Old Oil Better

[TooSlick]

The additive chemistry in new oils is very strong.... Every time you change fluids, you disrupt the very thin AW films on wearing surfaces such as cam lobes, valve lifters and cylinder walls. It can take up to 1000-2000 miles for these films (iron-phosphate, iron-borate, iron-moly-sulphur, etc) to fully re-form. During this period, wear under boundary lubrication conditions is measurably increased.

The other effect that contributes to lower wear over longer service intervals is the oxidative thickening process. Oil oxidation results in the formation of higher molecular weight species within the oil that effectively increase it's film strength and viscosity - sort of like using a thicker basestock. It has been proposed by researchers at Ford that these secondary species are also partially responsible with the lower wear rates seen with oils that have been in use for some time.

I should note that most of this discussion relates to rates of valvetrain and ring/cylinder wear, ie the Fe and Cr wear. By and large, engine bearings do best with perfectly clean oil that has lots of TBN reserve to rapidly neutralize organic acids.

So the overall message is somewhat mixed, and things are not as simple as folks searching for some "silver bullet", would like to think.

 

[Gary Allan]

The suggestion that there's more "wear" during the 2-3k mark is pretty lame. 1sttruck and I went around and around about this in one post.

I believe that there is an entrainment of material in the bonding of AW packages. Once the film is established ..the entrainment of material drops off and then normal rates of ejecta are observed.

The way to semi dispute this is to do back to back 1500 mile OCI, testing each, and then do a 3k OCI to see if the same event occurs. The first two should establish the film ..leaving the new oil with nothing to do.

(yes, it's on my list of things to do someday).

 

[tenderloin]

If LC helps prevent oxidizing, does this interfere with the "good" process of oils aging?

 

[Flimflam]

quote:

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Originally posted by nascarnation:
I know a fellow who worked for Standard Oil (now BP). They used to run production passenger cars at Daytona on the track as part of their oil test program (this is back in prehistoric times, like the early 60s). He said one mystery they never really understood was that when an engine blew up, it was almost always in the first few hundred miles after an oil change - and it wasn't due to some mistake like incorrect fill level or leaks or whatever.

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nascarnation, funny that you mention this. An old uncle of mine used to say, "Brand new car, not even 3000 miles on the clock. It goes in for a service, and........never runs right again."

There is a strange correlation between messing with a car and never having it work well again.

Some people say the mechanic sabotaged it, but I say, "No." Sometimes, replacing one new part in a System will cause the other components in the System to blow out. This from real-life factual observations. I am busy now and have to run, but will supply the cases, dates, places on request.

 

[davefr]

If having oxidized ZDDP's is critical to low engine wear then maybe you should perform oil changes seperate from filter changes so that the old oil in the filter helps out until the new oil gets "broken in". Then at that point (ex: 3000 miles), change the filter only.

 

[y_p_w]

quote:

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Originally posted by davefr:
If having oxidized ZDDP's is critical to low engine wear then maybe you should perform oil changes seperate from filter changes so that the old oil in the filter helps out until the new oil gets "broken in". Then at that point (ex: 3000 miles), change the filter only.

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I wouldn't know if it's "critical". It's just more or less an interesting aside. Nobody has really established that the wear rates are excessively high with new oil, only that it can be measured.

 

[Ugly3]

Gary Allen - Here is some data that is close to what you are looking for.

Following a 14,000 run of Amsoil here are the numbers for the flush with Mobil 1.

1000 miles - iron=5, copper=14, lead=2
3000 miles - iron=9, copper=30, lead=4

Starting the Mobil 1 run:
1000 miles - iron=4, copper=10, lead=1

 

[TooSlick]

Gary,

I think we're in violent agreement....

The fresh oil disturbs the stable AW films on the surfaces - particularly the ferrous surfaces in the valve train, but perhaps on bearings as well (not sure about any ZDDP/Pb/Cu reaction?).

The more often you change oil, the more often you disturb these films and remove this entrained material - which has to be considered part of the wearing surface, since it's not in solution.

So the wear rate due to the reaction between the AW (and FM?) additives and ferrous substrates DOES INCREASE with more frequent oil changes.

A good analogy is to think about using a harsh & abrasive, cleaner/wax on your car finish. The more often you wax, the more of the clearcoat is removed...

 

[Jay]

I wonder if the new oil wear phenomenon is as complicated as "unstable" AW films or oxidized ZDDP. It may just be that many new oils are very dirty, and it takes time for the oil filter to clean the dirty oil.

Stinky Peterson tried to drive that point home with his suggestion that one shouldn't pre-fill an oil filter. He's posted many VOAs with particle counts that really look ugly from a contamination point of view.

The particle counts on my UOAs with 7000 miles on them are orders of magnitude cleaner than many of the virgin particle counts that Stinky posted.

 

[Gary Allan]

quote:

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I think we're in violent agreement....

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Yes, it appears so ...although we appear to look at things from the opposite ends

I keep envisioning something like a resin bed exchange going on ..where new oil "gang tackles" the existing film/barrier layer ...basically kicking it out of it's seat. I think that mulitiple short OCI's should stiffle this event since the film layer should always be robust and more resistant to disruption ..as in more at par with the newer oil.

Then we should be able to figure out if the actual numbers that we see, or at least a decent percentage of them, are merely decaying barrier layers ..much like the water softener resin bed ejects a sodium molecule every time a Mg or Calcium molecule attaches to the resin. This would make new oil addition the equivalent of the shock that the resin bed sees during the brine rinse during regeneration ..where the Mg and Calcium are "gang tackled" off of the resin beads.

So many questions ...so many tests ..only so much one can do at one time. (so many cats ..so few recipies)

 

[Rev440]

2000 hours old oil is better than 200 hours old oil
Noria Oil Board Link.................

 

[Winston]

As far as new oil being dirty. Solar Turbines requires all new oil be filtered with a 10 micron filter before being installed in their turbines. I also noticed high particle counts with Stinky's VOA's.

I wonder why no one has considered filtering their new motor oil before putting it in the car?

 

[Audi Junkie]

I wanted to get a look at this thread so I can think about it a bit. Kinda busy now but my 1st thought is that maintaing the same brand of oil (add pack) over the course of multiple changes would seem to minimise the effects of "frequent" changes.

 

[Ugly3]

quote:

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Originally posted by Winston:
As far as new oil being dirty. Solar Turbines requires all new oil be filtered with a 10 micron filter before being installed in their turbines. I also noticed high particle counts with Stinky's VOA's.

I wonder why no one has considered filtering their new motor oil before putting it in the car?

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After you add 5 quarts of the "dirty" new oil and start the engine it takes 1 minute to run the new oil through the full flow filter 5 times. Should be pretty clean by then.

 

[y_p_w]

quote:

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Originally posted by haley10:

quote:

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Originally posted by tenderloin:
If LC helps prevent oxidizing, does this interfere with the "good" process of oils aging?

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Maybe that is why Ted has cautioned against overdosing?? You can get too much of a good thing. For now I'm choosing not to run it, but in the amounts Terry suggests for the application, I think the benefit is there. I think LC should be used as prescribed. My thought is that you might well increase wear if you overdose and don't follow directions.

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I've seen a few citations where it was stated that ZDDPs are also antioxidants. My basic understanding of what that means is that they oxidize rapidly and sacrifice themselves to prevent other components from oxidizing. One explanation is that they neutralize peroxides that form in the oil. So (anyone correct me if I'm wrong) the point is that the "virgin" ZDDP serves as an antioxidant, at which point it's "activated" such that it readily bonds to metal surfaces as an antiwear agent.

 

[sjlee]

Interesting read. The original article is only related to Mobil 1, a synthetic. It doesn't say if this applies to dino oils.

 

[haley10]

Very interesting thread with a lot of great links. Very informative.

As I hear additive packages are getting more expensive all the time and may be a bigger price factor than basestocks.

A lot of dino's just don't seem to have good TBN retention. Extending drains is probably a good thing, but you need the right additive pak to be able to do that.

Was not a part of the premise behind the factors calculated by the GM OLM based on theoretical ZDDP depletion?? You really can't see that in a uoa, but in certain oils you may be able to look at boron depletion and be able to tell, right?

 

[haley10]

quote:

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Originally posted by tenderloin:
If LC helps prevent oxidizing, does this interfere with the "good" process of oils aging?

---

Maybe that is why Ted has cautioned against overdosing?? You can get too much of a good thing. For now I'm choosing not to run it, but in the amounts Terry suggests for the application, I think the benefit is there. I think LC should be used as prescribed. My thought is that you might well increase wear if you overdose and don't follow directions.

[ July 21, 2005, 12:25 PM: Message edited by: haley10 ]

 

[bruce381]

Sorry to disagree but Fresh oil or ZDDP does not disturb or wash away the Phosphate "film" from previously used motor oils. This film is a reaction that has been mesured deep into the metal subsrate it is not as surface film at all. The high FE numbers shown up after a oil change are more likly due to the higher surface activity of the fresh oil's DI package cleaning off surface debris. The new ZDDP oil does not wash off this film and then float around waiting to oxidize so it can lay down a new film.
In fact the ZDDP reaction is immediate at operating temps and is part of the function of ZDDP reacting to any bare metal forming a phosphate "coating" which is why ZDDP works well as an AW additive.

I do agree about oxidized oils getting thicker and more polar and sticking to metal better, but that is a long shot to depend on oxidation to protect an engine from wear.

Also if oxidized ZDDP had any improvement over fresh there would be a product on the market and there are none I know of claming this.

Any suportive data published in known journals I would like to see maybe I can learn something new.
bruce

 

[bruce381]

I stand corrected I will have to read the SAE Technical Paper 2003-01-3119. Till then I'll have to keep an open mind I guess.
Bruce