Additives settling out of oil. Test results...

If it's smaller than 20 µm then likely most of it will pass the oil filter. I don't think that's a good thing or it doesn't even matter.




My first thought when watching your video. I used to shake any bottle before, but I will have to rethink this common practice. That said I have never observed anything settling out yet. Perhaps your old Shell example is a rare exception? Even then the result of your OAs remain true anyway. Common additives do not settle out. Thank you very much for your effort.
.

Re whether it's damaging... Yes, if it were as big as 20 that could be a concern IF there was enough of it to worry about. But some will get trapped by the filter, some will settle out and that's from a starting point of there probably being less then 66 ppm of it. It's not something I would worry about because there is so little of it to start with.
 
So if this is correct then what is settling out would likely not appear on a spectrographic analysis:


I would take a different view... I think it would show up on a full spectrographic analysis but It won't appear in the tests done for regular oil analysis because it's not one of the "things normally tested for". If we had a research lab available and could collect a sample of the gray muck we could find out exactly what it is. I didn't see the material you quoted from the oil company before but it matches, at least in a general way, what I was thinking might be the case. I'm sure there is a lot of "chemistry" going on beyond the routine oil lab testing categories and very possibly it's trade secret stuff they would prefer not to get too specific about. I would not be surprised if there might be very slow chemical reactions that precipitate out molecules/particles of the "gray stuff", either as true chemical reactions or more simply as compounds/elements coming out of solution.
 
Re whether it's damaging... Yes, if it were as big as 20 that could be a concern IF there was enough of it to worry about. But some will get trapped by the filter, some will settle out and that's from a starting point of there probably being less then 66 ppm of it. It's not something I would worry about because there is so little of it to start with.
Or none of it is of sufficient hardness to cause a problem and it solubilizes once the oil heats up.
 
Last edited:
I would take a different view... I think it would show up on a full spectrographic analysis but It won't appear in the tests done for regular oil analysis because it's not one of the "things normally tested for". If we had a research lab available and could collect a sample of the gray muck we could find out exactly what it is. I didn't see the material you quoted from the oil company before but it matches, at least in a general way, what I was thinking might be the case. I'm sure there is a lot of "chemistry" going on beyond the routine oil lab testing categories and very possibly it's trade secret stuff they would prefer not to get too specific about. I would not be surprised if there might be very slow chemical reactions that precipitate out molecules/particles of the "gray stuff", either as true chemical reactions or more simply as compounds/elements coming out of solution.
Only if it is composed of metal or some metalloid elements. As Pennzoil notes they state it is possibly part of the TBN package and that will likely be carbon and nitrogen atoms. No ICP is going to test for those even if they could considering that's the composition of the rest of the oil. If you want to find out what the gray muck is you'd use several other analytical methods besides elemental analysis.

It's not a "secret" as much as it may show (again) the limitations of this type of analysis.
 
About four days ago I took a sealed jug of PP SN in the silver bottle off a shelf and poured it directly into the engine of a T100. I looked inside and the sun was out. Nothing in the bottom of the jug except the usual coating of oil that is there after pouring. No black, nothing. No shaking the bottle. It had to be five years without moving also, just like this guy. I have oils older than that, never see anything, don’t understand why I am so lucky. But I do believe others see it, so maybe the tiny amount of gray matter is like from the piping system or something at the filling plant. Nothing is perfectly clean. Maybe at the beginning of a shift some pipe dope or something is first flushed out. Then lucky people get the good stuff after that.
 
I've just watched this. Before I comment I'll mention that I have a university degree in Analytical Chemistry and one of my previous jobs was running the investigational laboratory at a major oil supplier. My simple reaction: all three samples are the same. The differences in results are down to reproducibility, experimental error and test method resolution. The small amount of deposit at the bottom was miniscule - it could have been some poorly mixed additive settling out or perhaps an inter-additive reaction but the oil was generally clear and bright and, as far as I could see, in good condition. That small deposit could have been there since the day it was purchased.

I've said it before, a well-blended oil stays blended - the additives are generally miscible* and therefore once mixed don't separate. It's like mixing some water with some whisky - it won't unmix no matter how long you leave it. An oil that hasn't had a good amount of mixing or was blended too cold may well not be fully blended and then you can see stratification of the various components by density, but this is rare for a production sample.

*One exception is the antifoam, which is usually a silicone fluid that is immiscible with oil and is added with a high shear stirrer to create very fine droplets that disperse within the oil. Over time these can, and do, separate out of the oil but the factors that influence this are manifold and usually it's not a problem.
 
Memory is getting less reliable these days but if I recall correctly,
most complaints of additives settling out are with blends or even synthetics.
The sample in question is conventional oil, and rather old spec.
I'd like to see this 'test' on a synthetic or a blend 5W-30 or 5W-20 oil.
Just my opinion.


My 2¢
 
Stuff like this is why I come back to this site despite the “I put in Castrol GTX and my butt dyno can confirm I’m getting at least 30 extra HP” threads. Thank you for the informative post and well made video.
 
The small amount of deposit at the bottom was miniscule - it could have been some poorly mixed additive settling out or perhaps an inter-additive reaction but the oil was generally clear and bright and, as far as I could see, in good condition. That small deposit could have been there since the day it was purchased.
I've said it before, a well-blended oil stays blended - the additives are generally miscible* and therefore once mixed don't separate.

As a generale rule, would you recommend to shake the bottle or better leave deposits where they are?
.
 
Keep in mind that oil drums pump from the bottom, from oil change places.

The tubes through which the oil is drawn from
the tank are normally two or so inches from contacting the bottom. One reason for this is to prevent sucking up deposits off the bottom.
Also, oil is often delivered into tanks in such a manner that the product in the tank is well mixed with the oil being pumped.

Memory is getting less reliable these days but if I recall correctly,
most complaints of additives settling out are with blends or even synthetics.

I first saw this in 1985, years before that company introduced synthetics or blends.
 
Back
Top