Best NOACK for 0w20
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Let’s ask ourselves what makes a motor oil have exceptionally low volatility? I know the answers but want to hear what others think.
My answer: Quality base stocks but add-packs also have a hand in this as well somewhat.
wemay
Site Donor 2023
I always believed base oil was the main determinant as well. But then why do some 10W30 conventional oils have better Noack numbers than say a 5W30 synthetic? This can get very complicated.
Anyone remember Synlube? Here's their explaination:
http://www.synlube.com/SynLube_Magic3.htm
Anyone remember Synlube? Here's their explaination:
http://www.synlube.com/SynLube_Magic3.htm
Originally Posted By: wemay
I always believed base oil was the main determinant as well. But then why do some 10W30 conventional oils have better Noack numbers than say a 5W30 synthetic? This can get very complicated.
Anyone remember Synlube? Here's their explaination:
http://www.synlube.com/SynLube_Magic3.htm
5W has a thinner base oil than 10W, therefore having a higher volatility all things held equal.
I always believed base oil was the main determinant as well. But then why do some 10W30 conventional oils have better Noack numbers than say a 5W30 synthetic? This can get very complicated.
Anyone remember Synlube? Here's their explaination:
http://www.synlube.com/SynLube_Magic3.htm
5W has a thinner base oil than 10W, therefore having a higher volatility all things held equal.
Effects of motor oil ingredients on volatility:
1. Viscosity of each base oil. For a given base oil type, more viscous == larger molecular size & weight == less volatile. Motor oils may have viscosity index improvers (VIIs) that considerably increase the viscosity over that of the base oil mix. For a given kinematic viscosity at 100 C, the more the VIIs increased the viscosity, the lower the base oil viscosity mix is, and therefore the more volatile it is.
2. Variation of viscosity across the multiple base oils (if there are multiple). A single base oil with 6 cSt viscosity could be chosen or a mix made from multiple viscosities could be made to have 6 cSt viscosity. The latter are sometimes called dumbbell blends. Since the volatility vs viscosity curve for a given base oil type has an exponential-like shape, the oil with low viscosity used in the blend will have a disproportionately high volatility, causing the 6cSt blend to have a higher volatility than the single-cut 6 cSt oil.
3. Type of each base oil; this is more complicated.
- Oils made from crude oil are a mix of aromatic, naphthenic, and paraffinic oils, which are defined by their molecular structure. For each type of equal viscosity, the paraffinic type will have the lowest volatility, even if within each type, every molecule was identical in size/weight. This is due to molecular structure. As the severity of refining increases to produce oils of Group I - III, the aromatic and napthenic oil content decreases (with paraffinic increasing), decreasing volatility. PAO base oils have no aromatics or naphthenics.
- Molecular size/weight distribution effect: it is like the dumbbell blend taken to the extreme. An oil that has only one molecular size/weight (no variability). Oils refined from crude oil have a considerably wide distribution of molecular size/weight. Increased refining severity tends to reduce it, further decreasing volatility as refining severity increases, beyond that caused by the effect of increasing paraffinic content. Here is where PAO should be mentioned again. For a given viscosity/cut of it, it will have a smaller distribution of molecular size/weight than Groups I - III. That decreases its volatility.
- Esters have not been mentioned so far. They tend to have lower volatility than PAO, for a given viscosity. A given ester type of a given viscosity will have a narrow distribution of molecular size/weight like PAO, which benefits volatility. One reason they are typically less volatile than PAO is because of their inter-molecular attraction which limits the occurrence of a molecules separating from the liquid phase and going to the gas phase. Another reason for the low volatility at a given viscosity is because they tend to be more dense than other oils, which effects the kinematic viscosity. Kinematic viscosity is measured using the force of gravity to move the oil, and a more dense oil has a higher weight force pulling on it. It’s kinematic viscosity is a function of its density and its true (dynamic) viscosity. Esters tend to be less volatile than PAOs of a given dynamic viscosity because of the polar molecular attraction effect.
4. Motor oil additive packages tend to have much lower volatility than base oils, plus they usually comprise at most around 25% of the motor oil, which further limits its volatility contribution.
1. Viscosity of each base oil. For a given base oil type, more viscous == larger molecular size & weight == less volatile. Motor oils may have viscosity index improvers (VIIs) that considerably increase the viscosity over that of the base oil mix. For a given kinematic viscosity at 100 C, the more the VIIs increased the viscosity, the lower the base oil viscosity mix is, and therefore the more volatile it is.
2. Variation of viscosity across the multiple base oils (if there are multiple). A single base oil with 6 cSt viscosity could be chosen or a mix made from multiple viscosities could be made to have 6 cSt viscosity. The latter are sometimes called dumbbell blends. Since the volatility vs viscosity curve for a given base oil type has an exponential-like shape, the oil with low viscosity used in the blend will have a disproportionately high volatility, causing the 6cSt blend to have a higher volatility than the single-cut 6 cSt oil.
3. Type of each base oil; this is more complicated.
- Oils made from crude oil are a mix of aromatic, naphthenic, and paraffinic oils, which are defined by their molecular structure. For each type of equal viscosity, the paraffinic type will have the lowest volatility, even if within each type, every molecule was identical in size/weight. This is due to molecular structure. As the severity of refining increases to produce oils of Group I - III, the aromatic and napthenic oil content decreases (with paraffinic increasing), decreasing volatility. PAO base oils have no aromatics or naphthenics.
- Molecular size/weight distribution effect: it is like the dumbbell blend taken to the extreme. An oil that has only one molecular size/weight (no variability). Oils refined from crude oil have a considerably wide distribution of molecular size/weight. Increased refining severity tends to reduce it, further decreasing volatility as refining severity increases, beyond that caused by the effect of increasing paraffinic content. Here is where PAO should be mentioned again. For a given viscosity/cut of it, it will have a smaller distribution of molecular size/weight than Groups I - III. That decreases its volatility.
- Esters have not been mentioned so far. They tend to have lower volatility than PAO, for a given viscosity. A given ester type of a given viscosity will have a narrow distribution of molecular size/weight like PAO, which benefits volatility. One reason they are typically less volatile than PAO is because of their inter-molecular attraction which limits the occurrence of a molecules separating from the liquid phase and going to the gas phase. Another reason for the low volatility at a given viscosity is because they tend to be more dense than other oils, which effects the kinematic viscosity. Kinematic viscosity is measured using the force of gravity to move the oil, and a more dense oil has a higher weight force pulling on it. It’s kinematic viscosity is a function of its density and its true (dynamic) viscosity. Esters tend to be less volatile than PAOs of a given dynamic viscosity because of the polar molecular attraction effect.
4. Motor oil additive packages tend to have much lower volatility than base oils, plus they usually comprise at most around 25% of the motor oil, which further limits its volatility contribution.
wemay
Site Donor 2023
Thank you JAG
Originally Posted By: ChrisD46
I believe for a GDI engine you would want as low a NOACK oil as possible to keep intake valve deposits at bay (along with top tier gas , shorter OCI's , etc.) with a GDI engine.
Nope, on the contrary, the lower the NOACK and/or higher the base-oil viscosity, the more the intake-valve deposits will be. Alternatively, the higher the NOACK and/or lower the base-oil viscosity, the less the intake-valve deposits will be.
This is because one mechanism of cleaning of the intake-valve deposits is evaporation. If NOACK volatility is low or the base-oil is thick, the oil will spend more time on the valves as it evaporates more slowly, therefore leaving more deposits behind.
Intake-valve and combustion-chamber depo...ts their growth
So, if you want the least intake-valve deposits in a GDI engine, you need to pick up a 0W-20 with higher NOACK. A 10W-30, which has both a thick base oil and low NOACK would be the worst choice as far as the intake-valve deposits are concerned.
From the article: "The most important lubricating-oil component for deposit formation is the base oil. Increasing the high molecular weight (high viscosity) and low volatility content of the oil increases deposit formation."
I believe for a GDI engine you would want as low a NOACK oil as possible to keep intake valve deposits at bay (along with top tier gas , shorter OCI's , etc.) with a GDI engine.
Nope, on the contrary, the lower the NOACK and/or higher the base-oil viscosity, the more the intake-valve deposits will be. Alternatively, the higher the NOACK and/or lower the base-oil viscosity, the less the intake-valve deposits will be.
This is because one mechanism of cleaning of the intake-valve deposits is evaporation. If NOACK volatility is low or the base-oil is thick, the oil will spend more time on the valves as it evaporates more slowly, therefore leaving more deposits behind.
Intake-valve and combustion-chamber depo...ts their growth
So, if you want the least intake-valve deposits in a GDI engine, you need to pick up a 0W-20 with higher NOACK. A 10W-30, which has both a thick base oil and low NOACK would be the worst choice as far as the intake-valve deposits are concerned.
From the article: "The most important lubricating-oil component for deposit formation is the base oil. Increasing the high molecular weight (high viscosity) and low volatility content of the oil increases deposit formation."
Originally Posted By: Gokhan
Originally Posted By: ChrisD46
I believe for a GDI engine you would want as low a NOACK oil as possible to keep intake valve deposits at bay (along with top tier gas , shorter OCI's , etc.) with a GDI engine.
Nope, on the contrary, the lower the NOACK and/or higher the base-oil viscosity, the more the intake-valve deposits will be. Alternatively, the higher the NOACK and/or lower the base-oil viscosity, the less the intake-valve deposits will be.
This is because one mechanism of cleaning of the intake-valve deposits is evaporation. If NOACK volatility is low or the base-oil is thick, the oil will spend more time on the valves as it evaporates more slowly, therefore leaving more deposits behind.
Intake-valve and combustion-chamber depo...ts their growth
So, if you want the least intake-valve deposits in a GDI engine, you need to pick up a 0W-20 with higher NOACK. A 10W-30, which has both a thick base oil and low NOACK would be the worst choice as far as the intake-valve deposits are concerned.
From the article: "The most important lubricating-oil component for deposit formation is the base oil. Increasing the high molecular weight (high viscosity) and low volatility content of the oil increases deposit formation."
Question: this study comes from Europe. I am wondering if they don’t have the emission controls like we have in the States which aggravate this condition? Also they have had better gasoline than we get. I keep reading how higher octane gasoline is better for higher compression GDI engines.
Originally Posted By: ChrisD46
I believe for a GDI engine you would want as low a NOACK oil as possible to keep intake valve deposits at bay (along with top tier gas , shorter OCI's , etc.) with a GDI engine.
Nope, on the contrary, the lower the NOACK and/or higher the base-oil viscosity, the more the intake-valve deposits will be. Alternatively, the higher the NOACK and/or lower the base-oil viscosity, the less the intake-valve deposits will be.
This is because one mechanism of cleaning of the intake-valve deposits is evaporation. If NOACK volatility is low or the base-oil is thick, the oil will spend more time on the valves as it evaporates more slowly, therefore leaving more deposits behind.
Intake-valve and combustion-chamber depo...ts their growth
So, if you want the least intake-valve deposits in a GDI engine, you need to pick up a 0W-20 with higher NOACK. A 10W-30, which has both a thick base oil and low NOACK would be the worst choice as far as the intake-valve deposits are concerned.
From the article: "The most important lubricating-oil component for deposit formation is the base oil. Increasing the high molecular weight (high viscosity) and low volatility content of the oil increases deposit formation."
Question: this study comes from Europe. I am wondering if they don’t have the emission controls like we have in the States which aggravate this condition? Also they have had better gasoline than we get. I keep reading how higher octane gasoline is better for higher compression GDI engines.
I just read another paper by access through my library:
Formation of Intake Valve Deposits in Gasoline Direct Injection Engines
Gregory Guinther and Scott Smith -- Afton Chemical Corporation
October 17, 2016
https://saemobilus.sae.org/content/2016-01-2252
I will put their conclusions here. IVD means intake-valve deposits.
SUMMARY/CONCLUSIONS
* A standardized, vehicle-based GDI IVD test has been developed that is both repeatable and responsive to known additive chemistry.
* Higher engine loads lead to an increased rate of deposit formation.
* IVD formation in this protocol is an oil-related process, and the majority of the oil that finds its way onto the intake valves comes from the PCV system.
* The oil leaving the crankcase through the PCV system is whole oil containing additives and contaminants (not distilled base oil vapor which contains no additives).
* PCV gas flow in the intake manifold is inconsistently distributed among the eight runners of the manifold leading to the valves.
* Inhibiting the carbon-formation process lessens the rate of deposit formation on the intake valves.
* Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles.
* Particles found in EGR exacerbate deposit formation rate.
* Particles found in EGR appear to incorporate combusted oil additive components, engine wear metals, and ambient air contamination.
Gregory Guinther and Scott Smith
Afton Chemical Corporation
Note the conclusions I highlighted. They are saying that the main source of the intake-valve deposits is PCV. However, it's liquid oil (whole oil) coming through PCV as a mist, not evaporated oil (oil vapor). So, the amount of oil coming through PCV has nothing to do with the NOACK volatility.
My recommendations:
* Pick a dexos1 Gen 2 0W-20 with low ash (low detergent) content (most intake-valve deposits are ash, especially coming from the detergent) and PAO or GTL base oil. I would say Mobil 1 Extended Performance 0W-20 is a good choice. PPPP 0W-20, TGMO 0W-20, and Super Tech High Mileage 0W-20 are also good choices, not necessarily in the order written.
* Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines. If you can find ACEA C1 or C4 low-SAPS oils, they would be a good choice, too.
* Go with the thinnest base oil possible (0W-xx), as thicker base oils may have too low NOACK, which increases deposit formation due to decreased volatility (decreased evaporative cleaning), and also have less cleaning ability due to higher aniline points.
Formation of Intake Valve Deposits in Gasoline Direct Injection Engines
Gregory Guinther and Scott Smith -- Afton Chemical Corporation
October 17, 2016
https://saemobilus.sae.org/content/2016-01-2252
I will put their conclusions here. IVD means intake-valve deposits.
SUMMARY/CONCLUSIONS
* A standardized, vehicle-based GDI IVD test has been developed that is both repeatable and responsive to known additive chemistry.
* Higher engine loads lead to an increased rate of deposit formation.
* IVD formation in this protocol is an oil-related process, and the majority of the oil that finds its way onto the intake valves comes from the PCV system.
* The oil leaving the crankcase through the PCV system is whole oil containing additives and contaminants (not distilled base oil vapor which contains no additives).
* PCV gas flow in the intake manifold is inconsistently distributed among the eight runners of the manifold leading to the valves.
* Inhibiting the carbon-formation process lessens the rate of deposit formation on the intake valves.
* Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles.
* Particles found in EGR exacerbate deposit formation rate.
* Particles found in EGR appear to incorporate combusted oil additive components, engine wear metals, and ambient air contamination.
Gregory Guinther and Scott Smith
Afton Chemical Corporation
Note the conclusions I highlighted. They are saying that the main source of the intake-valve deposits is PCV. However, it's liquid oil (whole oil) coming through PCV as a mist, not evaporated oil (oil vapor). So, the amount of oil coming through PCV has nothing to do with the NOACK volatility.
My recommendations:
* Pick a dexos1 Gen 2 0W-20 with low ash (low detergent) content (most intake-valve deposits are ash, especially coming from the detergent) and PAO or GTL base oil. I would say Mobil 1 Extended Performance 0W-20 is a good choice. PPPP 0W-20, TGMO 0W-20, and Super Tech High Mileage 0W-20 are also good choices, not necessarily in the order written.
* Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines. If you can find ACEA C1 or C4 low-SAPS oils, they would be a good choice, too.
* Go with the thinnest base oil possible (0W-xx), as thicker base oils may have too low NOACK, which increases deposit formation due to decreased volatility (decreased evaporative cleaning), and also have less cleaning ability due to higher aniline points.
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Originally Posted By: Gokhan
Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines.
Shhhh...be sure not to tell Mercedes or BMW about this.
Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines.
Shhhh...be sure not to tell Mercedes or BMW about this.
I am retired and only drive 3-5K miles a year. For my application I use a dino oil and change it once a year with the filter. Some time ago I purchased a couple of cases of Pennzoil Yellow Bottle 5W20 on clearance at Autozone. It seemed to have been run by many members here at the time, with good results. It works well for me. It has a NOAK of 6.5%. Quaker State dino also has a pretty low NOAK under 9%.
I don't think these oils are better than synthetic oils but they fit MY application. If I drove 10K miles/year I would switch to a synthetic.
Here is a chart for test results for some 5w20 oils, most dino or blends.
http://www.pqiamerica.com/Feb2014/consolidated5w20ALL.html
I don't think these oils are better than synthetic oils but they fit MY application. If I drove 10K miles/year I would switch to a synthetic.
Here is a chart for test results for some 5w20 oils, most dino or blends.
http://www.pqiamerica.com/Feb2014/consolidated5w20ALL.html
wemay
Site Donor 2023
In this old thread, what Gokhan is positing is similar. Unfortunately the link to the study doesn't work anymore...
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3687558/1
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3687558/1
Originally Posted By: wemay
In this old thread, what Gokhan is positing is similar. Unfortunately the link to the study doesn't work anymore...
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3687558/1
Found it!
BITOG was referenced (The Critic's post [link]).
Considerations on carbon-deposit formation in gasoline direct-injection engine (link)
Gyu-Sob Cha
GS Caltex Corporation
2013/09/04
In this old thread, what Gokhan is positing is similar. Unfortunately the link to the study doesn't work anymore...
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3687558/1
Found it!
BITOG was referenced (The Critic's post [link]).
Considerations on carbon-deposit formation in gasoline direct-injection engine (link)
Gyu-Sob Cha
GS Caltex Corporation
2013/09/04
wemay
Site Donor 2023
Bingo, thanks.
I followed you until you said that using a high Noack oil is better for IVD. Just because low Noack doesn’t help IVD (according to the study), I don’t think you say high Noack is better for IVD. Sort of like the whole the enemy of my enemy is my friend fallacy.
The base oil viscosity and how many cuts of base oil used can make oils with the same Noack provide different consumption. Noack isn't that related to direct injection. High Noack could just be due to light mineral base oil which wont cause problems. I believe it is when the blow by gases start taking additives and combustion byproducts that cause issues.
Originally Posted By: 2015_PSD
Originally Posted By: Gokhan
Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines.
Shhhh...be sure not to tell Mercedes or BMW about this.
Well stated PSD.
Originally Posted By: Gokhan
Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines.
Shhhh...be sure not to tell Mercedes or BMW about this.
Well stated PSD.
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