0w vs 5w in a typical winter.... Does it matter?

[JT20]

Before answering I'd like to know what your meaning of "getting roasted" is. Is it you mean that others are roasting me, or that I'm getting heated about it? . Heard it both ways.

Nothing about a feel, but the time it took to make the normal startup revolutions was definitely longer with the 5w, and the difference became larger the colder it got. Yeah nothing scientific here but I did try to time it once or twice.

Yes, lol, what I mean is.. others are roasting you. I get what you mean.

I'll quickly say, because this thread seems like it *wants to* become a dogpile, Steel Cage match, I want no parts of it.. Except to observe, the time you noticed your car spun over easier on one oil than the other, that seems valid to me. You were there. Nobody else was. These people on the Internet, they will presume to know that your car either a. Didn't do what you say it did, or that b. "Well, so what, even if it did, that doesn't matter." Typical if/then arguments. You were there, you know it spun over easier, that's about the end of it.

The best some of the pundits can do is say "Yeah, seems valid to you," or one of about ohh 384 different variants. That's the dogile/UFC Control Of The Octagon part.

You perhaps ruffle some feathers when you SUGGEST that what you FEEL and observe is a criterion for saying you like an oil BETTER, or it is BETTER.

I'm feeling punchy, but wanted to elaborate on that because recently I've had weights lifted off my shoulders, and these victories are mine and mine alone.

Here, you will be judged on your oil and if your observations are not "scientific" (always changing) you will/may/shall be ridiculed.

I'm done now, just thought I would share. Kuato you are cool.

 

[Kuato]

Well, maybe I said it poorly. You don't know WHY you are experiencing the WHAT.

At least two things are in play here, condition of the battery and the oil.

Unless you had the same battery condition during your experiences with both 0W and 5W you cannot say with any certainty that the difference was due to the oil. Ditto for exact same temperatures, exact same quality of electrical connections, condition of the starter, engine, etc.

I'm not saying it's not, I'm saying that unless you had all other variables the same, the two experiences are subject to a host of variables, not just the oil.

I didn't mean to say you didn't know WHAT you were experiencing.

Cool. Yes, all was the same. I started the winter with 5w and when it got really cold and cranking noticeably slowed, switched to 0w.

As I was waiting for the right time (aka not too cold) to make the change, I paid attention to the cranking speed at different temps. After the change (same vehicle, same battery, approx same temps) I did notice it turned over faster.

Now I didn't have any scientific instrumentation that automatically timed the ignition on to all cylinders firing, or anything that showed cranking speed, so sorry to anyone who says my observations are not scientific.

 

[OVERKILL]

Noticeably quicker turnover at cold temperatures with the 0w.

If you've started a car at low temperature you may have noticed how it cranked more slowly and the starter had to work harder than when started when it's hot out.

With a 0w as opposed to a 5w, the vehicle cranked faster.

Once you get down toward the CCS temp for a given Winter rating, that's the entire purpose of it, to set a standard as to a viscosity ceiling to minimize the impact on cranking speed.

For a 5w-xx that's -30C, for a 0w-xx that's -35C. And of course oils are allowed to slip a winter rating in service.

This is where the halving/doubling rule can be used, as just because the standards for visc ceilings are set here doesn't mean that a given engine/battery/starter combo isn't more sensitive than the standard.

So, let's say you had two oils, a 5w30 and a 0w-30. The 5w30 had a CCS visc of 5,800cP and the 0w30 had a CCS visc of 6,200cP and it's -25C.

At that temperature the rough CCS visc for each oil will be:
0w-30: 1,550cP
5w30: 2,900cP

(not adjusting for slip due to age)

So the 0w30 is roughly 1/2 the CCS visc, so yes, somebody could definitely notice that if their combo was more sensitive than the standard.

 

[JT20]

Cool. Yes, all was the same. I started the winter with 5w and when it got really cold and cranking noticeably slowed, switched to 0w.

As I was waiting for the right time (aka not too cold) to make the change, I paid attention to the cranking speed at different temps. After the change (same vehicle, same battery, approx same temps) I did notice it turned over faster.

Now I didn't have any scientific instrumentation that automatically timed the ignition on to all cylinders firing, or anything that showed cranking speed, so sorry to anyone who says it's not scientific.

People chide me too. I used to put Redline in cars. I liked that Redline 0W-20 has an HTHS of the thinnest 30. This means a lot to me. Moving on.

It was very awesome, that in 2 degree, 4 degree.. Im sure it got colder than that a handful of times, but.. I could go out to the car, it would turn over maybe 3-4 times (one turn per cylinder is what I seem to have noticed as having perfect compression. Then sometimes you tuen the key and it just starts like instantly but let us stay focused) and start right up, no engine noise either.

This was incredible to me and this was on the 0W oil.

Now, that is "speculative," perhaps.. I have heard Mobil 1 15W-50 would have yielded the exact same result.. But, was I willing to find out? I went with 0W. And didn't feel like changing my oil, starting the car, changing the oil, putting something else in, and starting it again to compare.

So, basically, I'm saying that I am on your side, and can vouch for that a "feel" isn't as "completely worthless" as some would suggest.

I think it is because they are scientists and tribologists, to be fair, so while I'm not sure it is the same as spitting in one's face, it may lead to some.. chortling, or ruffling of the feathers, if you maybe wanted to see the other side, both sides, etc.

You may PM me at any time, I don't want to take over the thread, quite the opposite, I like that you stated what oil made your car turn over faster. I understand.

 

[PimTac]

Well, this thread is getting ish.

 

[JT20]

 

[Quattro Pete]

I want no parts of it.. Except to observe,

I don't want to take over the thread,

 

[farrarfan1]

As my mother used to say: Some people like to talk just to hear themselves talk.

 

[Snagglefoot]

Don’t freezem.

 

[JT20]

As my mother used to say: Some people like to talk just to hear themselves talk.

See Rush Hour 1, Carter gets Lee from the airport.

 

[PimTac]

I am reminded of this movie scene.

 

[Greasymechtech]

I don't care for pour point. But, the oil needs to return to the pan. And, it definitely gauges the performance of a lubricant at cold temperatures. Its just not a pumping/cranking test which leaves out the return trip to the pump thru smaller engine block drain passages. Doesn't it? Its just not a SAE requirement. Big deal. Dexos isn't an API/ILSAC requirement and VW 508 doesn't cut it for SP/GF6. I'm sad that some thing that only SAE counts and nothing else does.

And, I do understand the inferiority of the cold cranking and pump simulators, and other not useful in the real world testing. I don't just realize it. I've worked with it. Give you a little hint.... some of the MRV/CCS data points were catered, by vote and politics, to make conventional oil more feasible. If API/SAE/ILSAC were serious about certain tests, they wouldn't bow to the politics or automakers. And, automakers wouldn't have to be more serious and come out with their own requirements.

Sometimes the simplest explanation is more useable and viable than CCS/MRV tests. I use a 5w30 synthetic because a 5w30 conventional meeting the specs is pathetic when cold. And, I have no need for a 0w. Maybe when SAE releases 2.5w, 7.5w, and 12.5 ranges, and tightens up the cold CCS/MRV test considerably, I'll give them some merit. Until then, SAE J300 is just a joke in the real world. The engine cranks starts.. big deal.

 

[OVERKILL]

I don't care for pour point. But, the oil needs to return to the pan. And, it definitely gauges the performance of a lubricant at cold temperatures. Its just not a pumping/cranking test which leaves out the return trip to the pump thru smaller engine block drain passages. Doesn't it? Its just not a SAE requirement. Big deal. Dexos isn't an API/ILSAC requirement and VW 508 doesn't cut it for SP/GF6. I'm sad that some thing that only SAE counts and nothing else does.

And, I do understand the inferiority of the cold cranking and pump simulators, and other not useful in the real world testing.

You clearly don't.

If the oil can be pumped, it gets heated by the action of the pump, it gets heated while it passes through the bearings, the oil isn't the viscosity it was in the pan by the time it gets to a location where it needs to go down a return hole.

The first step, the most important step, is that the oil can be pumped. And that's why the MRV test was implemented, because Pour Point didn't properly capture that, that's why a test that actually tests for pumpability was employed.

CCS and MRV actually set viscosity ceilings at two specific temperatures for each Winter rating, whether you "care" for them or not is wholly irrelevant, they are THE standard by which cold performance is measured, you pontificating that it's about politics and "you know stuff" is just blowing smoke. If you disregard the bodies that define the engineering and science by which almost every topic on this board is governed then I am really at a loss as to why you are here. To showcase your ignorance or mistrust for regulating bodies? Bravo I guess? Are you also into the earth being flat and other such nonsense?

 

[4wd]

And what does an MRV measure … ? Shear stress ?

 

[OVERKILL]

And what does an MRV measure … ? Shear stress ?

It's measured with a specific shear stress and is measuring yield stress and viscosity which correlates with the ability to be drawn up the pick-up tube by virtue of a device that's designed to mimic an oil pump.

ASTM paper on the reason for its existence here: https://www.astm.org/DIGITAL_LIBRARY/STP/PAGES/STP19594S.htm

Abstract:

The current ASTM Test Method for Determination of Yield Stress and Apparent Viscosity of Engine Oils at Low Temperature (D4684-89) was designed to cool an engine oil at a rate that will maximize its tendency to form a flow limiting structure. The cooling program development work with the Pumpability Reference Oils (PRO) demonstrated that temperature control and cooling rate could greatly effect the observed viscosity of the test oil. By utilizing this method, all oils with known field problems are identified by exhibition of a yield stress greater than 35 Pa, and/or excessive viscosity at the appropriate test temperature. During the evaluation of cooling rates, it was found that small differences in test temperature resulted in large differences in observed viscosity of temperature sensitive engine oils. This paper shows the importance of closely monitoring and controlling the cooling rate as well as the final test temperature. Inaccuracy of temperature measurement was the largest contributor to measurement error in determining pumping viscosity.

Current standard:
https://www.astm.org/Standards/D4684.htm

 

[wpod]

Why would the 0W make it better?

 

[4wd]

It's measured with a specific shear stress and is measuring yield stress and viscosity which correlates with the ability to be drawn up the pick-up tube by virtue of a device that's designed to mimic an oil pump.

ASTM paper on the reason for its existence here: https://www.astm.org/DIGITAL_LIBRARY/STP/PAGES/STP19594S.htm

Abstract:


Current standard:
https://www.astm.org/Standards/D4684.htm

Good summary … I have actually used viscometers … my question was more of a statement … what I have called shear stress some might call yield stress …
And pump-able is a minimum standard right? … what gets called a PD pump here has no seals similar to a plunger pump - so it’s either dragging or pushing fluid along at a cost of HP when extremely cold. Viscous coupling if you will … So, pump-able is a minimum ? … for some reason R&D types even mention “flow” … but perhaps it’s more like proportional flow … like Exxon’s old UniFlo may have insinuated

 

[OVERKILL]

Good summary … I have actually used viscometers … my question was more of a statement … what I have called shear stress some might call yield stress …
And pump-able is a minimum standard right? … what gets called a PD pump here has no seals similar to a plunger pump - so it’s either dragging or pushing fluid along at a cost of HP when extremely cold. Viscous coupling if you will … So, pump-able is a minimum ? … for some reason R&D types even mention “flow” … but perhaps it’s more like proportional flow … like Exxon’s old UniFlo may have insinuated

Correct, in automotive applications it's a gear-driven pump (single or twin gear) that can, in practice, only create a certain amount of suction for drawing the oil up the pick-up and this standard ensures that to be the case by putting a ceiling on viscosity and yield derived from this test. Oils can, and typically do, a lot better than the limit of the test.

The typical fail appears to be CCS visc, which has a much lower limit.

 

[4wd]

Correct, in automotive applications it's a gear-driven pump (single or twin gear) that can, in practice, only create a certain amount of suction for drawing the oil up the pick-up and this standard ensures that to be the case by putting a ceiling on viscosity and yield derived from this test. Oils can, and typically do, a lot better than the limit of the test.

The typical fail appears to be CCS visc, which has a much lower limit.

Seems the vane pumps are taking over … and since they can alter the axis of symmetry … likely can “gap” enough to push goo with less effort ? Yet shift tight for high volume - hotter oil when needed …

Not hearing about a bunch of failures … so here to stay ?

 

[OVERKILL]

Seems the vane pumps are taking over … and since they can alter the axis of symmetry … likely can “gap” enough to push goo with less effort ? Yet shift tight for high volume - hotter oil when needed …

Not hearing about a bunch of failures … so here to stay ?

Yes, the variable displacement pumps are becoming more popular for sure. I expect they suffer the same suction issue as the gear pumps due to the same issue: Lack of perfect seal, but I must assume that the existing testing methodology sufficiently captures this, hence the lack of revisions. Chasing losses has definitely resulted in some interesting changes and this is one of them.