Originally Posted By: used_0il
Is that GMO popcorn your eating?
GMO sprinkled with TGMO.
Is that GMO popcorn your eating?
GMO sprinkled with TGMO.
Viscosity Index Improvers are not bad.
- Thread starter Solarent
- Start date
I'm going to answer this:
Originally Posted By: hatt
Originally Posted By: Solarent
Firstly - my point is that members who think their oil has little or no VM's (and therefore must be better) may be surprised to learn what the real ratios are. For example odds are your 10W30 has a higher concentration of VM's than a 0W20.
You think it has a lot of VII with the 4.7 Noack?
And this:
Originally Posted By: Hangfire
I'll stick to VII since that's the standard BITOG term.
Aren't you just making the point of the other thread? If the heavier graded oils use lighter base stocks, then they are more susceptible to high NOACK.
And if they have high NOACK and lots of VII additives, we are more likely to see deposits. Thus the 10w-40 debacle in days of old.
In both your cases you are making assumptions about the base oil combination and type of VII. It is true that lighter grade oils can contribute to a higher rating in NOACK Volatility tests. However lighter PAO's (as was in my original examples) have inherently better volatility results. Also through the use of the right esters and VII's it is also possible to keep volatility at manageable levels.
There are many formula options for 10W30, just as there are for 0w40. Often they use very different combinations of base oils, and equally different types of VII. Without knowing the details of the formula, it is impossible to predict what kind of performance you are going to get or make any educated comments on VII concentration. It is possible that a 10W30 could have up to 11% VII when the 0W20 or 0W40 even could have much less. But that is much more dependent on they type of VII and base oil combinations, because these things are not all created equal.
Viscosity modifiers are an essential part of all multi grade engine oils. How much is used and what type depends on a great number of factors including price, desired performance and how the polymers interact with the base oil.
Originally Posted By: hatt
Originally Posted By: Solarent
Firstly - my point is that members who think their oil has little or no VM's (and therefore must be better) may be surprised to learn what the real ratios are. For example odds are your 10W30 has a higher concentration of VM's than a 0W20.
You think it has a lot of VII with the 4.7 Noack?
And this:
Originally Posted By: Hangfire
I'll stick to VII since that's the standard BITOG term.
Aren't you just making the point of the other thread? If the heavier graded oils use lighter base stocks, then they are more susceptible to high NOACK.
And if they have high NOACK and lots of VII additives, we are more likely to see deposits. Thus the 10w-40 debacle in days of old.
In both your cases you are making assumptions about the base oil combination and type of VII. It is true that lighter grade oils can contribute to a higher rating in NOACK Volatility tests. However lighter PAO's (as was in my original examples) have inherently better volatility results. Also through the use of the right esters and VII's it is also possible to keep volatility at manageable levels.
There are many formula options for 10W30, just as there are for 0w40. Often they use very different combinations of base oils, and equally different types of VII. Without knowing the details of the formula, it is impossible to predict what kind of performance you are going to get or make any educated comments on VII concentration. It is possible that a 10W30 could have up to 11% VII when the 0W20 or 0W40 even could have much less. But that is much more dependent on they type of VII and base oil combinations, because these things are not all created equal.
Viscosity modifiers are an essential part of all multi grade engine oils. How much is used and what type depends on a great number of factors including price, desired performance and how the polymers interact with the base oil.
Originally Posted By: Shannow
(*) and it could mean that I'm looking in the wrong direction.
To that end, do you have any data on how VMs work on the High Shear "Viscosity Index" ?
BY that I mean that the VI is based on the KV40/KV100. However, above 10^6 shear rate, they are entering their second Newtonian period, when the polymer alignment is such that the viscosity is reduced to another "stable point", through temporary shear.
If an HTHS40 and HTHS100 are used, what's the slope of the Viscosity Index that is formed compared to the VI in kinematic terms ?
I've only found a couple of products that give HTHS 150 and HTHS 100, and it appears from one or two data points that a high shear VI is probably closer to the VI of the bases than the finished oil.
BUT if the VMs DO give a matching VI in the High Shear range, then TGMO makes much more sense.
Unfortunately I don't have any specific information I can give on High "temporary" Shear viscosity conditions. What I can say is that as far as I understand it, different polymer types respond in different ways to the high shear conditions (and as has been shown in bench tests there are different types of temporary shear which can evoke different results dependant on the VM). For example most complex PMAs will have better shear rates than OCPs. Generally speaking oils that are have VI above 200 (TGMO as the typical BITOG example) will use a more complex VM with better shear stability.
In some cases having a lots of temporary shear can be advantageous to an oil formula, imagine an oil that dependent on engine pressures morphed its viscosity to produce the optimal oil film thickness and then returned to grade where it would flow to achieve maximum fuel economy. This is the direction that the thinner formulas are headed into, but it takes a wildly complex blend of advanced polymers combined with premium base oils.
We often forget in these hypothetical conversations that engine oil has to perform many operations simulataneously. Not all the oil in the engine is subjected to high temperatures or high shear, and in some parts of the engine where temporary shear is desirable, there are other parts where it is not. Engine oil formulas are therefore always a compromise, but we shouldn't make assumptions about performance when we don't know what was going on in the formulator's mind.
(*) and it could mean that I'm looking in the wrong direction.
To that end, do you have any data on how VMs work on the High Shear "Viscosity Index" ?
BY that I mean that the VI is based on the KV40/KV100. However, above 10^6 shear rate, they are entering their second Newtonian period, when the polymer alignment is such that the viscosity is reduced to another "stable point", through temporary shear.
If an HTHS40 and HTHS100 are used, what's the slope of the Viscosity Index that is formed compared to the VI in kinematic terms ?
I've only found a couple of products that give HTHS 150 and HTHS 100, and it appears from one or two data points that a high shear VI is probably closer to the VI of the bases than the finished oil.
BUT if the VMs DO give a matching VI in the High Shear range, then TGMO makes much more sense.
Unfortunately I don't have any specific information I can give on High "temporary" Shear viscosity conditions. What I can say is that as far as I understand it, different polymer types respond in different ways to the high shear conditions (and as has been shown in bench tests there are different types of temporary shear which can evoke different results dependant on the VM). For example most complex PMAs will have better shear rates than OCPs. Generally speaking oils that are have VI above 200 (TGMO as the typical BITOG example) will use a more complex VM with better shear stability.
In some cases having a lots of temporary shear can be advantageous to an oil formula, imagine an oil that dependent on engine pressures morphed its viscosity to produce the optimal oil film thickness and then returned to grade where it would flow to achieve maximum fuel economy. This is the direction that the thinner formulas are headed into, but it takes a wildly complex blend of advanced polymers combined with premium base oils.
We often forget in these hypothetical conversations that engine oil has to perform many operations simulataneously. Not all the oil in the engine is subjected to high temperatures or high shear, and in some parts of the engine where temporary shear is desirable, there are other parts where it is not. Engine oil formulas are therefore always a compromise, but we shouldn't make assumptions about performance when we don't know what was going on in the formulator's mind.
Temporary shear in the bearing space occurs at high rpm/bearing speed or shear rate.
The long un-coiled VIIs align themselves in the direction of rotation, reducing their thickening effect on viscosity.
High shear rates caused by speed in this case, reduces the viscosity requirement of the bearing for a given load.
However, the cone shaped VM presented in the Evonik video, may not be affected by shear speed, (ha!) like the classic VIIs are.
Temporary shear loss in a bearing can reduce the viscous drag or friction, increase the side leakage and reduce the heating of the engine oil to name a few.
Every engine in it's unique application may need it's own designated engine oil in the future.
The long un-coiled VIIs align themselves in the direction of rotation, reducing their thickening effect on viscosity.
High shear rates caused by speed in this case, reduces the viscosity requirement of the bearing for a given load.
However, the cone shaped VM presented in the Evonik video, may not be affected by shear speed, (ha!) like the classic VIIs are.
Temporary shear loss in a bearing can reduce the viscous drag or friction, increase the side leakage and reduce the heating of the engine oil to name a few.
Every engine in it's unique application may need it's own designated engine oil in the future.
Last edited by a moderator:
Originally Posted By: used_0il
Temporary shear in the bearing space occurs at high rpm/bearing speed or shear rate.
The long un-coiled VIIs align themselves in the direction of rotation, reducing their thickening effect on viscosity.
I thought that was a good thing and is called reptiling and increases the effective viscosity as the oil film gets thinner.
I don't understand all the teeth knashing over oil shearing down a grade. Change the oil in summer let it shear and run the sheared down oil in the winter. Perfect.
Temporary shear in the bearing space occurs at high rpm/bearing speed or shear rate.
The long un-coiled VIIs align themselves in the direction of rotation, reducing their thickening effect on viscosity.
I thought that was a good thing and is called reptiling and increases the effective viscosity as the oil film gets thinner.
I don't understand all the teeth knashing over oil shearing down a grade. Change the oil in summer let it shear and run the sheared down oil in the winter. Perfect.
Originally Posted By: turtlevette
I thought that was a good thing and is called reptiling and increases the effective viscosity as the oil film gets thinner.
Sounds like you need to start a thread in science and technology and explain it all in detail to us, rather than drag (another) thread into the ditch.
I thought that was a good thing and is called reptiling and increases the effective viscosity as the oil film gets thinner.
Sounds like you need to start a thread in science and technology and explain it all in detail to us, rather than drag (another) thread into the ditch.
Quote:
My commentary, not against VIIs is that there are two memes in BITOG that have evolved.
* Higher Viscosity Index is always better;
* 0W is always better.
I'm just trying to bring to light the compromises that are made to achieve both of those, and say that they are not necessarily better, depending on the question that's being asked of the oil.
Right.
Per a Mobil SAE Paper via a member who read it:
Advanced Synthetic Passenger Vehicle Engine Oils for Extended Oil Drain Performance
"It featured 9 Mobil synthetic motor oil formulations that appear almost identical to the current M1 product line, right down to the additive proportions and viscosity data. Anyway, they publish the data on the performance of all these formulations for all engine sequences. The only trend I found from several studies, is that 0w-x lubricants have higher rates of consumption and rate slightly lower on cleanliness/varnish. This goes along with what Pennzoil said in their FAQs about narrow span motor oils having better deposit control. Increased VIIs are the culprit. I did also see on graphs that 0w-x lubricants had a higher spread of higher wear rates compared to 5w-x of the same grade, but the authors said it was insignificant. And finally, wear rates were significantly correlated differences to engine design and build quality (tolerances, metallurgy, etc) and not with lubricant viscosity. "
My commentary, not against VIIs is that there are two memes in BITOG that have evolved.
* Higher Viscosity Index is always better;
* 0W is always better.
I'm just trying to bring to light the compromises that are made to achieve both of those, and say that they are not necessarily better, depending on the question that's being asked of the oil.
Right.
Per a Mobil SAE Paper via a member who read it:
Advanced Synthetic Passenger Vehicle Engine Oils for Extended Oil Drain Performance
"It featured 9 Mobil synthetic motor oil formulations that appear almost identical to the current M1 product line, right down to the additive proportions and viscosity data. Anyway, they publish the data on the performance of all these formulations for all engine sequences. The only trend I found from several studies, is that 0w-x lubricants have higher rates of consumption and rate slightly lower on cleanliness/varnish. This goes along with what Pennzoil said in their FAQs about narrow span motor oils having better deposit control. Increased VIIs are the culprit. I did also see on graphs that 0w-x lubricants had a higher spread of higher wear rates compared to 5w-x of the same grade, but the authors said it was insignificant. And finally, wear rates were significantly correlated differences to engine design and build quality (tolerances, metallurgy, etc) and not with lubricant viscosity. "
Originally Posted By: buster
Quote:
My commentary, not against VIIs is that there are two memes in BITOG that have evolved.
* Higher Viscosity Index is always better;
* 0W is always better.
I'm just trying to bring to light the compromises that are made to achieve both of those, and say that they are not necessarily better, depending on the question that's being asked of the oil.
Right.
Per a Mobil SAE Paper via a member who read it:
Advanced Synthetic Passenger Vehicle Engine Oils for Extended Oil Drain Performance
"It featured 9 Mobil synthetic motor oil formulations that appear almost identical to the current M1 product line, right down to the additive proportions and viscosity data. Anyway, they publish the data on the performance of all these formulations for all engine sequences. The only trend I found from several studies, is that 0w-x lubricants have higher rates of consumption and rate slightly lower on cleanliness/varnish. This goes along with what Pennzoil said in their FAQs about narrow span motor oils having better deposit control. Increased VIIs are the culprit. I did also see on graphs that 0w-x lubricants had a higher spread of higher wear rates compared to 5w-x of the same grade, but the authors said it was insignificant. And finally, wear rates were significantly correlated differences to engine design and build quality (tolerances, metallurgy, etc) and not with lubricant viscosity. "
Thanks for this information, Buster. can you find the SAE paper reference code, I'd like to pull it up and compare to my other notes in this regard.
Quote:
My commentary, not against VIIs is that there are two memes in BITOG that have evolved.
* Higher Viscosity Index is always better;
* 0W is always better.
I'm just trying to bring to light the compromises that are made to achieve both of those, and say that they are not necessarily better, depending on the question that's being asked of the oil.
Right.
Per a Mobil SAE Paper via a member who read it:
Advanced Synthetic Passenger Vehicle Engine Oils for Extended Oil Drain Performance
"It featured 9 Mobil synthetic motor oil formulations that appear almost identical to the current M1 product line, right down to the additive proportions and viscosity data. Anyway, they publish the data on the performance of all these formulations for all engine sequences. The only trend I found from several studies, is that 0w-x lubricants have higher rates of consumption and rate slightly lower on cleanliness/varnish. This goes along with what Pennzoil said in their FAQs about narrow span motor oils having better deposit control. Increased VIIs are the culprit. I did also see on graphs that 0w-x lubricants had a higher spread of higher wear rates compared to 5w-x of the same grade, but the authors said it was insignificant. And finally, wear rates were significantly correlated differences to engine design and build quality (tolerances, metallurgy, etc) and not with lubricant viscosity. "
Thanks for this information, Buster. can you find the SAE paper reference code, I'd like to pull it up and compare to my other notes in this regard.
Originally Posted By: Solarent
Thanks for this information, Buster. can you find the SAE paper reference code, I'd like to pull it up and compare to my other notes in this regard.
This is probably it:
http://papers.sae.org/981444/
First hit in google.
Just curious, but has there been any improvement in VII technology since 1998 when this paper was published?
Thanks for this information, Buster. can you find the SAE paper reference code, I'd like to pull it up and compare to my other notes in this regard.
This is probably it:
http://papers.sae.org/981444/
First hit in google.
Just curious, but has there been any improvement in VII technology since 1998 when this paper was published?
Originally Posted By: used_0il
Is that GMO popcorn your eating?
It might as well be, for where I think this thread is heading with the majority VII haterz on this site. LOL
Is that GMO popcorn your eating?
It might as well be, for where I think this thread is heading with the majority VII haterz on this site. LOL
Originally Posted By: Quattro Pete
Originally Posted By: used_0il
Is that GMO popcorn your eating?
GMO sprinkled with TGMO.
Nope, SUSTINA (FTW)!!
Originally Posted By: used_0il
Is that GMO popcorn your eating?
GMO sprinkled with TGMO.
Nope, SUSTINA (FTW)!!
Originally Posted By: Solarent
hatt said:
I do not recall any of the respected members here, which I think this thread is aimed at, ever say that VIIs are bad all together. They simply questioned the commonly accepted logic, at the time, that the higher the VI number, the better the oil was.
Then we had few threads debunking the myths perpetuated by some members that VIIs have no negatives and only positives.
The VIIs obviously have their place and are here to stay, but they are not without shortcomings.
Then we had few threads debunking the myths perpetuated by some members that VIIs have no negatives and only positives.
The VIIs obviously have their place and are here to stay, but they are not without shortcomings.
That's exactly it, I would agree. A higher VI certainly gives you better fuel economy. That doesn't mean it makes the oil better under all circumstances and in all applications. There still are reasons to choose oils with lower usage of VIIs. Obviously, though, we in Canada aren't too likely to be using monogrades on a regular basis.
Have your Canadian Tires yanked virtually all the 10w-30 synthetics, too?
And the questions still remain unanswered...
Man, if I ever won the lottery, some serious ultra high shear rate viscosity testing would be on my to do list for sure. I guarantee the answers to these questions exist, but we are not quite privileged enough to be exposed.
Shannow, I'm still searching but coming up empty... and even university profs in the field of bearing design/analysis and Tribology are unable to answer. Where's a loose-lipped powertrain Engineer when you need one?
Man, if I ever won the lottery, some serious ultra high shear rate viscosity testing would be on my to do list for sure. I guarantee the answers to these questions exist, but we are not quite privileged enough to be exposed.
Shannow, I'm still searching but coming up empty... and even university profs in the field of bearing design/analysis and Tribology are unable to answer. Where's a loose-lipped powertrain Engineer when you need one?
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