5w-20 and engine longevity

[bruce381]

Quote:
Another thing I find fascinating, is the people who have the most faith in UOAs predicting wear in an engine, totally ignore the great results we've seen in virtually all the 5w20 UOAs.

That is true and UOA's are great and show wear RATES but it do not show any metal fatique stress until a part breaks and stuff goes into the oil.

I do not like 20wt think it is too thin my opinion. 20wt in mind does not offer the same amount of "cushion" to slideing or pounding parts.

I think the best all around motor oil is a good
CI-4/SL 15/40.
Bruce CLS

 

[buster]

http://www.machinerylubrication.com/article_detail.asp?articleid=518&relatedbookgroup=Maintenance

It's so hard to really answer this question because what we are doing is essentially taking one variable that impacts wear, viscosity, and only focusing on that specific variable. Additives, engine design etc. all have to be considered and that is why this "thick vs thin" argument can't be put to rest. I will say that while the UOA's have been among the best with the 20wt oils, most of the people I've spoken too (Redline/Amsoil/Elf etc.) are not big fans of 20wt oils. The link above is old but does suggest 20wt oils are not ideal all the time.

 

[nickmckinney]

20W is super ideal when you dump a full bottle of Valvoline Synpower oil treatment (VSOT) in the pan making it a super friction modified 30W for cheap.

I am still researching this VSOT stuff, so far 3 for 3 on increased city gas mileage of 5~8% confirmed.

 

[bulwnkl]

quote:

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Originally posted by Mitch Alsup:
see the links at : http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=4;t=000494

and click on the article : http://www.iantaylor.org.uk/papers/IMechEFE2000.pdf

At the end of page 20 in a section called "Impact on durability" and at the top of page 21 they discuss the relevent data.

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Interesting links; thanks! What I was referring to, however, was the statement:
"Conversely, overhead cam engines that directly push on the cam buckets don't seem to be able to be engineered to put up with really thin oils. Overhead cam engine with finger followers can be rollerixzed, but nobody does this yet."

I was thinking that the term "finger follower" (the design which the paper says could exhibit high wear even with HTHS>3.5) meant a rocker assembly or other method of following the cam lobe from a distance and thereby multiplying lift. It does not appear to me, superficially at least, that Honda is suffering from an inability to "put up with really thin oils" in their OHC engine designs which use this type of system.

So, what I mean is, am I thinking of the wrong type of system? Or is it the case that only some companies have difficulty engineering low-wear lifter systems in OHC engine designs?

 

[Geoff]

My view is it varies quite extensively by engine design and to a lesser extent, usage patterns.

As an example, the engine in our Land Rover Discovery has a non-roller old style cam/followers and large oil passages. The dealer (factor maintenance program) uses Castrol 20w-50 and there were TSBs that said that "dropping" to 10w-40 was acceptable in colder conditions to aid starting. These engines don't make a lot of oil pressure and rely on the volume thrown up there - the bypass valve kicks in at 50 psi.

US owners report worn cams and valve problems (the lifters bleed down on hot engines with low pressure so the valves don't open enough). You don't hear about these problems from European owners, where 5w-30 is not the convention.

On the CAFE thing, this is definately driving the thin oil programs quickly based on my research. However, engine designs have been generally been updated by these companies through new oiling systems and roller valve trains (eg the Hemi). I agree with the statement that non-roller OHC designs might still be susceptable to lighter grades.

 

[427Z06]

quote:

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Originally posted by buster:
The link above is old but does suggest 20wt oils are not ideal all the time.

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The problem with this article is that it is all theory. I personally would put more faith in information gathered through testing by researchers and manufacturers than a lot of theoretical mumbo jumbo. Reminds me of the time someone "used physics" to prove that a no dragster could accelerate faster than 9.1 seconds in the 1/4 mile.

 

[427Z06]

quote:

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Originally posted by Roger:
In response to the original question, I remember reading that member airbus posted that he has an 01 Civic with 169,000 miles on it and ran all Mobil 1 0W20 oil in the thread, "Those with 150,000 miles or more please check in..."

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This guy?

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=004953;p=9#000215

 

[z917990]

Thank you for your responses. Although all of the theoretical information and your opinions are appreciated, I still wonder if there are any people who have engines with over 100,000 miles using 5w-20, either dino or synthetic. To me, the best proof of the viability (or lack thereof)of this oil is the actual longevity of the engine i.e "real world" experience, not tests done in a lab. I'm not an engineer or a chemist, so much of the technical information is lost on me. Bottom line: does this stuff work or not? Thanks.

 

[cyclic]

Well I have an 05 vehicle and I use 5w20 (MC), I am not the LEAST bit worried about longevity as a friend of mine is a tech at Ford and has seen no ill effects from vehicles with over 160,000 kms that got a diet of Motocraft 5w20. My Trib runs great on 5w20 and the oil warms up faster and cools easier, if you live in hi heat areas, then run a synthetic 5w20 if you're worried. I'll never run anything but 5w20 in my vehicle.

 

[TallPaul]

Once upon a time an auto company could spec 10w30 and it was pretty much good for the entire life of the engine, barring severe abuse. For example, my '95 F150 inline six (123,000 miles) could still run 10w30 but I choose 10w40 to maintain oil pressure in the spec range (40-60 psi @ 2000 rpm).

But with 5w20 spec, I really think there will be cases where an older engine will need to increase the viscosity, but the auto manufacturers never (that I am aware of) give such instruction. But then likely most 5w20 engines will do fine on it--for the warranty period! What does the auto company care beyond that? But the poor sucker that buys a used car that is out of warranty and follows the book could be in for an unpleasant suprise.

Just the other day I ran my F150 so hard (not carrying a load) that my oil pressure with 10w40 fell to what it would be with 10w30! Just think if I had obliviously been runnint 5w20 as Ford back spec'ed for my engine.

 

[Steve S]

quote:

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Originally posted by 1999nick:


Who wants a car to last 400,000 miles, anyway? That is 20 years at 20,000 miles a year. What would the rest of the car look like, inside and out?

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I do ,my 92 toyota p/u has about 113,500 miles ,in 30 more years maybe the odometer will hit 400,000

 

[Mitch Alsup]

quote:

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Originally posted by bulwnkl:
Interesting links; thanks! What I was referring to, however, was the statement:
"Conversely, overhead cam engines that directly push on the cam buckets don't seem to be able to be engineered to put up with really thin oils. Overhead cam engine with finger followers can be rollerixzed, but nobody does this yet."

I was thinking that the term "finger follower" (the design which the paper says could exhibit high wear even with HTHS>3.5) meant a rocker assembly or other method of following the cam lobe from a distance and thereby multiplying lift. It does not appear to me, superficially at least, that Honda is suffering from an inability to "put up with really thin oils" in their OHC engine designs which use this type of system.

So, what I mean is, am I thinking of the wrong type of system? Or is it the case that only some companies have difficulty engineering low-wear lifter systems in OHC engine designs?

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What I really meant is that there are a number of different mechanisms by which valves are actuated. Several of the ones used in engines with high specific outputs* are not ameanable to using really thin oils and achieving long lives in the valve train. Whereas the typical cam-in-block American V8 can use a very thin oil and the valve train is happy as a clam. Therefore, just because some kinds of engine architectures can use thin oils, does not mean that all engine architectured can.

[*] Think about engines with > 100HP/1litre {Ferraris; BMW M3, M5; Porsche GT3, Turbo; Honda S2000; Sport Bikes,...}

 

[1999nick]

quote:

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Originally posted by Steve S:

quote:

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Originally posted by 1999nick:


Who wants a car to last 400,000 miles, anyway? That is 20 years at 20,000 miles a year. What would the rest of the car look like, inside and out?

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I do ,my 92 toyota p/u has about 113,500 miles ,in 30 more years maybe the odometer will hit 400,000

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In 30 more years, I will be 99 years old.

 

[buster]

quote:

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Therefore, just because some kinds of engine architectures can use thin oils, does not mean that all engine architectured can.

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Excellent point. It's simply one variable we are looking at. I called Shell today and asked about the new 0w-20 Hybrid oil and how it compares to the Platinum. He really didn't specify other then it will be thinner at start up. He told me that with his car, under warranty he ran a 5w-20 in his Ford, but after that he switched to a 5w-30. Even among engineers their seems to be hesitation to using 20wt oils.

They have shown to be outstanding on BITOG however and I see no problems with long engine life. The auto engineers test these engines under conditions most of us cannot replicate. Let the UOA's speak for themselves.

 

[Etcetera]

quote:

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Originally posted by z917990:
Thank you for your responses. Although all of the theoretical information and your opinions are appreciated, I still wonder if there are any people who have engines with over 100,000 miles using 5w-20, either dino or synthetic.

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There's a guy who posts on ford-trucks.com with a fleet of grain trucks with v-10's. All of them are over 250,000, always used MC 5w20 with MC filters. All day those trucks drive back and forth carrying 10000 lbs of grain.

Actually there are plenty of guys at the forums at that site with well over 100,000 miles using MC oil.

Eric

 

[427Z06]

quote:

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Originally posted by Mitch Alsup:
Therefore, just because some kinds of engine architectures can use thin oils, does not mean that all engine architectures can.

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Correctomundo. I don't know how many times this has been repeated by myself an others.

Although what makes me laugh is when people try to reverse the logic. Thin oils are bad in some engines, therefore they are bad for all engines.

 

[buster]

quote:

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Correctomundo. I don't know how many times this has been repeated by myself an others.

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Exactly...

I've been a bit hypocritical I guess being I made the choice to run GC, mainly bc of the phenomenal wear #'s it shows, however I do think it's too thick for my application. I was betting on the oil reducing friction low enough that I wouldn't notice it, but I was wrong. I'm going to look into Schaeffer's/M1 5w-20 SM.

To think we know more the engineers who test these oils is a bit ridiculous in all honesty. The testing Motorcraft and Ford did was very stringent. The last thing an auto maker wants is engine failures due to $1.50 qt of oil being used.

And when you take the data from this website, for whatever it's worth, the 20wts are stellar.

 

[Big O Dave]

quote:

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Originally posted by Mitch Alsup:
Therefore, just because some kinds of engine architectures can use thin oils, does not mean that all engine architectured can.

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After reading this wonderful thread, I have to agree with you, Mitch.

My wife's '95 Explorer (4.0L V6) has roller tappets (I'm not sure what type of rockers it has), and thus would likely do okay on 5W-20, right?

My '76 C20 has a '00 Vortec 350 in it with roller tappets and roller rockers, and also seems likely to do well with 5W-20.

My daughter's '05 Focus specs 5W-20, and therefore is VERY likely to do well on it.

Here's the big question: my '83 F250 (460 V8) has flat tappets and sled-type rocker fulcrums. Even though it's an American V8 with the cam in the block, I have to imagine that with flat tappets and sled-type rocker fulcrums it would NOT do too well on 5W-20... am I right? It is spec'd for 5W-30, which is what's in it right now (rinse phase of ARX treatment).

My point is this: it seems that the consensus here is that where there are sliding surfaces to be lubricated (other than pistons in bores), thicker oils protect better, and older engines have such sliding surfaces in their cam-to-tappet and rocker arm fulcrums.

More modern engines have rollerized tappets and rockers, and thus are more tolerant of thinner oils.

Am I interpreting things correctly here?

 

[Drew99GT]

I'd consider using 5w-20 if they bumped the HT/HS viscosity to at least 2.9. That's what scares me. The actual measured viscosity of many 5w-20s, especially Motorcraft and Mobil 1 0w-20 ends up being right at where 5w-30 shear down to after a run in an engine. The question is, as 5w-30 shears down to a 20 weight, does it lose it's HT/HS viscosity as well?

The one analysis that really woke me up was Gman's run of 5w-20 in his minivan. If ya believe UOA tell the tale, then 5w-20 maybe isn't so bad. I ain't tryin it anytime soon unless I can find one (other than Redline) with a higher HS viscosity.

 

[bulwnkl]

quote:

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Originally posted by Mitch Alsup:
Therefore, just because some kinds of engine architectures can use thin oils, does not mean that all engine architectured can.

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Yes, I certainly agree. Thanks for helping clarify what you mean/what I understand.

This still seems to me to be a case of designs having to mesh well with one another. Arbitrarily changing one aspect of design may disrupt the entire system, but designing the whole system to operate with the new aspect you want to change should be no problem at all.