10w30 & low temps

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Originally Posted By: Shannow
Except "pour" testing was abandoned decades ago as the cold measurement for "W" gradings, as it proved to be too unreliable for actual engine starting.

If you need to know which oil will tip into your engine faster at 5F, then have at it with the freezer tests.

It was replaced with MRV, which is the ability of the oil to refill the oil pump suction pipework...that measure and that measure alone has a correlation with time to build oil pressure and fill galleries in test engines at extreme cold.

Yes. If you wish to start your car at low temperatures, then go by the W rating.
 
I hate to re-introduce facts into a fun emotional debate, but here are the test limits for the various "W" grades...

" CCS (mPa.s) MRV (mPa.s)
0W 6200 at -35C 60 000 at -40C
5W 6600 at -30C 60 000 at -35C
10W 7000 at -25C 60 000 at -30C
15W 7000 at -20C 60 000 at -25C
20W 9500 at -15C 60 000 at -20C
25W 13 000 at -10C 60 000 at -15C"

CCS simulates cold cranking and MRV is a pumpability test, as mentioned before.

Doesn't matter if it's synth or dino, the test limits are all the same. In my experience, when a manufacturer gives MRV results, they are much lower than the test limits. CCS results can often be much closer to the limits. If an oil can pass both the 0WXX test limits, for example, it is supposed to be marketed as such and not as, say, a 5WXX. If a 5W30 dino oil is not liquid at -20F/-29C, you've probably bought a PQIA red dot special at a dollar store.
1.8(temp in C) + 32 = temp in F
 
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All good. I’ve posted this myself in the past. Now one thing that is missing is direct measurement of kinematic viscosity of various oils at the same low temperature. Notice the CCs and MRV was at the same loading but different temps for each oil. I came across a 2013 paper written by Kumbar and Sabaliauskas entitled Low Temperature Behavior of Engine Oil. They plotted the kinematic viscosities actually measured for each oil. The oils were 5W-40, 10W-40, 15W-40, and 20W-40. At 15 C, they all had a similar viscosity of 1.0 m^2/s. As the tempeature dropped to freezing at 0C they start to diverge and by the time they hit -15 C, they had the following kinematic viscosities in m^2/s.

5W-40 2.0
10W-40 3.0
15W-40 5.5
20W-40 9.0

The graphs were trending such that the differences were getting larger as the temperature dropped.

If anyone else has similar data it would be interesting to see.

SF
 
Originally Posted By: Snagglefoot
Originally Posted By: Cujet
Originally Posted By: Snagglefoot


We’re talking about cold weather starts. A 5W-xx, recommended by most manufacturers for almost the last 20 years will allow an easier start than 10W-xx. Cold starts are a leadind cause of engine wear, but that part can be discussed in a seperate thread. . Just say’in.



While that should be true, it's clear to anyone that's ever put a bottle of oil in the chest freezer, even at -10F, oils of the same grade, but different brands and types, pour and flow very differently. There is so much variation between oils at very low temperatures that it's quite likely a quality high viscosity synthetic will massively outflow a conventional, low viscosity oil.

The older version of Mobil 1, 15W-50 remained liquid at -20, where as conventional 5W-30 was nearly a gel. That version of M1 used to have a -55F pour point!



Good point and great idea. Buy a quart of M1 synthetic 5-30, then a quart of your favorite oil. Put them in the freezer over night. Since most freezers are somewhere around 5 degrees F, it approximates the coldest temps we see with the exception of Inuvik, NWT, Canada and Edmonton, Canada. Take them out of the freezer and pour them into plastic cups. See for yourself if you are happy then let it ride.

SF

banana2.gif



Er...Joke, right?

Surely no one would ever be daft enought to actually do that?
 
Originally Posted By: Snagglefoot
All good. I’ve posted this myself in the past. Now one thing that is missing is direct measurement of kinematic viscosity of various oils at the same low temperature. Notice the CCs and MRV was at the same loading but different temps for each oil. I came across a 2013 paper written by Kumbar and Sabaliauskas entitled Low Temperature Behavior of Engine Oil. They plotted the kinematic viscosities actually measured for each oil. The oils were 5W-40, 10W-40, 15W-40, and 20W-40. At 15 C, they all had a similar viscosity of 1.0 m^2/s. As the tempeature dropped to freezing at 0C they start to diverge and by the time they hit -15 C, they had the following kinematic viscosities in m^2/s.

5W-40 2.0
10W-40 3.0
15W-40 5.5
20W-40 9.0

The graphs were trending such that the differences were getting larger as the temperature dropped.

If anyone else has similar data it would be interesting to see.

SF


https://acta.mendelu.cz/media/pdf/actaun_2013061061763.pdf




These are the results purely with the KV40 and KV100 of the quoted oils.

As can be seen, it's mostly Viscosity Index, not the W rating.

They aren't all the same(ish) at 0C, there's a rank order at every temperature for the oils that doesn't change.

More to come after dinner
 
Couple of bits on the paper...

They've got their units all messed up.

Claim measuring units are in stokes (100Cst), but claim that the units are m^2/sec...that's 100 stokes.
9m^2/sec translates to 9,000,000 Cst...should be 9,000Cst.
0.3-0.6m^2/sec (the around 15C viscosity for the oils) should be ~400Cst, not 400,000cst.

Just assume that the error is in the paper, not the measurement (it is), so 9 on the scale is 9,000Cst.
 
OK, the MRV limits at temperature are 60,000Cp, 66,000Cst give or take assuming a density of around 0.9.
the temperatures are -20C, -25C, -30C, -35C, and -40C respectively for 20W down to 0W.

So that's like about 10 times where the 20W40 in the lower chart ends up.

Here's another cold start paper, that shows for the test engine considered a correlation of oil pressure time and Rocker arm oiling time with temperature note the curves flattening out at the -15C mark.




the testers tried to correlate these parameters to Pout Point, and found no effect.

But DID find correltion with Brookfield viscosity (the MRV is a scanning brookfield method with shear stress measurement)




Note that both correlations have a fixed component, which is essentially a gallery filling time, plus a viscosity component, which is the delay created by viscosity either not getting through the pickup effectively, or dragging in the galleries.

So using my calced figures off the Widman charting tool, and a density of 0.9.
Code:


Grade -15C Cst -15(P) RAOT 3Bar P

0W40 1662 15 8.3 4.2

10W40 3430 31 9.4 5.2

15W40 4944 44 10.3 6.0

20W40 6738 61 11.6 7.1


Note, that these LOOK significant, but the correlations are off the second set of charts, in which the measurements don't even START until 100P...these are all in the flat RHS region...tehy are essentially the same.

Shown here...different engine, different testing and if I recall correctly prior to the MRV units.


so the SAE30 at 20F, 10W30 at 9F, and 5W20 at -11F are all about the same, but none would ever "beat" the 6 seconds to full oil pressure regardless of "W" rating when into their pumpable range.
 
Also, engine design plays a part...here's two OHC 4 cylinders of different manufacturer. Note the grossly different behaviours.


This is a fairly typical trace...SFA difference down to where the lubricant pumpability starts to wane.

Versus this one...


One can only assume that the 2.2 in question was still able to achieve 100,000 miles of service for it's owners, even if it DID take over a minute for oil flow to the last cam journal
 
Originally Posted By: Shannow
OK, the MRV limits at temperature are 60,000Cp, 66,000Cst give or take assuming a density of around 0.9.
the temperatures are -20C, -25C, -30C, -35C, and -40C respectively for 20W down to 0W.

So that's like about 10 times where the 20W40 in the lower chart ends up.

Here's another cold start paper, that shows for the test engine considered a correlation of oil pressure time and Rocker arm oiling time with temperature note the curves flattening out at the -15C mark.




the testers tried to correlate these parameters to Pout Point, and found no effect.

But DID find correltion with Brookfield viscosity (the MRV is a scanning brookfield method with shear stress measurement)




Note that both correlations have a fixed component, which is essentially a gallery filling time, plus a viscosity component, which is the delay created by viscosity either not getting through the pickup effectively, or dragging in the galleries.

So using my calced figures off the Widman charting tool, and a density of 0.9.
Code:


Grade -15C Cst -15(P) RAOT 3Bar P

0W40 1662 15 8.3 4.2

10W40 3430 31 9.4 5.2

15W40 4944 44 10.3 6.0

20W40 6738 61 11.6 7.1


Note, that these LOOK significant, but the correlations are off the second set of charts, in which the measurements don't even START until 100P...these are all in the flat RHS region...tehy are essentially the same.

Shown here...different engine, different testing and if I recall correctly prior to the MRV units.


so the SAE30 at 20F, 10W30 at 9F, and 5W20 at -11F are all about the same, but none would ever "beat" the 6 seconds to full oil pressure regardless of "W" rating when into their pumpable range.


Thanks for putting pen to paper on this subject. My unscientific demarcation line is sustained, >2 days’, -10C as the change over point to 5W oils. That seems to correlate well with your findings providing me that extra peace of mind.

The previous winter, 2016-17, was mild where I used 10W30 for half the season. My self-imposed line was rarely, if at all, broken. There was no appreciable difference in start ability.
 
Originally Posted By: ndfergy

Thanks for putting pen to paper on this subject. My unscientific demarcation line is sustained, >2 days’, -10C as the change over point to 5W oils. That seems to correlate well with your findings providing me that extra peace of mind.

The previous winter, 2016-17, was mild where I used 10W30 for half the season. My self-imposed line was rarely, if at all, broken. There was no appreciable difference in start ability.

No probs.

It's a fair line in the sand, but that's probably where I'd switch from 15W to 10W....but that's me.
 
Originally Posted By: Shannow
Originally Posted By: ndfergy

Thanks for putting pen to paper on this subject. My unscientific demarcation line is sustained, >2 days’, -10C as the change over point to 5W oils. That seems to correlate well with your findings providing me that extra peace of mind.

The previous winter, 2016-17, was mild where I used 10W30 for half the season. My self-imposed line was rarely, if at all, broken. There was no appreciable difference in start ability.

No probs.

It's a fair line in the sand, but that's probably where I'd switch from 15W to 10W....but that's me.



True enough. With todays oils I could probably go lower but my but-o-meter, sans garage, is more the deciding factor. It does, however, allow me to push my seasonal change if need be.

Thanks again.
 
Originally Posted By: Shannow
Also, engine design plays a part...here's two OHC 4 cylinders of different manufacturer. Note the grossly different behaviours.


This is a fairly typical trace...SFA difference down to where the lubricant pumpability starts to wane.

Versus this one...


One can only assume that the 2.2 in question was still able to achieve 100,000 miles of service for it's owners, even if it DID take over a minute for oil flow to the last cam journal


That's very interesting. Big difference there.

This could explain why different owners manuals have differing cut off points for low ambient temperatures and corresponding winter grades.
 
Originally Posted By: CharlieBauer

That's very interesting. Big difference there.

This could explain why different owners manuals have differing cut off points for low ambient temperatures and corresponding winter grades.


Per other threads, and something that OVERKILL brought to other topics, that's certainly so...the Jeep I6 in lots of test papers has proven to be ridiculously sensitive to cold flow, the Buick V-6 much less so.
 
Originally Posted By: Shannow
Originally Posted By: CharlieBauer

That's very interesting. Big difference there.

This could explain why different owners manuals have differing cut off points for low ambient temperatures and corresponding winter grades.


Per other threads, and something that OVERKILL brought to other topics, that's certainly so...the Jeep I6 in lots of test papers has proven to be ridiculously sensitive to cold flow, the Buick V-6 much less so.


I had a few high mileage 90's Jeep Cherokees over the years and still own two of them..On a cold morning with 15-40 Rotella the engine makes all sorts of noise for a few seconds until oil pressure comes up...With 10/30 it makes the same noises only a bit quieter..Over the long run it's doesn't seem to hurt it based on the long engine live...
 
Originally Posted By: Shannow

https://acta.mendelu.cz/media/pdf/actaun_2013061061763.pdf

These are the results purely with the KV40 and KV100 of the quoted oils.

As can be seen, it's mostly Viscosity Index, not the W rating.

They aren't all the same(ish) at 0C, there's a rank order at every temperature for the oils that doesn't change.

More to come after dinner


Great info...I have been one of the posters saying they will all be about the same until you get really cold, and I have been full of it.
Thanks so much for sharing the facts here!
 
Originally Posted By: Virtus_Probi
Great info...I have been one of the posters saying they will all be about the same until you get really cold, and I have been full of it.
Thanks so much for sharing the facts here!


No probs...it's hard to counter "facts" when they are both wrong and baseless, but also "common knowledge", isn't it ?
 
Originally Posted By: ndfergy
True enough. With todays oils I could probably go lower but my but-o-meter, sans garage, is more the deciding factor. It does, however, allow me to push my seasonal change if need be.

Now, that gives me the chance to be difficult.
wink.gif
What would be the concern with the Mobil Super 1000 5w-30 in the summer?
 
Originally Posted By: JohnnyJohnson
This is a non issue for 90 + % of the people on BITOG.


Explain that to the BITOG brothers in Williston, North Dakota this morning. LOL!
 
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