm. Thus it generally disappears completely in the bore of the oil pan out and is not higher.