Too low of a NOACK

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What problems would/could arise in the formulation and/or service of an oil that aimed at a very low volatility?

I am kind of wondering what comprolises must be made- whether monetary or making other aspects of the oil suffer.

ASTM D-5800



What does NOACK stand for? It is all capitals so I doubt it is someone's name.
 
The NOACK Volatility Test, otherwise known as ASTM D-5800, determines the evaporation loss of lubricants in high-temperature service.[1] The more motor oils vaporize, the thicker and heavier they become, contributing to poor circulation, reduced fuel economy and increased oil consumption, wear and emissions.

References

This is your answer sir. Lower NOACK is a GOOD thing; especially for turbo engines
 
Seems he was German and wrote papers, but was a name, Noack, but we say NOACK.


I am questioning your answer.

What are the trade offs or other compromises for lower Noack? Like, would an oil with a Volatility of 1% be crem dela crem?



Noack mass % loss in one hour @ 250C
 
Originally Posted By: mjoekingz28
What does NOACK stand for? It is all capitals so I doubt it is someone's name.

Dr. Kurt Noack came up with an apparatus and published a paper in 1936. This has been posted here before.
 
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?
 
I don't know if there would be any compromises sir. If anything I would say a oil with a low NOACK would be a service able oil. That's my thoughts
 
This particular test is used by the lubes industry more for the protection of emissions systems than the claimed changes in viscosity.

The 250C simulates what happens in the ring belt, where lubricants and phosphorous evaporate out, sending phosphorous downstream to the catalyst.

I can't see how it could be too low, in terms of affecting some other performance aspect.

But I doubt given typical viscosities and basestocks that you can get into the 1s anyway.
 
Originally Posted By: wemay
Does a low Noack number mean there has to be a compromise elsewhere?


No, it generally means that better and more expensive base oils are used that are less volatile, that's it.
 
Originally Posted By: wemay
Does a low Noack number mean there has to be a compromise elsewhere?


That's the point really...I can't see that it could.
 
Originally Posted By: mjoekingz28
Still, what has not been answered that I can find is what compromises should be made to have a low Volatility?

Maybe Mola will wander in and let us know. I know he's already posted here before about how one can get a very low Noack without using synthetic base stocks, notably the last time that PYB had a really low Noack.

As for a compromise, I suppose even cost can be a compromise. I gather most oil companies are interested in beating the required specification, but not leapfrogging it like in the PYB example. If it were "free" to make a very low Noack conventional and there were no other compromises to be had, wouldn't everyone be doing it? Or, is it simply that there's no point in chasing one specification?
 
Good idea Garak! "Is it simply that there's no point in chasing one specification?"

Guess it may not matter below a certain %.

One criteria I can think of is in Wankel rotaries. I think they banned synthetics from use since they metered oil into the combustion chamber to lubricate the seals (generalization). So a low Noack volatility would resist the burn and maybe gum up the engine or something. I remember reading of some 'over-maintainer' that used syn despite online advice and the OM and had early engine failure.






FWIW, I have just kind of started to have a novice layman's understanding of oil analyses (my own judgement). And I am just trying to understand. Like, who here would want an oil with a 300 viscosity index and a 1.5% Noack?


The point of this thread, I think, is to question whether a lubricant that excels on paper and in tests will be 'good'.......as in, run smoother, more power, last years, not leak, handle cold starts, high temps, short trips, go the distance, lubricate the metals, keep them clean, resist rust, and other things we want out of an engine and oil combo.





Kind of like what do you want? More power, well okay your engine will only last a year before rebuild/overhaul. Want it to last forever without maintaining it properly? Well ok, it will have a lower power output, not be too smooth..


The cost, weight, performance circle comes to mind.



Sometimes I feel we get caught up in the statistics and bench racing. Wile my car beats your on corrected magazine tests, you beat me stop light to stoplight and lap me at the closed circuit.


Good day/night all!
 
Originally Posted By: OVERKILL
Originally Posted By: wemay
Does a low Noack number mean there has to be a compromise elsewhere?


No, it generally means that better and more expensive base oils are used that are less volatile, that's it.


So thats why Redline is rated at "6"
 
Originally Posted By: Garak
Maybe Mola will wander in and let us know. I know he's already posted here before about how one can get a very low Noack without using synthetic base stocks, notably the last time that PYB had a really low Noack.

As for a compromise, I suppose even cost can be a compromise. I gather most oil companies are interested in beating the required specification, but not leapfrogging it like in the PYB example. If it were "free" to make a very low Noack conventional and there were no other compromises to be had, wouldn't everyone be doing it? Or, is it simply that there's no point in chasing one specification?
The oils with the lowest Noack seem to be the red headed stepchildren grades. I doubt Pennzoil is spending any time, effort, or money getting 10W-30(that no one specs in new cars) Noacks low while forsaking all the other more popular grades in that area. Pretty clear the low number is simply a side effect of formulating 10W-30.
 
Originally Posted By: mjoekingz28
One criteria I can think of is in Wankel rotaries.

That brings up some interesting speculation. There was a synthetic out there designed specifically for the Mazda rotary, and some variant even reportedly used in their 787B. It would be interesting to hear what would be the "ideal" oil for these engines, if the engineers could specify what they wanted relatively freely and without worrying about what's really on the market.

hatt: Well, we did see a decent 5w-20 PYB, but as was mentioned in the other thread, are the samples we're seeing outliers? Are they specifically formulated this way within conventional base stocks? Is there a different base stock for some reason? Unless we see a 5% Noack on a spec sheet for a PYB grade that is currently actually specified, I wouldn't rely on actually getting "that" when I grab a jug at the store.

Seeing decent 10w-30 Noack numbers isn't always uncommon. I should look through my data sheets, but numbers under 10% aren't exactly shocking.
 
Quote:
I wouldn't rely on actually getting "that" when I grab a jug at the store.
That's for sure. I am thinking about getting a jug to mix with my remaining 4 qts of PP for my next oil change since I haven't seen any Pennzoil deals recently. Ford specs a semisyn for my OCI anyway. I'm not sure a good "real" conventional wouldn't make it fine.
 
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.
wink.gif
 
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