Oil for extreme cold

[Garak]

Originally Posted By: PimTac
Considering that 10w-30 or 40 was the go to oil for many years I wonder what the actual gain is of 5w or 0w? Granted, if I was in Minnesota I would probably run the 5 or 0w oil. The big question here is how quick does each weight take to get to the top end of the engine? If we are talking a second or two or even fractions, then it may not be as clear an answer.

If it pumps, it won't make much of a measurable difference. But, given what's available on the shelves, there's simply nothing wrong with running, say, a 5w-XX over a 10w-XX year round. I often say, if someone considers a 5w-30 ILSAC too thin or not robust enough for a certain application, then a 10w-30 ILSAC is hardly the solution.

There's certainly nothing wrong with a 10w-30, generally speaking, but if one is in a position where a 5w-30 is useful at least some of the year, I can't see a lot of reasons not to run the 5w-30 year round. But, as you indicate, the "gain" if you're in a climate where you're not testing those pumpability limits really isn't there.

 

[Shannow]

Only decent correlation I've found in time I've been here is this (and it's engine specific)



Take Rocker Arm Oiling as being delivery to the top end...
7.1 seconds (gallery filling time) + 0.072 times the dynamic viscosity at the test temperture.

Therefore Delta T is 0.072*v, in seconds.

Rough as gutz...at -30C...using the 60,000Cp max (600P), and the halving per 5C rule of thumb.

-30C - for the test engine...at the grade limits for MRV (Mobil Special 10W30 is 1/3 of the absolute limit for the grade, so "beats" the 5W30 calced below)
10W30 - 51 sec
5W30 - 29 sec
0W30 - 18 sec

Don't use the above to extrapolate what a 10W30 would do at -35, like the bottle glug tests...there's other factors at play down there.

At 40C...all the M1 ILSAC grades are immeasurably apart, as the curve is calculated around the steep end...not the flat warm end.

 

[PimTac]

I didn’t realize there was that much difference between those grades. The difference between 0and 5w are quite apart. Thanks for the informative comment.

 

[Shannow]

Originally Posted By: PimTac
I didn’t realize there was that much difference between those grades. The difference between 0and 5w are quite apart. Thanks for the informative comment.


No probs...don't get me wrong with my position on oils.

If I had SAE30 or 15W30 or 10W30s here that met the OEMs specs, I'd be using them continually in my environment...I prefer the balance of the compromises made there.

But IF I was crazy enough to decide to live somewhere that went regularly into the extremes of temperature, I would certainly be SEEKING 5W30s, or 0W30s as the climate dictated...

Here's some more from similar papers.






The regression equations basically tell you the mechanical filling time...plus the (brookfield, used before MRV) viscosity effect...

At "normal" tmerpatures all play the same...when it gets cold (naturally) they differ.

 

[irv]

Originally Posted By: PimTac
I didn’t realize there was that much difference between those grades. The difference between 0and 5w are quite apart. Thanks for the informative comment.


Me neither!

Shannow, do you have any idea how old those tests are? Certainly not disputing it, just curious as I thought with today's oils, especially, that those numbers would be a lot less.

I get a kick out of people saying, imagine if we lived in Canada.

http://twentytwowords.com/guess-how-many...oint-of-canada/
http://barelybad.com/north_of_canada_map.htm

 

[Shannow]

Originally Posted By: irv
Originally Posted By: PimTac
I didn’t realize there was that much difference between those grades. The difference between 0and 5w are quite apart. Thanks for the informative comment.


Me neither!

Shannow, do you have any idea how old those tests are? Certainly not disputing it, just curious as I thought with today's oils, especially, that those numbers would be a lot less.


The numbers are old(ish), Ford 2.3 old but viscosity and physics hasn't changed.

Engine designs ARE changing, in that the fill volumes are less, as oil passages are being made narrower...but then crank driven oil pumps well above sump level are more common than just about anything else these days.

And sumps aren't ANYTHING like the old SBC or Pinto (here's an LS sump from an AWD Commodore)...maybe they need all the pumpability that they can get to suck oil through 3 feet of plumbing.

Really, there's so much residual oil and remnant tribofilm, that I don't think the 10-15 seconds that the oil takes to get up there every single time that you start it is significant to longevity.

 

[Garak]

In addition to what Shannow mentioned, there have been some modifications to SAE J300 over the years, but when an oil is capable of being pumped, it is capable of being pumped. Modifications to SAE J300 have included some specs tightening up, but for reasons of backwards compatibility and to avoid confusion, it's not like a modern SAE 30 is like a hypothetical 0w-20 would have been 30 years ago. SAE J300 wasn't turned on it's head; it was tweaked. I think the KV values changed the least.

 

[Shannow]

One of the problems with restricting to "fresh" stuff is that once a problem is investigated and solved, they don't spend much more time investigating it again.

I can't find ANY papers on flow and gallery filling at 100F...because there's never been an issue with that (well except the Toyota case when the factory fill and service fill didn't play, and the 10W40 plastic oils in the '70s...but they were investigated and solved, and stopped being a problem).

 

[Shannow]

Originally Posted By: Garak
In addition to what Shannow mentioned, there have been some modifications to SAE J300 over the years, but when an oil is capable of being pumped, it is capable of being pumped. Modifications to SAE J300 have included some specs tightening up, but for reasons of backwards compatibility and to avoid confusion, it's not like a modern SAE 30 is like a hypothetical 0w-20 would have been 30 years ago. SAE J300 wasn't turned on it's head; it was tweaked. I think the KV values changed the least.

eg...and I've got heaps more, just got to rescue them from photobucket...






This last one was what Selby (one of the best researchers IMO, who did cold temperature pumping plus HTHS apparent viscosity - find a Selby paper, and you'll thoroughly enjoy it).

 

[3800Series]

I've learned a lot from this and I just wanted to take a moment and thank you all for sharing your time and knowledge with me

 

[Shannow]

All good mate, anytime.