I previously had a 2011 D4 that under load and when the secondary turbo kicked in it kicked a load of smoke out the rear. The repair for this was the turbo drain mod, this ‘mod’ only affected certain years, definitely ‘rectified’ prior to my MY.

My question is, what could give me the same symptoms now on my later engine? I’m getting smoke but only after around 2k revs, no oil usage over the last 3k miles 2004 D3 HSE TDV6

2011 D4 HSE SDV6

2015 L494 RRS Autobiography SDV6

I could be wrong but the problem with using the virtual oil level as a guide is it is not 100% accurate. Also depending on your driving habits, oil dilution could in reality match your oil usage making it seem like you have zero oil usage.

If you get smoke when the secondary turbo kicks in, logic would say it’s oil related.