Oils change color when extremely cold.

[S12]

So I left nine different oils out side over night when the temps got down to -15 Fahrenheit and something surprising happened.

Nine different oils: Valvoline straight 30, Valvoline conventional 10W-40, Pennzoil Conventional 10w30, Pennzoil Conventional 5w20, Pennzoil Platinum 5W-20, Pennzoil Platinum 10w30, CG 0W-30, Mobil Super 5w30, AMSOIL 10W-40.

So at -15 all of the conventional oils accept one turned from their normal room temperature amber colors to cloudy and opaque. Also all of the Pennzoil Platinum
synthetic oils also became cloudy but not as bad as the Pennzoil conventional.

The German Castrol and AMSOIL did not change in color at all but what kind of shocked me is that the Mobil Super which is a conventional oil did not change color at all and it even didn't thicken up like the other conventional oils.

So my question to the oil experts here is why would all of the conventional oils and even the Pennzoil Platinum synthetics change color so much at -15? Is the color change evidence of wax forming in the oils? And why would Mobil conventional oil not change at all at -15 accept for the oil thickening from the cold?

[img:center]https://plus.google.com/u/0/photos/10291...579039675336810[/img]

 

[michaelluscher]

Same thing in my V/Q
Less then 1k old PU with a Denso FTF Filter

Looks pretty bad when cold, after a warm up cycle and a good drive, it clears up.

 

[Eddie]

Probably the result of microscopic air bubbles and moisture trapped in the oil. I would expect that if you put the oil in a vacuum to remove the air, then the color would not change at all. Ed

 

[JAG]

I'd say some combination of moisture freezing and wax formation are responsible. If you could heat the oils up to evaporate the moisture equally across the oils and then repeat the test, that would eliminate that variable.

 

[sir1900]

YouTube has a number of videos that demo what oils looks like in extreme cold temperatures.

 

[Rand]

highly doubt it has anything to do with "wax"

moisture?

try heating the oil to 225F hold it at 225f~~ for 15m then put it in a tightly closed jar

 

[jrustles]

Originally Posted By: Rand
highly doubt it has anything to do with "wax"

moisture?

try heating the oil to 225F hold it at 225f~~ for 15m then put it in a tightly closed jar


What if it had everything to do with wax, then what?

What is wax? Is it not hydrocarbon chains attempting to arrange themselves into a lattice structure?

Although the 'cloud point' isn't used in motor oils because more specific parameters are defined (PP, fluidity/cP), it's essentially what you're observing.

The GC and AMSOIL are most likely PAO based which are resistant to exhibiting the aforementioned properties.

"Many poly-alpha-olefins have flexible alkyl branching groups on every other carbon of their polymer backbone chain. These alkyl groups, which can shape themselves in numerous conformations, make it very difficult for the polymer molecules to align themselves up side-by-side in an orderly way. This results in lower contact surface area between the molecules and decreases the intermolecular interactions between molecules."

PPDs work by disrupting the alignment of lattice structures- not from entirely happening, but from becoming to large which adversely affects viscosity.

 

[Errtt]

Guess I'll keep my stash in one of the spare rooms indoors as usual, and as usual, shake each bottle well just when about to crack open the cap to pour into the fill hole.
Condensation/moisture... wax. Didn't some of the earlier years oils contain paraffin waxes?

 

[S12]

My problem with the cloudiness of the oils being moisture is that I bought all of the oils new and unopened with the exception of the GC 0W-30, AMSOIL 10W-40 and the Pennzoil Platinum 5W-20. I can't see virgin oil having significant water in it and besides that the AMSOIL and GC were opened a year ago and did not have any color change when at -15 or at room temperature.If moisture was to get into any of the oils it should be in the ones that were in my basement for a year and previously opened and half empty.

I can't help but think that what I am observing is the formation of wax in all but the GC, AMSOIL and the Mobil Super.

 

[Nyquist]

It's doubtful it's wax as those base oils are refined enough to remove wax and prevent it from 'clumping' when cold.

My bet is that it is just one of the additives reacting (temporarily) to the cold. Since many oils use common additives, that may explain things.

 

[jrustles]

Originally Posted By: Nyquist
It's doubtful it's wax as those base oils are refined enough to remove wax and prevent it from 'clumping' when cold.



What do you call the finest, 'cleanest' most saturated GrIII+ or synthetic base oil at -150 degrees Celsius? A crayon!

Don't get it twisted, I don't want to suggest these products have actual parrafinic wax that melts at ~45degrees C, I'm just trying to point out that the exact physical phenomenon responsible for solidifying long chain wax molecules into a crystal lattice structure, is the same phenomenon that drives motor oil base molecules (no matter how refined or synthetic) to arrange themselves into small lattice structure groups. It's that same small-scale molecular arrangement to vaying degrees that causes all oil to increase viscosity as it cools and in some oils, more readily changes opacity from transparent to translucent. Like I said some PPD formulations and some base oils resist this behavior better than others, but all eventally succomb to the phenomenon-- No motor oil will be fluid or even malleable at -225 celcius for instance.

We have not discovered a useful oil that does not want to form a lattice structure (crystallize and thicken) the colder it gets.