Is 5W-30 in a 5W-20 engine O.K.?

[BuickGN]

Originally Posted By: sayjac
First to answer the OP's question, as said it should be OK to run the 30 weight in your car. That said, it sounds to me like your local dealer, like many, is trying to save money, by having a bulk 5w30 instead of the recommended 5w20.



That's a guess, there's no proof. Maybe the dealership that sees 100s of these cars a month knows something we don't.

Originally Posted By: sayjac

Now for the rest of the urban legend myths being spun by the ever present heavier is better spin doctors. The same heavier is better folks that always point to what the Euro's do. Who cares what they do? Not me.


The point most make when looking at the Europeans is they don't have CAFE to push them into something that may not be in the best interest of longevity of the engine. They are free to use whatever keeps the engine running the longest. They tend to drive harder like some Americans do and they require thicker oils. The other point is I don't see the junkyards full of dead engines from the use of 40wt over there..... see, it works both ways.

Originally Posted By: sayjac

The next move after what the Euro's do deal, is to point out some anecdotal tidbit like cam lobe failure or now even better, total engine failure. That's rich.

And? I've had engine failre from too thin of oil. I've seen it with my own eyes a few times. Do I believe the guy on the internet that has never torn down an engine or do I believe my eyes?
Originally Posted By: sayjac

Of course one of the anecdotal tidbits is spread by the same poster that said to "stay away" from Motorcraft Syn Blend, that it is a "Bad oil" and "Waste of money", so what would you expect?

Go back and read buster's and ekpolk's posts, that spells it out in a nutshell.


Again, they are knowlegable but have they ever torn an engine down or been heavily involved in the racing scene? The standard answer when a newb asks if he can run a 20wt in his non-backspec'd car is an overwhelming yes when most people don't know the first thing about engines. Risking more wear for an immeasurable gas mileage gain is not smart.

 

[FZ1]

No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.

 

[OVERKILL]

Originally Posted By: FZ1
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


Better go tell those 1-million+ mile OTR transport trucks to start blowing up due to their too thick of oil and slow start up flow, not to mention the high friction!

 

[ekpolk]

Originally Posted By: BuickGN
. . .

There are some of us that realize UOAs don't tell the whole story when teardowns show the opposite of what the UOAs showed.

. . .


I didn't say that UOA tell the whole story. But they can and do tell an important part of it. Do you really think that in all those consistently strong UOA, all those engines are suffering wear that conveniently, always escapes detection through one of the primary means of detecting it?

 

[Bryanccfshr]

Originally Posted By: OVERK1LL
Originally Posted By: FZ1
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


Better go tell those 1-million+ mile OTR transport trucks to start blowing up due to their too thick of oil and slow start up flow, not to mention the high friction!


That is seriously taking application and recomendations out of context OVERKILL. AN OTR truck rarely is shutdown having many less cold starts per mile factor than a passenger car, if you were being honest with yourself you would realize this.

Please don't try to justify your personal choices with analogies that are not analogous and simply are misleading. It discredits your position.
I would never recomend anyone vary from factory recomended spec. These take into account duty cycles and design. If you choose to go outside what the factory trecomends for you and american with american oil and gasoline then that is fine. You should be very carefull about being a proponenet of going outside the manufacturere specs and suggesting that others do the same.
Good luck with your personal expiriments but rtealize ...you are on the fringe not the other way around.

 

[ekpolk]

Originally Posted By: BuickGN
. . .
That's a guess, there's no proof. Maybe the dealership that sees 100s of these cars a month knows something we don't.

Except for the member here who works at one, and admitted a day or so ago that they buy bulk 30 because it's cheaper. I don't doubt that for a second.
. . .
Originally Posted By: BuickGN
. . . The other point is I don't see the junkyards full of dead engines from the use of 40wt over there..... see, it works both ways.

It would if we were saying that heavier-than-spec oils were putting you at risk for higher wear. While you may be, that's not the argument here. My position is that the 20s are fine where they're meant to be used, not that using a 40 in a 30 car is dangerous. So no, in this case, it does not cut both ways.

. . .
Originally Posted By: BuickGN
And? I've had engine failre from too thin of oil. I've seen it with my own eyes a few times. Do I believe the guy on the internet that has never torn down an engine or do I believe my eyes?

More info would be required before this statement becomes persuasive. I'm going to guess we're not talking about a Honda Accord or a Ford Fusion being used as intended. Beyond that, how do you isolate the failure to oil? How do you know the oil was not compromised in some manner not its fault? And so on. Rarely are such things so simple.

. . .
Originally Posted By: BuickGN
Again, they are knowlegable but have they ever torn an engine down or been heavily involved in the racing scene? The standard answer when a newb asks if he can run a 20wt in his non-backspec'd car is an overwhelming yes when most people don't know the first thing about engines. Risking more wear for an immeasurable gas mileage gain is not smart.


Can't speak for Buster, but I have seen and been involved in various degrees of engine disassembly, but it has been a long time. Nope, no organized racing. I would hasten to point out that racing (unless it's something special like qualifying) would likely be a place where lower vis oils are a poor choice.

One of the fundamental errors the "thick crowd" makes, in my opinion, is the unspoken assumption that thicker is always better and thinner is always dangerous.

 

[OVERKILL]

Originally Posted By: Bryanccfshr


That is seriously taking application and recomendations out of context OVERKILL.


That was the point. I was being absurd to exemplify the absurdity of the statement that he's killing his engine with cold starts by running a thicker oil.

Quote:
AN OTR truck rarely is shutdown having many less cold starts per mile factor than a passenger car, if you were being honest with yourself you would realize this.


Perhaps sarcasm doesn't translate well over the keyboard?

Quote:
Please don't try to justify your personal choices with analogies that are not analogous and simply are misleading.


But rings perfectly true for my EXACT SAME engine being run in Australia? Come now. I was using sarcasm to draw attention to the absurdity of the statement the person I was replying to was making.

Quote:
It discredits your position.


That is unfortunate. I never realized I had a "position"?

Quote:
I would never recomend anyone vary from factory recomended spec.


Most of the time, neither do I. My 302's both have 40-weight oils spec'd in the manual and my 5.4L is spec'd for 5w40 in Australia.

Quote:
These take into account duty cycles and design. If you choose to go outside what the factory trecomends for you and american with american oil and gasoline then that is fine. You should be very carefull about being a proponenet of going outside the manufacturere specs and suggesting that others do the same.


I have suggested nothing other than common sense. And I am Canadian, not American.

Quote:
Good luck with your personal expiriments but rtealize ...you are on the fringe not the other way around.


The fringe of what, running my engine on the same oil as my engine in Australia????? Lets get a more solid grip on reality here.

I used an "out there" example to exemplify the absurdity of the suggestion that the cold starts were going to kill an engine running a thicker oil!

High friction? Come on. Read back, the post I was replying to was ridiculous.

 

[FZ1]

So,then, you don't agree that a higher weight oil flows less quickly on start up? Further,you don't agree that a higher weight oil has more friction and therefore generates more heat than a thinner oil? Now,that's what I would call.......... Ridiculous!!

 

[OVERKILL]

Originally Posted By: FZ1
So,then, you don't agree that a higher weight oil flows less quickly?


Oil pumps are positive displacement. They don't care if they are pumping roofing tar or water. A heavier oil will simply cause the pump relief to open (or open sooner) by providing more resistance to flow in the oil passages.

Furthermore, the engine already contains oil. My Mustang 302 hasn't been run in 4 years and still has an oily coating on everything under the valve covers.

"DRY" starts are really not. There is a protective coating left by the oil that will easily protect the metal until fresh oil from the pump reaches it.

Quote:
Further,you don't agree that a higher weight oil has more friction and therefore generates more heat than a thinner oil? Now,that's what I would call ridiculous!!


No, I don't. And neither does Ford, otherwise they wouldn't be spec'ing 5w50 for the Ford GT or the GT500.

What the thinner oil DOES do is provide less resistance on the oil pump through ease of pumpability, providing SLIGHTLY less drag, and reducing overall fuel consumption providing a benefit to CAFE. It also does a [censored]-good job of protecting an engine with an oil pump that can provide enough VOLUME through the system to provide adequate protection.

This is the part you don't seem to be "getting". This stuff is application-specific. That is why I brought up my "loony" transport analogy to show how ridiculous your blanket statement was.

There are applications that REQUIRE heavy oil. Most of these applications are high HP and have an intended usage that is far beyond what most people would consider reasonable, or rather, they would consider it ABUSE. The heavier oil offers......

BETTER PROTECTION.

Which I know, is the complete antithesis to your argument here, but I have already provided TWO factory examples as an indicator that OEM's subscribe to this theory as well.

 

[FZ1]

More friction = more heat. Yes or no?

 

[OVERKILL]

Originally Posted By: FZ1
More friction = more heat. Yes or no?


Of course it does.

Now what provides more friction:

1. Inadequate oil volume through a rod journal leading to metal-to-metal contact by running an overly light oil with a pump that is unable to provide adequate volume.

2. Running a slightly heavier oil that doesn't require the same volume of oil to provide the protection, subsequently preventing the metal-to-metal contact and the subsequent bearing failure.

Which scenario provides "more friction"?


You are using viscosity as a single qualifier for "friction" here, where there are far more than one in play.

Pump output volume being a big one for example.........

 

[FZ1]

I'm not talking about what you think happens next. I'm just talking about the oil. Thinner oil flows more quickly at start up and generates less heat.

 

[OVERKILL]

Originally Posted By: FZ1
I'm not talking about what you think happens next. I'm just talking about the oil. Thinner oil flows more quickly at start up and generates less heat.


No no no, you aren't weaselling out of your original statement this easily.

You said:

Quote:
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


You specifically stated that BuickGN is:

1. Risking more wear from slower start up flow.

BUT, there is already oil throughout the engine. And the positive displacement pump means that there is FLOW almost instantly. How many times have you had the valve covers off an engine to observe this?

2. Risking higher heat from higher friction.

And you are stating this to a guy who has already had to put a bottom-end in his turbocharged 3.8L because he ran an oil that was TOO THIN and DID NOT provide ADEQUATE PROTECTION. The HIGHER FRICTION here was the METAL ON METAL that caused his bearings to become toast.

3. Running a higher than OEM-spec'd oil is not smart.

And if his car was stock, perhaps you'd have a point. Unfortunately, his car probably makes more HP than everything you'd owned combined, and subsequently needs more protection than the stock grade of oil provides.


There are QUALIFIERS here. If it was safe to just run 5w20 in EVERYTHING, then we would be seeing Porsche putting it in their cars. We'd see it in the Ford GT, and the GT500. But we DO NOT.

In regards to your most recent point:

1. Thinner oil flows more quickly: Not through the pump. They are POSITIVE DISPLACEMENT, unless the pump is in relief, the VOLUME of oil will be the same. The lighter oil will return to the PAN faster though.

2. ARP makes a lube called ARP moly lube. It has the consistency of a light grease. When ARP spec's a torque spec for a bolt, they list two specs:

a. For a 30-weight engine oil
b. For ARP moly lube

Which do you think has the higher torque value, the "grease" or the oil? Would you be surprised to hear that it is the OIL?

Why? Because the ARP moly lube generates LESS FRICTION under load than a 30-weight oil and subsequently will reach the necessary clamping PSI using less torque than is necessary with a 30-weight engine oil.

A heavier oil that can reduce friction may actually generate LESS heat than a lighter oil that has poor anti-friction properties.

And then you need to consider pumping losses.

In order to maintain adequate protection with a lighter oil, you need more oil VOLUME. This means you need a higher volume pump. This requires more power to spin. This means there is more of your favourite buzzword: FRICTION here.

Ford did NOT back-spec certain engines to 5w20 because the pump was NOT able to provide adequate volume to maintain proper PROTECTION with the lighter oil.

 

[BuickGN]

Originally Posted By: FZ1
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


Startup flow is identical in my setup whether it's a 20w-50 or a 10w-30. I've had pressure guages on the turbo and after the filter. There is no measurable difference so get that out of your head.

As OVERKILL stated, everything is coated before pressure gets there and your hydrodynamic wedge in the bearings is there as soon as the crank moves, before pressure gets there .01 second after startup from the POSITIVE DISPLACEMENT pump.

And also as he stated, what makes more heat, metal to metal friction or a very slight increase in viscosity? You want anyone to take you seriously when you suggest this nonsense?

All this stuff about starup wear sounds like someone's theory that has never been there, done that.

 

[Bryanccfshr]

Your paradigm differs from mine Let's leave it at that. Way to much energy wasted on this topic.

 

[Gary Allan]

Well ...it's a deep subject

My name is Gary Allan ..and I'm an OEM spec violator

Proud user of Bruceblend 0w oils. Always in style and never in stock.

 

[jorton]

Originally Posted By: FZ1
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


Right. Avoid HM 20w-50.

 

[ekpolk]

Originally Posted By: OVERK1LL
. . . If it was safe to just run 5w20 in EVERYTHING, then we would be seeing Porsche putting it in their cars. We'd see it in the Ford GT, and the GT500. But we DO NOT.
. . .


Whoa there! Let's keep it fair now. Who ever said it was OK to blindly run a 20 wt oil in everything, all the time??? Certainly not me, and to my knowledge, none of the thoughful proponents of the use of lighter vis oils in proper circumstances. I doubt even our esteemed Dr. Haas would recommend 20 wt oil for everything.

 

[FZ1]

No,man. Your inference is not necessarily my implication. Reduce your Milligrams.
Originally Posted By: OVERK1LL
Originally Posted By: FZ1
I'm not talking about what you think happens next. I'm just talking about the oil. Thinner oil flows more quickly at start up and generates less heat.


No no no, you aren't weaselling out of your original statement this easily.

You said:

Quote:
No,man. Risking more wear from slower start up flow and higher heat from higher friction caused by a higher than oem spec'd weight is not smart.


You specifically stated that BuickGN is:

1. Risking more wear from slower start up flow.

BUT, there is already oil throughout the engine. And the positive displacement pump means that there is FLOW almost instantly. How many times have you had the valve covers off an engine to observe this?

2. Risking higher heat from higher friction.

And you are stating this to a guy who has already had to put a bottom-end in his turbocharged 3.8L because he ran an oil that was TOO THIN and DID NOT provide ADEQUATE PROTECTION. The HIGHER FRICTION here was the METAL ON METAL that caused his bearings to become toast.

3. Running a higher than OEM-spec'd oil is not smart.

And if his car was stock, perhaps you'd have a point. Unfortunately, his car probably makes more HP than everything you'd owned combined, and subsequently needs more protection than the stock grade of oil provides.


There are QUALIFIERS here. If it was safe to just run 5w20 in EVERYTHING, then we would be seeing Porsche putting it in their cars. We'd see it in the Ford GT, and the GT500. But we DO NOT.

In regards to your most recent point:

1. Thinner oil flows more quickly: Not through the pump. They are POSITIVE DISPLACEMENT, unless the pump is in relief, the VOLUME of oil will be the same. The lighter oil will return to the PAN faster though.

2. ARP makes a lube called ARP moly lube. It has the consistency of a light grease. When ARP spec's a torque spec for a bolt, they list two specs:

a. For a 30-weight engine oil
b. For ARP moly lube

Which do you think has the higher torque value, the "grease" or the oil? Would you be surprised to hear that it is the OIL?

Why? Because the ARP moly lube generates LESS FRICTION under load than a 30-weight oil and subsequently will reach the necessary clamping PSI using less torque than is necessary with a 30-weight engine oil.

A heavier oil that can reduce friction may actually generate LESS heat than a lighter oil that has poor anti-friction properties.

And then you need to consider pumping losses.

In order to maintain adequate protection with a lighter oil, you need more oil VOLUME. This means you need a higher volume pump. This requires more power to spin. This means there is more of your favourite buzzword: FRICTION here.

Ford did NOT back-spec certain engines to 5w20 because the pump was NOT able to provide adequate volume to maintain proper PROTECTION with the lighter oil.

 

[FZ1]

You are right on one point. Unlike you,I've never blown a motor.