Fresh Oil = Stripped AW ???
- Thread starter Phishin
- Start date
- Status
Originally Posted By: GMorg
In the thread below, Molekule and bruce381 went for "new is always better". The literature suggested otherwise then and now. I'm with Jim Allen and the literature on this one. However, I think that changing oil too soon is much better for your engine than changing too late.
Your last sentence I think is very illuminating - it's not really a zero-sum game. Even if wear reduction improves as oil ages (within its service life, of course), does not mean you have to run an oil out to its absolute condemnation point. Obviously, it's counterproductive in a couple ways to change too early, but it's not the end of the world, either. One should find the happy medium.
Now, part of the issue here is semantics. Does fresh oil deplete the AW layer? Does it prevent the AW layer from being deposited at the same rate it's being worn down? Does it prevent the AW layer from being replenished at all?
None of those are exactly the same thing. And, I'm not going to lie awake worrying about it (I tell myself that anyhow). I don't think anyone here is claiming you'll blow your engine by changing your oil too often. Some of us change oil way too often and some are negligent. There's a happy medium, I guess.
In the thread below, Molekule and bruce381 went for "new is always better". The literature suggested otherwise then and now. I'm with Jim Allen and the literature on this one. However, I think that changing oil too soon is much better for your engine than changing too late.
Your last sentence I think is very illuminating - it's not really a zero-sum game. Even if wear reduction improves as oil ages (within its service life, of course), does not mean you have to run an oil out to its absolute condemnation point. Obviously, it's counterproductive in a couple ways to change too early, but it's not the end of the world, either. One should find the happy medium.
Now, part of the issue here is semantics. Does fresh oil deplete the AW layer? Does it prevent the AW layer from being deposited at the same rate it's being worn down? Does it prevent the AW layer from being replenished at all?
None of those are exactly the same thing. And, I'm not going to lie awake worrying about it (I tell myself that anyhow). I don't think anyone here is claiming you'll blow your engine by changing your oil too often. Some of us change oil way too often and some are negligent. There's a happy medium, I guess.
Originally Posted By: Shannow
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
Originally Posted By: GMorg
Shannow,
Doesn't that paper refer to film deposition as opposed to film removal. The suggestion in this thread appears to be that detergents can remove AW films. Since some of the film deposition appears to be covalent (attached through a chemical bond), I don't see how the base of the film could be removed by detergent. I do see how the composition of the new film would be affected by the entire formulation.
yeah, it does...I was responding to the claim that detergents "attack" the metal...
Wasn't going to post the article in this thread, like I said, going to do it elsewhere, but it DID go through how multiple chemistries interact...admittedly on deposition.
Shannow,
Doesn't that paper refer to film deposition as opposed to film removal. The suggestion in this thread appears to be that detergents can remove AW films. Since some of the film deposition appears to be covalent (attached through a chemical bond), I don't see how the base of the film could be removed by detergent. I do see how the composition of the new film would be affected by the entire formulation.
yeah, it does...I was responding to the claim that detergents "attack" the metal...
Wasn't going to post the article in this thread, like I said, going to do it elsewhere, but it DID go through how multiple chemistries interact...admittedly on deposition.
Out of all the sludged engine pictures posted on here and other places none of those issues claimed to be a result of "too frequent" oil changes. Most, if not all, except head gasket failure etc, were extended oil changes intervals and/or neglectful owners, or in the case of BMW, in the last decade, a manufacturer who claimed yearly OCI were OK...then later retracted.
That's all the evidence I need. I'd change early rather than go 15,000 miles. $25 extra once a year for 10 years is cheaper than a new engine.
That's all the evidence I need. I'd change early rather than go 15,000 miles. $25 extra once a year for 10 years is cheaper than a new engine.
That's nothing new. Plenty here push the limits of OCIs or at least extend, so "not changing oil" is no big surprise.
Never heard of this and dont have any reason to believe it either.
Be careful,this forum lately is full of opinions and non-factual "data".
Be careful,this forum lately is full of opinions and non-factual "data".
Originally Posted By: bvance554
Am I the only one who has noticed we have a thread here that is against changing oil? I thought changing oil was a sort of hobby, and now we're warning against it?
It's about getting the most out of your lubricant. You can easily under utilize an oil just as easy as another person could over utilize theirs.
If you run an oil properly to TBN depletion when TAN starts to overtake it you are getting the most out of your additives and also your anti wear additives.
Of course without utilizing a used oil analysis most people tend to play it safe or say it's cheap insurance but there are many different types of people on this forum and no data will keep some people from changing their oil every 5k even if it has double the life in it.
Yes I love you to know my engine oil is fresh but my brain knows that my 5,000 mile old PP is still doing just fine in my engine, which is why I'm keeping it longer and going to UOA to extend my interval.
The point is changing oil is okay, but too often can be a waste of money. Everything varies by application which is why many questions need to be answered before guessing at your oci.
Am I the only one who has noticed we have a thread here that is against changing oil? I thought changing oil was a sort of hobby, and now we're warning against it?
It's about getting the most out of your lubricant. You can easily under utilize an oil just as easy as another person could over utilize theirs.
If you run an oil properly to TBN depletion when TAN starts to overtake it you are getting the most out of your additives and also your anti wear additives.
Of course without utilizing a used oil analysis most people tend to play it safe or say it's cheap insurance but there are many different types of people on this forum and no data will keep some people from changing their oil every 5k even if it has double the life in it.
Yes I love you to know my engine oil is fresh but my brain knows that my 5,000 mile old PP is still doing just fine in my engine, which is why I'm keeping it longer and going to UOA to extend my interval.
The point is changing oil is okay, but too often can be a waste of money. Everything varies by application which is why many questions need to be answered before guessing at your oci.
Take the spacebears extended oil test...
http://www.brianschreurs.org/neptune.spacebears.com/cars/stories/amsoil.html
And look at the increase in wear metals for the first 7,000 miles, versus the increase in the second...set your "zero" at 7,000, and the wear metals from a sump full of "used" oil are lower than the fresh sump of new oil.
Does that mean that if they'd taken 5 qts of the used oil, carried out a VOA to find the baseline, and used it as an oil change in another car the wear results would be duplicated ?
Possibly...the oil would still be down in TBN, and be carrying junk with it...but the additives would be "activated" for want of a better word, and the one or two anion species in fresh oil (DDP, or CO3 etc) have devolved (see paper I liked earlier) into a LOT of different species, all with different energies to get them functioning with the surfaces...a bit like an oil formulation that has a bunch of smaller amounts of different adds to protect more/quicker.
http://www.brianschreurs.org/neptune.spacebears.com/cars/stories/amsoil.html
And look at the increase in wear metals for the first 7,000 miles, versus the increase in the second...set your "zero" at 7,000, and the wear metals from a sump full of "used" oil are lower than the fresh sump of new oil.
Does that mean that if they'd taken 5 qts of the used oil, carried out a VOA to find the baseline, and used it as an oil change in another car the wear results would be duplicated ?
Possibly...the oil would still be down in TBN, and be carrying junk with it...but the additives would be "activated" for want of a better word, and the one or two anion species in fresh oil (DDP, or CO3 etc) have devolved (see paper I liked earlier) into a LOT of different species, all with different energies to get them functioning with the surfaces...a bit like an oil formulation that has a bunch of smaller amounts of different adds to protect more/quicker.
Originally Posted By: Wilhelm_D
Originally Posted By: Shannow
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
I've always heard growing up that once you pick an oil for your engine, you should stick with it. I imagine "seating" would be the reasoning behind this theory?
Originally Posted By: Shannow
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
I've always heard growing up that once you pick an oil for your engine, you should stick with it. I imagine "seating" would be the reasoning behind this theory?
Originally Posted By: Garak
Most of the detergents are metals.
Yes, there is a metal cation ion that is a part of the detergent molecule. The metal is usually Ca, Mg, or Na. HOWEVER, those metals do NOT do the cleaning. It's the anion that does the "cleaning".
Here is a little info for those that are MASSIVELY misinformed and CONFUSED.
1.) Detergents do some "cleaning" because they neutralize acids in the oil. When acids are present, they break down the oil and these byproducts cause deposits to form. So, detergents prevent the acids from creating byproducts and thus, prevent deposits. This is is how detergents "clean". They aren't really cleaning....they are preventing deposits from being formed. Detergents in oil aren't like Dawn Dish Soap and "dissolve" dirt.
2.) Acids are usually seen as positive hydrogen ions (H+). Bases are usually seen as negative hydroxide ions (OH-). When you mix an H+ and a OH- together, they neutralize eachother and you get water (H2O). Too many H+'s around, and you have an acidic environment....which, as I stated above, acids break down oil, cause byproducts, which leads to "dirty" deposits in an engine. Detergents are in oil to prevent this. So, detergents are ionic molecules that are cations (positively charged) and anions (negatively charged). The cations are usually Ca+, Mg+, and Na+. This is what we measure when we do VOA's/UOA's. HOWEVER, it's the ANION that does all the work. It's the negatively charged ANION that will seek out the acidic H+'s in the oil and neutralize them.
Here is an equation: H+ (positive charged, bad acid!) + detergent anion- (negative charged) = HAnion (neutral charge)
GET IT? It's the ANION that has the ability to neutralize the acidic H+'s in the oil. The Ca, Mg, and Na just go along for the ride.
So, detergents aren't really doing any cleaning. They are prevent deposits from forming.
Dissperents hold the particles in solution if they form, sort of "dissolving them". Which prevents them from adhering to our engines. Particles are gonna form, you can't prevent it...no matter how much acid-neutralizing detergents are present. Dissperents are part of an oil's add pack as well....and these dissperents help prevent the particles from sticking to our pretty engines, so they can washed away when we do an oil change.
Most of the detergents are metals.
Yes, there is a metal cation ion that is a part of the detergent molecule. The metal is usually Ca, Mg, or Na. HOWEVER, those metals do NOT do the cleaning. It's the anion that does the "cleaning".
Here is a little info for those that are MASSIVELY misinformed and CONFUSED.
1.) Detergents do some "cleaning" because they neutralize acids in the oil. When acids are present, they break down the oil and these byproducts cause deposits to form. So, detergents prevent the acids from creating byproducts and thus, prevent deposits. This is is how detergents "clean". They aren't really cleaning....they are preventing deposits from being formed. Detergents in oil aren't like Dawn Dish Soap and "dissolve" dirt.
2.) Acids are usually seen as positive hydrogen ions (H+). Bases are usually seen as negative hydroxide ions (OH-). When you mix an H+ and a OH- together, they neutralize eachother and you get water (H2O). Too many H+'s around, and you have an acidic environment....which, as I stated above, acids break down oil, cause byproducts, which leads to "dirty" deposits in an engine. Detergents are in oil to prevent this. So, detergents are ionic molecules that are cations (positively charged) and anions (negatively charged). The cations are usually Ca+, Mg+, and Na+. This is what we measure when we do VOA's/UOA's. HOWEVER, it's the ANION that does all the work. It's the negatively charged ANION that will seek out the acidic H+'s in the oil and neutralize them.
Here is an equation: H+ (positive charged, bad acid!) + detergent anion- (negative charged) = HAnion (neutral charge)
GET IT? It's the ANION that has the ability to neutralize the acidic H+'s in the oil. The Ca, Mg, and Na just go along for the ride.
So, detergents aren't really doing any cleaning. They are prevent deposits from forming.
Dissperents hold the particles in solution if they form, sort of "dissolving them". Which prevents them from adhering to our engines. Particles are gonna form, you can't prevent it...no matter how much acid-neutralizing detergents are present. Dissperents are part of an oil's add pack as well....and these dissperents help prevent the particles from sticking to our pretty engines, so they can washed away when we do an oil change.
Originally Posted By: kjbock
Originally Posted By: Wilhelm_D
Originally Posted By: Shannow
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
I've always heard growing up that once you pick an oil for your engine, you should stick with it. I imagine "seating" would be the reasoning behind this theory?
Growing up I heard the same thing, and followed it until I came to Bitog.
This is interesting, according to "seating" then frequently changing brands of oil is not a good idea at all. It contradicts information given here on the board that changing oil brands is fine, the truth is it "might" not be so fine? Interesting thread, it's a real eye opener.
Originally Posted By: Wilhelm_D
Originally Posted By: Shannow
It's not "attacking" metals...the more different species you have present, the less any one of them has a chance to dominate the films formed.
http://home.physics.wisc.edu/gilbert/publications/101.PDF
Gives a good idea what "competing" chemistries get up to.
Deserves (and will get it's own thread in the papers section)
There is a term called "seating". When you run a motor oil that takes a particular approach to anti-wear, such as Red Line 0W-40, it creates its own environment which "surfaces" wear points and reaches an equilibrium with its various stocks. Red Line, for this example, relies heavily on molybdenum and a polyolester stock.
Switch that engine then over to an oil with a very different anti-wear approach, Mobil 1 0W-40 for an example, and it takes a period of time for the environment to reach a new equilibrium. During that change you may obtain unusual elemental analyses.
This has been a well-known phenomenon for many years, but I don't think I've ever seen a paper or study on it.
I've always heard growing up that once you pick an oil for your engine, you should stick with it. I imagine "seating" would be the reasoning behind this theory?
Growing up I heard the same thing, and followed it until I came to Bitog.
This is interesting, according to "seating" then frequently changing brands of oil is not a good idea at all. It contradicts information given here on the board that changing oil brands is fine, the truth is it "might" not be so fine? Interesting thread, it's a real eye opener.
Originally Posted By: Clevy
The new oil cleans everything the old oil has left behind then applies its own anti-wear layer.
If this action didn't take place moving parts would get layer upon layer of stuff stuck too it,then we'd call it varnish.
Try reading dnewtons articles on the homepage. You might learn something.
No....moly and zinc won't "plate" itself thick. That reaction won't take place. Chemically, it's impossible.
The new oil cleans everything the old oil has left behind then applies its own anti-wear layer.
If this action didn't take place moving parts would get layer upon layer of stuff stuck too it,then we'd call it varnish.
Try reading dnewtons articles on the homepage. You might learn something.
No....moly and zinc won't "plate" itself thick. That reaction won't take place. Chemically, it's impossible.
Originally Posted By: demarpaint
I read here a while back that the fresh oil with the fresh add pack does some cleaning of deposits that accumulated during the prior OCI. That cleaning frees up wear metals that might have been trapped in those deposits. That could be the cause for a slight spike in wear metals early on in the OCI. That also made sense to me.
Sounds like common sense to me especially in an older engine when filled with the new generation of oils that really have some impressive cleaning abilities.
I read here a while back that the fresh oil with the fresh add pack does some cleaning of deposits that accumulated during the prior OCI. That cleaning frees up wear metals that might have been trapped in those deposits. That could be the cause for a slight spike in wear metals early on in the OCI. That also made sense to me.
Sounds like common sense to me especially in an older engine when filled with the new generation of oils that really have some impressive cleaning abilities.
Originally Posted By: demarpaint
Growing up I heard the same thing, and followed it until I came to Bitog.
This is interesting, according to "seating" then frequently changing brands of oil is not a good idea at all. It contradicts information given here on the board that changing oil brands is fine, the truth is it "might" not be so fine? Interesting thread, it's a real eye opener.
I don't believe it is evidence against changing brands of oil. What it does is explain temporary abnormalities in a UOA after a brand switch.
Growing up I heard the same thing, and followed it until I came to Bitog.
This is interesting, according to "seating" then frequently changing brands of oil is not a good idea at all. It contradicts information given here on the board that changing oil brands is fine, the truth is it "might" not be so fine? Interesting thread, it's a real eye opener.
I don't believe it is evidence against changing brands of oil. What it does is explain temporary abnormalities in a UOA after a brand switch.
Originally Posted By: TFB1
So I suppose we need to start conditioning our fresh oil in the beater for 500-1000 miles before dumping it into our good vehicles??????????
So I suppose we need to start conditioning our fresh oil in the beater for 500-1000 miles before dumping it into our good vehicles??????????
Originally Posted By: Trav
Originally Posted By: demarpaint
I read here a while back that the fresh oil with the fresh add pack does some cleaning of deposits that accumulated during the prior OCI. That cleaning frees up wear metals that might have been trapped in those deposits. That could be the cause for a slight spike in wear metals early on in the OCI. That also made sense to me.
Sounds like common sense to me especially in an older engine when filled with the new generation of oils that really have some impressive cleaning abilities.
The observation isn't that the spike is a one off. It is that in the same car, for several oci's, wear is always higher on a per mile basis for a short oci than for a long oci.
If these modern oils are cleaning deposits in say 1000 mile oci's, are they doing it every time? Ie in the 1st, 5th, 10th, 20th oci? So each time, the fresh oil frees metals trapped in deposits from the last time?
The spike theory does not make sense in repeated short oci's because there should be no deposits left to clean and therefore no trapped wear particles to free time and time again.
Originally Posted By: demarpaint
I read here a while back that the fresh oil with the fresh add pack does some cleaning of deposits that accumulated during the prior OCI. That cleaning frees up wear metals that might have been trapped in those deposits. That could be the cause for a slight spike in wear metals early on in the OCI. That also made sense to me.
Sounds like common sense to me especially in an older engine when filled with the new generation of oils that really have some impressive cleaning abilities.
The observation isn't that the spike is a one off. It is that in the same car, for several oci's, wear is always higher on a per mile basis for a short oci than for a long oci.
If these modern oils are cleaning deposits in say 1000 mile oci's, are they doing it every time? Ie in the 1st, 5th, 10th, 20th oci? So each time, the fresh oil frees metals trapped in deposits from the last time?
The spike theory does not make sense in repeated short oci's because there should be no deposits left to clean and therefore no trapped wear particles to free time and time again.
Originally Posted By: TrevorS
The spike theory does not make sense in repeated short oci's because there should be no deposits left to clean and therefore no trapped wear particles to free time and time again.
There will always be microscopic deposits. Always. I don't care what oil you use or how short of an OCI you have, there will always be wear and there will always be deposits. No oil's high level of detergents are going to prevent acids from being present (detergents NEUTRALIZE the acids, not prevent them....therefore acidic byproducts cannot be totally avoided, but their quantity can be diminished with high levels of detergents), and no amount of dispersants is going to carry away all of the deposits. Therefore, as deposits form, there is always a chance that the deposits will contain wear metals present in the oil.
I'd be willing to bet if someone was crazy enough to change their oil every 500 miles in a new car (so deposits, varnish, and wear metals are at a steady state), after the break-in miles, you wouldn't see all these "spikes" anymore.
The spike theory does not make sense in repeated short oci's because there should be no deposits left to clean and therefore no trapped wear particles to free time and time again.
There will always be microscopic deposits. Always. I don't care what oil you use or how short of an OCI you have, there will always be wear and there will always be deposits. No oil's high level of detergents are going to prevent acids from being present (detergents NEUTRALIZE the acids, not prevent them....therefore acidic byproducts cannot be totally avoided, but their quantity can be diminished with high levels of detergents), and no amount of dispersants is going to carry away all of the deposits. Therefore, as deposits form, there is always a chance that the deposits will contain wear metals present in the oil.
I'd be willing to bet if someone was crazy enough to change their oil every 500 miles in a new car (so deposits, varnish, and wear metals are at a steady state), after the break-in miles, you wouldn't see all these "spikes" anymore.
Last edited:
I bought the paper and have read it twice. Where to begin? I might as well jump right to the meat of the matter.
This paper does not show that new oil strips the previous anti-wear layers and changing your oil frequently will result increased engine wear. In fact, shows that that doesn't happen. Quoting directly from SAE 2007-01-4133:
Quote:
It has been shown earlier (see Figure 2) that the wear rate of the shim changed from 0.365 nm/h when the oil was fresh to nearly zero when tested with the 7500 mile drain oil. After that, the 7500 mile oil was drained, and the system was flushed twice with the fresh oil prior to putting in the final charge for evaluation. It was observed that the wear rate was no longer "near-zero" as observed with the 7500 mile oil, but it was about 0.11 nm/h over the test duration, lower than what was observed with the fresh oil before. The reason for this lower wear rate could be because the surface film laid out by the 7500 mile drain oil was not completely removed. It was observed before (2) that once a ZDDP derived film is formed, it stayed on the surface even when rubbing continued with base oil only. It is likely that the film will be removed ultimately or replaced by a different type of film, but it points to the fact that once the film is formed with a fully formulated oil, it is not removed very quickly. The existing film may affect the chemical mechanism for forming the new film which provided the reduced friction and wear rate benefit.
This was a bench test. The oil was aged in the taxies and then run on a bench top apparatus. Each oil started with its own new cam lobe and lifter. The new oil was always run first. Break-in of the parts and the fact that there was no previous anti wear layer in place were uncontrolled variables. The effect of an existing layer was stumbled on later in the experiment.
There are some major anomalies in the oil data that are ignored or just given a hand wave that raise several red flags for me. That's best left to another post, likely to be unmade.
Ed
SAE 2007-01-4133 The Effect of Oil Drain Interval on Valvetrain Friction and Wear. A.K. Gangopadhyay, R.O. Carter III, D. Uy, S.J. Simko and M. Riley. Ford Motor Company. C.B Phillips and H Gao. ConocoPhillips Company
This paper does not show that new oil strips the previous anti-wear layers and changing your oil frequently will result increased engine wear. In fact, shows that that doesn't happen. Quoting directly from SAE 2007-01-4133:
Quote:
It has been shown earlier (see Figure 2) that the wear rate of the shim changed from 0.365 nm/h when the oil was fresh to nearly zero when tested with the 7500 mile drain oil. After that, the 7500 mile oil was drained, and the system was flushed twice with the fresh oil prior to putting in the final charge for evaluation. It was observed that the wear rate was no longer "near-zero" as observed with the 7500 mile oil, but it was about 0.11 nm/h over the test duration, lower than what was observed with the fresh oil before. The reason for this lower wear rate could be because the surface film laid out by the 7500 mile drain oil was not completely removed. It was observed before (2) that once a ZDDP derived film is formed, it stayed on the surface even when rubbing continued with base oil only. It is likely that the film will be removed ultimately or replaced by a different type of film, but it points to the fact that once the film is formed with a fully formulated oil, it is not removed very quickly. The existing film may affect the chemical mechanism for forming the new film which provided the reduced friction and wear rate benefit.
This was a bench test. The oil was aged in the taxies and then run on a bench top apparatus. Each oil started with its own new cam lobe and lifter. The new oil was always run first. Break-in of the parts and the fact that there was no previous anti wear layer in place were uncontrolled variables. The effect of an existing layer was stumbled on later in the experiment.
There are some major anomalies in the oil data that are ignored or just given a hand wave that raise several red flags for me. That's best left to another post, likely to be unmade.
Ed
SAE 2007-01-4133 The Effect of Oil Drain Interval on Valvetrain Friction and Wear. A.K. Gangopadhyay, R.O. Carter III, D. Uy, S.J. Simko and M. Riley. Ford Motor Company. C.B Phillips and H Gao. ConocoPhillips Company
- Status
Similar threads
- Locked
