Too low of a NOACK
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Baad Noack # oil (specially conventional) example is at 1:42' to 2:35' in this vid. Look how volatility and oxidation made the oil become a Tar like goo.
https://www.youtube.com/watch?v=oi_J4SZUlSo
https://www.youtube.com/watch?v=oi_J4SZUlSo
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Originally Posted By: Garak
Are they really specifying a semi-synthetic? I thought there specification was met by several conventionals out there, although finding a complete Group I/II oil out there these days, particularly in 5w-30, might be a bit more of a challenge than we realize.
Just checked, Pennzoil does say that PYB meets the current Ford spec.
Are they really specifying a semi-synthetic? I thought there specification was met by several conventionals out there, although finding a complete Group I/II oil out there these days, particularly in 5w-30, might be a bit more of a challenge than we realize.
Just checked, Pennzoil does say that PYB meets the current Ford spec.
Yep, that's what I thought. I'm sure QSGB and Mobil Super conventional do as well. Of course, synthetics and blends often will, too, but that's understood.
MolaKule
Staff member
Originally Posted By: mjoekingz28
I have found it Garak, but all other details were in foreign languague(s).
Still, what has not been answered that I can find is what compromises should be made to have a low Volatility?
If one could find a set of additives AND base oils with zero volatility, there would be no compromises whatsoever.
Certain PAOs, Esters, and GTL's (not all), have very low NOACk's in the range of 3%, but the use of a majority of those in a formulation mix would be costly at current prices, hence the use of Group III and Group II oils with PAOs, Esters, and GTL's.
There is a new base oil on the market composed of a reacted PAO/Ester that promises < 3% NOACK.
I have found it Garak, but all other details were in foreign languague(s).
Still, what has not been answered that I can find is what compromises should be made to have a low Volatility?
If one could find a set of additives AND base oils with zero volatility, there would be no compromises whatsoever.
Certain PAOs, Esters, and GTL's (not all), have very low NOACk's in the range of 3%, but the use of a majority of those in a formulation mix would be costly at current prices, hence the use of Group III and Group II oils with PAOs, Esters, and GTL's.
There is a new base oil on the market composed of a reacted PAO/Ester that promises < 3% NOACK.
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There you go - cost is a compromise in that case.
Originally Posted By: OVERKILL
No, it generally means that better and more expensive base oils are used that are less volatile, that's it.
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
That is: Cheaper lower viscosity oil to meet cold flow specs. (pour point depressant is expensive, less to add). 100C plumped up with VII.
High NOACK combined with a low HTHS screams lots of VII to me....
No, it generally means that better and more expensive base oils are used that are less volatile, that's it.
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
That is: Cheaper lower viscosity oil to meet cold flow specs. (pour point depressant is expensive, less to add). 100C plumped up with VII.
High NOACK combined with a low HTHS screams lots of VII to me....
Originally Posted By: Tempest
Originally Posted By: OVERKILL
No, it generally means that better and more expensive base oils are used that are less volatile, that's it.
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
That is: Cheaper lower viscosity oil to meet cold flow specs. (pour point depressant is expensive, less to add). 100C plumped up with VII.
High NOACK combined with a low HTHS screams lots of VII to me....
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
Originally Posted By: OVERKILL
No, it generally means that better and more expensive base oils are used that are less volatile, that's it.
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
That is: Cheaper lower viscosity oil to meet cold flow specs. (pour point depressant is expensive, less to add). 100C plumped up with VII.
High NOACK combined with a low HTHS screams lots of VII to me....
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
Originally Posted By: Tempest
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
No, this is wrong. The reason you might see higher Noack (note: not all CAPITALS) with higher VII dosage is because you would, for a given KV100, be starting with a lighter base oil, which will be more volatile (on a like-for-like basis). So, light base oil + lots of VII = high Noack. VII has a very large molecular weight compared to base oil and will be more likely to thermally decompose than evaporate.
Originally Posted By: Tempest
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
As stated above, you can't relate VII dosage to Noack. Noack is almost exclusively determined by the base oil mix, both its type and its viscosity (which is, itself, related to it molecular weight). One benefit of synthetics vs minerals is that a mineral is a broad mixture of molecules, whereas a synthetic is a much purer substance. The mineral has a mix of molecules, some 'big', some 'little'. The little ones will tend to evaporate more readily.
To the best of my understanding, VII is more volatile than is the base oil. So the more VII, the higher the NOACK.
No, this is wrong. The reason you might see higher Noack (note: not all CAPITALS) with higher VII dosage is because you would, for a given KV100, be starting with a lighter base oil, which will be more volatile (on a like-for-like basis). So, light base oil + lots of VII = high Noack. VII has a very large molecular weight compared to base oil and will be more likely to thermally decompose than evaporate.
Originally Posted By: Tempest
Also, more VII will show a higher 100C temp (relative to lower amounts of VII), so NOACK can be a rough way to scope out VII concentration in an oil.
As stated above, you can't relate VII dosage to Noack. Noack is almost exclusively determined by the base oil mix, both its type and its viscosity (which is, itself, related to it molecular weight). One benefit of synthetics vs minerals is that a mineral is a broad mixture of molecules, whereas a synthetic is a much purer substance. The mineral has a mix of molecules, some 'big', some 'little'. The little ones will tend to evaporate more readily.
Another consideration is the VII is usually about 90% base oil and 10% polymer / rubber. If you have 10% VII in a motor oil, you are putting in about 9% more base oil. What base oil is used to dilute the polymer, think cheap.
Originally Posted By: DWC28
Another consideration is the VII is usually about 90% base oil and 10% polymer / rubber. If you have 10% VII in a motor oil, you are putting in about 9% more base oil. What base oil is used to dilute the polymer, think cheap.
Not quite. Are there VI improvers that are 90% base oil? Yes absolutely, but there are also ones that are 100% polymer. What that ratio is completely depends on the specific VI improver used. To say they are usually 90% base oil is not accurate at least from my experience.
Another consideration is the VII is usually about 90% base oil and 10% polymer / rubber. If you have 10% VII in a motor oil, you are putting in about 9% more base oil. What base oil is used to dilute the polymer, think cheap.
Not quite. Are there VI improvers that are 90% base oil? Yes absolutely, but there are also ones that are 100% polymer. What that ratio is completely depends on the specific VI improver used. To say they are usually 90% base oil is not accurate at least from my experience.
Originally Posted By: MotoTribologist
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
My post was in the context of oils that meet a particular spec.
Wouldn't it be likely that an oil that meets a particular spec. (say 5W30) with higher Noack will likely have lighter fractions of oil and more VII to make up the difference?
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
My post was in the context of oils that meet a particular spec.
Wouldn't it be likely that an oil that meets a particular spec. (say 5W30) with higher Noack will likely have lighter fractions of oil and more VII to make up the difference?
Originally Posted By: weasley
No, this is wrong. The reason you might see higher Noack (note: not all CAPITALS) with higher VII dosage is because you would, for a given KV100, be starting with a lighter base oil, which will be more volatile (on a like-for-like basis). So, light base oil + lots of VII = high Noack. VII has a very large molecular weight compared to base oil and will be more likely to thermally decompose than evaporate.
Ok, I'll go with that.
No, this is wrong. The reason you might see higher Noack (note: not all CAPITALS) with higher VII dosage is because you would, for a given KV100, be starting with a lighter base oil, which will be more volatile (on a like-for-like basis). So, light base oil + lots of VII = high Noack. VII has a very large molecular weight compared to base oil and will be more likely to thermally decompose than evaporate.
Ok, I'll go with that.
Originally Posted By: Tempest
Originally Posted By: MotoTribologist
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
My post was in the context of oils that meet a particular spec.
Wouldn't it be likely that an oil that meets a particular spec. (say 5W30) with higher Noack will likely have lighter fractions of oil and more VII to make up the difference?
Yes it could be true that a high volatility oil might have high VI improver content, Likely? Maybe, I honestly don't know.
There is no correlation between volatility and VI improver content though. Neither one is an indicator of the other.
Originally Posted By: MotoTribologist
Quite an old thread to dig up, and no, that is incorrect. NOACK volatility can in now way tell you the VII content of an oil, roughly or otherwise.
The only thing high NOACK with low HTHS screams is low viscosity oil with a high volatility.
My post was in the context of oils that meet a particular spec.
Wouldn't it be likely that an oil that meets a particular spec. (say 5W30) with higher Noack will likely have lighter fractions of oil and more VII to make up the difference?
Yes it could be true that a high volatility oil might have high VI improver content, Likely? Maybe, I honestly don't know.
There is no correlation between volatility and VI improver content though. Neither one is an indicator of the other.
MolaKule
Staff member
Originally Posted By: MotoTribologist
There is no correlation between volatility and VI improver content though. Neither one is an indicator of the other.
There is no correlation between volatility and VI improver content though. Neither one is an indicator of the other.
One of the problems is that people get confused when observing oil 'thickening', i.e. viscosity increase, assuming that viscosity increase equals oxidation.
The NOAK ASTM D5800 is a measure of evaporation loss and normally in specifications is defined as a percent loss.
Evaporation loss obviously gives rise to oil 'thickening'. However many get confused because they assume that viscosity increase is always due to oxidation, which is not the case. An easy thing to do is to observe the TAN trend to see whether the viscosity increase is oxidation related or not.
The NOAK ASTM D5800 is a measure of evaporation loss and normally in specifications is defined as a percent loss.
Evaporation loss obviously gives rise to oil 'thickening'. However many get confused because they assume that viscosity increase is always due to oxidation, which is not the case. An easy thing to do is to observe the TAN trend to see whether the viscosity increase is oxidation related or not.
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