are these cold flow tests overblown between conventional and synthetic?

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387
watching these cold flow tests has got me confused. for example, if we are comparing a 5w30 conventional/semi syn vs a 5w30 full syn for example. they are both the exact same weight, so how come they have very large difference in cold flow tests example youtube etc. is it for example those tests are 'fake'? or overblown?

i am probably wrong here but if they have exact same viscosity how come one of the oil 'flows' easier which would mean technically less viscous

for comparison sake lets say -30 celcius


thanks!
 

jalikaria24

Thread starter
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387
are they being tested within their rating?
i assume the tests on youtube for example are comparing the same weight oils example 5w30 vs 5w30.
if not, that seems to be very very very bad marketing and youtube ploy. they dont state it but i assume they need to be the same weight
 

jalikaria24

Thread starter
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387
The problem with these tests is that they have no bearing on how the oil flows in your engine. They are more eye candy than anything.
fair fair and maybe the reasoning could be used that a slower flowing oil in the cold could also be better considering it would kinda keep a film on all engine parts rather then completely falling into the oil pan? just a thought
 
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1,853
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Indiana
If you stop wasting your time watching those silly “cold flow tests” and research cold cranking simulator and mini-rotary viscometer testing that is done in real laboratories by trained professionals instead of some Youtubers basement or garage you’d be less confused.
 
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16,542
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Upper Midwest
Or just purchase an oil with a winter rating that’s appropriate for your climate and expected starting temperatures. That’s what it’s for.

And as everyone else has stated (and has been discussed on here countless times) those videos only show how the oil flows in the plastic tubes or containers and is not representative of what happens in or is relevant to ICE operation. Do some searching around the site.
 
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Northeast Nebraska
i assume the tests on youtube for example are comparing the same weight oils example 5w30 vs 5w30.
if not, that seems to be very very very bad marketing and youtube ploy. they dont state it but i assume they need to be the same weight
In your OP your example is conventional/blend vs synthetic which isn't exactly fair either, of course the synthetic will flow better.
 
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1,438
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Indiana
There can be significant differences between brands too. I remember when "semi syn" Dex VI came out (not sure of the source back then), we ran it at -40F in transmissions and it didn't flow as well as the "conventional" Dex III that was sourced from Petro Canada, and not nearly as well as the PAO TranSynd from Castrol.
 
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1,119
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Vancouver
There can be significant differences between brands too. I remember when "semi syn" Dex VI came out (not sure of the source back then), we ran it at -40F in transmissions and it didn't flow as well as the "conventional" Dex III that was sourced from Petro Canada, and not nearly as well as the PAO TranSynd from Castrol.

Fun fact, -40 is the same temp both F and C :)
 

OVERKILL

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45,331
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Ontario, Canada
There can be significant differences between brands too. I remember when "semi syn" Dex VI came out (not sure of the source back then), we ran it at -40F in transmissions and it didn't flow as well as the "conventional" Dex III that was sourced from Petro Canada, and not nearly as well as the PAO TranSynd from Castrol.

Indeed, unlike engine oils, there is no "Winter" rating for fluids like PSF and ATF, though there may be something as part of the approval process that sets a baseline? I expect there's some broad variability there though.
 
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1,528
Location
California
In your OP your example is conventional/blend vs synthetic which isn't exactly fair either, of course the synthetic will flow better.
I think his question was more like this: If these are all 5w30 oils, why does one flow better than the other?
My answer: viscosity is not a hard number. All oils rated at a certain viscosity will fall within the *same standard range* for that viscosity, but they are not equal. The real-world question is this: how important is cold viscosity rating at your ambient temperatures? My Corvette specs 5w30 but I'm running 10w30 and it is very, very happy. I suspect it would also be happy with an 0w30, but my temps never get below 25F and I'm quelling a noisy lifter with the 10w.
 
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2,113
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WA
I remember this pour test:
All oils were 5w-30 at -2° F. Few were more viscous than others.

In this chart, 5w-xx oils can't be above 6600 Centipoise at -30° C. Some oils are at the higher end of that limit and some are well below the limit. https://pqia.org/pqia-viscosity-quick-reference-guides/

They all look within "spec" to me. lol
i.e. Not a huge difference whether the test means anything or not.

btw, I like your pqia link!
 
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694
Location
Alaska and Wisconsin
There can be significant differences between brands too. I remember when "semi syn" Dex VI came out (not sure of the source back then), we ran it at -40F in transmissions and it didn't flow as well as the "conventional" Dex III that was sourced from Petro Canada, and not nearly as well as the PAO TranSynd from Castrol.
That's why this Alaskan buys and uses ACDelco GM Dexron VI Full Synthetic ATF (10-9244 or 10-9243 for example) in his long-lasting pickup truck, not undesignated Dex VI fluids.

BTW, Petro-Canada does a respectable job manufacturing lubrication products specifically designed for extreme cold environs. The Frozen Chosen tip their hat...
 
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