It's not a dumb subject for some of us dumb people. Also an average # is better than no number. I've also learned some things about the effects of VIIs on oil density
Wear Relationship to Motor Oil Density
- Thread starter AEHaas
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It's not a dumb subject for some of us dumb people. Also an average # is better than no number. I've also learned some things about the effects of VIIs on oil density
I find it interesting that the couple of densities listed for straight weight oil are in in the .89 range.
I have not been a straight weight believer and I still am not. But it may shed light on what makes density go down -- mixing other suff in.
I have not been a straight weight believer and I still am not. But it may shed light on what makes density go down -- mixing other suff in.
Lets see, HDEO's:
Delvac 1 - 0.86
Delo 400 15w40 CI4+ - 0.88
Esso XD-3 - 15w40 - 0.88
These oils yield good results in many applications. Good luck? Perhaps not...
Delvac 1 - 0.86
Delo 400 15w40 CI4+ - 0.88
Esso XD-3 - 15w40 - 0.88
These oils yield good results in many applications. Good luck? Perhaps not...
That doesn't make it SI.
Juste adde an e at the ende, ande it becomese metric.
tonne
pounde
gramme
tonne
pounde
gramme
Thats what i'm sayin! The correlations are quite convincing. From a viscosity standpoint, many have a hard time understanding that viscosity alone does not guarantee protection and why straight weigth oils are still widely available, let alone recommended for most mission-critical applications. Maybe equipment operators and engineers know the truth that viscosity is not the only factor in wear prevention and that despite more desiable flows, there is still a price to be paid for using VIIs/PPDs etc. Less-dense solutions may be prone to 'tearing' or temporary shear (which under certain heat/pressure conditions can result in permanent shear). This is what I gather, again I could be off base here.
I agree with the stupid thread label. Just another thread with no backbone. Three pages with no real evidence or data to support the suggestion that specific gravity has any bearing on oil performance in an engine.
I found Bruce’s comment interesting:
When I apply that logic to comparing different oils (via used oil analysis) in my own engine over months/years in all kinds of weather, it’s impossible to accurately gauge the differences in engine wear between the oils tested. Changes in oil formulations, driving habits, gasoline formulations, weather, and other variables will effectively mask whatever differences may exist between the oils. Need a bigger data base to draw accurate conclusions. Poorly designed or problem engines would be only exceptions.
I found Bruce’s comment interesting:
When I apply that logic to comparing different oils (via used oil analysis) in my own engine over months/years in all kinds of weather, it’s impossible to accurately gauge the differences in engine wear between the oils tested. Changes in oil formulations, driving habits, gasoline formulations, weather, and other variables will effectively mask whatever differences may exist between the oils. Need a bigger data base to draw accurate conclusions. Poorly designed or problem engines would be only exceptions.
This certainly doenst mean that other people can't detect trends from an assortment of information, not just our personal used oil analysis. used oil analysis vary even within the same lab, so let's not go there. The variations in density throughout the grade range do sometimes change, yes, but the variences tend to be more or less equillibrium
Obvious question: what's the density of GC?
This thread reminds me of a statistics class where the professor had a chart that showed a strong correlation between the numbers of winos in St James park in San Jose and the carbon monoxide levels at an air resources board sampling site a couple of blocks from there.
What amazed me was that well into a university statistics class, some of the students still thought that correlation showed cause.
What amazed me was that well into a university statistics class, some of the students still thought that correlation showed cause.
how gullable
Fwiw, the Mobil 1 Extended Performance line all have a much higher density under the ASTM D 4052 compared to regular Mobil 1.
Mobil 1 Extended Performance 5w20 - .86
Mobil 1 5w20 - .80
All grades of EP are over .86
Most regular Mobil 1 are around .80
Mobil 1 Extended Performance 5w20 - .86
Mobil 1 5w20 - .80
All grades of EP are over .86
Most regular Mobil 1 are around .80
I have been observing this data item for sometime and I have a few questions:
- Why are dino specific gravities typically higher than syns when compared in the same grade and dinos typically have higher wear?
- Why is specific gravity only tested at 60°F and not at both a cold temp (such as 32°F) and at an operating temp (such as 212°F) like viscosity data?
- Is there any value in seeing specific gravity at a cold temp to see if there is a wear relation at startup?
- How does API Gravity data playing into wear?
- How does API Gravity compare to specific gravity?
Thanks.
- Why are dino specific gravities typically higher than syns when compared in the same grade and dinos typically have higher wear?
- Why is specific gravity only tested at 60°F and not at both a cold temp (such as 32°F) and at an operating temp (such as 212°F) like viscosity data?
- Is there any value in seeing specific gravity at a cold temp to see if there is a wear relation at startup?
- How does API Gravity data playing into wear?
- How does API Gravity compare to specific gravity?
Thanks.
MolaKule
Staff member
I think you have to examine the total rheology of the fluid; the base oil characteristics coupled with the additive package.
Trying to couple density alone with wear is like saying TBN alone determines wear.
Trying to couple density alone with wear is like saying TBN alone determines wear.
MolaKule
Staff member
Ask yourself, does the Delta (numerical differences) and wear results between an oil with a density of 0.86 and another oil of say 0.89, give you a statistically meaningful indicator or correlation?
Not sure what you can tell from these numbers
nothing other than base stock/VII diferences
bruce
nothing other than base stock/VII diferences
bruce
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