Insoluables, is it a measure of filter performance

[Ugly3]

From time to time I see people mention that high levels of insoluables is a reason to change the oil filter. However, in the 3MP Synthetic Oil Life Study when the filter was changed for a new one the insoluables did not go down with a new filter. Just what is the relationship here?

 

[ekpolk]

Perhaps the old filter had already trapped all that could be trapped by physical filtration, and the new filter did nothing more than continue filtering out only the same, above size-X particles, while leaving the smaller component of the total insolubles untouched?

 

[Gary Allan]

I'm not cemented in my take on this yet, but I'd say that higher insolubles would be, perhaps, and indication of poor filtration more then low being in indication of "good". When I did a 60 mile "in engine voa" the insolubles were rather high. The filter was new. We can assume that the insolubles were not from accumulated combustion byproducts. They may have been additives that were not fully suspended to the particle level within 60 miles. I dunno

Again, I'm uncertain, but I would reason that there's a combination of elements keeping insolubles low. I imagine our detergent packages, to some extent, floculates these particles and allows the filter to trap them. I'm also sure that not all insolubles are created equal and will have different affinities for "flocking together". Many are of the 2um +/- size ..and, as ekpolk suggest, probably are accumulative when you're into an extended drain situation of the nature that the space bears study was. Most who do extended drains aren't doing extended drains like 3 Mad Ponchos conducted the test. They're doing 15k-25k a year and rarely doing it over one OCI.

 

[JAG]

I think insolubles are too small for typical spin-on filters to filter out. Many times I've let drained oil sit in a container and after a few months or less, a layer of black solids settles on the bottom. It certainly was dispersed in the oil when it went into the container.

 

[harry j]

Quote:

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I think insolubles are too small for typical spin-on filters to filter out. Many times I've let drained oil sit in a container and after a few months or less, a layer of black solids settles on the bottom. It certainly was dispersed in the oil when it went into the container.

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JAG,

Try the same thing after using an Eao, should prove very interesting.

Harry

 

[JAG]

I plan to when I'm done using up my Mann filters.

 

[GeorgeCLS]

The insoluble discussion (427 asked me re EaO performance) is all rather unknown to me as it relates to filter performance. In those rare cases where insolubles are looked at, it is in relation to soot or some other specific issue, and not relative to abrasive particulate wear and filtration..

As it relates to normal engine wear, I look at an oil filter's performance in the >10 micron level, as I have found it to be the most abrasive, most affecting size spectrum, of contaminants from my experience. So it is a simple case of establishing a target ISO cleanliness for the required needs.. Frankly, from a lube engineer's perspective, we simply do not look at retained solids...
Thus "retained solids" is answering a question that I am not asking as a lube engineer......
George Morrison, STLE CLS

 

[427Z06]

Here's Balackstone's take on insolubles:

http://www.blackstone-labs.com/what_are_insolubles.html