Why iron ppm numbers are NOT good wear indicators.

[RDMgr]

The combination of fine and coarse wear metals is a more true indicator of current unit condition then fine metals determined by ICP, ICP being the most commonly used method for oil analysis. ICP measures particles up to about 7 or 8 microns, within the size range for normal rubbing wear. Unfortunately, particles that indicate initial problems are larger then this and they are not aspirated into the plasma, that is, they're not seen.

PQ Index is a unit-less index of the effect that the magnetic particles in a sample have on a magnetic field. If the iron content by plasma and the PQI are approximately equal then the ICP number is representative and particles are most likely normal rubbing wear. If the PQI is larger than the ICP number it suggests that something beyond normal rubbing wear is occuring and exception tests are needed. Similar correlations can be seen between ICP and x-ray fluoresence. PQI is excellent for problematic trends once a problem has been identified.

 

[daman]

So see M1 is a good oil!

 

[buster]

Terry Dyson also said M1 had solvency issues for years when that couldn't be further from the truth!

 

[OVERKILL]

Doesn't this completely destroy the "M1 iron myth" then?

It also backs up what Doug has been saying all along.

Those chasing the minute changes in Fe between different oils with inexpensive UOA's and only doing UOA's for that reason are just wasting money.

 

[d00df00d]

Originally Posted By: OVERK1LL
Doesn't this completely destroy the "M1 iron myth" then?

It also backs up what Doug has been saying all along.

Those chasing the minute changes in Fe between different oils with inexpensive UOA's and only doing UOA's for that reason are just wasting money.

Yes.

 

[demarpaint]

Originally Posted By: d00df00d
Originally Posted By: OVERK1LL
Doesn't this completely destroy the "M1 iron myth" then?

It also backs up what Doug has been saying all along.

Those chasing the minute changes in Fe between different oils with inexpensive UOA's and only doing UOA's for that reason are just wasting money.

Yes.


Which brings me back to what I've thought all along about them.

They are good for detecting fuel in oil.
Coolant in oil.
Maybe a major spike in some metal could indicate a problem, maybe.
And perhaps determining if an OCI can be extended.
Lets not forget they make for some good discussions here on Bitog.

 

[JOD]

Originally Posted By: OVERK1LL
Doesn't this completely destroy the "M1 iron myth" then?


I don't really see how? It's not a myth. M1 consistently demonstrates higher iron levels when measured in PPM. This isn't a myth, it's fact. Whether or not it's relevant is a totally different question.


Originally Posted By: OVERK1LL
It also backs up what Doug has been saying all along.

Those chasing the minute changes in Fe between different oils with inexpensive UOA's and only doing UOA's for that reason are just wasting money.


It doesn't "back up" what anyone says, it simply shows the limitation of the common FE measurement protocol. Who knows, maybe PQ would indicate higher FE as well? I'm NOT saying that's the case, simply that this sell sheet doesn't really answer that question...

To you final point though, I totally agree. Chasing minute changes in PPM is a waste of money and time.

 

[d00df00d]

Originally Posted By: JOD
Originally Posted By: OVERK1LL
Doesn't this completely destroy the "M1 iron myth" then?


I don't really see how? It's not a myth. M1 consistently demonstrates higher iron levels when measured in PPM. This isn't a myth, it's fact. Whether or not it's relevant is a totally different question.

The mythical part is that the differences in the Fe numbers mean what people think they mean (i.e. excess wear).

 

[demarpaint]

Originally Posted By: d00df00d
Originally Posted By: JOD
Originally Posted By: OVERK1LL
Doesn't this completely destroy the "M1 iron myth" then?


I don't really see how? It's not a myth. M1 consistently demonstrates higher iron levels when measured in PPM. This isn't a myth, it's fact. Whether or not it's relevant is a totally different question.

The mythical part is that the differences in the Fe numbers mean what people think they mean (i.e. excess wear).


LOL. Or as some believe better cleaning and freeing excess metal caught up in dirt and junk. All depends on what you want to believe. The only weakness in that comment is what about the engine that was fed M1 all its life????

 

[daman]

Originally Posted By: demarpaint
The only weakness in that comment is what about the engine that was fed M1 all its life????

And is still alive and functioning fine!!

 

[demarpaint]

Originally Posted By: daman
Originally Posted By: demarpaint
The only weakness in that comment is what about the engine that was fed M1 all its life????

And is still alive and functioning fine!!

And why I won't spend money on a UOA, since they are not so cut and dry, leave lots of room for debate, and are meaningless according to the real experts for determining engine wear. Yet when the so called wear numbers are low everyone in favor of the oil seems to believe the numbers mean something. Then when they show higher levels of metal those in favor of the oil say the numbers are meaningless, those who dislike the oil are locked, loaded and ready to attack.

 

[OVERKILL]

Originally Posted By: JOD


I don't really see how? It's not a myth. M1 consistently demonstrates higher iron levels when measured in PPM. This isn't a myth, it's fact. Whether or not it's relevant is a totally different question.


The "myth" is that the elevated PPM (in some grades; not all grades of M1 show it) is paraded around as definitive proof of wear. Which this article points out, may not be the case at all!


Quote:
Originally Posted By: OVERK1LL
It also backs up what Doug has been saying all along.

Those chasing the minute changes in Fe between different oils with inexpensive UOA's and only doing UOA's for that reason are just wasting money.


It doesn't "back up" what anyone says, it simply shows the limitation of the common FE measurement protocol. Who knows, maybe PQ would indicate higher FE as well? I'm NOT saying that's the case, simply that this sell sheet doesn't really answer that question...

To you final point though, I totally agree. Chasing minute changes in PPM is a waste of money and time.


Doug's point was that forming hard conclusions based on the results of inexpensive UOA's and making choices based on minute variances in PPM was a waste of time. And not the correct use of the tool (my summation of one of his past dissertations, definitely not his exact words). This backs up that argument. That is what I was saying.

 

[Capa]

Originally Posted By: FZ1
That's right,boys. Net of the variables,Uoas are Alchemy;not Science. Interesting Alchemy,though.


Excellent quote. Should be a sticky. This is a very fascinating thread. I agree that an UOA is very limited in the actual meaningful information that it renders. I personally have never had one done and probably never will unless I wanted to do a very long OCI. I've always have found it silly when people would quibble over 5 or 15 Fe ppm. Those numbers are insignificant and even if accurate the same car would more than likely last just as long with either reading.

 

[steve20]

"The "myth" is that the elevated PPM (in some grades; not all grades of M1 show it) is paraded around as definitive proof of wear. Which this article points out, may not be the case at all!"

That, and the fact that it protects 4X less than Synpower

 

[fsskier]

A couple of years ago someone posted a link - to either a Royal Purple or Redline tech article, I forget which- that stated:

Some anti wear additives form a chemical alloy with the iron that:
1. Greatly decrease the engine wear
2. Increase the ppm of fe in oil samples!

So, higher iron may be a result of additive choices that decrease wear, note that this article was from a competitor of Mobil 1

They stressed the importance of engine oils being certified with actual wear measurements, not by guess-testing the oil going to recycling!