Lower NOACK = Better Oil???

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I was curious about this when I read this off of the Discovery Channel site:

An oil's total base number tells us how the oil reacts to acid buildup in the engine. The better the oil withstands acid buildup, the higher the total base number.
The NOACK volatility number also reflects the oil's quality. A volatile compound is one that evaporates when heated. When oil is heated, the smaller molecules can evaporate while the larger molecules remain. This makes the oil sluggish and depletes oil volume over time. The more volatile an oil is, the higher its NOACK volatility number. Therefore, a low NOACK rating indicates high-quality oil.
My assumption is that the NOACK testing though is done at a temp of which most engines never really reach. So in Theory is NOACK a fair test to judge an oil's quality?

Sure an oil is a sum of its parts, but with more and more engines going to DI fuel delivery and forced induction people need to know what to really look for to make a solid oil choice for their car.

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Jeff
 
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This has been discussed a lot already in some recent posts.

As you've alluded, if the oil you're using doesn't have an especially low Noack rating and you're not consuming any significant amount of oil, running an oil with a lower Noack will also have no measurable benefit, DI engine or otherwise.

Noack is an interesting spec' that can indicate the chemistry and viscosity of the base oils used but it's low down the list of attributes I consider in choosing a motor oil.
 
Originally Posted By: Jeffs2006EvoIX
My assumption is that the NOACK testing though is done at a temp of which most engines never really reach. So in Theory is NOACK a fair test to judge an oil's quality?

There are certain parts of the engine that do get that hot, and therefore the oil reaching those places may get super hot, even though the oil at the oil temp sensor area never gets as hot.

Also, oil evaporates at all temps, but obviously slower at lower temps (below where Noack is measured). So, an oil with high Noack will generally evaporate faster than an oil with low Noack, regardless of actual operating temp.
 
Originally Posted By: Quattro Pete
Oil evaporates at all temps, but obviously slower at lower temps (below where Noack is measured). So, an oil with high Noack will generally evaporate faster than an oil with low Noack, regardless of actual operating temp.


Well said!
 
Originally Posted By: 147_Grain
Originally Posted By: Quattro Pete
Oil evaporates at all temps, but obviously slower at lower temps (below where Noack is measured). So, an oil with high Noack will generally evaporate faster than an oil with low Noack, regardless of actual operating temp.


Well said!

Really!
And how much oil has evaporated if you're not consuming any measurable amount of oil over an OCI despite the fact that all engines do allow some oil past the rings?
All motor oil today must have a NOACK no higher than 15%.
That percentage is low enough to render volatility a non issue in most applications.
 
I understand that certain parts of an engine, especially forced induction, can get extremely hot. I personally have seen turbo's glowing red after a few laps on the track, so imagine how hot the journals get inside there?

I bring this up because I know I am confused still about it, so I feel others may be too. In my Evo Days of seeing weekly track events, hours upon hours tuning on the dyno etc you can put an oil through its paces very quickly. I have personally seen how oil temps get with one oil, vs another, UOA's showing wear with one, vs another as these take years to examine over thousands of miles, or hours on the track.

Then, my car was simpler to some degree. No DI, mainly. So oil choice was simplified by what held up. I wont go into a debate over which oil held up better vs another because its irrelevant to most because those results would be limited to my particular application, with my particular mods, making my particular HP/TQ.

So fast forward to 2013+ Most cars now are DI, More and More are becoming forced induction, and we are still using oil that we did prior to these technologies. Granted the API and such try and keep up, but the Lubrizol Presentation proves that we need oils to stand up to the new demands.

Problem is, our fuel in the USA is vast and varied, not only in octane, ethanol content but quality. Add to that manufacturers EDI's to keep overall cost down as a selling point to the cosumer, not to mention warranties that end prior to any problems arising (inlet/exhaust valve deposits) makes well me anyway re-think this whole oil game. Lubrizol showed us the proof, and as folks like EDYVW is doing, testing his engine on these LOW SAPS LOW NOACK oils to see how they hold up.

I for one, want to keep the performance of my vehicle as high as possible, While keeping maintenance costs down. I feel folks like "Us" here on BITOG like to find faults and think outside of the box. Most people wont keep their cars long enough to even find fault in any oil you may use.

For me? as like many I am sure on here, we keep looking and looking to get as much performance, dependability and reliability out of our car.

Anyway, just my thoughts.
36.gif


Jeff
 
Originally Posted By: CATERHAM
All motor oil today must have a NOACK no higher than 15%.
That percentage is low enough to render volatility a non issue in most applications.

Why do most German car mfgs insist that it'll be notably lower than 15% then?
 
Because they specify heavier synthetic oils for the higher oil temp's that may be encountered under extreme use such as during high speed driving. The higher the oil temp's, the greater the actually volatility which means higher oil consumption and oil thickening. The increased oil consumption associated with constant high rev's during high speed driving is an issue.

The 15% limit is of course for all motor oil including the cheapest mineral oil. Whether you need it or not, no 30 grade or heavier synthetic oil worth it's salt is going to have a Noack that high. For a 40 grade and heavier the better premium syn's are no high than 11%, many around 9%.
And 10-12% is common for an A5/B5 30 grade.
 
It's obvious that some people don't get the concept of Noack...it's not something that has anything to do with the temperature of the oil in the sump...absolutely nothing to do with sump temperature...oils don't "run cool enough" for Noack to be irrelevant no matter how the science "feels"

It's supposed to represent what happens to the oil that is left above the rings on the downstroke (the rings are hydrodynamically lubricated on the upstroke when the piston speeds up, so the oil has to be the film that has been on the wall, exposed to the heat, oil pressure doesn't get it there).

Studies show that this oil is enriched in additives, so must be so as the oil evaporates off...smaller engines with greater BMEP are MORE likely to have cylinder temperatures that evaporate more.

Noack IS relevent, has nothing to do with sump temperatures and turbos
 
Originally Posted By: Jeffs2006EvoIX
So fast forward to 2013+ Most cars now are DI, More and More are becoming forced induction, and we are still using oil that we did prior to these technologies. Granted the API and such try and keep up, but the Lubrizol Presentation proves that we need oils to stand up to the new demands.

Problem is, our fuel in the USA is vast and varied, not only in octane, ethanol content but quality. Add to that manufacturers EDI's to keep overall cost down as a selling point to the cosumer, not to mention warranties that end prior to any problems arising (inlet/exhaust valve deposits) makes well me anyway re-think this whole oil game. Lubrizol showed us the proof, and as folks like EDYVW is doing, testing his engine on these LOW SAPS LOW NOACK oils to see how they hold up.

I for one, want to keep the performance of my vehicle as high as possible, While keeping maintenance costs down. I feel folks like "Us" here on BITOG like to find faults and think outside of the box. Most people wont keep their cars long enough to even find fault in any oil you may use.

For me? as like many I am sure on here, we keep looking and looking to get as much performance, dependability and reliability out of our car.

Anyway, just my thoughts.
36.gif


Jeff


ACEA have similar thoughts...can't just chuck anyhting in the tank and expect results...

http://www.acea.be/publications/article/worldwide-fuel-charter

want economy, efficiency, and emissions, then the fuels need to be calibrated so that the engines can be too.

and people will still run a quart of ATF in their tank.
 
Originally Posted By: Shannow
Originally Posted By: Jeffs2006EvoIX
So fast forward to 2013+ Most cars now are DI, More and More are becoming forced induction, and we are still using oil that we did prior to these technologies. Granted the API and such try and keep up, but the Lubrizol Presentation proves that we need oils to stand up to the new demands.

Problem is, our fuel in the USA is vast and varied, not only in octane, ethanol content but quality. Add to that manufacturers EDI's to keep overall cost down as a selling point to the cosumer, not to mention warranties that end prior to any problems arising (inlet/exhaust valve deposits) makes well me anyway re-think this whole oil game. Lubrizol showed us the proof, and as folks like EDYVW is doing, testing his engine on these LOW SAPS LOW NOACK oils to see how they hold up.

I for one, want to keep the performance of my vehicle as high as possible, While keeping maintenance costs down. I feel folks like "Us" here on BITOG like to find faults and think outside of the box. Most people wont keep their cars long enough to even find fault in any oil you may use.

For me? as like many I am sure on here, we keep looking and looking to get as much performance, dependability and reliability out of our car.

Anyway, just my thoughts.
36.gif


Jeff


ACEA have similar thoughts...can't just chuck anyhting in the tank and expect results...

http://www.acea.be/publications/article/worldwide-fuel-charter

want economy, efficiency, and emissions, then the fuels need to be calibrated so that the engines can be too.

and people will still run a quart of ATF in their tank.



Nice link.
 
Originally Posted By: Shannow
It's obvious that some people don't get the concept of Noack...it's not something that has anything to do with the temperature of the oil in the sump...absolutely nothing to do with sump temperature...oils don't "run cool enough" for Noack to be irrelevant no matter how the science "feels"

It's supposed to represent what happens to the oil that is left above the rings on the downstroke (the rings are hydrodynamically lubricated on the upstroke when the piston speeds up, so the oil has to be the film that has been on the wall, exposed to the heat, oil pressure doesn't get it there).

Studies show that this oil is enriched in additives, so must be so as the oil evaporates off...smaller engines with greater BMEP are MORE likely to have cylinder temperatures that evaporate more.

Noack IS relevent, has nothing to do with sump temperatures and turbos


In relation to DI fuel delivery and intake valve deposits perspective the above statement makes sense. High Saps having more detergents higher NOACK would equate to more vapor going out the valves and being recirc'd.

So in essence in a DI motor particularly this may prove that low saps and low NOACK WOULD equate to a lower risk of deposit formation.

So do manufacturers like VW stating to use 502 oils in North America (amongst other places) is for the sole purpose of having an oil that can last for their 10k mile oil changes. Not necessarily that 502 oils provide better lubrication or what not. Correct?

That M1 ESP 5w30 is looking real good to me now. Low Saps AND low NOACK. Just need way more frequent changes.

I feel some folks actually feel 502 oils actually "lubricate" better due to all the additives. I disagreed.

Jeff
 
Originally Posted By: Shannow
It's obvious that some people don't get the concept of Noack...it's not something that has anything to do with the temperature of the oil in the sump...absolutely nothing to do with sump temperature...oils don't "run cool enough" for Noack to be irrelevant no matter how the science "feels"

It's supposed to represent what happens to the oil that is left above the rings on the downstroke (the rings are hydrodynamically lubricated on the upstroke when the piston speeds up, so the oil has to be the film that has been on the wall, exposed to the heat, oil pressure doesn't get it there).

Studies show that this oil is enriched in additives, so must be so as the oil evaporates off...smaller engines with greater BMEP are MORE likely to have cylinder temperatures that evaporate more.

Noack IS relevent, has nothing to do with sump temperatures and turbos

It never ceases to amaze me how much you like to spread miss information. The December issue of Lubes "N' Greases has an interesting article titled "Volatility: The Inside Story", for those that want to read it.

Some basic facts.
Limiting engine oil volatility has everything to do with controlling oil consumption and oil thickening as a result.
A couple of quotes from the paper:
"The question was, how to maintain healthy engine oil viscosity when vapor losses kept eroding the oil in the sump?"

"Low temperature oil viscosity can suffer when vehicles operate under high-temperature conditions (which volatilize the light ends of the oil and lead to thickening)."
 
From Tooslick:

Quote:
The technical reason for doing the NOACK test at 250C/482F is simply to obtain data in a reasonable amount of time - in this case one hour. If you ran the test at 200F-250F, you would expect the relative rankings to be the same. However, it might take many hours or even a couple days to get enough evaporation to make for a reasonable test.

By raising the test temp, you greatly reduce the test time and the cost of testing. This is a very common practice when doing materials testing ....
 
buster thanks for that link (quote), very interesting.
Although I suspect, if the test was done at normal hot operating temp's (200F-250F) even for an appropriate lengthy time period, the total volatility percentage would be still be lower than at the current 482F. The reason being that certain light fraction that do evaporate at the higher temp' wouldn't at the much lower temp' no matter how long the oil is cooked.
 
Originally Posted By: CATERHAM
It never ceases to amaze me how much you like to spread miss information. The December issue of Lubes "N' Greases has an interesting article titled "Volatility: The Inside Story", for those that want to read it.

Some basic facts.
Limiting engine oil volatility has everything to do with controlling oil consumption and oil thickening as a result.
A couple of quotes from the paper:
"The question was, how to maintain healthy engine oil viscosity when vapor losses kept eroding the oil in the sump?"

"Low temperature oil viscosity can suffer when vehicles operate under high-temperature conditions (which volatilize the light ends of the oil and lead to thickening)."


As an engineer, I was trained to go to references and papers not puff pieces...at University, it was explained that volatility of the lubricant in the hot cylinder was significant to the process, and that the issue was primarily cat life, not viscosity/economy

e.g. "Sources and Chracterisitcs of Oil Consumption in a Spark-Ignition Engine" - section 4.2...it's even got pictures

Originally Posted By: CATERHAM
buster thanks for that link (quote), very interesting.
Although I suspect, if the test was done at normal hot operating temp's (200F-250F) even for an appropriate lengthy time period, the total volatility percentage would be still be lower than at the current 482F. The reason being that certain light fraction that do evaporate at the higher temp' wouldn't at the much lower temp' no matter how long the oil is cooked.


Like I keep saying, it's NOT about bulk oil temperatures (and 20s that run so cool that it's not a problem)...

http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=1634308
 
Originally Posted By: Shannow
e.g. "Sources and Chracterisitcs of Oil Consumption in a Spark-Ignition Engine" - section 4.2...it's even got pictures


Here's the buyable version

http://papers.sae.org/2004-01-2909/

You can google the title and find an MIU PDF.

Google link

At this point I will throw myself upon the mercy of BITOGers in dearest apology for continually spreading mis-information
 
http://www.savantgroup.com/ASTMSym04-PEI.pdf

gives the reasons for using Noack...followed by modified procedures.

Quote:
Association of Phosphorus Emission with Oil Consumption and Volatility - Oil consumption caused by oil volatility has always been a concern for automotive engineers because of the associated deposits often formed on piston rings and combustion chambers. Concern that oil volatility could cause phosphorus in the exhaust stream, added to the desire to reduce oil volatility. Consequently, progressively lower formulated engine oil volatility (as measured by the classic Noack volatility test [9-12]) was required for oils meeting API and ILSAC GF-2 (22% loss) and GF-3 (15% loss) specifications.


Same researchers...in "Phosphorus Emission Index (PEI) Studies Of ZDDP in Engine Oils" (Googlable, and has pictures)

Quote:
Temperatures of 250°C at which the special Noack was normally run to generate PEI values (PEI250) reflected reported upper-cylinder, ring-belt temperatures


Demonstrates that longer exposure, at lower temperatures still liberated volatile phosphorus...

Both indicate that volatility and phosphorus levels don't either equal cat poisoning, but can be cumulative...and (really interestingly) that certain additive chemistries allow higher ZDDP species, with lower cat poisoning ability.
 
250C is the temperature of the NOACK test. Ring pack temperatures often exceed this, so yes Noack is releveant.

However two oils can both have a 10% NOACK but with a very different base oil mix. One could be all 5cSt base oil, the other a mix of 4 and 6 cSt. What is important for oil consumption is the smount of light ends as the engine is effectively a distillation tower.


The IIIGB is a Phos volatility test, important for catalyst protection, and has zero correlation with Noack
 
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