Understanding NOACK and Base Oil Quality

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Very simplistically, is an oils’ lower NOACK mainly attributable to base oil quality (PAO) or is more representative of an oil’s additive package?

I guess I am also asking if an oils' lower NOACK is attributable to more PAO vs additives, then the more PAO based oils offer more Noack stability throughout an OCI vs additive based?

Just curious how it all works.
 
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Noack is the base oil blend. It is like running a 0W oil for cold pumpability worrys when you live in the Tropics.
 
Volatility is generally a reflection of a higher concentration of light base oil cuts of any type (ie 2 cSt vs 3cSt or 4cSt). It can be impacted by the base oil mixture, the choice of VII and the use of some esters. Dilution also can impact the volatility over the life of a drain, but the NOACK test does not take this into account. The most common way to lower an oil's NOACK is to rebalance the base oil mix in the formula, but there are much more important performance properties than NOACK.
 
Don't try to assume that PAO magically makes something better.

Viscosity, molecular weight, and volatility should be loosely linked.

So there's really a matter of tighter viscosity ranges, of less volatile molecules to keep NOACK down. That generally means smaller viscosity spreads of heavier (larger) molecules, that still exhibit good cold flow properties.
 
It is usually the spread between the numbers on both side of the W of the weight.

Valvoline Synpower for example in 10w30 and 5w20 has lower Noack (i.e 7.6 and 8.0) than 0w20 and 5w30 (i.e. 11+), because a more uniformed, medium chain oil has lower noack than a blend with both light and heavy chain. The lighter chain base oil evaporate during usage.
 
Originally Posted By: PandaBear
It is usually the spread between the numbers on both side of the W of the weight.

Valvoline Synpower for example in 10w30 and 5w20 has lower Noack (i.e 7.6 and 8.0) than 0w20 and 5w30 (i.e. 11+), because a more uniformed, medium chain oil has lower noack than a blend with both light and heavy chain. The lighter chain base oil evaporate during usage.


This is really interesting, I went to peek at the Synpower info and the link for the the PDS takes me to a page for Valvoline Advanced Full Synthetic oils with the term Synpower not in evidence. Also interesting is that this sheet is dated 10/12/17, replacing info from 9/22/17...often these sheets don't change for years.

Whatever products these may be, the 0W20/5W20 NOACK losses are 11.1/7.6%, 5W30/10W30 are 9.3/8.0%. Definite advantage to the higher W grades in both cases, particularly for XW20 (nearly 50% higher relative loss for the 0W20 compared to 5W20).
 
Geez, I actually understood most of that. Thank you. You guys are wicked smart.
grin2.gif
 
Originally Posted By: Virtus_Probi
Originally Posted By: PandaBear
It is usually the spread between the numbers on both side of the W of the weight.

Valvoline Synpower for example in 10w30 and 5w20 has lower Noack (i.e 7.6 and 8.0) than 0w20 and 5w30 (i.e. 11+), because a more uniformed, medium chain oil has lower noack than a blend with both light and heavy chain. The lighter chain base oil evaporate during usage.


This is really interesting, I went to peek at the Synpower info and the link for the the PDS takes me to a page for Valvoline Advanced Full Synthetic oils with the term Synpower not in evidence. Also interesting is that this sheet is dated 10/12/17, replacing info from 9/22/17...often these sheets don't change for years.

Whatever products these may be, the 0W20/5W20 NOACK losses are 11.1/7.6%, 5W30/10W30 are 9.3/8.0%. Definite advantage to the higher W grades in both cases, particularly for XW20 (nearly 50% higher relative loss for the 0W20 compared to 5W20).





VSP seems to being going away in favor of VAS but now this news of VME is confusing as all get out.
 
I remember that too, something about using additives to increase NOACK, but never saw how that's done. That was during the couldn't believe the PQIA's PYB results era- he didn't like us assuming it was GTL based
 
Put down NOACK and pick up HTHS if you want to know about base oils. The extra heat in the hths weeds out the inferior bases, if you are simply trying to find oil that doesn't break down under heat and load. Now, many applications might see benefit from high hths, but the trend is to actually have low hths for gas mileage. In that case the low hths wouldn't mean inferior base oil, just a base that was made for gas mileage or some other spec. Soon the oil formulations will be pretty similar when gf-6 drops, best strategy just to find a cheap group 3 like m1 costco deal. You may find variances that you like, but will it be worth double the cost when you can get m1 for 4 bucks a qrt, not to my pocket book.
 
Originally Posted By: burla
Put down NOACK and pick up HTHS if you want to know about base oils. The extra heat in the hths weeds out the inferior bases, if you are simply trying to find oil that doesn't break down under heat and load. Now, many applications might see benefit from high hths, but the trend is to actually have low hths for gas mileage. In that case the low hths wouldn't mean inferior base oil, just a base that was made for gas mileage or some other spec. Soon the oil formulations will be pretty similar when gf-6 drops, best strategy just to find a cheap group 3 like m1 costco deal. You may find variances that you like, but will it be worth double the cost when you can get m1 for 4 bucks a qrt, not to my pocket book.


I completely disagree with everything you say here. Oils are now being deliberately formulated with LOWER HTHS and this is one of the major drivers in upgrading base oil quality in most formulations. Too much HTHS and all you are doing is wasting energy. There is wisdom in the adage - as thin as possible, as thick as necessary.
 
Originally Posted By: burla
The extra heat in the hths weeds out the inferior bases, if you are simply trying to find oil that doesn't break down under heat and load.

What about old school monogrades, which have rather high HTHS but nothing spectacular by way of base stock?
 
I'll stick to Red Line 10W-30 with a low NOACK (6) and reasonably high HTHS (3.5). Seems like the best of both worlds and it's what Honda recommends in my performance cars.
 
Originally Posted By: Solarent
Originally Posted By: burla
Put down NOACK and pick up HTHS if you want to know about base oils. The extra heat in the hths weeds out the inferior bases, if you are simply trying to find oil that doesn't break down under heat and load. Now, many applications might see benefit from high hths, but the trend is to actually have low hths for gas mileage. In that case the low hths wouldn't mean inferior base oil, just a base that was made for gas mileage or some other spec. Soon the oil formulations will be pretty similar when gf-6 drops, best strategy just to find a cheap group 3 like m1 costco deal. You may find variances that you like, but will it be worth double the cost when you can get m1 for 4 bucks a qrt, not to my pocket book.


I completely disagree with everything you say here. Oils are now being deliberately formulated with LOWER HTHS and this is one of the major drivers in upgrading base oil quality in most formulations. Too much HTHS and all you are doing is wasting energy. There is wisdom in the adage - as thin as possible, as thick as necessary.


No, that isn't the only thing that you are doing when you increase hths, lol. You argument is energy, IE fuel economy, not protecting metal to metal wear. If you actually think lower hths base oils protect metal better, I can't reasonable have a conversation with you because that isn't true. We aren't talking about hths in a different grade oil, but the same grade. It likely isn't going to matter as we all know ad naseum you can run 7'11 oil for 200k miles, but at least know high hths is good for metal to metal constant/
 
Originally Posted By: burla
Put down NOACK and pick up HTHS if you want to know about base oils. The extra heat in the hths weeds out the inferior bases, if you are simply trying to find oil that doesn't break down under heat and load. Now, many applications might see benefit from high hths, but the trend is to actually have low hths for gas mileage. In that case the low hths wouldn't mean inferior base oil, just a base that was made for gas mileage or some other spec. Soon the oil formulations will be pretty similar when gf-6 drops, best strategy just to find a cheap group 3 like m1 costco deal. You may find variances that you like, but will it be worth double the cost when you can get m1 for 4 bucks a qrt, not to my pocket book.


Depends on what you use your oil for. One of my car is a DI with intake valve deposit issue but was never driven hard, so I'd care more about Noack than HTHS.

Now if I have a turbo with port injection then what you suggested make sense.
 
Sorry for you and everyone with the DI, they should have went to PI for longevity. Uncle Obama and his kind did a number on the auto manufacturers. But then again this gov't makes a windfall everytime they sell a car, so maybe that is the real plan to all of these thin oils anyway, Japan, make vehicles life span shorter and shorter by policy. It benefits the gov't for sure.

FCA had so many engine fails with the eco diesel they changed the oil viscosity to go heavier, I bet the hemi fail numbers are almost similar but if they even tried to recommend 30 weight for the 5.7 they would likely be hung for treason. After seeing the many internal fails on the hemi board, nearly 70-80 percent of the guys are running 30 weight w/o issue. If oyu guys want to run 20 weight I respect that, but 30 weight as a lubrication strategy has it merits as well. In fact, when the engine wears, the heavier weight is needed to keep the same fuel mileage performance as the 20 weight when new. white paper
 
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Originally Posted By: burla
You argument is energy, IE fuel economy, not protecting metal to metal wear. If you actually think lower hths base oils protect metal better, I can't reasonable have a conversation with you because that isn't true.


You clearly don't understand how engine oil is formulated. My point was that they are deliberately being made to have lower HTHS - that doesn't just mean taking out some thicker base oil or vm and substituting a lighter one and changing nothing else. When you deliberately formulate a lower HTHS oil - enabling less energy loss and yes, better fuel economy - you also have to carry that philosophy through the rest of the formula as well and make sure that metal parts are protected - by using different/better/more additives or creating new synergies that enable this advantage.

SO YES I believe lower HTHS base oils DOES protect metal better - because oil formulators are finally focusing on actually protecting the metal without relying on a higher HTHS as a crutch for protection.

Just compare CK-4 and FA-4 oils on the HD side - most CK-4 additive packages are boosted with additional additives if used in an FA-4 formula. I've seen the wear results in industry tests like the DDC scuffing testing. If it didn't protect better and give better fuel economy, why would Detroit Diesel be promoting lower HTHS oils at all? They don't even recommend CK-4 anymore (starting in 2017MY engines).
 
Disagree in part...

Look at the Stribeck curve, and the stribeck curve with surface active agents.

Hydrodnamic, back in the day was described as "zero wear" regime. The parts were separated physically by the oil film. That's what HTHS does. Can do that entirely additive free.

No you wouldn't do it, because cams, piston rings etc. aren't hydrodynamic.

When the viscosity drops and asperite contact occurs, you need the additives. If you don't friction goes up, and wear skyrockets. With additives, the contact (full/partial) is there, but a sacrificial film prevents the parent metal parts from contacting/siezing/galling.

In these regimes, wear is CONTROLLED, maybe to an extremely high degree, but one could claim that additives are the crutch for reducing viscosity...which the OEMS ALL say is for economy/CO2.

If it's controlled to the point that the engine only lasts 50% longer than the rest of the car versus 60% longer and the owner saves some money on fuel, then it's a fair trade off.

(as long as the oil doesn't now cost more than the fuel savings)
 
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