Noack is meaningless... ???

[Shannow]

Have read in recent times that Noack is :
* meaningless, as your engine oil never gets to 250C and sits there for an hour (multiple times);
* not relevant for xW-20 oils as they run so cool;
* not relevant as catch can deposits are oil mist, not light hydrocarbons.

Major problem with all of these arguments is that volatility tests are there to assess the behaviours of oil that's left above the top ring, hot, and washed by air/gas flow within the cylinder.

These films, and the vapours that are released have direct access to the catalyst on the exhaust stroke, and therefore have relevance, particularly for emissions system performance.

 

[SteveSRT8]

volatility is a huge factor ever since we went to 'dry' manifold designs as oil buildup in certain styles of intakes can cause issues at high miles.

 

[Garak]

Shannow, you forgot to add that the limits have been decreased over the years simply because the API, ILSAC, and ACEA people were just bored.

 

[Eddie]

SteveSRT8. Please elaborate on your statement. Thanks. Ed

 

[SteveSRT8]

Originally Posted By: Eddie
SteveSRT8. Please elaborate on your statement. Thanks. Ed


Sure, Ed.

Ever since we went to port fuel injection long ago the cars with certain types of designs accumulate oil in them due to PCV vapors that condense. Some cars can actually exhibit some symptoms that are undesirable, but most folks will never notice.

The volatility of the oil in the engine is a major contributor to the many factors that influence this build up and its effects...

 

[OVERKILL]

Originally Posted By: Garak
Shannow, you forgot to add that the limits have been decreased over the years simply because the API, ILSAC, and ACEA people were just bored.

This. And companies like Mercedes and GM also place their own limits on NOACK. If it was irrelevant, why would they bother?

 

[Trav]

Originally Posted By: OVERKILL
Originally Posted By: Garak
Shannow, you forgot to add that the limits have been decreased over the years simply because the API, ILSAC, and ACEA people were just bored.

This. And companies like Mercedes and GM also place their own limits on NOACK. If it was irrelevant, why would they bother?


Funny thing is though no company specifies a VI level.

 

[OVERKILL]

Originally Posted By: Trav
Originally Posted By: OVERKILL
Originally Posted By: Garak
Shannow, you forgot to add that the limits have been decreased over the years simply because the API, ILSAC, and ACEA people were just bored.

This. And companies like Mercedes and GM also place their own limits on NOACK. If it was irrelevant, why would they bother?


Funny thing is though no company specifies a VI level.


LMAO! Oh, you and Shannow are on a roll here

 

[Doog]

Originally Posted By: SteveSRT8
volatility is a huge factor ever since we went to 'dry' manifold designs as oil buildup in certain styles of intakes can cause issues at high miles.


+1 exactly. Pull an intake manifold off an older Mopar 4.7L

 

[FZ1]

Interesting conversation,guys. Thanks.

 

[Garak]

Originally Posted By: Trav
Funny thing is though no company specifies a VI level.

They do in a roundabout way, in that we don't get to use monogrades any longer.

 

[Eddie]

Thanks Steve. Ed

 

[TrevorS]

Originally Posted By: Garak
Originally Posted By: Trav
Funny thing is though no company specifies a VI level.

They do in a roundabout way, in that we don't get to use monogrades any longer.

Specifying 0w20 instead of 5w20 does force the VI up.

 

[OVERKILL]

Originally Posted By: TrevorS
Originally Posted By: Garak
Originally Posted By: Trav
Funny thing is though no company specifies a VI level.

They do in a roundabout way, in that we don't get to use monogrades any longer.

Specifying 0w20 instead of 5w20 does force the VI up.


Really?

Mobil
M1 5w-20 is 160
M1 0w-20 is 173

SOPUS
PU 5w-20 is 154
PP 5w-20 is 169

Castrol
Edge 0w-20 is 161
Edge 5w-20 is 161

Looks like a 5w-20 can be higher VI than a 0w-20

 

[TrevorS]

Yes but a 5w20 can be a dino with much lower VI whereas the lowest possible VI of a 0w20 is significantly above that.

What did Shannow say about selective data?

 

[OVERKILL]

Originally Posted By: TrevorS
Yes but a 5w20 can be a dino with much lower VI whereas the lowest possible VI of a 0w20 is significantly above that.

What did Shannow say about selective data?


Yes, and I would say IN GENERAL, that the 0w-20 oils will have higher VI's than their 5w-20 siblings, but it is certainly not a rule. Therefore, the move to 0w-20 may encourage the circulation of higher VI lubricants because of that generality, but it certainly doesn't force it, which is what you had stated

Selective or not, the data was there to invalidate your statement. I was just proving a point

 

[Gokhan]

I don't worry about losing oil thanks to higher NOACK myself -- running 0W-20 in a 1985 engine in Southern California weather with almost no oil consumption.

However, let's not forget that there is a good correlation between base-oil quality and NOACK volatility. If NOACK volatility is low, meaning that the oil evaporates less, chances are that it also oxidizes less. Lower-NOACK oils are synthetic oils, meaning they are made of higher-quality base oil. While there isn't an absolute relation between oil oxidization and NOACK volatility, there is a good correlation. If you buy a lower-NOACK oil, you are usually buying a higher-quality oil with less oxidization, which also means longer OCIs. However, again, there is no absolute relation between NOACK and oxidization -- only a good correlation.

 

[TrevorS]

Originally Posted By: OVERKILL
Originally Posted By: TrevorS
Yes but a 5w20 can be a dino with much lower VI whereas the lowest possible VI of a 0w20 is significantly above that.

What did Shannow say about selective data?


Yes, and I would say IN GENERAL, that the 0w-20 oils will have higher VI's than their 5w-20 siblings, but it is certainly not a rule. Therefore, the move to 0w-20 may encourage the circulation of higher VI lubricants because of that generality, but it certainly doesn't force it, which is what you had stated

Selective or not, the data was there to invalidate your statement. I was just proving a point

Yes I originally meant in general, as I suspect you know. After all, it is important to prove points on BITOG!

 

[OVERKILL]

Originally Posted By: TrevorS
Originally Posted By: OVERKILL
Originally Posted By: TrevorS
Yes but a 5w20 can be a dino with much lower VI whereas the lowest possible VI of a 0w20 is significantly above that.

What did Shannow say about selective data?


Yes, and I would say IN GENERAL, that the 0w-20 oils will have higher VI's than their 5w-20 siblings, but it is certainly not a rule. Therefore, the move to 0w-20 may encourage the circulation of higher VI lubricants because of that generality, but it certainly doesn't force it, which is what you had stated

Selective or not, the data was there to invalidate your statement. I was just proving a point

Yes I originally meant in general, as I suspect you know. After all, it is important to prove points on BITOG!


Sure is. After all, we are obsessing about motor oil right? So being pedantic and griping about the minutiae is what it is all about, LOL!

 

[TrevorS]