What is the best oil ingredient to protect against cold start wear?

[ABN_CBT_ENGR]

Yes, I agree, which is why I found it interesting that the AMC/Jeep 4.0L was a particularly sensitive case, I assume due to what you've touched-on in your post.

Exactly, and obviously this is not to say that colder oils don't bring problems to the table- they do and that's a fact.

That said,

Many of the problems attributed to cold oil aren't. That too is a fact.

Remember basic physical science and physics- if the compound is in a liquid state at all, it will flow,. Then its a question of the power required to make it flow.

A PD gear pump "has that power" so if its built right and turning with the starter- its got the NPSH to lift that fluid what amounts to about an inch (horizontal doesn't matter) and will do so with full force and in a fraction of a second.

By virtue of the gear mesh it will also impart mechanical shear and heat into the fluid so its warming as it moves.

If the oil ever reached a state where it would take more force than the pump can generate, then ZERO oil moves and will NOT "move" until someone thaws it. If that were the case the engine would lock up in just a second or two so there would be no need to thaw the oil then.

It wouldn't clunk, clunk and eventually smooth out- that's a sign right there that the oil was fluid enough to be picked up and pumped.

 

[kschachn]

Absolutely, and I respectfully invite you or anyone else to demonstrate otherwise with a real world example

Here is a reference to the issue. Since you have peers in the SAE I'd expect that you can find out background information and perhaps even symposium proceedings around that time. It shouldn't be too difficult.

https://www.lubesngreases.com/magazine/automotive-183/

 

[ABN_CBT_ENGR]

Here is a reference to the issue. Since you have peers in the SAE I'd expect that you can find out background information and perhaps even symposium proceedings around that time. It shouldn't be too difficult.

https://www.lubesngreases.com/magazine/automotive-183/

No, you just made my case and point.

The oil failed a lab test- not a real world condition. That ground has been long plowed

 

[kschachn]

It was indeed a real-world condition, that's what initiated the inquiry. What are you reading?

 

[ABN_CBT_ENGR]

It was indeed a real-world condition, that's what initiated the inquiry. What are you reading?

The article you linked ( and already familiar with the subject before)

Its all about testing to meet a standard and neither the test nor the standard represent or replicate real world conditions in a true PD ump system under actual conditions.

There is one vague reference >"For the next two years, there was an outbreak of low-temperature pumping failures in the field." and nothing more. Theres not enough there to even ask questions about.

The entire article was a series of words saying little of value

 

[kschachn]

Oh you were already familiar with it, is that why we had the long discussion here?

One is free to interpret things in their own way of course in order to cast the most positive light.

 

[ABN_CBT_ENGR]

Oh you were already familiar with it, is that why we had the long discussion here?

One is free to interpret things in their own way of course in order to cast the most positive light.

Yes, familiar with the subject matter, not the article proper. ( had this similar discussion many times over the years)

Its not about interpretation, its about not reading things into the data that the data doesn't suggest or state.

Its also then about comparing that data (and conclusions drawn from it) against other hard data.

The article is a generalized puff piece, not a technical analysis.

I respectfully invite you to show me the technical part if I missed it that contradicted anything I posted on the subject in context.

 

[CKN]

But they're not all exactly the same, and if some folks weren't interested in the finer details this site wouldn't get much traffic.

And by "cold start" I don't mean winter necessarily, I mean after not having been driven recently.

True...but your motor isn't going to blow up using any oil specified for your vehicle/application. So there you go..................

Useless topic of the day.......................

 

[kschachn]

Yes, familiar with the subject matter, not the article proper. ( had this similar discussion many times over the years)

Its not about interpretation, its about not reading things into the data that the data doesn't suggest or state.

Its also then about comparing that data (and conclusions drawn from it) against other hard data.

The article is a generalized puff piece, not a technical analysis.

I respectfully invite you to show me the technical part if I missed it that contradicted anything I posted on the subject in context.

What other "hard data" are we talking about here? You mean something that conclusively shows that the oil did not gel under shear in the vicinity of the oil pump pickup tube and cause the engine to fail? I'm the one who missed that if you posted it.

Despite your uncorroborated assertion to the contrary I'll take the word of the SAE (and the resulting revision to J300) before I believe someone random on the Internet. But maybe that's just me. Somehow I think that's the actual issue here rather than anything technical or calls for "real world examples". I'm still a little unsure why you don't just ask your peers in SAE for proceedings or presented papers.

 

[Snagglefoot]

Here is a real world situation. Ford has released their oil recommendations for their 6.7 Turbodiesel in the 2020 Ford owners manual. This is a 475 HP diesel with over 1000 ft lbs of torque. At temps below -20 F they are recommending a 0w40, not a 5w40. Yeah they will both pump but be my guest and try it with your own diesel. You might be pleasantly surprised.

 

[Oildudeny]

Correct oil grade and a block warmer if necessary.

 

[RazorsEdge]

Correct oil grade and a block warmer if necessary.

Living in the Midwest it gets very cold, especially in January and February. I just used synthetic oil,good battery and a engine heater.

 

[Oildudeny]

Living in the Midwest it gets very cold, especially in January and February. I just used synthetic oil,good battery and a engine heater.

you'll be alright

 

[CR94]

... Remember basic physical science and physics- if the compound is in a liquid state at all, it will flow,. Then its a question of the power required to make it flow.
...
If the oil ever reached a state where it would take more force than the pump can generate, then ZERO oil moves and will NOT "move" until someone thaws it. ...

That all misses the point. The problem occurs when the oil reaches a state such that gravity can not generate enough shear stress to deliver oil to the pump entrance. That has nothing to do with "power required to make it flow" through and beyond the pump.

 

[bbhero]

All I can say is.... I saw that show on the Weather channel in northwestern territories of Canada about those guys flying airplanes of like darn near WW II vintage running a pretty heavy oil for those old piston engines.... And like ABT said..... They had to thaw out that oil enough to even think of starting those engines on that plane. Because that oil was frozen at like -45. ( Don't know what oil was in those airplanes.... surely wasn't Castrol 0w40 evidently ) Engines were wrapped with a heavy cover and heaters applied for quite a while before they could even think of starting those engines.

 

[PimTac]

All I can say is.... I saw that show on the Weather channel in northwestern territories of Canada about those guys flying airplanes of like darn near WW II vintage running a pretty heavy oil for those old piston engines.... And like ABT said..... They had to thaw out that oil enough to even think of starting those engines on that plane. Because that oil was frozen at like -45. ( Don't know what oil was in those airplanes.... surely wasn't Castrol 0w40 evidently ) Engines were wrapped with a heavy cover and heaters applied for quite a while before they could even think of starting those engines.

Those conditions are brutal. The temperature is bad enough but the winds exacerbate the issue.

 

[ABN_CBT_ENGR]

That all misses the point. The problem occurs when the oil reaches a state such that gravity can not generate enough shear stress to deliver oil to the pump entrance. That has nothing to do with "power required to make it flow" through and beyond the pump.

Respectfully, "gravity" has no part ( good or bad) or influence in the pump process. The pump NPSH is all about pressure.

High pressure to low pressure. That applies to all scenarios in this universe and the ICE and engine oils are no exception.

The pump does not "pull" it creates a low pressure area where the fluid pressure combined with the atmosphere pushes the fluid into the void.

Shear stresses and all this other made up stuff has nothing to do with it.

If the fluid in question is not a solid and the pump generates a low pressure zone lower than the combined force of the mass of the fluid being pushed by the force of the local atmosphere over the area then the oil WILL FLOW into the intake. ( it can do nothing else but that)

So, with the conditions as previously set forth above, if the oil doesn't get into the intake, its due to a mechanical issue ( to be determined) and not because of some wax or thickening or whatever.

 

[ka9mnx]

All true. I think he may be referring to atmospheric pressure which moves the oil into the pump.

 

[el Nuke]

Whether it's an additive, or a certain type of base stock, or both.

Titanium? Moly? "Intelligent molecules?" Etc...

There is no answer to this question that won’t result in the thread getting closed. Or perhaps that is the intention of the question all along?

 

[ABN_CBT_ENGR]

What other "hard data" are we talking about here? You mean something that conclusively shows that the oil did not gel under shear in the vicinity of the oil pump pickup tube and cause the engine to fail? I'm the one who missed that if you posted it.

Despite your uncorroborated assertion to the contrary I'll take the word of the SAE (and the resulting revision to J300) before I believe someone random on the Internet. But maybe that's just me. Somehow I think that's the actual issue here rather than anything technical or calls for "real world examples". I'm still a little unsure why you don't just ask your peers in SAE for proceedings or presented papers.

Respectfully, I am just stating facts as they are. I'm not attempting to convince anyone of anything or change anyone's mind.

You mean something that conclusively shows that the oil did not gel under shear in the vicinity of the oil pump pickup tube and cause the engine to fail? I'm the one who missed that if you posted it.

That was part of if. Not the gel part but the actual failure mode part.

Despite your uncorroborated assertion to the contrary I'll take the word of the SAE (and the resulting revision to J300) before I believe someone random on the Internet. But maybe that's just me.

That's fine and to a degree you are getting that now as I have been a professional member (inactive now) and such back in the day for about 40 years and have been one of those doing this. Believe as you see fit but understand that some of that information is less than fully vetted and is a reason SAE is considered very weak in many areas.

I'm still a little unsure why you don't just ask your peers in SAE for proceedings or presented papers.

I don't need to because the process basically is: ( some studies are directly commissioned)

Call for papers or a sponsor> application as author>Review by assigned committee ( which can have some Q&A)> vote>revision>publish

Nowhere in that process is a "validation process" where people rigorously vet everything for accuracy or even functionality ( to a large degree) via a scientific method based process.

That's not different than many other institutions also and I'm not saying anything to denigrate SAE or anything like that.

Just pointing out that having an SAE "stamp of approval" isn't the Holy Grail or final word in anything.