Does lower ZDDP protect less or for shorter time?

[OceanRuns]

Assuming an older engine that may benefit from ZDDP...

Let's say one oil has around 750-800 PPM ZDDP. Another has 1,200.

My simple understanding is that ZDDP is consumed in a sacrificial capacity as it protects high-wear surfaces. (May or not my be saying this correctly.)

If this is accurate, then does the lower ZDDP oil above provide protection, just for a lower number of miles?

Would an oil with 750-800 PPM provide protection for a certain number of miles before being 'used up'? And, would the higher ZDDP oil provide the same protection, just for a greater number of miles?

Or, does a higher ZDDP concentration protect better right from the start? Is more ZDDP needed initially to coat what needs coating? Or, is a lower level of ZDDP sufficient?

 

[turtlevette]

Since they put over 2000 ppm in race oils and race oils are changed frequently, I would say a higher ppm protects better.

 

[Joe90_guy]

This is an excellent question which I should know the answer to but don't!

However if I were to hazard a guess I'd say that ZDDP doesn't deplete in quite the way suggest. Corrected for oil loss and fuel dilution, I suspect that an oil contains exactly the same level of zinc & phosphorus after use, as it did when you added it fresh. The amount you are actually sacrificing (ie bonding with metal on things like cam tips) will be tiny. Remember that you only get sacrifice when metal touches metal and for a lot of the time, this doesn't actually happen in an engine because the surfaces are forcibly separated by a hydrodynamic film of oil.

Although I never purposely looked, my guess is that the first few ppm of ZDDP are extremely effective in preventing wear, but the more you add the less bang for your buck you get. Doubling the level of ZDDP in an oil probably doesn't half the level of wear you get or make the ZDDP last twice as long.

People like me whine about lower ZDDP levels not so much because of their impact on wear but on their impact on oil oxidation; particularly on the TEOST MHT-4 test (winner of The World-wide All-time Dumbest Oil Test competition, fifteen years in a row)...

I'm happy to be contradicted if there's some smart Alec from Lubrizol wot knows better!

 

[440Magnum]

Both, really. A higher percentage of ZDDP means that more ZDDP molecules are available at the cam/lifter interface at any given instant in the event that loading punches through the oil film strength and it has to be called into play, so having more results in an oil that is at least able to protect better. IMO, the better broken-in the engine is, the less critical that becomes.

But ZDDP is also consumed as it protects- its a sacrificial additive(*). So having more floating around in the oil means that there's more to be used up for a longer period.

(*)- note that Zn and P levels in used oil don't change much from initial values, but the Zn and P may no longer be in the USEFUL form of ZDDP... I don't know the whole story on how much is actually consumed during metal-to-metal contact events, or what the resulting Zn and P compounds might be.

 

[Jetronic]

Originally Posted By: Joe90_guy


People like me whine about lower ZDDP levels not so much because of their impact on wear but on their impact on oil oxidation; particularly on the TEOST MHT-4 test (winner of The World-wide All-time Dumbest Oil Test competition, fifteen years in a row)...

I kinda feel the same way, though not for 15 years yet, and not as outspoken...

 

[edhackett]

Originally Posted By: 440Magnum
Both, really. A higher percentage of ZDDP means that more ZDDP molecules are available at the cam/lifter interface at any given instant in the event that loading punches through the oil film strength and it has to be called into play, so having more results in an oil that is at least able to protect better. IMO, the better broken-in the engine is, the less critical that becomes.

But ZDDP is also consumed as it protects- its a sacrificial additive(*). So having more floating around in the oil means that there's more to be used up for a longer period.

(*)- note that Zn and P levels in used oil don't change much from initial values, but the Zn and P may no longer be in the USEFUL form of ZDDP... I don't know the whole story on how much is actually consumed during metal-to-metal contact events, or what the resulting Zn and P compounds might be.



All of the above is essentially correct.

The anti-wear film is a complex made primarily of Zn, P, and Fe. Only the ZDDP and several generations of daughter products of the break down of the ZDDP can form the film. Eventually they get sheared into molecules that can no longer form a protective film. Those molecules still contain the Zn and P present in the original ZDDP. Analysis of the used oil will still show the same levels as the new oil. The instrumentation only sees Zn and P atoms. They could come from an old piece of chain link fence and dishwasher detergent as far as it knows.

Ed

 

[Solarent]

Originally Posted By: Joe90_guy
However if I were to hazard a guess I'd say that ZDDP doesn't deplete in quite the way suggest. Corrected for oil loss and fuel dilution, I suspect that an oil contains exactly the same level of zinc & phosphorus after use, as it did when you added it fresh.

Phosphorus loss is an important part of the current API specifications. In order to hold the GF-5 (or API Resource Conserving Mark) the used oil cannot loose more than 21% of the initial phosphorus - which seems like quite alot.

When GF-5 was first introduced, Phosphorus retention was one of the key issues that OEM's were pushing for and the 79% Limit in the Sequence III G part B test is how the additive and oil companies responded. This also required new kinds of low volatility ZDDP to be developed.

Here are some Lubrizol articles for you

:
High Phosphorus Retention ZDP Technology: A Breakthrough in Performance, Lubrizol Engine Oils
ZDDP Technology Offers Engine Protection Extends Exhaust Catalyst Performance
SAE 2007-011990
SAE 2007-010410

So while phosphorus depletion is much less of an issue today than it was with previous generation engine oils, it still is an issue.

Quote:
Although I never purposely looked, my guess is that the first few ppm of ZDDP are extremely effective in preventing wear, but the more you add the less bang for your buck you get. Doubling the level of ZDDP in an oil probably doesn't half the level of wear you get or make the ZDDP last twice as long.

I'm also not 100% on this but if I recall correctly you are right here. Double concentration of ZDDP isn't necessarily going to equal half wear, but maybe some extra benefit. There is a point where more isn't going to do you any good - which based on the current API specs is 800ppm.

 

[djb]

My understanding is that the ZDDP only comes into play as the base oil itself fails. Like most other EP additives, it keeps the metal surfaces from sticking together, roughly by smearing zinc on the contacting surfaces to prevent smearing transfer of the bearing surfaces themselves.

So for each bit of ZDDP 'consumed', even more oil will be sheared.

 

[edhackett]

Originally Posted By: Joe90_guy

Although I never purposely looked, my guess is that the first few ppm of ZDDP are extremely effective in preventing wear, but the more you add the less bang for your buck you get. Doubling the level of ZDDP in an oil probably doesn't half the level of wear you get or make the ZDDP last twice as long.


I think you are correct on this. There seems to be a lower threshold of about 0.05% for effectiveness. More buys you more protection and more time, but only to a certain point. The relationship is not linear. I'd venture a guess that protection tops out before time.

Based on the studies done by Ford on ZDDP effectiveness in used oil, other factors like TBN, TAN, and oxidation condemn the oil long before the ZDDP gives up its ability to form an effective anti-wear layer.

Ed

 

[Joe90_guy]

If I'm honest, I don't think anyone alive today truly understands what ZDDP does in a modern engine. Remember ZDDP dates back to early WWII. I am sure a lot of testing was done back then but all the clever bods that did the original R&D are long since dead.
For as long as I can remember, the amount of ZDDP in an oil is simply maxed out consistent with what's allowed by the spec. People don't think much beyond this essential fact. Add to that for a long time, wear hasn't been much of a big deal for the people that develop oils relative to issues like oxidation, viscosity increase, fuel economy and piston deposits.
I think it's okay for everyone to have their own particular opinions on how ZDDP works and how long it lasts for as long as people realise that's all they are; opinions. No-one knows what the definitive truth is anymore...
As regards Phosphorus Retention, all can I say is that this is yet another test dreamt up by the same bunch of crazies that inflicted TEOST MHT-4 on an unsuspecting industry! Had these people been in the UK, as opposed to the US, we would have had them sectioned a long time ago!
Outspoken? Moi??

 

[Solarent]

Apparently you haven't seen this video yet


Lubrizol would have you believe that they can see exactly what zddp is doing on the level of the surface. (not that they didn't know before - but now you can see it).

 

[edhackett]

Here's a start for papers on how ZDDP works. New analytical methods have allowed a lot to be done in the past few years. You are correct that in the past little was known about how it worked. Now the mechanism has been pretty well defined.

https://scholar.google.com/scholar?q=zdd...wIVCgaSCh1tNAmO

It's similar to the indophenol blue method of analyzing ammonia. The technique has been used since about 1890. The exact reactions and the order they occurred was not known until 1983.

Ed

 

[Joe90_guy]

No, I haven't seen this.

It's very good isn't it? The animations are so convincing aren't they? All they needed to made this perfect were the little firemen from the Gaviscon adverts squirting ZDDP onto the metal surfaces. The only thing that surprises me is that Lz didn't hire Tom Hanks to do the narration.

If that sounds a tad cynical it's because it's meant to. I remember the early days of fuel additives. Beautifully posed photographs of cars on normal fuel belching out smoke and the same photograph showing the same car on additive treated fuel with perfectly clean exhaust. Except it wasn't quite like that. More a case of a photograph of the car with the engine turned on versus one with the engine turned off.

I also recall a wonderful little movie of a combustion chamber comparing untreated fuel to treated fuel. The first was a bit patchy (clearly all those areas of incomplete combustion) and the second was soooo bright it was like looking at the sun. Just look at what additives do! Surely only a cynic would be so crass to as to suggest that you can achieve exactly the same effect by over exposing the film for the second clip.

I could go on and on and on...

Did anyone on this video lie. Certainly not. Did they tell you the whole truth? I suspect not. Was the first intent (as it usually is in the additive industry) to make you think they know more than they actually do. What do you think?

 

[aquariuscsm]

Originally Posted By: djb
by smearing zinc on the contacting surfaces to prevent smearing transfer of the bearing surfaces themselves.


That's the best way I've ever heard it explained. The zinc on zinc (microscopic metals) rub against each other instead of the camshaft metals rubbing against each other. Basically allowing the metal shields (zddp layers) to rub against each other protecting the high contact "moving metal" engine internals.

 

[Peter_M]

This may assist: http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3568809/2

 

[garyb80]

Originally Posted By: Joe90_guy
No, I haven't seen this.

It's very good isn't it? The animations are so convincing aren't they? All they needed to made this perfect were the little firemen from the Gaviscon adverts squirting ZDDP onto the metal surfaces. The only thing that surprises me is that Lz didn't hire Tom Hanks to do the narration.

If that sounds a tad cynical it's because it's meant to. I remember the early days of fuel additives. Beautifully posed photographs of cars on normal fuel belching out smoke and the same photograph showing the same car on additive treated fuel with perfectly clean exhaust. Except it wasn't quite like that. More a case of a photograph of the car with the engine turned on versus one with the engine turned off.

I also recall a wonderful little movie of a combustion chamber comparing untreated fuel to treated fuel. The first was a bit patchy (clearly all those areas of incomplete combustion) and the second was soooo bright it was like looking at the sun. Just look at what additives do! Surely only a cynic would be so crass to as to suggest that you can achieve exactly the same effect by over exposing the film for the second clip.

I could go on and on and on...

Did anyone on this video lie. Certainly not. Did they tell you the whole truth? I suspect not. Was the first intent (as it usually is in the additive industry) to make you think they know more than they actually do. What do you think?



That may not have been impressive to you, but I was very impressed with the atomic knife technology. In my industry, to look at the cross section of a small sample under an electron microscope, we had to physically cut off a small sample. Then we would take the sample, pot it in epoxy, and then lap it down until we exposed the proper cross section to observe. On a very small sample, this is fairly difficult.
Using an atomic knife to slice a cross section and welding a needle to it, wow. Very impressive.

 

[440Magnum]

Originally Posted By: aquariuscsm
Originally Posted By: djb
by smearing zinc on the contacting surfaces to prevent smearing transfer of the bearing surfaces themselves.


That's the best way I've ever heard it explained. The zinc on zinc (microscopic metals) rub against each other instead of the camshaft metals rubbing against each other. Basically allowing the metal shields (zddp layers) to rub against each other protecting the high contact "moving metal" engine internals.


Except that its really the phosphorous that does most of the protecting, IIRC.

 

[MolaKule]

Originally Posted By: Solarent
Apparently you haven't seen this video yet


Lubrizol would have you believe that they can see exactly what zddp is doing on the level of the surface. (not that they didn't know before - but now you can see it).


Jim Puckace, PHD., I know personally and is a sharp guy; a regular Joe.

Ion Bombardment techniques, especially Ion microscopy, is a very useful tool for doing surficial analysis, and it is an especially useful tool for doing surface incisions for subsequent specimen analysis.

If you look back through past issues of the Journal "Wear" you will see we knew quite a bit about the AW and AO properties of ZDDP. We did not have a clear picture of the exact chemistry at the Nano-meter scale.

 

[Pontual]

ZDDP acts as AW, related with temperature. Threshold efficiency is above 125C and deplets quickly above 240-250C. There was a study on this a while ago. If I find it I'll link on.

 

[Nate1979]

Anybody have the link to the explanation by the GM engineer on here who explained how the GM OLM was tied to ZDDP depletion? I recall reading this in a previous thread on how GM OLM works (at least that is what I remember, I could be wrong).