Cold Weather...pour point question

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I read on here about people recommending synthetic because it flows so much better in cold weather. Well, looking at Pennzoil Platinum, it's pour point is -39 (5w30) and for Pennzoil conventional 5w30 it's also -39. (This is the weight rec. for my car) I don't see any advantage to synthetic other than longer drain intervals with respect to cold temperatures. Even if your temps never got below zero during the winter, would your engine notice any difference running synthetic vs. conventional?
 
Although I am no expert, I think you will have a better protected engine with synthetic. I recently inquired what the actual temperature the oil would be usable at and was told as a general rule, about 20 degrees above the pour point. This was according to Amsoil.
 
Pour point doesn't tell you anything about how the oil actually pumps and flows at low temps.

Think about water vs. honey. Honey has a much lower pour point. However, it's thick as all heck at 1º C, whereas water flows very easily at that temperature even though that's very close to its freezing point.

Similarly, if you see a synthetic oil and a conventional oil with the same pour point, it's still very likely that the synthetic will be much more pumpable than the conventional at low temperatures.

Hope that made sense.
 
Look at BITOG home page then look at "Effects of Shearing". There is some mention of the "w" pour point.(I think I remember that right).
 
Originally Posted By: d00df00d
Pour point doesn't tell you anything about how the oil actually pumps and flows at low temps.

Think about water vs. honey. Honey has a much lower pour point. However, it's thick as all heck at 1º C, whereas water flows very easily at that temperature even though that's very close to its freezing point.

Similarly, if you see a synthetic oil and a conventional oil with the same pour point, it's still very likely that the synthetic will be much more pumpable than the conventional at low temperatures.

Hope that made sense.


Couldn't have said it better if I wanted to.
 
So let's say at 10 degrees, one could notice a difference pouring syn vs. conventional (same weights) out of an oil jug sitting out all night?
 
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Right, so forget about PP and look to the Borderline Pumping (MRV) spec' for extreme cold temp' performance.

Of course that has nothing to do with how light an oil is at 0C.
Unfortunately there is no viscosity measure taken at that temp' or anywhere near it.
Many use the KV40 spec' to compare oils at modestly cold temp's and extrapolate down to 0C or so. Since kinematic vis' measures aren't reliable, you can improve the accuracy of doing this by only comparing oils with the same HTHS vis' spec's and similar VI's; oil's with higher VI's will be lighter.
 
"So let's say at 10 degrees, one could notice a difference pouring syn vs. conventional (same weights) out of an oil jug sitting out all night?
"

No, I had a pair of 5-30's out last year just to do this. Even down to about -10 F there was little difference. They were night and day from the conventional 10-40 also on the shelf.
 
Take a look at Redline 0W30. Is there any oil that possesses a lower advertised PP than it i.e. a sexy -76 F BUT digging a bit deeper you find that its MRV is an 'ordinary' 28,000cP
(@-40°C).
 
Originally Posted By: 21Rouge
Take a look at Redline 0W30. Is there any oil that possesses a lower advertised PP than it i.e. a sexy -76 F BUT digging a bit deeper you find that its MRV is an 'ordinary' 28,000cP
(@-40°C).


Excellent example.
The only value for the PP stat' is for misleading marketing purposes.
 
Originally Posted By: CATERHAM
Originally Posted By: 21Rouge
Take a look at Redline 0W30. Is there any oil that possesses a lower advertised PP than it i.e. a sexy -76 F BUT digging a bit deeper you find that its MRV is an 'ordinary' 28,000cP
(@-40°C).


Excellent example.
The only value for the PP stat' is for misleading marketing purposes.

Just to clarify, for anyone who might be confused: PP in these posts stands for pour point, not Pennzoil Platinum.
 
5w30 Pennzoil Yellow bottle conventional on the left hand side, 5w30 Pennzoil Platinum on the right hand side.


-39 Pour point -39

5,800(-30) CCS(cP) 5,150(-35)

15,900(-35) MRV(cP) 14,800(-35)


Even though the pour points are the same, the MRV number is 7% thinner at the same -35°C. CCS is 12% thinner even though the tested temperature for Platinum is 5° colder than the yellow bottle measurement.
 
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Originally Posted By: 21Rouge
Take a look at Redline 0W30. Is there any oil that possesses a lower advertised PP than it i.e. a sexy -76 F BUT digging a bit deeper you find that its MRV is an 'ordinary' 28,000cP
(@-40°C).


Just curious, where did you get this spec?
 
Originally Posted By: Samilcar
Pennzoil Yellow bottle conventional on the left hand side, Pennzoil Platinum on the right hand side.


-39 Pour point -39

5,800(-30) CCS(cP) 5,150(-35)

15,900(-35) MRV(cP) 14,800(-35)


Even though the pour points are the same, the MRV number is 7% thinner at the same -35°C. CCS is 12% thinner even though the tested temperature for Platinum is 5° colder than the yellow bottle measurement.


And that is how to compare oils re their cold weather abilities i.e. PP is of minimal importance.
 
Originally Posted By: 21Rouge
Originally Posted By: Samilcar
Pennzoil Yellow bottle conventional on the left hand side, Pennzoil Platinum on the right hand side.


-39 Pour point -39

5,800(-30) CCS(cP) 5,150(-35)

15,900(-35) MRV(cP) 14,800(-35)


Even though the pour points are the same, the MRV number is 7% thinner at the same -35°C. CCS is 12% thinner even though the tested temperature for Platinum is 5° colder than the yellow bottle measurement.


And that is how to compare oils re their cold weather abilities i.e. PP is of minimal importance.


I disagree. Pour point has some importance
 
Originally Posted By: 21Rouge
Originally Posted By: Samilcar
Pennzoil Yellow bottle conventional on the left hand side, Pennzoil Platinum on the right hand side.


-39 Pour point -39

5,800(-30) CCS(cP) 5,150(-35)

15,900(-35) MRV(cP) 14,800(-35)


Even though the pour points are the same, the MRV number is 7% thinner at the same -35°C. CCS is 12% thinner even though the tested temperature for Platinum is 5° colder than the yellow bottle measurement.


And that is how to compare oils re their cold weather abilities i.e. PP is of minimal importance.


It's important if the temperature -40°C and you are using Platinum.
 
Originally Posted By: Ben99GT
Originally Posted By: 21Rouge
Originally Posted By: Samilcar
Pennzoil Yellow bottle conventional on the left hand side, Pennzoil Platinum on the right hand side.


-39 Pour point -39

5,800(-30) CCS(cP) 5,150(-35)

15,900(-35) MRV(cP) 14,800(-35)


Even though the pour points are the same, the MRV number is 7% thinner at the same -35°C. CCS is 12% thinner even though the tested temperature for Platinum is 5° colder than the yellow bottle measurement.


And that is how to compare oils re their cold weather abilities i.e. PP is of minimal importance.


It's important if the temperature -40°C and you are using Platinum.


Of course I am considering the 99% of us which never encounter
temps anywhere near the PP of a reasonable quality oil. And in this much more likely situation the MRV and CCS are more telling of how the oil will behave in more reasonable cold weather conditions.
 
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