Idemitsu 0w20 - Unique high density, good or bad?

[HKPolice]

I've never seen a 0w20 oil with higher than ~0.85 g/cm3 density. Even much heavier synthetic oils are all around the 0.86g/cm3 area. Is this higher density a good thing? Does it mean that it uses less VI additives? How does this affect HT/HS vis?

The previous API SM high VI version of Idemitsu 0w20 only had a density of 0.84 g/cm3 but had a VI of 197: http://www.worldpac.com/tagged/IDEMITSU_Motor_Oil_0W20.pdf

 

[HKPolice]

No one cares about density? So I guess it doesn't matter at all?

 

[Shannow]

I do, as it's a part of the correlation between kinematic and absolute viscosity, and you've raised an outlier.

Why, what are your thoughts on the issue ?

 

[HKPolice]

I'm not sure what to think. It most likely has less VII than all other 0w20 oils since VII lowers density? This suggests a very high quality base stock, the 169 calculated VI might even be all natural without any VII. Is that even possible?

It's hard to imagine a thin 0w20 oil being denser than even a heavy 10w40 but this seems to be the case.

 

[A_Harman]

.89 density is pretty high. The only motor oil I know that is higher is Redline, which is .91. Density is an important characteristic because it affects the relationship between kinematic and dynamic viscosity: kinematic vis = dynamic vis / density.

Additionally, thermal conductivity and specific heat are affected by density. Higher density decreases both.

 

[jrustles]

Originally Posted By: A_Harman
.89 density is pretty high. The only motor oil I know that is higher is Redline, which is .91. Density is an important characteristic because it affects the relationship between kinematic and dynamic viscosity: kinematic vis = dynamic vis / density.

Additionally, thermal conductivity and specific heat are affected by density. Higher density decreases both.


EXACTLY what I was thinking upon reading that density value- Redline. I am VERY interested now in this SGMO. Usually the lightweights are well below 0.85

 

[CATERHAM]

Originally Posted By: HKPolice
I'm not sure what to think. It most likely has less VII than all other 0w20 oils since VII lowers density? This suggests a very high quality base stock, the 169 calculated VI might even be all natural without any VII. Is that even possible?

It's hard to imagine a thin 0w20 oil being denser than even a heavy 10w40 but this seems to be the case.

Not necessarily less VIIs but a different type.
And since a typical GP III base oil has a VI in the 130-135 range you still need VIIs to formulate a oil with a 169 finished VI.

An oils density can tell you something of an oils chemistry but how important is it to the bottom line which in terms od high temp' viscosity is the oils' HTHSV spec'.

I'd also take the MSDS density spec' with a grain of salt as they are notoriously inaccurate.