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I am on the opposite side of the fence. I switched to M1 AFE 0W-20 and there was no increased noise and it produced the best 10K and 15K UOA in my truck to date.
Engine Noise From Synthetic Oil - Does It Do Damag
- Thread starter Verminator
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Originally Posted By: 2010_FX4
I am on the opposite side of the fence. I switched to M1 AFE 0W-20 and there was no increased noise and it produced the best 10K and 15K UOA in my truck to date.
I tried that oil in my 04 ram hemi last winter. It was slightly more noisy than eneos 0w-20 and pp 5w-20.
But I didn't care about noise,I cared about it starting in -40 mornings.
I used to think more noise was a big deal and that more noise equalled more wear,then I learned a ton from a few knowledgeable members here and I discovered that whole way of thinking isn't applicable when it comes to an ICE. and the various types of lubrication they require.
AFE is a stellar product though and if I could find it at the right price I'd be using it without question.
And the used oil analysis you posted using it for 22000 miles just floored me. It's no wonder the mod motors run forever. They she'd almost no wear metals. It's the timing chains that grenade them,and spitting out spark plugs.
I am on the opposite side of the fence. I switched to M1 AFE 0W-20 and there was no increased noise and it produced the best 10K and 15K UOA in my truck to date.
I tried that oil in my 04 ram hemi last winter. It was slightly more noisy than eneos 0w-20 and pp 5w-20.
But I didn't care about noise,I cared about it starting in -40 mornings.
I used to think more noise was a big deal and that more noise equalled more wear,then I learned a ton from a few knowledgeable members here and I discovered that whole way of thinking isn't applicable when it comes to an ICE. and the various types of lubrication they require.
AFE is a stellar product though and if I could find it at the right price I'd be using it without question.
And the used oil analysis you posted using it for 22000 miles just floored me. It's no wonder the mod motors run forever. They she'd almost no wear metals. It's the timing chains that grenade them,and spitting out spark plugs.
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I've worked on newer mack/volvo engines the past few years where some run nice and quiet and some make all kinds of valvetrain noise. I've pulled the valve cover on the noisy ones, everything looks ok, adjusted the valves and injectors, and once finished, guess what, they still are just as noisy. There is no excessive wear to the cam or rollers on the rockers. I think its just a matter of what oil the customer is using allowing more noise. And these engines will still go 500,000 miles or more before needing a rebuild, and most times, the cam and rocker assemblies can still be used. I think that goes a long way in showing that noise does not really indicate excessive metal to metal contact and excessive wear. I think sometimes its just the oil being used, or just the characteristics of the particular engine in question.
Originally Posted By: Clevy
Originally Posted By: tig1
Clevy,
Since I've used M1 oils through out all the formulation changes, I have never experienced any unusual engine noise or quality reduction. In fact I have noticed the quality of M1 oils for the last 36 years have improved, as all other oils have.
What have you got to compare current engine acoustics to though tig. If you've never used anything but M1 you have nothing to compare it against whereas I use a different oil at every oil change so I can compare acoustics directly and I remember what the last oil change sounded like etc etc.
1) I have had a fair amount of experience with engines since the early 60s and have heard more than one engine with excess noise.
2)Most of the vehicles I have purchased have been used and had other oils in them at the time of purchase. After changing to M1(started 36 years ago) not a single one had increase noise, and if anything I noticed a smoother quiter engine with M1.
3) I have several friends and family that have been using M1 oil for years now because of my success. Not a single one has had nothing but long lived, smooth running, and often quiter engines with M1.
Originally Posted By: tig1
Clevy,
Since I've used M1 oils through out all the formulation changes, I have never experienced any unusual engine noise or quality reduction. In fact I have noticed the quality of M1 oils for the last 36 years have improved, as all other oils have.
What have you got to compare current engine acoustics to though tig. If you've never used anything but M1 you have nothing to compare it against whereas I use a different oil at every oil change so I can compare acoustics directly and I remember what the last oil change sounded like etc etc.
1) I have had a fair amount of experience with engines since the early 60s and have heard more than one engine with excess noise.
2)Most of the vehicles I have purchased have been used and had other oils in them at the time of purchase. After changing to M1(started 36 years ago) not a single one had increase noise, and if anything I noticed a smoother quiter engine with M1.
3) I have several friends and family that have been using M1 oil for years now because of my success. Not a single one has had nothing but long lived, smooth running, and often quiter engines with M1.
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Originally Posted By: Verminator
So while this "dispute" rages on, does anyone else agree that Mobil 1 High Mileage is much quieter than regular Mobil 1??
No. I used mostly M1 10-30 in a 96 Merc GM, but did try M1 10-30HM for one OC. No differance.
So while this "dispute" rages on, does anyone else agree that Mobil 1 High Mileage is much quieter than regular Mobil 1??
No. I used mostly M1 10-30 in a 96 Merc GM, but did try M1 10-30HM for one OC. No differance.
The human ear is capable of really amazing hearing volume range.
That's why we can hear a dripping faucet in the middle of the night yet hear someone talking while a jet flies overhead.
This also makes it very difficult to objectively determine how loud something is. To accurately measure volume changes a volume meter should be used.
I really wonder how much difference in volume an oil brand can make. Maybe a little bit but I doubt it could be very much.
This makes me wonder how accurately people can assess it.
That's why we can hear a dripping faucet in the middle of the night yet hear someone talking while a jet flies overhead.
This also makes it very difficult to objectively determine how loud something is. To accurately measure volume changes a volume meter should be used.
I really wonder how much difference in volume an oil brand can make. Maybe a little bit but I doubt it could be very much.
This makes me wonder how accurately people can assess it.
I'm not a fan of Mobil either but I don't believe it's bad or anything, it's actually the over the top rabid fanboys here that nauseate me enough to want to avoid it.
They have a couple offerings I will probably try anyway at some point, like the 0w30 AFE.
From what I have seen noise does not equate to wear. In the Jeep 4.0 I study so hard, both Maxlife and Rotella perpetually turn in some of the best looking UOA's, yet both tend to be noisy in the 4.0.
I personally like quiet though, my operator satisfaction with a lube is much higher when I have it.
They have a couple offerings I will probably try anyway at some point, like the 0w30 AFE.
From what I have seen noise does not equate to wear. In the Jeep 4.0 I study so hard, both Maxlife and Rotella perpetually turn in some of the best looking UOA's, yet both tend to be noisy in the 4.0.
I personally like quiet though, my operator satisfaction with a lube is much higher when I have it.
Quote:
Is this why we see all this massive wear on M1 UOAs and all those poor engines filled with M1 blown up on the side of the road?
To be fair, has anybody seen "massive wear on UOA" after using recommended oil, be it synthetic or regular?
Aren't we discussing whether the engine will last 700K miles or worn out in only 500K miles here?
Is this why we see all this massive wear on M1 UOAs and all those poor engines filled with M1 blown up on the side of the road?
To be fair, has anybody seen "massive wear on UOA" after using recommended oil, be it synthetic or regular?
Aren't we discussing whether the engine will last 700K miles or worn out in only 500K miles here?
Originally Posted By: datech
The human ear is capable of really amazing hearing volume range.
That's why we can hear a dripping faucet in the middle of the night yet hear someone talking while a jet flies overhead.
This also makes it very difficult to objectively determine how loud something is. To accurately measure volume changes a volume meter should be used.
I really wonder how much difference in volume an oil brand can make. Maybe a little bit but I doubt it could be very much.
This makes me wonder how accurately people can assess it.
And wouldn't a competitor have seized on the opportunity to imply that a noisier oil can't be as good as their quieter oil?
The human ear is capable of really amazing hearing volume range.
That's why we can hear a dripping faucet in the middle of the night yet hear someone talking while a jet flies overhead.
This also makes it very difficult to objectively determine how loud something is. To accurately measure volume changes a volume meter should be used.
I really wonder how much difference in volume an oil brand can make. Maybe a little bit but I doubt it could be very much.
This makes me wonder how accurately people can assess it.
And wouldn't a competitor have seized on the opportunity to imply that a noisier oil can't be as good as their quieter oil?
Originally Posted By: Vikas
To be fair, has anybody seen "massive wear on UOA" after using recommended oil, be it synthetic or regular?
Aren't we discussing whether the engine will last 700K miles or worn out in only 500K miles here?
You're helping make my point - the whole noise thing has no effect on the life of your engine.
To be fair, has anybody seen "massive wear on UOA" after using recommended oil, be it synthetic or regular?
Aren't we discussing whether the engine will last 700K miles or worn out in only 500K miles here?
You're helping make my point - the whole noise thing has no effect on the life of your engine.
Originally Posted By: jrustles
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
Nice post, very interesting about the P-V co with the common bases
One thing about this discussion worth noting is that "synthetic" should not be directly correlated to "engine noise". Not every friction surface 'style' (gear, rocker arm, tappet bucket and the various individual designs thereof) across engine manufacturers respond the identically to various oil formulas. Also, some synthetics like GTL and POE seem to have superior 'damping' than others, similar to lower group bases. If someone has Pressure-Viscosity data for GTL/POE it's be awesome to see
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
Nice post, very interesting about the P-V co with the common bases
One thing about this discussion worth noting is that "synthetic" should not be directly correlated to "engine noise". Not every friction surface 'style' (gear, rocker arm, tappet bucket and the various individual designs thereof) across engine manufacturers respond the identically to various oil formulas. Also, some synthetics like GTL and POE seem to have superior 'damping' than others, similar to lower group bases. If someone has Pressure-Viscosity data for GTL/POE it's be awesome to see
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
Originally Posted By: Clevy
Originally Posted By: tig1
Why do you guys hate XM? I hear you say it but no explaination.
Years ago I was an M1 fanboy. Then I got caught up in the whole basestock debacle,then the castrol hearings and I just swung over to the Amsoil bench.
And if you like a Amsoil you naturally have to hate Mobil.
Then I tried it out for old times sake and my engines got very noisy and I didn't like that they cheapened the basestocks after the castrol thing but the cost to the consumer didn't change so I just decided that's it,no more Mobil.
I'll buy the stuff when its cost effective and on sale but I won't go out of my way to search got it.
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
So this explains why conventional oils tend to make an engine very quiet,because the oil film is thicker but not necessarily stronger.
Am I to infer that yes a conventional oil has a thicker oil film at any given temp however the film strength is lesser than their synthetic counterparts?
Thanks in advance for any answers if you know them.
I don't think "oil-film strength" is a scientific term.
If you mean how much pressure it takes an oil before it's squeezed out in the EHL regime, it's the same as oil-film thickness. If you mean how much protection an oil offers in the boundary lubrication regime, it mostly has to do with the AW/EP/FM additives and has little to do with the base oil.
Therefore, "oil-film strength" is primarily a gimmick used by some boutique synthetic-oil manufacturers.
The bottom line is that, in the EHL regime, Group I base oils provide better wear protection than Group II, which provide better wear protection than Group III, which provide better wear protection than Group IV and GTL. This is because their pressure - viscosity coefficient is higher and they maintain thicker oil films under high-pressure conditions.
Does this mean that we should worry about using synthetic oil because their oil film breaks down more easily than conventional oil in the EHL regime? Probably not. I know Mobil 1 had poor wear protection in their SM formulation but this has been corrected in their SN formulation. Even if the oil film breaks down and you go into boundary lubrication (metal-to-metal contact), than the AW/EP/FM additives will protect against wear. Besides, I believe the valvetrain primarily works in the boundary-lubrication regime to begin with, and thereofe the AW/EP/FM additives, not the base oil, is the most critical factor there.
Originally Posted By: tig1
Why do you guys hate XM? I hear you say it but no explaination.
Years ago I was an M1 fanboy. Then I got caught up in the whole basestock debacle,then the castrol hearings and I just swung over to the Amsoil bench.
And if you like a Amsoil you naturally have to hate Mobil.
Then I tried it out for old times sake and my engines got very noisy and I didn't like that they cheapened the basestocks after the castrol thing but the cost to the consumer didn't change so I just decided that's it,no more Mobil.
I'll buy the stuff when its cost effective and on sale but I won't go out of my way to search got it.
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
So this explains why conventional oils tend to make an engine very quiet,because the oil film is thicker but not necessarily stronger.
Am I to infer that yes a conventional oil has a thicker oil film at any given temp however the film strength is lesser than their synthetic counterparts?
Thanks in advance for any answers if you know them.
I don't think "oil-film strength" is a scientific term.
If you mean how much pressure it takes an oil before it's squeezed out in the EHL regime, it's the same as oil-film thickness. If you mean how much protection an oil offers in the boundary lubrication regime, it mostly has to do with the AW/EP/FM additives and has little to do with the base oil.
Therefore, "oil-film strength" is primarily a gimmick used by some boutique synthetic-oil manufacturers.
The bottom line is that, in the EHL regime, Group I base oils provide better wear protection than Group II, which provide better wear protection than Group III, which provide better wear protection than Group IV and GTL. This is because their pressure - viscosity coefficient is higher and they maintain thicker oil films under high-pressure conditions.
Does this mean that we should worry about using synthetic oil because their oil film breaks down more easily than conventional oil in the EHL regime? Probably not. I know Mobil 1 had poor wear protection in their SM formulation but this has been corrected in their SN formulation. Even if the oil film breaks down and you go into boundary lubrication (metal-to-metal contact), than the AW/EP/FM additives will protect against wear. Besides, I believe the valvetrain primarily works in the boundary-lubrication regime to begin with, and thereofe the AW/EP/FM additives, not the base oil, is the most critical factor there.
Originally Posted By: tig1
Originally Posted By: Clevy
Originally Posted By: tig1
Clevy,
Since I've used M1 oils through out all the formulation changes, I have never experienced any unusual engine noise or quality reduction. In fact I have noticed the quality of M1 oils for the last 36 years have improved, as all other oils have.
What have you got to compare current engine acoustics to though tig. If you've never used anything but M1 you have nothing to compare it against whereas I use a different oil at every oil change so I can compare acoustics directly and I remember what the last oil change sounded like etc etc.
1) I have had a fair amount of experience with engines since the early 60s and have heard more than one engine with excess noise.
2)Most of the vehicles I have purchased have been used and had other oils in them at the time of purchase. After changing to M1(started 36 years ago) not a single one had increase noise, and if anything I noticed a smoother quiter engine with M1.
3) I have several friends and family that have been using M1 oil for years now because of my success. Not a single one has had nothing but long lived, smooth running, and often quiter engines with M1.
So are you saying that you used other oils 36 years ago and you want to compare those oils to today's oils and then compare the acoustics from engines 36 years ago.
Or you want to compare how your cars ran when you got them prior to their first oil change with m1.
At what mileages are your vehicles today.
I'm just saying that you don't have much volume of experience when it comes to using anything other than m1 since you've said many times your using m1 exclusively since the 70s
Originally Posted By: Clevy
Originally Posted By: tig1
Clevy,
Since I've used M1 oils through out all the formulation changes, I have never experienced any unusual engine noise or quality reduction. In fact I have noticed the quality of M1 oils for the last 36 years have improved, as all other oils have.
What have you got to compare current engine acoustics to though tig. If you've never used anything but M1 you have nothing to compare it against whereas I use a different oil at every oil change so I can compare acoustics directly and I remember what the last oil change sounded like etc etc.
1) I have had a fair amount of experience with engines since the early 60s and have heard more than one engine with excess noise.
2)Most of the vehicles I have purchased have been used and had other oils in them at the time of purchase. After changing to M1(started 36 years ago) not a single one had increase noise, and if anything I noticed a smoother quiter engine with M1.
3) I have several friends and family that have been using M1 oil for years now because of my success. Not a single one has had nothing but long lived, smooth running, and often quiter engines with M1.
So are you saying that you used other oils 36 years ago and you want to compare those oils to today's oils and then compare the acoustics from engines 36 years ago.
Or you want to compare how your cars ran when you got them prior to their first oil change with m1.
At what mileages are your vehicles today.
I'm just saying that you don't have much volume of experience when it comes to using anything other than m1 since you've said many times your using m1 exclusively since the 70s
Originally Posted By: Gokhan
Originally Posted By: Clevy
Originally Posted By: tig1
Why do you guys hate XM? I hear you say it but no explaination.
Years ago I was an M1 fanboy. Then I got caught up in the whole basestock debacle,then the castrol hearings and I just swung over to the Amsoil bench.
And if you like a Amsoil you naturally have to hate Mobil.
Then I tried it out for old times sake and my engines got very noisy and I didn't like that they cheapened the basestocks after the castrol thing but the cost to the consumer didn't change so I just decided that's it,no more Mobil.
I'll buy the stuff when its cost effective and on sale but I won't go out of my way to search got it.
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
So this explains why conventional oils tend to make an engine very quiet,because the oil film is thicker but not necessarily stronger.
Am I to infer that yes a conventional oil has a thicker oil film at any given temp however the film strength is lesser than their synthetic counterparts?
Thanks in advance for any answers if you know them.
I don't think "oil-film strength" is a scientific term.
If you mean how much pressure it takes an oil before it's squeezed out in the EHL regime, it's the same as oil-film thickness. If you mean how much protection an oil offers in the boundary lubrication regime, it mostly has to do with the AW/EP/FM additives and has little to do with the base oil.
Therefore, "oil-film strength" is primarily a gimmick used by some boutique synthetic-oil manufacturers.
The bottom line is that Group I base oils provide better wear protection than Group II, which provide better wear protection than Group III, which provide better wear protection than Group IV and GTL in the EHL regime. This is because their pressure - viscosity coefficient is higher and they maintain thicker oil films under high-pressure conditions.
Does this mean that we should worry about using synthetic oil because their oil film breaks down more easily than conventional oil in the EHL regime? Probably not. I know Mobil 1 had poor wear protection in their SM formulation but this has been corrected in their SN formulation. Even if the oil film breaks down and you go into boundary lubrication (metal-to-metal contact), than the AW/EP/FM additives will protect against wear. Besides, I believe the valvetrain primarily works in the boundary-lubrication regime to begin with, and thereofe the AW/EP/FM additives, not the base oil, is the most critical factor there.
That was an awesome explanation. Thank you for correcting me. I was mistaken on a few points which you've clarified in a stellar fashion for me.
Thank you very much. Fantastic explanation.
Originally Posted By: Clevy
Originally Posted By: tig1
Why do you guys hate XM? I hear you say it but no explaination.
Years ago I was an M1 fanboy. Then I got caught up in the whole basestock debacle,then the castrol hearings and I just swung over to the Amsoil bench.
And if you like a Amsoil you naturally have to hate Mobil.
Then I tried it out for old times sake and my engines got very noisy and I didn't like that they cheapened the basestocks after the castrol thing but the cost to the consumer didn't change so I just decided that's it,no more Mobil.
I'll buy the stuff when its cost effective and on sale but I won't go out of my way to search got it.
Originally Posted By: Gokhan
Elastohydrodynamic-lubrication (EHL) film thickness is given by (reference):
Here H_c is the EHL film thickness, alpha is the pressure - viscosity coefficient, and eta_0 is the high-shear (HTHS) viscosity.
The goal is to have the pressure - viscosity coefficient as high as possible, as well as the HTHS viscosity, to achieve a higher EHL film thickness.
Unfortunately, Group IV (PAO) has the smallest pressure - viscosity coefficient, followed by Group III, which is followed by Group II. Group I has the largest pressure - viscosity coefficient. Here is why (from page 180 of the reference):
Therefore, synthetic oils will give smaller oil film thickness than Group II oils and Group II oils will give smaller oil film thickness than Group I oils in the EHL regime. EHL regime and boundary-lubrication regime both apply to the valvetrain.
One advantage of synthetic oils is that, due to their use of lower concentration of viscosity-index improvers, their HTHS viscosity will shear less than for conventional oils over the OCI. Higher HTHS viscosity is good for oil-film thickness. Therefore, synthetic oils will maintain their oil-film thickness better than conventional oils over the OCI.
After all this said, am I worried about using synthetic oil? No, I am not. I believe the most important protection against wear in the valvetrain is ZDDP, moly, and other antiwear additives. So, if you have a decent concentration of quality (mostly secondary kind) ZDDP, the trinuclear kind of moly, and some additional quality AW/EP/FM additives, you should have good wear protection in the valvetrain regardless of the viscosity or the pressure - viscosity coefficient. This is not a proven statement though but more my current understanding. Engine tests are always the most authoritative in reaching a conclusion.
So this explains why conventional oils tend to make an engine very quiet,because the oil film is thicker but not necessarily stronger.
Am I to infer that yes a conventional oil has a thicker oil film at any given temp however the film strength is lesser than their synthetic counterparts?
Thanks in advance for any answers if you know them.
I don't think "oil-film strength" is a scientific term.
If you mean how much pressure it takes an oil before it's squeezed out in the EHL regime, it's the same as oil-film thickness. If you mean how much protection an oil offers in the boundary lubrication regime, it mostly has to do with the AW/EP/FM additives and has little to do with the base oil.
Therefore, "oil-film strength" is primarily a gimmick used by some boutique synthetic-oil manufacturers.
The bottom line is that Group I base oils provide better wear protection than Group II, which provide better wear protection than Group III, which provide better wear protection than Group IV and GTL in the EHL regime. This is because their pressure - viscosity coefficient is higher and they maintain thicker oil films under high-pressure conditions.
Does this mean that we should worry about using synthetic oil because their oil film breaks down more easily than conventional oil in the EHL regime? Probably not. I know Mobil 1 had poor wear protection in their SM formulation but this has been corrected in their SN formulation. Even if the oil film breaks down and you go into boundary lubrication (metal-to-metal contact), than the AW/EP/FM additives will protect against wear. Besides, I believe the valvetrain primarily works in the boundary-lubrication regime to begin with, and thereofe the AW/EP/FM additives, not the base oil, is the most critical factor there.
That was an awesome explanation. Thank you for correcting me. I was mistaken on a few points which you've clarified in a stellar fashion for me.
Thank you very much. Fantastic explanation.
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[/img]Originally Posted By: satinsilver
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I'm being completely serious.
I wasn't aware that group 1 oils were better in relation to film strength and lessens wear.
No sarcasm at all from me.
^^^^^^^^ [img:right]http://
[/img]I'm being completely serious.
I wasn't aware that group 1 oils were better in relation to film strength and lessens wear.
No sarcasm at all from me.
Here is an excellent article (PDF link) on challenges of using more refined base oils, such as Group II, III, IV, and GTL, as well as esters.
Challenges are great, as Group III, IV, and GTL base oils are regarded as "dry oils" with poor solubility and lubricity. Esters have excellent lubricity but they passivate the metal surfaces and block the AW/EP/FM additives and may therefore increase the wear greatly.
The article doesn't seem to discuss the pressure - viscosity coefficient, which is also important for wear protection but the synthetic base oils have poor pressure - viscosity coefficents as well. Despite this apparent omission, the article is excellent and discusses some great disadvantages and challenges of synthetic base oils and how to possibly overcome these challenges and disadvantages.
Challenges are great, as Group III, IV, and GTL base oils are regarded as "dry oils" with poor solubility and lubricity. Esters have excellent lubricity but they passivate the metal surfaces and block the AW/EP/FM additives and may therefore increase the wear greatly.
The article doesn't seem to discuss the pressure - viscosity coefficient, which is also important for wear protection but the synthetic base oils have poor pressure - viscosity coefficents as well. Despite this apparent omission, the article is excellent and discusses some great disadvantages and challenges of synthetic base oils and how to possibly overcome these challenges and disadvantages.
Originally Posted By: Gokhan
Here is an excellent article (PDF link) on challenges of using more refined base oils, such as Group II, III, IV, and GTL, as well as esters.
Challenges are great, as Group III, IV, and GTL base oils are regarded as "dry oils" with poor solubility and lubricity. Esters have excellent lubricity but they passivate the metal surfaces and block the AW/EP/FM additives and may therefore increase the wear greatly.
The article doesn't seem to discuss the pressure - viscosity coefficient, which is also important for wear protection but the synthetic base oils have poor pressure - viscosity coefficents as well. Despite this apparent omission, the article is excellent and discusses some great disadvantages and challenges of synthetic base oils and how to possibly overcome these challenges and disadvantages.
Great read. Thanks for posting.
There certainly is more to motor oil than most think.
Here is an excellent article (PDF link) on challenges of using more refined base oils, such as Group II, III, IV, and GTL, as well as esters.
Challenges are great, as Group III, IV, and GTL base oils are regarded as "dry oils" with poor solubility and lubricity. Esters have excellent lubricity but they passivate the metal surfaces and block the AW/EP/FM additives and may therefore increase the wear greatly.
The article doesn't seem to discuss the pressure - viscosity coefficient, which is also important for wear protection but the synthetic base oils have poor pressure - viscosity coefficents as well. Despite this apparent omission, the article is excellent and discusses some great disadvantages and challenges of synthetic base oils and how to possibly overcome these challenges and disadvantages.
Great read. Thanks for posting.
There certainly is more to motor oil than most think.
Originally Posted By: Gokhan
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
So what do you think about the Alkylaromatics... the Alkyl Benzenes and Alkyl Naphthalenes. Do these Grp V oil have a P-V relationship nearer to the Grp I or nearer to Grp III base oils ?
Are they not used in a big way in the engine oils because of any technical deficiencies in these oils OR some other reasons ?
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
So what do you think about the Alkylaromatics... the Alkyl Benzenes and Alkyl Naphthalenes. Do these Grp V oil have a P-V relationship nearer to the Grp I or nearer to Grp III base oils ?
Are they not used in a big way in the engine oils because of any technical deficiencies in these oils OR some other reasons ?
Originally Posted By: fpracha
Originally Posted By: Gokhan
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
So what do you think about the Alkylaromatics... the Alkyl Benzenes and Alkyl Naphthalenes. Do these Grp V oil have a P-V relationship nearer to the Grp I or nearer to Grp III base oils ?
Are they not used in a big way in the engine oils because of any technical deficiencies in these oils OR some other reasons ?
Alyklated naphthalene is a truly excellent Group V synthetic base oil, surpassing Group IV PAO and Group V esters in many ways. They are very stable and they have excellent P - V coefficients, even larger than Group I, comparable to naphthalene. They also have good lubricity and solubility. They don't suffer from potentially high wear problem of Group V esters (due to the ester's blocking of the AW/EP/FM additives). (See this reference.)
However, their viscosity indexes are very low. For example the the 5 cSt (@ 100 C) Exxon Mobil Synnestic 5 has a VI of only 74. (See the ExxonMobil synthetic formulations guide.) Because of this reason, they cannot be used on their own in multigrade oils, which would require too large concentrations of viscosity-index improvers. Also, interestingly, the previous ExxonMobil formulation guide examples had used an alyklated naphthalene in their PAO blends but the new guide mostly uses an ester in their PAO blends. (You don't want to have pure PAO base stocks [or even pure GTL or Group III] because of their poor lubrication properties as explained earlier.) Use of alkylated naphthalene vs. esters in the examples may be due to changing marketing strategies more than anything else.
Incidentally, TGMO 0W-20 SN seems to have a fairly significant concentration of alkylated naphthalene, as I can smell the rather intense odor of naphthalene from the bottle. I don't know if it's used as a base oil or a pour-point depressant. I would very much like to have alkylated naphthalene as a base oil in my motor oil because of its superior pressure - viscosity coefficient, lubricity, solubility, and other properties.
Originally Posted By: Gokhan
I expect the GTLs to have poor oil film thickness in the EHL regime like the PAO oils, as they also have very uniform long molecular chains. Alternatively stating the same thing, I expect the GTLS to have very small pressure - viscosity coefficients like the PAO oils, as they also have very uniform long molecular chains.
Group III molecular chains are not as uniform as PAO and GTL; so, Group III has a higher pressure - viscosity coefficient. It's still much lower than Group II, which is in turn much lower than Group I.
So what do you think about the Alkylaromatics... the Alkyl Benzenes and Alkyl Naphthalenes. Do these Grp V oil have a P-V relationship nearer to the Grp I or nearer to Grp III base oils ?
Are they not used in a big way in the engine oils because of any technical deficiencies in these oils OR some other reasons ?
Alyklated naphthalene is a truly excellent Group V synthetic base oil, surpassing Group IV PAO and Group V esters in many ways. They are very stable and they have excellent P - V coefficients, even larger than Group I, comparable to naphthalene. They also have good lubricity and solubility. They don't suffer from potentially high wear problem of Group V esters (due to the ester's blocking of the AW/EP/FM additives). (See this reference.)
However, their viscosity indexes are very low. For example the the 5 cSt (@ 100 C) Exxon Mobil Synnestic 5 has a VI of only 74. (See the ExxonMobil synthetic formulations guide.) Because of this reason, they cannot be used on their own in multigrade oils, which would require too large concentrations of viscosity-index improvers. Also, interestingly, the previous ExxonMobil formulation guide examples had used an alyklated naphthalene in their PAO blends but the new guide mostly uses an ester in their PAO blends. (You don't want to have pure PAO base stocks [or even pure GTL or Group III] because of their poor lubrication properties as explained earlier.) Use of alkylated naphthalene vs. esters in the examples may be due to changing marketing strategies more than anything else.
Incidentally, TGMO 0W-20 SN seems to have a fairly significant concentration of alkylated naphthalene, as I can smell the rather intense odor of naphthalene from the bottle. I don't know if it's used as a base oil or a pour-point depressant. I would very much like to have alkylated naphthalene as a base oil in my motor oil because of its superior pressure - viscosity coefficient, lubricity, solubility, and other properties.
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