variations in reported pour points of a motor oil

[merconvvv]

I do glance at pour points of motor oil after considering other important properties. The reported pour points for a given motor oil vary enough to cause concern and hence the post.

Mobil 1 10w30 from msds has pour point of -36c/-33 f while web site ad states minus -42c/-43.6 f.

Mobil 1 0W20 ep -45c/-49f from msds and -54c from web site ad.

Large variations from bottle to bottle for a given weight?

 

[MolaKule]

Formulation changes always precede marketing and labeling.

Hence, the need to do a VOA before you take any post oil change samples.

 

[SonofJoe]

I'd say this is about par for the course.

The pour point test has a repeatability of about plus or minus 3°C (because the test is 'stepped' in 3°C increments). If the 'real' pour point of the 10W30 was -39, then you could just as easily measure -36 (3°C high) or -42 (3°C low).

Basically it's nowt to fret about...

 

[53' Stude]

Originally Posted By: MolaKule
Formulation changes always precede marketing and labeling.

Hence, the need to do a VOA before you take any post oil change samples.


+10,000 sir

 

[Tom NJ]

MSDSs are conservative, often taking into account worse case scenarios using batch-to-batch variations and test reproducibility. Since pour point is not a safety issue there is no need for precision. The results in technical data sheets are usually typical figures based on actual data and are more accurate.

Tom NJ/VA

 

[kschachn]

What is the significance of pour point exactly? As long as you're using a grade that is appropriate for your operating conditions how exactly does pour point relate to operating performance in an engine?

 

[y_p_w]

Typical properties are just that. It's not as of their base oils, additives, etc can be produced exactly the way they want down to the molecular level (regardless of advertising). There's always going to be some sort of variation unless someone is willing to pay ridiculous prices.

 

[y_p_w]

Originally Posted By: kschachn
What is the significance of pour point exactly? As long as you're using a grade that is appropriate for your operating conditions how exactly does pour point relate to operating performance in an engine?

Bragging to your buds that you could start your car in Siberia I guess.

 

[kschachn]

Originally Posted By: y_p_w
Originally Posted By: kschachn
What is the significance of pour point exactly? As long as you're using a grade that is appropriate for your operating conditions how exactly does pour point relate to operating performance in an engine?

Bragging to your buds that you could start your car in Siberia I guess.

But wouldn't that be covered by the grade? Does pour point relate to the pumpability of the oil at some related temperature?

 

[merconvvv]

Mobil 1 likes to brag about pour points and !siberian starts!
It advertises mrv for 0w40 but not other weights.
One cannot go by weight alone either. We all talk about heavy and light oils in the same weight class.
Is mobil 1 implying as atleast i would speculate that there is correlation between mrv, pour point and start up protection.

 

[53' Stude]

Mobil 1: good oil

End of b.s.

 

[BobFout]

Pour point is not a criteria for SAE J300 winter grades. Low temp cranking and pumping are.

 

[merconvvv]

Bad language car51.
I have used more mobil 1 than you ( most likely).

 

[53' Stude]

Dunno about that either

 

[kschachn]

Originally Posted By: merconvvv
Mobil 1 likes to brag about pour points and !siberian starts!
It advertises mrv for 0w40 but not other weights.
One cannot go by weight alone either. We all talk about heavy and light oils in the same weight class.
Is mobil 1 implying as atleast i would speculate that there is correlation between mrv, pour point and start up protection.

And Amsoil likes to brag about NOACK and battery companies like to brag about CCA.

I wouldn't go by weight at all to be honest, I'd go by the cold weather performance spec (W rating). Match that to what is required for your location and expected operating conditions and be done with it. The weight of the oil has more to do with your owner's manual requirements than the weather.

 

[53' Stude]

Originally Posted By: merconvvv
Bad language car51.
I have used more mobil 1 than you ( most likely).


Basically M1 is good oil. If you don't like something about a oil; don't use it. I remember "red cap" M1 15w50 before M1 0w40 was famous

 

[Shannow]

Originally Posted By: kschachn
Originally Posted By: y_p_w
Originally Posted By: kschachn
What is the significance of pour point exactly? As long as you're using a grade that is appropriate for your operating conditions how exactly does pour point relate to operating performance in an engine?

Bragging to your buds that you could start your car in Siberia I guess.

But wouldn't that be covered by the grade? Does pour point relate to the pumpability of the oil at some related temperature?


Pour point was part of the J300 W grading for a fairly long time...here's a 1984 case...

But hasn't been in the specs since MRV and CCS were adopted after a number of failures that occurred with lubricants rated in the "traditional" way.

That's why those -40 freezer gloop tests don't give any clue as to what happens (bar how easily you can do an oil change with a 5W at -40C)

 

[kschachn]

Originally Posted By: Shannow
That's why those -40 freezer gloop tests don't give any clue as to what happens (bar how easily you can do an oil change with a 5W at -40C)

That's a good analogy, I've done pour point tests and it's pretty much exactly what you're checking for.

 

[Virtus_Probi]

Originally Posted By: Shannow
Pour point was part of the J300 W grading for a fairly long time...here's a 1984 case...

But hasn't been in the specs since MRV and CCS were adopted after a number of failures that occurred with lubricants rated in the "traditional" way.

That's why those -40 freezer gloop tests don't give any clue as to what happens (bar how easily you can do an oil change with a 5W at -40C)


Cmon, Shannow...you have to stick with the excellent term you already coined..."glug test".
;^)

I have seen some 10WXX oils with really impressive reported pour points, so I know to not worry about them too much. Kind of like how I might suspect an oil with a really high flashpoint will have a low NOACK loss, but I sure wouldn't count on it.

 

[kschachn]

Originally Posted By: Virtus_Probi
I have seen some 10WXX oils with really impressive reported pour points, so I know to not worry about them too much. Kind of like how I might suspect an oil with a really high flashpoint will have a low NOACK loss, but I sure wouldn't count on it.


Well exactly. A 10W with a "really impressive" pour point is still a 10W, which may or may not be appropriate or optimal for a specific operating environment.