anti wear additives depletion

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After how many miles does the anti wear additives (like zinc, phosphorus etc..) depletes from the oil (approx.) ?? does it deplete as fast as the other additives like detergent or dispersants ??
 
After how many miles does the anti wear additives (like zinc, phosphorus etc..) depletes from the oil (approx.) ?? does it deplete as fast as the other additives like detergent or dispersants ??
After 5k them additives start to deplete and oil should be changed.
 
I think we will get the answer if we get the additive value for new oil and then for used oil at various mileages. Ed
Only if the additive in question is being "plated out" onto surfaces or otherwise being physically removed from the oil. A spectrographic analysis only measures elements that are decomposed from a compound, so if the additive is degrading somehow (such as oxidation) then the total amount of element the original compound held will still show up the same on a UOA. Spectrographic analysis does not show compounds.

The other problem is that some additives are not metal based and organics do not show up on a standard UOA. Elements such as carbon, nitrogen and oxygen are not able to be analyzed in an ICP. Even if they were the oil itself is full of those elements. FTIR would be of some help here but that's not part of a standard analysis.
 
I'd say a lot of factors are in play here. I ran Wolf's Head 5W-30 for 12,000 miles (GMOLM) in a 2004 Chevy truck, 5.3. Sent a sample to Blackstone and they said it could go longer.
This was long ago, like 2005 or 06.
 
I'd say a lot of factors are in play here. I ran Wolf's Head 5W-30 for 12,000 miles (GMOLM) in a 2004 Chevy truck, 5.3. Sent a sample to Blackstone and they said it could go longer.
This was long ago, like 2005 or 06.
That's probably based on the TBN or some vague serviceability recommendation. I doubt Blackstone (or anyone else for that matter) bases an OCI recommendation on the antiwear additive levels as the OP is asking about.
 
Only if the additive in question is being "plated out" onto surfaces or otherwise being physically removed from the oil. A spectrographic analysis only measures elements that are decomposed from a compound, so if the additive is degrading somehow (such as oxidation) then the total amount of element the original compound held will still show up the same on a UOA. Spectrographic analysis does not show compounds.

The other problem is that some additives are not metal based and organics do not show up on a standard UOA. Elements such as carbon, nitrogen and oxygen are not able to be analyzed in an ICP. Even if they were the oil itself is full of those elements. FTIR would be of some help here but that's not part of a standard analysis.
Yeah - BASF & EMRE have worked on metal free additives - do you think that’s more for the M1 ESP lines ?
 
A Comprehensive Chemical Assessment of Engine Oil Degradation in a Passenger Car.

For the understanding of oil degradation in a combustion engine, in particular zinc dialkyl dithiophosphate (ZDDP) deterioration and its impact on wear expressed as iron content, a field test with a passenger car was carried out, which covered a distance of 19,800 km and represented an entire oil change interval. Condition monitoring of the SAE 5W-30 engine oil used in the turbocharged petrol engine combined the use of conventional and advanced analytical methods.

The conventional data collected from the used oils revealed the progress of additives (antioxidants, base reserve, ZDDP), oil degradation products (oxidation, nitration, sulfation, acids), and contaminations (water, soot, wear, fuel dilution). High-resolution mass spectrometry was included to identify ZDDP additive compounds and their fate during the field test as well as their correlation with wear formation. Dialkyl dithiophosphates as the main ZDDP compounds were rapidly degraded and no longer detected after 6000 km. Dialkyl thiophosphate as intermediate ZDDP degradation product was formed and largely depleted within the first 6000 km. Dialkyl phosphates, phosphoric acid, and sulfuric acid as organic and inorganic ZDDP degradation products were generated early and reached high levels at the end of the field test.

The presence of intact ZDDP and its degradation products, notably phosphoric and sulfuric acid, correlated with the oil’s iron content. Wear largely remained at low level as long as intact ZDDP was available for tribofilm formation. The lack of ZDDP along with the formation of inorganic acids from ZDDP resulted in an increase in the wear rate by a factor of four.

 
A Comprehensive Chemical Assessment of Engine Oil Degradation in a Passenger Car.

For the understanding of oil degradation in a combustion engine, in particular zinc dialkyl dithiophosphate (ZDDP) deterioration and its impact on wear expressed as iron content, a field test with a passenger car was carried out, which covered a distance of 19,800 km and represented an entire oil change interval. Condition monitoring of the SAE 5W-30 engine oil used in the turbocharged petrol engine combined the use of conventional and advanced analytical methods.

The conventional data collected from the used oils revealed the progress of additives (antioxidants, base reserve, ZDDP), oil degradation products (oxidation, nitration, sulfation, acids), and contaminations (water, soot, wear, fuel dilution). High-resolution mass spectrometry was included to identify ZDDP additive compounds and their fate during the field test as well as their correlation with wear formation. Dialkyl dithiophosphates as the main ZDDP compounds were rapidly degraded and no longer detected after 6000 km. Dialkyl thiophosphate as intermediate ZDDP degradation product was formed and largely depleted within the first 6000 km. Dialkyl phosphates, phosphoric acid, and sulfuric acid as organic and inorganic ZDDP degradation products were generated early and reached high levels at the end of the field test.

The presence of intact ZDDP and its degradation products, notably phosphoric and sulfuric acid, correlated with the oil’s iron content. Wear largely remained at low level as long as intact ZDDP was available for tribofilm formation. The lack of ZDDP along with the formation of inorganic acids from ZDDP resulted in an increase in the wear rate by a factor of four.

Thanks for that, so they were using mass spec for their analysis.
 
A Comprehensive Chemical Assessment of Engine Oil Degradation in a Passenger Car.

For the understanding of oil degradation in a combustion engine, in particular zinc dialkyl dithiophosphate (ZDDP) deterioration and its impact on wear expressed as iron content, a field test with a passenger car was carried out, which covered a distance of 19,800 km and represented an entire oil change interval. Condition monitoring of the SAE 5W-30 engine oil used in the turbocharged petrol engine combined the use of conventional and advanced analytical methods.

The conventional data collected from the used oils revealed the progress of additives (antioxidants, base reserve, ZDDP), oil degradation products (oxidation, nitration, sulfation, acids), and contaminations (water, soot, wear, fuel dilution). High-resolution mass spectrometry was included to identify ZDDP additive compounds and their fate during the field test as well as their correlation with wear formation. Dialkyl dithiophosphates as the main ZDDP compounds were rapidly degraded and no longer detected after 6000 km. Dialkyl thiophosphate as intermediate ZDDP degradation product was formed and largely depleted within the first 6000 km. Dialkyl phosphates, phosphoric acid, and sulfuric acid as organic and inorganic ZDDP degradation products were generated early and reached high levels at the end of the field test.

The presence of intact ZDDP and its degradation products, notably phosphoric and sulfuric acid, correlated with the oil’s iron content. Wear largely remained at low level as long as intact ZDDP was available for tribofilm formation. The lack of ZDDP along with the formation of inorganic acids from ZDDP resulted in an increase in the wear rate by a factor of four.

Thanks alot, very informative,
I watched some YouTube videos about oil analysis and it appears that zinc and phosphorus can last up to 10,000 miles from test results,
Here are the videos:







 
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It seems like Boron depletes pretty significantly between VOA and UOA of the same oil. Some examples:
M1 0W40 - virgin=313, UOA after 4700 miles= 150
Supertech FS HM 5W20 - virgin=240, UOA after 3500 miles=88
 
After how many miles does the anti wear additives (like zinc, phosphorus etc..) depletes from the oil (approx.) ?? does it deplete as fast as the other additives like detergent or dispersants ??
Stuff like ZDDP doesn't deplete, it gets constantly recycled in the engine. Detergents and dispersants load up, VI improvers shear, and oxidation starts setting in, that's why oil must be changed.
 
Stuff like ZDDP doesn't deplete, it gets constantly recycled in the engine. Detergents and dispersants load up, VI improvers shear, and oxidation starts setting in, that's why oil must be changed.
It degrades and no longer can perform the intended function. Here is an article that describes using NMR to track the depletion:


This article again illustrates that emission spectrography isn't going to show this since it only indicates bare elements.
 
This is a deeper topic than I think most realize. There's more questions involved here like... (looking at just ZDDP)

The type of ZDDP? Primary vs secondary alkyl and their chaining?
Synergy of ZDDP with other additives?
Reactivity of ZDDP in engines that depend on it more than others?

To add somewhat to this, primary alkyl ZDDP is less reactive but lasts longer. Secondary alkyl ZDDP is more reactive but is depleted faster. A blend of the two gives you a best of both worlds with more reactive secondary ZDDP to establish protective tribofilms (of iron sulfide and phosphate "glass") early with the primary ZDDP carrying the load over the OCI. Typical ZDDP content in engine oils is ~70% primary and ~30% secondary.
 
The OPs question is way too broad to give specific answers. This is because he's not referring to any one specific lube, and in what engine is it being used, and under what conditions ... I'll confine my answer to the generalizations around modern fuel-injected engines, modern well-forumlated oils, and modern well-made filters.

The add-pack isn't like a light switch; it doesn't "deplete" all at once, causing wear to go from "normal" to "abnormal" at mile X,xxx+1. Further, the add-pack is only part of the wear control system; the other main contributors are the air filter, the oil filter and the TCB. And those, plus the oil, are only inputs to a forumla.

What you should care about is the outout; the wear metals; these directly indicate how an engine is wearing. (You'll not see ALL wear from an engine in a UOA, but you'll see a very good representation of wear, and in healthy engines, the small wear particles are generally the most prominent and therefore give you a view of the majority of wear). If one wants to know how well the engine is wearing, get a UOA. And as a generalization, the VAST majority of all engines experience wear rates which drop after 1k miles and then continue to drop out to 15k miles. So, the oil and filters and TCB are all working well enough in concert that out to 15k miles, it's not a concern.
 
Where in those videos are they measuring intact and functioning ZDDP?
I think Test results only show the ppm of zinc and phosphorus regardless if they are functioning or not
 
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I think Test results only show the ppm of zinc and phosphorus regardless if they are functioning or not
Right, Zinc and Phos will still show up on UOA because it has not 'disappeared'.
Its whether it remains in a form that is still useful or as useful as it was originally.

The time it takes to deplete depends on a number of factors. Note the references given above apply to very specific cases.
 
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