[RockCrusher]

As I think I mentioned a while back I was going to have the oil from my 2024 230i xDrive analyzed at the first oil change. This would be the factory fill oil.

At the same time I was going to have a sample of the oil the tech was going to put back into the engine analyzed.

The results are below. (Don't know why the scans turned out a bit out of focus.)

Oil-1 is the virgin oil sample. BMW Group 0w-20 LL-17 FE+.

Oil-2 is the oil from the engine with 624 miles from new. Probably 0w-20 oil but I have no confirmation of that...

Some observations....

Oils-1:

Virgin sample of the oil used to refill the engine. BMW Group 0w-20 LL-17 FE+.

Wear Levels metals are nil. Of course.

Some additives worth noting…

Molybdenum: 68 (ppm)
Zinc: 903 (ppm)
Magnesium: 882 (ppm)

Water: nil

Viscosity at 100C: 8.577



Oils-2:

Factory fill oil. Details unknown but could be: BMW Group 0w-20 LL-17 FE+.

Miles on oil: 624.

As expected wear metal levels are “elevated”. Copper, iron, aluminum, silicon.

Additives…
Molybdenum: 504 (ppm)!
Zinc: 848 (ppm)
Magnesium: 11 (ppm)

Water: nil

Viscosity at 100C: 7.373


Takeaways?

The virgin sample of oil has a 1 point higher viscosity index. This suggests the factory fill oil has suffered some viscosity loss.

Molybdenum level in virgin sample low (58ppm) while the factory fill oil has 504 (ppm). This suggests Molybdenum might have been added at the factory. (As an aside, for additional wear protection Porsche techs recommended I add a Molybdenum additive to my Porsche engines. Specifically SWEPCO 502 Engine Oil Improver with 200ppm Molybdenum (I had a sample analyzed)).

Added to the oil or possibly the result of pre-lubing the valve hardware with a moly based grease. When I rebuilt a couple of engines the cam maker included a can of special grease to apply to the cam lobes to provide lubrication until the oil reached these areas. Of course the grease washes away in nearly no time as the oil flows but the grease ends up dissolved in the oil and any anti-wear additive it contains (and molybdenum is favored) ends up in the oil.

However, from viewing a number of engine assembly videos of BMW, Porsche, M-B (to name 3) I have not seen any thing that suggests that any additional lubrication is applied. The tech does use a bottle of oil to apply oil at various times to various areas/assemblies but that is all.

So I'm leaning towards the molybdenum being in the factory fill oil due to use of a molybdenum oil additive.

Next is magnesium.

Virgin oil has 882ppm. Factory fill oil has but 11ppm! Believe magnesium is part of the detergent additive package. But why the big difference in magnesium? Does this suggest the factory fill oil is short on magnesium? That seems contrary to what one would expect. If the factory fill oil had a similar amount of magnesium what happened to the magnesium? To suggest an answer to my question Magnesium is supposed to keep contaminants suspended in the oil so they can be carried to the filter and removed. To see magnesium that low suggests a lot (so to speak) of contaminants were removed (trapped in the filter).

Water content is nil. This is good! Think it is due to BMW running the engine oil (based on my observations) hot, at or above 212F.

(Might mention my Boxster engine ran pretty cool in the winter and at 4K miles -- all accumulated in winter driving -- when analyzed the oil had a water content of 7%. With just over 9 quarts of oil capacity this worked out to about 1/2 quart of water! All due to condensation. There was no coolant leak.)