Why do so many people want to run 0 weight oils?

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Originally Posted By: Gary Allan
Ask him what happens to Canadian Fords using 5w-20 as opposed to Texan Fords using 5w-20.

Do they have lifter issues?

Is a 5w-20 in even a Texas operated Ford anywhere near operating visc for the first 15 minutes or so? Where is it? Somewhere in the 30, 40, or 50 weight range? How about the Canadian Ford?

Those are the conditions you ask to be rationalized/resolved under the proposed "truth".

Ask him if his belief is based on certain year modular engines blowing filters off when heavier oils were used. Ask him if he knows that those engines had defective/dysfunctional relief valves in the oil pumps.

Some people connect the right dots for the wrong reasons.


LOL! Do you know this guy? Don't get me wrong, he's a very apt mechanic, but can be a little close minded at times.

If I can remember and work it into the conversation, I'll try it..
Originally Posted By: d00df00d
Originally Posted By: The_Eric
While we're at it, I have a question... My boss (I work at a small shop) insists on ONLY using listed parts for a given application- which is an admirable trait for the most part. I know he's a little behind the times in terms of oil tech (so am I), but he insists that Ford (I believe) NEEDS to have the 5w-20 oil otherwise problems can arise in the form of lifters doing something out of the sorts (memory is a little fuzzy)... Whatever it is, is definitely bad in his book. I'm not so quick to believe it, but I'm a little more open minded.

Is there any merit to his accusations?

Does he mean that you have to use the FORD brand (Motorcraft) 5w-20? There would be something to that, since it's usually hard (although certainly not impossible) to beat an oil formulated by a company for its own engines.

Otherwise, if he's just obsessing over the viscosity grade, then he's definitely worrying about the wrong thing. He should be obsessing over the Ford approval, not the viscosity grade. Oils of a given viscosity grade can still perform very differently from each other, but the approval means that Ford tested the oil and knows it will work.


No, just that it has the specified grade oil. He'd probably label the Motorcraft oil as "junk" anyways... He's a big Kendall fan. The shop has been using it since 1936.

Originally Posted By: CATERHAM
Right; in other words "don't try to confuse me with the facts, I've already got my mind made up".


LOL- very funny... I'm going to have to use that quote!
 
Originally Posted By: OVERK1LL
Originally Posted By: ekpolk
Originally Posted By: RageOfFury
I got my [censored] kicked in another forum for saying I use 0w30 GC in my Jeep Liberty. They were saying how 0w30 is like water and will mess up the 3.7L in my Jeep.

I just laughed. The 0w30 too thin myth has been dubunked here and elsewhere many times. It's just funny to see people clinging on to old myths.

Thoughts?


I see that others have already responded. I'd just do a screen capture (or block and copy) directly from the specs from the Castrol site. At about 12.5 cSt, GC is, as we all know, on the very thick end of the 30 wt range. Post the data, challenge them to rebut. That ought to do it.


The response will be "I don't care what the sheet says". I've had this argument before. With those who had their mind made up before the conversation even commenced, there is no turning them.

That's exactly how they responded. Said it the spec sheet was all marketing [censored] and that 0W-xx oil is thin as water. I tried my best to show them facts, articles that rebut what they say. They turned nasty, starting insulting me, saying I was preaching [censored]. I decided to leave that Jeep forum. Unbelievable how far they have their head stuck up.

The only car tech forum I'm going to stick with is this one. I've had nothing but good experiences here and you boys and girls know your oil, car tech, tools, etc. Very happy to have found this awesome place.
 
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BuickGN, I think you clearly fixate on the SAE grade without fully appreciating the underlying spec's of the oil.

RL's 5W-20 would have to be classified as a 30wt oil if the published 100C vis spec was a negligible 0.2 cSt higher and every VOA and UOA of this oil I've seen reports a 100C vis in the 30wt range. I compared it to RL's own 0w30 because they have similar HTHS viscosities (3.3 cP vs 3.2 cP respectively) the true measure of an oils operational viscosity not just at 150C.
But the main point of the comparison is to point out that RL's 0w30 is actually lighter at temps as high as 90F. RL's 5W-20 40C vis of 55 cSt is higher than any other 20wt made including all 5W-20 dino's. Yes RL's 0w30 40C vis is marginally higher at 57 cSt but it's much higher VI of 186 vs the paltry 145 of the older 5W-20 formulation is the reason the 0w30 is lighter at all typical start-up temperatures. The break even point as the temps drop is 35C. At 20C (68F) the 0w30 is 8% lighter, at 10C (50F) 14%, and at 0C (32)a whopping 22% lighter and the trend continues as the temps continue to drop.

I'd say anyone who uses a 20wt, particularly a synthetic 20wt
expects it to be lighter than a 30wt at most typical start up temp's. As you can see that's not the case with RL 5W-20 in fact it is on par with most 5w30's.
 
Originally Posted By: CATERHAM
BuickGN, I think you clearly fixate on the SAE grade without fully appreciating the underlying spec's of the oil.

RL's 5W-20 would have to be classified as a 30wt oil if the published 100C vis spec was a negligible 0.2 cSt higher and every VOA and UOA of this oil I've seen reports a 100C vis in the 30wt range. I compared it to RL's own 0w30 because they have similar HTHS viscosities (3.3 cP vs 3.2 cP respectively) the true measure of an oils operational viscosity not just at 150C.
But the main point of the comparison is to point out that RL's 0w30 is actually lighter at temps as high as 90F. RL's 5W-20 40C vis of 55 cSt is higher than any other 20wt made including all 5W-20 dino's. Yes RL's 0w30 40C vis is marginally higher at 57 cSt but it's much higher VI of 186 vs the paltry 145 of the older 5W-20 formulation is the reason the 0w30 is lighter at all typical start-up temperatures. The break even point as the temps drop is 35C. At 20C (68F) the 0w30 is 8% lighter, at 10C (50F) 14%, and at 0C (32)a whopping 22% lighter and the trend continues as the temps continue to drop.

I'd say anyone who uses a 20wt, particularly a synthetic 20wt
expects it to be lighter than a 30wt at most typical start up temp's. As you can see that's not the case with RL 5W-20 in fact it is on par with most 5w30's.


Just about every 20wt is on the thick end of the spectrum. Redline is a little close, so what, it's still a 20wt.

You're completely overlooking the fact that 5w-20 has a lower operating viscosity while having a higher HTHS. Some people want that lower operating viscosity of the 20wt.

Of course as temps get lower the 0w30 is going to at some point be thinner than the 5w-20 that goes without saying.

You guys get so caught up on the warm up viscosity that you put no weight in the operating viscosity.

At 50F, the 0w30 is 14% lighter. Who cares? Do you think you will ever be able to measure the difference whether it be mpg or wear?

Their break even temperature is a normal summer startup temp for me and many people.

Quite honestly I'm too tired to organize this into any sort of readable manner. Maybe later on I'll try and clarify some of this.

I'll just end by saying I understand your point and I agree with you to an extent.
 
Originally Posted By: The_Eric
but he insists that Ford (I believe) NEEDS to have the 5w-20 oil otherwise problems can arise in the form of lifters doing something out of the sorts (memory is a little fuzzy)...


There are no lash aduster issues whatsoever in stock Modulars running a heavier weight oil, especially in trucks. Your boss is dead wrong.

What can happen in Modulars is thicker oils can help to induce lifter pump up which can kick off roller finger followers, but this only happens in race engines that see well upwards of 8000 rpm. It just doesn't happen in engines that operate in the stock RPM range (even Cobras and Mach 1s that see 7000 rpm), and will never be an issue in a 5000 rpm truck engine, not even with a 60 weight. I've known guys that have run 5w30 in 7800 rpm 4Vs with zero pump up issues.
 
Originally Posted By: Ben99GT
Originally Posted By: The_Eric
but he insists that Ford (I believe) NEEDS to have the 5w-20 oil otherwise problems can arise in the form of lifters doing something out of the sorts (memory is a little fuzzy)...


There are no lash aduster issues whatsoever in stock Modulars running a heavier weight oil, especially in trucks. Your boss is dead wrong.

What can happen in Modulars is thicker oils can help to induce lifter pump up which can kick off roller finger followers, but this only happens in race engines that see well upwards of 8000 rpm. It just doesn't happen in engines that operate in the stock RPM range (even Cobras and Mach 1s that see 7000 rpm), and will never be an issue in a 5000 rpm truck engine, not even with a 60 weight. I've known guys that have run 5w30 in 7800 rpm 4Vs with zero pump up issues.


I kinda thought so. I already knew that in a limited sense, too much oil pressure can cause some headaches with lifters- it happened on the wife's Sunfire with a 2.4... Turned out to be a faulty relief valve (so we were told).

Like I said, my memory is a little fuzzy and I well could be confusing Ford for Dodge???? I do know that he said it could cause trouble though...
 
BuickGN, for someone who puts a high value on HTHS viscosity I'm somewhat surprised that you clearly do not understand the relationship between HTHS vis and kinematic viscosity at 100C.

You're statement - "You're completely overlooking the fact that 5W-20 having a lower operating viscosity while having a higher HTHS. Some people want the lower operating viscosity of a 20 wt."

You're discription couldn't be more wrong. You cannot separate the HTHS viscosity from the operational viscosity because oil flows under pressure in an engine.
Or to put it another way, HTHS vis trumps the kinematic viscosity spec at 100C. Kinematic viscosity is not measured under pressure or stress so it correlates poorly to how oil behaves in an engine. HTHS vis is measured at 150C but it's affect applies to more typical operating temps.

RL 5W-20 has HTHS vis of 3.3 cP which is typical of a fairly robust 30wt oil, consiquently that is how it will behave in an engine and this is reflected in the oil pressure which will be higher than many 30 wt oils that have a HTHS vis say in the 3.0cP to 3.1cP area.

And that is why RL says you can frequently drop down a grade, not as you say because the oil flows easier, which would actually result in lower oil pressure, but rather because the oil pressure is significantly higher with RL. Oil pressure is directly related to the HTHS vis as opposed to kinematic viscosity.

If you want to read up on this there is a recent posting titled,
"cSt @ 100C vs HTHS for determining mileage" that discussed the relationship between HTHS vis and Kinematic vis.
 
Originally Posted By: CATERHAM
BuickGN, for someone who puts a high value on HTHS viscosity I'm somewhat surprised that you clearly do not understand the relationship between HTHS vis and kinematic viscosity at 100C.

You're statement - "You're completely overlooking the fact that 5W-20 having a lower operating viscosity while having a higher HTHS. Some people want the lower operating viscosity of a 20 wt."

You're discription couldn't be more wrong. You cannot separate the HTHS viscosity from the operational viscosity because oil flows under pressure in an engine.
Or to put it another way, HTHS vis trumps the kinematic viscosity spec at 100C. Kinematic viscosity is not measured under pressure or stress so it correlates poorly to how oil behaves in an engine. HTHS vis is measured at 150C but it's affect applies to more typical operating temps.

RL 5W-20 has HTHS vis of 3.3 cP which is typical of a fairly robust 30wt oil, consiquently that is how it will behave in an engine and this is reflected in the oil pressure which will be higher than many 30 wt oils that have a HTHS vis say in the 3.0cP to 3.1cP area.

And that is why RL says you can frequently drop down a grade, not as you say because the oil flows easier, which would actually result in lower oil pressure, but rather because the oil pressure is significantly higher with RL. Oil pressure is directly related to the HTHS vis as opposed to kinematic viscosity.

If you want to read up on this there is a recent posting titled,
"cSt @ 100C vs HTHS for determining mileage" that discussed the relationship between HTHS vis and Kinematic vis.


Why does everything have to be an absolute in this forum?

5w-20 with a high HTHS will pump like a 20wt during easy use like flowing through the galleys and making it's way to the bearings and valvetrain. Once under high load and temp in a bearing, ringpack, or a cam and follower, it behaves more like a 30wt.

Oil pumps can sheer an oil and this would be the reason for higher oil pressure with the higher HTHS, not because it doesn't flow as it's grade indicates.

To take it to an extreme, you make it sound like if you had a 20wt and 60wt with the same HTHS, they would flow the same. This is not true.

This is why I always say it's the best of all worlds. Flow like a 20wt, protect like a 30wt.
 
Originally Posted By: Ben99GT
Originally Posted By: The_Eric
but he insists that Ford (I believe) NEEDS to have the 5w-20 oil otherwise problems can arise in the form of lifters doing something out of the sorts (memory is a little fuzzy)...


There are no lash aduster issues whatsoever in stock Modulars running a heavier weight oil, especially in trucks. Your boss is dead wrong.

What can happen in Modulars is thicker oils can help to induce lifter pump up which can kick off roller finger followers, but this only happens in race engines that see well upwards of 8000 rpm. It just doesn't happen in engines that operate in the stock RPM range (even Cobras and Mach 1s that see 7000 rpm), and will never be an issue in a 5000 rpm truck engine, not even with a 60 weight. I've known guys that have run 5w30 in 7800 rpm 4Vs with zero pump up issues.


Talked to him a little today about it. He said he was told that the heavier oil could cause the lifters to not bleed down right and cause a CEL. In extreme cases, he said that it cause the valves to hang open causing the keepers to come loose, then drop a valve... Noting too specific... All very vague and all second hand from a local Ford dealer. Personally I think it's a load of [censored]. Quite frankly, I'm surprised he bought it...
 
The types of lubrication in an engine are hydrodynamic, boundary and mixed. Kinematic viscosity, a steel ball falling through a column of oil under gravity, relates directly to none of those lubrication states.
HTHS viscosity which is measured under pressure is a more accurate and applicable measure and not surprisingly correlates well with the oil pressure you'll see in an engine at operational temps well below 150C.
AT best kinematic viscosity is a loose proxy for operational viscosity and when comparing oils with similar HTHS vis spec's works fine. But when HTHS vis is outside of the normal range of an SAE grade which relies on kinematic vis ratings, then you must make an adjustment. And in that regard, as I said before, HTHS vis trumps the kinematic vis spec at 100C.

To the best of my knowledge, RL's 5W-20 has the highest HTHS of any claimed SAE 20 oil at 3.3 cP. Your comparison to a 60wt is of course nonsense. What I am saying, and I have used RL's 5W-20 in a car with an oil pressure and temp' gauge, is that it behaves like a mid-grade 30wt and in reality that is what it is.

Somewhat unrelated to what I've said regarding comparing HTHS vis to the kinematic vis 100C spec, as I mentioned before, I believe RL is understating somewhat the 100C spec' for their 5W-20 oil just so that they can technically for marketing purposes call it a 20wt and therefore differentiate it from their other two 30wt oils. Keep in mind this oil was developed long before they came out with their 0W-XX range of oils.
 
Well I was out of town tonight. Hit a different Walmart. Aha! They had Mobil One 0w30 on the shelf. Grabbed 2 five qt bottles. Should last a while.
 
Originally Posted By: labman
Well I was out of town tonight. Hit a different Walmart. Aha! They had Mobil One 0w30 on the shelf. Grabbed 2 five qt bottles. Should last a while.

That's the Advance Fuel Economy stuff right? Green label? Because I don't believe there is a vanilla 0w30 M1.
21.gif
 
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Advanced Fuel Economy? Unless you are doing a lot of short trips with a cold engine, how much difference can an 0W make? I am interested in good flow on start up.

When it comes to millage, I would think a 5W-20 would make more difference. Hype?
 
Originally Posted By: CATERHAM
The types of lubrication in an engine are hydrodynamic, boundary and mixed. Kinematic viscosity, a steel ball falling through a column of oil under gravity, relates directly to none of those lubrication states.
HTHS viscosity which is measured under pressure is a more accurate and applicable measure and not surprisingly correlates well with the oil pressure you'll see in an engine at operational temps well below 150C.
AT best kinematic viscosity is a loose proxy for operational viscosity and when comparing oils with similar HTHS vis spec's works fine. But when HTHS vis is outside of the normal range of an SAE grade which relies on kinematic vis ratings, then you must make an adjustment. And in that regard, as I said before, HTHS vis trumps the kinematic vis spec at 100C.

To the best of my knowledge, RL's 5W-20 has the highest HTHS of any claimed SAE 20 oil at 3.3 cP. Your comparison to a 60wt is of course nonsense. What I am saying, and I have used RL's 5W-20 in a car with an oil pressure and temp' gauge, is that it behaves like a mid-grade 30wt and in reality that is what it is.

Somewhat unrelated to what I've said regarding comparing HTHS vis to the kinematic vis 100C spec, as I mentioned before, I believe RL is understating somewhat the 100C spec' for their 5W-20 oil just so that they can technically for marketing purposes call it a 20wt and therefore differentiate it from their other two 30wt oils. Keep in mind this oil was developed long before they came out with their 0W-XX range of oils.



Yes, my 60wt comparison was supposed to be nonsense as you noticed. Just trying to prove a point.

I agree with you more than I disagree about most things but of course what fun would it be discussing only things we agreed on.

I know the 5w-20 behaves like a mid grade 30 in operation and I know this is mostly due to it's high HTHS and the fact that it starts on the very high end of a 30wt.

What I disagree with is your statement that HTHS vis trumps the kinematic vis when it comes to flowability such as how quickly it gets to where it needs to be on a cold start. HTHS has very little impact on how easily oil will flow nearly unrestricted through galleys and even bearings. It just means that once in the bearing it won't give up the viscosity as easy so it acts just like a higher kinematic vis oil *once under load and high heat inside of the bearing/ring pack/cam follower*.
 
What I said was HTHS vis trumps the kinematic vis spec' at 100C, so you've miss quoted me.

As far as flowability is concerned I've already pointed out how uncompetitive RL's 5W-20 is compared to RL's own 0w30 and I further pointed out that it's no better than most 5w30's.

I believe that pretty much covers it, and I'm pleased we agree RL's 5W-20 is for all intents and purposes a mid grade 30wt oil.

Now a question for yourself. Why do you feel it's necessary to run a light 40wt oil (which is what RL's 5w30 is) in a car spec'd for a 5W-20 dino?
 
You know, I really shouldn't respond to an insult like this but what the heck, it's bitog.

Originally Posted By: CATERHAM
What I said was HTHS vis trumps the kinematic vis spec' at 100C, so you've miss quoted me.

I quoted nothing. In what way does "HTHS vis trump the kinematic vis spec' at 100C"?
Originally Posted By: CATERHAM

As far as flowability is concerned I've already pointed out how uncompetitive RL's 5W-20 is compared to RL's own 0w30


You've pointed out nothing but your opinion which is flawed.
RL's 5w-20 still flows better than their 0w30 at summer startup temps. So instead of these blanket statements how about qualifying it with something.

Originally Posted By: CATERHAM

and I further pointed out that it's no better than most 5w30's.

Again, qualify it with something. Redline's 5w-20 has a higher HTHS than most 5w30s. I would say that's a good thing. It's thinner at just about any normal starting temp and operating temp than most 5w30s so how is that "no better than most 5w30s"?
Originally Posted By: CATERHAM

I believe that pretty much covers it, and I'm pleased we agree RL's 5W-20 is for all intents and purposes a mid grade 30wt oil.

I'm not sure to call this one a misquote or an outright lie but it takes balls to say this when what I really said is just a few posts up.
What I said was Redline 5w-20 flows like a 20wt yet behaves and protects like a good 30wt once it's inside the bearing/ringpack/cam or lifter... I'm not sure how and I don't want to know how you got the "5w-20 is a mid grade 30wt oil" from what I said. It's a little scary though.
Originally Posted By: CATERHAM

Now a question for yourself. Why do you feel it's necessary to run a light 40wt oil (which is what RL's 5w30 is) in a car spec'd for a 5W-20 dino?




When I decide to run a 40wt I'll let you know the answer to that. Last I checked a kinematic vis of 10.6@100C puts it right in the light middle range of 30wt territory. There's a FAQ on the homepage if you need help with the SAE specs.
 
Originally Posted By: CATERHAM
I thought we were making some progress but I guess not.

Sometimes a debate goes on and on and nobody wins,

As to why I chose a "0" weight oil,is because it gets [censored] cold here during the winter months.

Bottom line: I wouldn't be afraid to run any "0" weight oil all year long,even in the summer months.
 
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