Viscosities: Mobil 1 5w30 vs 10w30?

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4,710
As much of what in it?

This thread highlights the misunderstanding about the winter rating, what it means and what it does not mean.

Viscosity Index Improvers.

Again, this is just random speculative stuff. I am not claiming I am correct. Simply thinking.
 
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Data from Post #1 info. The cross-over can be seen when plotted out. Hair splitting since the viscosity it almost identical above 40C.

0 to 100C Range

M1 Comparo-1.JPG


40 to 140C Range

M1 Comparo-2.JPG
 
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4,710
While we know the oil does not "Start out as a 5 when it is cold then warm up to a 30," as I hear a shockingly high number of people say, which is wrong..

What if, as I'm pondering, it needs more "stuff" in the oil, to make it be both a 5W, AND an API grade 30.

Not one turning into the other, no. But "stuff" (VIIs? Viscosity Index Improvers?) to make it meet both sides.

Wouldn't a 10W need less? Or is that wrong.
 
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16,998
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While we know the oil does not "Start out as a 5 when it is cold then warm up to a 30," as I hear a shockingly high number of people say, which is wrong..

What if, as I'm pondering, it needs more "stuff" in the oil, to make it be both a 5W, AND an API grade 30.

Not one turning into the other, no. But "stuff" (VIIs? Viscosity Index Improvers?) to make it meet both sides.

Wouldn't a 10W need less? Or is that wrong.
Yes, no, maybe so. Base stock composition also matters.

But as has been mentioned, VII of today are not necessarily the same same as those of years ago. SonofJoe discussed that when he was posting here. Plus it's highly application specific whether there is significant potential for mechanical shearing. Not all engines are the same and most are not particularly shear inducing.
 

JonnyAbs

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Why? They have different winter ratings. Perhaps someone needs that for where they live.
They are so close they are almost negligible, no? Or are you saying they would be vastly different at below freezing temps even though they are almost identical at 40C and 100C
 

JonnyAbs

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Data from Post #1 info. The cross-over can be seen when plotted out. Hair splitting since the viscosity it almost identical above 40C.

0 to 100C Range

View attachment 39321

40 to 140C Range

View attachment 39322
This is great. Where did you get this data? You can't get the curves just by having cst @ 40 and 100.

So based on this, at 0 C, the 5w30 has a cst of about 540 and the 10w30 has one of about 650. Negligible at that temp or no? I can see why the 5w would be more desirable in cold climates well below freezing. I feel manufacturers should also provide cst at 0 C and/or 0 F. It barely if ever gets down to zero F where I am in PA. Only during polar vortex /Jussie Smollett occurrences.
 
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This is great. Where did you get this data? You can't get the curves just by having cst @ 40 and 100.
It's the only tool I've found that gives you a comparitive plot of different oils using KV40 and KV100 data, which is pretty much available from most big oil maker's spec sheet info.


So based on this, at 0 C, the 5w30 has a cst of about 540 and the 10w30 has one of about 650. Negligible at that temp or no?
10W is still acceptible at 0C.
 
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They are so close they are almost negligible, no? Or are you saying they would be vastly different at below freezing temps even though they are almost identical at 40C and 100C
I never said anything like that. What is the point you’re trying to make in this thread? I don’t think it’s technical, what is it?
 

JonnyAbs

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I never said anything like that. What is the point you’re trying to make in this thread? I don’t think it’s technical, what is it?
To discuss oil and learn more about it. Is everything ok in your life? You seem negative and jaded. Wish there was a full block feature on the site instead of just Ignore.
 
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Why do the two tables list the items in varying order?
Perhaps a mis-print on their part?
It's all the same stuff, except for the label that is applied to the jug. It's a "single fill station" that then diverts jugs to two label machines. ;)
 
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I never said anything like that. What is the point you’re trying to make in this thread? I don’t think it’s technical, what is it?
I think he is asking about the real world difference between 0w20 and 5w20 oils. Maybe the 5-point W rating difference is such a small *real change* at subzero temps that oil makers should just make it all 0w20 or 5w20, one or the other. Why have both? That's what I am hearing in his questions.
 

JonnyAbs

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I think he is asking about the real world difference between 0w20 and 5w20 oils. Maybe the 5-point W rating difference is such a small *real change* at subzero temps that oil makers should just make it all 0w20 or 5w20, one or the other. Why have both? That's what I am hearing in his questions.
Exactly. Thank you. I think I made that pretty clear but maybe he was just having a bad day.
 
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Exactly. Thank you. I think I made that pretty clear but maybe he was just having a bad day.
I predict a response explaining that the different W numbers mean they have different low temp viscosities... which we have already covered.
The question is, how much different? Enough to truly justify the existence of both multigrades? I too have my doubts, but I don't know (and I don't run #w20 oils anyway). Maybe someday we will get an answer... unless it's already been posted and we both missed it LOL :D
 
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I'm betting if you plotted the data like I did in post #23 for 0W-20 vs 5W-20 you'd also see that from around 40C and above the viscosity vs temperature would be nearly on top of each other (hair splitting difference). The reason they get a different W rating is because their viscosity starts spreading apart enough at much lower temperatures to put them into a different W rating.
 
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