2008 MB C300, M1 0w-40 SN, 189 Miles

[Ayrton]

This newest reading is on oil in the car for 189 miles. I was confirming my Mobil 1 0w40 SN that I took in was used and I find the near virgin oil fascinating. The previous two columns were SM Mobil 1 0w40, and the oldest two columns were Mobil 1 5w40 (a special dealer product). This new fill of SN looks fine and richer in Boron and Calcium than the near virgin fill last year. However....Why do I have silicon at 7 after an oil change and sodium at 4? This is like 3/4 of the amount before the oil change I guess down to 4 Iron would be normal though? 1/2 the aluminum sticks around too. I wonder...my dealer likely sucks out oil. How clean is it when they do this? I guess I'm being picky, but it makes the end of year numbers more impressive when you see you start out with some of these numbers already a god bit higher than 0. I know there is residual, but some of it seems higher than you'd expect? I really think we should consider this when we look at people's UOAs, if after only 189 miles, a good chunk of the final contaminants were already in the oil. I didn't bother with TBN on this fresh oil since someone already has a SN VOA of 0w40.

 

[Pablo]

Originally Posted By: Ayrton

I guess I'm being picky, but it makes the end of year numbers more impressive when you see you start out with some of these numbers already a good bit higher than 0. I know there is residual, but some of it seems higher than you'd expect? I really think we should consider this when we look at people's UOAs, if after only 189 miles, a good chunk of the final contaminants were already in the oil.

It's partially this plus people read WAY too much into single digit fuzzy numbers in UOA's. Essentially all you did was a VOA and mix it with whatever was left behind. Interesting, not sure where you are going. Looks a great oil, run it.

 

[Quattro Pete]

So, down to a 30-weight after only 200 miles? M1 0w-40 haters will have a field day with this one.

 

[JAG]

Originally Posted By: Quattro Pete

So, down to a 30-weight after only 200 miles? M1 0w-40 haters will have a field day with this one.

They should know that the rate of shearing is at its highest with virgin oil and decreases over mileage as more and more polymers get broken. Long polymers are easiest to shear and once broken the leftover pieces may not be further broken down for the rest of the OCI.

 

[Artem]

Looking at the 100 mile UOA and the previous 4.7k run, it's clear that a good 1/4th of the wear metals that are produced are already in the oil after only 100 miles. The rest accumulate over the course of 5k miles. I'm sure if you dump the "Near Virgin" oil and refill with new juice and resample in 100 miles, the metals would be even lower as there will be less leftovers floating around in there after a "flush"