I normally have to top up my oil about 1/2 to 3/4 of a litre mid service interval.
I put it down whatís been blown out the crankcase into the turbo intake,
I have a Provent to stop it going into the turbo intake, it collects into a small bottle which I empty now and again.
TOP TIP, make sure you put the oil filler cap on fully, then double and triple check it after you top up the oil,
it makes one hell of a mess if itís even one little bit loose. I had oil dripping from everywhere after a 10 mile trip...... it's not funny