Originally Posted by romanonj
No oil leaks, Both cars are parked in the garage.. With leakdown test showing 14% on cylinder 6, it is pretty obvious where the oil is going.
As a preventive measure, I have also installed magnetic drain plug to give me insight on engines wear and tear. Nothing out of ordinary is seen between oil changes, some black dust residue, no metal shavings..
Having said that, I tried mobil 1, castrol, BMW.. Is there any oil that may preserve it's lubrication properties longer?
Seems like you've been through. Maybe add a quarter of Lucas Oil additive? I've never used it on a BMW, but had good luck with it on several other vehicles.