0w vs 5w cold weather.

[tig1]

Originally Posted By: Panzerman
Originally Posted By: kschachn
Originally Posted By: benjy
here in PA i use 10-30 group III oils mostly, no starting issues + better protection than the thinner xxW-20 when hot oils!!! on that note its known that any oil except real synthetic group IV PAO + group V ester + other oils continue to thin after the advertised viscosity tested @ 212F, + actually are thinner in hotter areas of an engine on a regular basis!!

Uhh, all oils continue to thin as the temperature is increased.

Exactly so why is everyone so concerned with using a super light weight oil for start up when that's Great but not so Great after a hour of heavy pulling. I am with Bengy 100%.
All this wear [censored] at start up, tell you what 100% of wear happens when metal touches metal, hot or cold.


Why did you call 20 wt oils "super light weight oil"? Heck, I was using 20 wt oils in the 60's and 70'S. Hundreds of thousands of truck owners use 20 WT oils in their tow vehicles. I also remember many years ago when 5-30 was considered Too light by some "who knew not what they speak of".

 

[PimTac]

The biases between thin and thick just never end

 

[tig1]

Originally Posted By: PimTac
The biases between thin and thick just never end


Also the era of time makes a difference what's considered thick and what's thin.

 

[Shannow]

Originally Posted By: tig1
Originally Posted By: PimTac
The biases between thin and thick just never end


Also the era of time makes a difference what's considered thick and what's thin.


Especially when, as we've discussed before, the 20s in the 60s and 70s had HTHS values equivalent to an ILSAC 30 under the current J300...

 

[PimTac]

Originally Posted By: tig1
Originally Posted By: PimTac
The biases between thin and thick just never end


Also the era of time makes a difference what's considered thick and what's thin.





I remember running 10w-40 as the norm, but times and circumstances change along with how we view things. 40 years ago I could have stated that cars would be glued together and got laughed at. Today I see no reason to doubt the capabilities of 0w-20.

 

[Shannow]

Originally Posted By: pbm
Shannow's graphs are a little over my head....Is it safe for me to assume that a 5w20 is not significantly different than a 0w20 at 0*F?....Let's use Mobil 1 as an example...How about Mobil 1 0w20 vs MS5K 5w20 (Mobil's dino) vs. M1 0w20 at 0*F?
Thanks...and sorry for my ignorance.

https://www.mobil.com/english-us/passenger-vehicle-lube/pds/glxxmobil-1-0w20
http://mobil.moovelub.com/sites/default/files/mobil_supertm_synthetic.pdf
MRV's, translated to "Poise", so you can follow them on the charts.
Code:


Temp M1 0W20 super 0W20 SUPER 5w20

-40C 92 268

-35C 45 (est) 130 (EST) 132 (EST)

-30C 22 (est) 65 (EST) 65 (est)

-25C 11 (est) 30 (est) 30 (EST)

-20c 5 (EST) 15 (EST) 15 (EST)

-15c 3 (est) 8 (est) 8 (est)


0F is -18C...not much difference between them.
at -40 (C or F), quite a bit.

 

[tig1]

Originally Posted By: Shannow
Originally Posted By: tig1
Originally Posted By: PimTac
The biases between thin and thick just never end


Also the era of time makes a difference what's considered thick and what's thin.


Especially when, as we've discussed before, the 20s in the 60s and 70s had HTHS values equivalent to an ILSAC 30 under the current J300...


And that makes no difference today. In yesteryear fuel contamination was a much bigger problem than today. But that doesn't have anything to do with today. In that day a 20 wt oil was thin compared to 40wt at that time when in some circles 30wt were considered too thin. The times they are a changing.

 

[Panzerman]

Fuel dilution was a bigger issue with carbureted cars but emmissions was not and what used to go out the tail pipe is now trapped in the engine to get dumped into the oil so I would say it's awash on that. Better oil, better additives but higher operating temperatures, more turbos and emmissions not allowed to leave makes up for it.

 

[StevieC]

When I ran 10w30 conventional back before BITOG I had problems even turning the engine over in -30c (-22F) temperatures.
I changed to 5w30 conventional and it also had a hard time at the same temperatures starting but turned over maybe 10 RPM faster if that.

I then found BITOG and learned about synthetics and ran 0w30's, 5w30's and 5w20's and all make for easy starting in these temperatures. I have a hard time seeing the difference between 0w and 5w but there definitely would be if temperatures were colder than -30c (-22F)

That said a lot of OE's do winter testing up here with conventional 5w20 / 5w30's in the winter so any synthetic you run should be more than fine and give you much easier starting in the winter. It saves your starter too.

 

[Shannow]

Originally Posted By: tig1
Originally Posted By: Shannow
Originally Posted By: tig1
Originally Posted By: PimTac
The biases between thin and thick just never end


Also the era of time makes a difference what's considered thick and what's thin.


Especially when, as we've discussed before, the 20s in the 60s and 70s had HTHS values equivalent to an ILSAC 30 under the current J300...


And that makes no difference today. In yesteryear fuel contamination was a much bigger problem than today. But that doesn't have anything to do with today. In that day a 20 wt oil was thin compared to 40wt at that time when in some circles 30wt were considered too thin. The times they are a changing.


Ahh, so they were exaclty the same in the 60s, only they were different...I get it

...no fuel dilution problems these days Okaaaaayyyyyyy...

 

[tig1]

Shannow,
You miss quoted. I actually said" "In yesteryear fuel contamination was a much bigger problem than today". Not" no fuel problems these days". OK...

 

[Shannow]

Originally Posted By: tig1
Shannow,
You miss quoted. I actually said" "In yesteryear fuel contamination was a much bigger problem than today". Not" no fuel problems these days". OK...


You missed the bit where the thread was specifically about 0W and 5W oils for winter before bringing in your regular "I used 20s in the 60s" line....

 

[bigj_16]

Originally Posted By: Shannow
Originally Posted By: Virtus_Probi
I doubt the two are going to be very different at 0F, although I think Shannow has showed some great curves in the past that gave some real numbers for the two across a wide temp range (and were probably killed by the Photobucket change since then).


I've found a new set, and will try to get some off photobucket when I've got time...



This one was good, in that it showed how a bunch of different oils thickened with the cold, affecting delivery times.

Plus had a regression equation for that particular engine in the test cell.



Points of note is that the regression equations are on the crazy end, the cold pumping end, so their absolute use in the freezing and above range aren't there.

Note also, it's in whole poise, not Centipoise.

So take M1 0W40 and M1 5W30 at 0C (I'll just use Cst=Cp, it's close enough).
5.62P versus 6.33P - Delta = 0.71

Delta ROAT - 0.072*0.71 = 0.05sec
Delta 3bar - 0.062*0.71 = 0.04sec

Like I said, the formulae are around the actual measurable part of the curve...in the flat part, there's no difference with a PD pump.


For the cold end, note that J300 MRV (flow to the pickup is about 600P depending on grade), and that MRV halves with every 5C temperature increase roughly.



So, as an example, if MRV is 10000 at -20(C) it will roughly be 5000 at -15(C), correct?

 

[Shannow]

Originally Posted By: bigj_16
So, as an example, if MRV is 10000 at -20(C) it will roughly be 5000 at -15(C), correct?


Very close to it.

 

[bigj_16]

Thanx!

 

[pbm]

Originally Posted By: Shannow
Originally Posted By: pbm
Shannow's graphs are a little over my head....Is it safe for me to assume that a 5w20 is not significantly different than a 0w20 at 0*F?....Let's use Mobil 1 as an example...How about Mobil 1 0w20 vs MS5K 5w20 (Mobil's dino) vs. M1 0w20 at 0*F?
Thanks...and sorry for my ignorance.

https://www.mobil.com/english-us/passenger-vehicle-lube/pds/glxxmobil-1-0w20
http://mobil.moovelub.com/sites/default/files/mobil_supertm_synthetic.pdf
MRV's, translated to "Poise", so you can follow them on the charts.
Code:


Temp M1 0W20 super 0W20 SUPER 5w20

-40C 92 268

-35C 45 (est) 130 (EST) 132 (EST)

-30C 22 (est) 65 (EST) 65 (est)

-25C 11 (est) 30 (est) 30 (EST)

-20c 5 (EST) 15 (EST) 15 (EST)

-15c 3 (est) 8 (est) 8 (est)


0F is -18C...not much difference between them.
at -40 (C or F), quite a bit.



Thanks Shannow:, Now I get it.

 

[Pelican]

I'm reading tings that do not make sense to me!
Why is 0W.... too thin on cold starts compared with 5W.... I'd think that 0W would start the flow faster and thereby lubricate sooner.

I can see how some oil may too thick when hot as in ...W30 vs ...W40 or 50; passages, clearances & tolerances may be too small to allow a thick oil through, but on cold starts the thinner the better IMO. Perhaps someone will explain. Thx

 

[CT8]

Originally Posted By: Pelican
I'm reading tings that do not make sense to me!
Why is 0W.... too thin on cold starts compared with 5W.... I'd think that 0W would start the flow faster and thereby lubricate sooner.

I can see how some oil may too thick when hot as in ...W30 vs ...W40 or 50; passages, clearances & tolerances may be too small to allow a thick oil through, but on cold starts the thinner the better IMO. Perhaps someone will explain. Thx
Clearance is the space between the parts . Tolerances is the allowed variance of the blue print cleatances + or - so much. Oil will go any where when hot . the 0W part flowing fasteri startup depends on the starting temps. What you need to think about is the time it takes for the oil to travel from the sump to the oil pump. These days a 0W-30 and 0W-40 oil will get you from close -40*c to +38* what is not to like

 

[Shannow]

Originally Posted By: Pelican
I can see how some oil may too thick when hot as in ...W30 vs ...W40 or 50; passages, clearances & tolerances may be too small to allow a thick oil through, but on cold starts the thinner the better IMO. Perhaps someone will explain. Thx


With a positive displacement pump doing the oil, it shifts the same volume of oil every revolution...

with oil in it's pumpable range, it takes the same time to fill the galleries, regardless of "W" rating, largely independent of viscosity.

Look at all the curves I posted above, that's the reason that they flatten out.



The above, for a given engine shows full oil pressure at 6 secs for SAE30 at 30F, 6 seconds for 10W30 at 9F, 6 secs for 5W20 at 12 F.

Put all of these oils at 60F, and they'll all take 6 seconds, because that's the time that it takes the pump to fill the engine.

Drop below the readilyy pumpable range, 10F for the 30, -9F for the 10W30, then the pumpability is starting to creep in.

If you are freezing and above, SAE30, or any of the W ratings will get there the same.

0F, vastly different issue, and you need to consider what you need to start.

 

[Pelican]

Originally Posted By: CT8
Originally Posted By: Pelican
I'm reading tings that do not make sense to me!
Why is 0W.... too thin on cold starts compared with 5W.... I'd think that 0W would start the flow faster and thereby lubricate sooner.

I can see how some oil may too thick when hot as in ...W30 vs ...W40 or 50; passages, clearances & tolerances may be too small to allow a thick oil through, but on cold starts the thinner the better IMO. Perhaps someone will explain. Thx
Clearance is the space between the parts . Tolerances is the allowed variance of the blue print cleatances + or - so much. Oil will go any where when hot . the 0W part flowing fasteri startup depends on the starting temps. What you need to think about is the time it takes for the oil to travel from the sump to the oil pump. These days a 0W-30 and 0W-40 oil will get you from close -40*c to +38* what is not to like


That was exactly my point, what's not to like about a 0W... Thanks for the reply CT8.