thin perhaps not as good as i thought

[Trav]

Quote:
Nice try

Try at what and to whom? You?

If i needed to apologize for something i have no problem with that but i don't have anything to apologize for.
Now go do what other kids do when they aren't in school.

 

[PSE]

Originally Posted By: demarpaint
Wow we're drifting a bit, this time the drift wasn't caused by me. LOL

I was looking for an answer for this hopefully someone with an engineering or mechanical background and not from a Google search.

I'll ask again.

Just out of curiosity how much more of a safety margin would a 30 grade oil provide over a 20 grade oil when a radiator hose lets go? Is there any testing that can be done to calculate at what extreme bearing temperature the different thicker or thinner oils have a real world advantage? Would the safety margin you mentioned in another thread allow you to run the engine any longer w/o damage using a thicker, or thinner oil? Just to be fair lets compare oils from 2012, since most of us don't have 10 or 20 year old oil in our stash that we use in our cars. Thanks

Hopefully an answer to my question will help me become my analytical self, with a

The higher vis oil will not provide much advantage in the situation you are describing but that's not why it was spec'ed in the first place.

 

[demarpaint]

Originally Posted By: PSE
Originally Posted By: demarpaint
Wow we're drifting a bit, this time the drift wasn't caused by me. LOL

I was looking for an answer for this hopefully someone with an engineering or mechanical background and not from a Google search.

I'll ask again.

Just out of curiosity how much more of a safety margin would a 30 grade oil provide over a 20 grade oil when a radiator hose lets go? Is there any testing that can be done to calculate at what extreme bearing temperature the different thicker or thinner oils have a real world advantage? Would the safety margin you mentioned in another thread allow you to run the engine any longer w/o damage using a thicker, or thinner oil? Just to be fair lets compare oils from 2012, since most of us don't have 10 or 20 year old oil in our stash that we use in our cars. Thanks

Hopefully an answer to my question will help me become my analytical self, with a

The higher vis oil will not provide much advantage in the situation you are describing but that's not why it was spec'ed in the first place.


Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks

 

[Sayjac]

Quote:
Back on topic please.
Quote:
Try at what and to whom?

Please.

 

[cp3]

Originally Posted By: demarpaint

Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks


To be technical, he did say "not much". Realistically we're not talking much of a difference to begin with, right? So once the temps start to climb that margin of difference is probably passed through fairly quickly, I would think.

 

[PSE]

Originally Posted By: demarpaint
Originally Posted By: PSE
Originally Posted By: demarpaint
Wow we're drifting a bit, this time the drift wasn't caused by me. LOL

I was looking for an answer for this hopefully someone with an engineering or mechanical background and not from a Google search.

I'll ask again.

Just out of curiosity how much more of a safety margin would a 30 grade oil provide over a 20 grade oil when a radiator hose lets go? Is there any testing that can be done to calculate at what extreme bearing temperature the different thicker or thinner oils have a real world advantage? Would the safety margin you mentioned in another thread allow you to run the engine any longer w/o damage using a thicker, or thinner oil? Just to be fair lets compare oils from 2012, since most of us don't have 10 or 20 year old oil in our stash that we use in our cars. Thanks

Hopefully an answer to my question will help me become my analytical self, with a

The higher vis oil will not provide much advantage in the situation you are describing but that's not why it was spec'ed in the first place.


Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks


Engine oil is not intended as a coolant for overheating components. If there is any benefit of the higher viscosty in this situation, it wouldn't be by design.

 

[demarpaint]

Originally Posted By: PSE
Originally Posted By: demarpaint
Originally Posted By: PSE
Originally Posted By: demarpaint
Wow we're drifting a bit, this time the drift wasn't caused by me. LOL

I was looking for an answer for this hopefully someone with an engineering or mechanical background and not from a Google search.

I'll ask again.

Just out of curiosity how much more of a safety margin would a 30 grade oil provide over a 20 grade oil when a radiator hose lets go? Is there any testing that can be done to calculate at what extreme bearing temperature the different thicker or thinner oils have a real world advantage? Would the safety margin you mentioned in another thread allow you to run the engine any longer w/o damage using a thicker, or thinner oil? Just to be fair lets compare oils from 2012, since most of us don't have 10 or 20 year old oil in our stash that we use in our cars. Thanks

Hopefully an answer to my question will help me become my analytical self, with a

The higher vis oil will not provide much advantage in the situation you are describing but that's not why it was spec'ed in the first place.


Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks


Engine oil is not intended as a coolant for overheating components. If there is any benefit of the higher viscosty in this situation, it wouldn't be by design.


Oil does cool engine internals, however it is not the same as coolant. My question is what happens if something goes wrong? Does the thicker oil help at all?

 

[friendly_jacek]

Originally Posted By: Trav

Lets take two examples.
Toyota and VW. Both have good engineering departments no one questions that, so how did it happen that both were cursed with such a massive sludge problem in their engines when owners followed their equally well engineered OLM using spec oil?

Its certain the Toyota and VW engineers ran the engines with spec oil in all conditions they thought the engine would encounter and with the recommended OCI. So what went wrong?

The answer is a simple one and it has nothing to do with poor engineering. It was a failure in every other department after the engineers were done.
The bean counters concluded a smaller pan would be just as good.
The marketing dept concluded that an even longer OCI would make their car appear less maintenance needy.
Management had a desire to appear "green" to the consumer.


Do you know that for a fact? My theory is they tested their engines on quality reference oils and problems started when users fed them the low quality API SL oils of the time. I did UOA once in corolla that showed 10W30 SL oil thickening to SAE40 in mere 5000 miles. That car had specified OCI at 7500 miles. I obviously didn't follow that.

 

[Trav]

Quote:
Do you know that for a fact?

Yes i do, i was there. The police/State dept vehicles (300 for that whole area) ran full factory spec oil at the manufactures interval for severe service as recommend by them.
Sludge was a very serious issue not only in that area but nation wide.

Many Toyota 3.0 engines that were dealer maintained also had issues not just the ones where the consumer did the OC, my daughters was one of them.
I wasn't where she lives to do the service or look at the engine.

 

[KrisZ]

Originally Posted By: demarpaint
Originally Posted By: PSE
Engine oil is not intended as a coolant for overheating components. If there is any benefit of the higher viscosty in this situation, it wouldn't be by design.


Oil does cool engine internals, however it is not the same as coolant. My question is what happens if something goes wrong? Does the thicker oil help at all?


This is very interesting because the extra marigin of protection is usually brought up in synthetic vs dino threads and the point is made that this is one of the advantages of synthetic oil. Now, it seems that this extra protection is being argued as not a big deal.

I have a feeling that in both cases the extra "room" is probably marginal, but it's pretty funny that it's an important factor in synthetic vs dino case, but not so much in thick vs thin.

 

[JAG]

If an engine blows its coolant hose and oil temperatures rise very high, a thicker oil will keep the bearings in the hydrodynamic lubrication regime to a higher temperature than a thinner oil that is otherwise formulated very similarly.

 

[demarpaint]

Originally Posted By: JAG
If an engine blows its coolant hose and oil temperatures rise very high, a thicker oil will keep the bearings in the hydrodynamic lubrication regime to a higher temperature than a thinner oil that is otherwise formulated very similarly.


That's what reading lead to believe I just wanted to confirm it. Thanks the reply.

 

[friendly_jacek]

Originally Posted By: Trav
Quote:
Do you know that for a fact?

Yes i do, i was there. The police/State dept vehicles (300 for that whole area) ran full factory spec oil at the manufactures interval for severe service as recommend by them.
Sludge was a very serious issue not only in that area but nation wide.

Many Toyota 3.0 engines that were dealer maintained also had issues not just the ones where the consumer did the OC, my daughters was one of them.
I wasn't where she lives to do the service or look at the engine.


Dude, I'm not talking whether sludge exists or not. I'm talking causes here.

 

[il_signore97]

Originally Posted By: Garak


Absolutely - match the weather and driving conditions to the oil choice, no big deal. That being said, folks, tonight my car was outside in ambient -16 C for a few hours. Dino 5w-30 didn't make any odd noises or fire a rod through my block upon starting it. And this will not be the coldest night of the year by a long shot.



You guys definitely beat us to it this year (again)! We're enjoying a balmy 1C on average these evenings. Lucky us

 

[il_signore97]

Originally Posted By: demarpaint

Just out of curiosity how much more of a safety margin would a 30 grade oil provide over a 20 grade oil when a radiator hose lets go? Is there any testing that can be done to calculate at what extreme bearing temperature the different thicker or thinner oils have a real world advantage? Would the safety margin you mentioned in another thread allow you to run the engine any longer w/o damage using a thicker, or thinner oil?



In my opinion, if you blow a coolant hose, you will need to get the car to the side quickly and shut it off to prevent damage. While I absolutely agree with JAG in that a thicker oil will prolong the onset of mixed lubrication in the bearings and cylinder walls while temps rise, the real damage from blowing a coolant hose is going to be in the form of a warped cylinder head, of which no oil can prevent. Also, the oil temp may not rise as quickly as one would think due to relatively poor heat transfer compared to coolant, especially considering where most of the heat comes from in the first place (cylinder head and cylinder bores).

Some vehicles (notably GM vehicles) have a special mode programmed into the ECU in which the vehicle can run indefinitely under light load with no coolant at all. It does this by selectively misfiring cylinders to give them a chance to cool and to even out the heat to prevent head warping. In my opinion, I would not rely on such a system, but (thankfully) I have never tested it in my Chev Venture!

 

[uart]

Originally Posted By: PSE
Originally Posted By: demarpaint

Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks


Engine oil is not intended as a coolant for overheating components. If there is any benefit of the higher viscosity in this situation, it wouldn't be by design.

I believe he was referring to thicker oil providing some margin in increased temperature before it reaches the point where it thins too much to provide effective lubrication.

JOD described the effect of thinner oil in a previous post as (very slightly) reducing wear, up to a point where it suddenly doesn't - and then the wear rate increases exponentially. I'm pretty sure that what demarpaint was asking is whether or not a thicker oil provides some kind of safety margin as to the exact point where this exponential increase in wear begins.

I believe that all other thing equal then yes it does.

I also believe that if all other thing are not equal, in particular if the thinner oil is very high VI and therefore thins less with temperature, then this could provide the same safety margin as the thicker oil. Actually I think this is the whole crux of the thin oil acceptance, that better quality synthetic/blend oils with better additives can prove the safety margin that heavier oils previously provided.

Let me repeat however that I think you're correct, that all other things equal (oil type) then the thicker oil would provide more safety margin. This seems to be a case of basic physics.

 

[demarpaint]

Originally Posted By: uart
Originally Posted By: PSE
Originally Posted By: demarpaint

Thicker oil film won't provide an additional margin of protection if things go bad? Is that what you're saying? Thanks


Engine oil is not intended as a coolant for overheating components. If there is any benefit of the higher viscosity in this situation, it wouldn't be by design.

I believe he was referring to thicker oil providing some margin in increased temperature before it reaches the point where it thins too much to provide effective lubrication.

JOD described the effect of thinner oil in a previous post as (very slightly) reducing wear, up to a point where it suddenly doesn't - and then the wear rate increases exponentially. I'm pretty sure that what demarpaint was asking is whether or not a thicker oil provides some kind of safety margin as to the exact point where this exponential increase in wear begins.

I believe that all other thing equal then yes it does.

I also believe that if all other thing are not equal, in particular if the thinner oil is very high VI and therefore thins less with temperature, then this could provide the same safety margin as the thicker oil. Actually I think this is the whole crux of the thin oil acceptance, that better quality synthetic/blend oils with better additives can prove the safety margin that heavier oils previously provided.

Let me repeat however that I think you're correct, that all other things equal (oil type) then the thicker oil would provide more safety margin. This seems to be a case of basic physics.


Thanks for the info. Let me clear things up a bit. Take an API SN 0W20 and an API SN 0W30 and use those to answer my question. Then we could do the same comparison of two API SN dino oils, lets say a 5W20 dino and a 5w30. Same brand of oil for the sake of the discussion.

 

[uart]

This is an "artists impression" of what I was referring to in the previous post. Please don't take it too literally, it's straight out of my imagination. It shows the basic features of how I think the wear rates would look like for different grade oils if all other things were equal. Blue is the thinnest oil and red is the heaviest.

 

[friendly_jacek]

I don't know about this. The thing is BITOG is not exactly about art.

 

[uart]

Originally Posted By: friendly_jacek
I don't know about this. The thing is BITOG is not exactly about art.
Haha

, I understand what you're saying. I felt a bit cheeky even posting that, since it was purely a "made up" graph. It's just meant to illustrate what others have been saying regarding the effect of viscosity upon wear rates. To illustrate the general features of this relationship. Read my previous post (two posts before it) to put it into context.