No, sir. That comment was nothing at all about you, it was about how we talk about oil. I was pointing out that "It acts like № 10 oil when it's cold and it acts like № 30 oil when it's warm" is good for a quick 'n' simple description, but not adequate if we're trying to think in detail about the subject. That's all. Please excuse my poor choice of words.

Any given oil (№ 10, № 30, whatever) will have a characteristic logarithmic viscosity/temperature curve. The oil will thicken as its temperature drops, and it'll thin as its temperature rises. This range of viscosity makes it difficult to have a straight-weight oil that is of optimal effective viscosity across all the operating conditions of a car even in ordinary, non-extreme service in mild weather (starting up the engine from cold...putting it under load when hot...etc).

Multigrade oils have a flatter temperature/viscosity curve: their effective viscosity doesn't change as much with temperature. They don't get as thick as they chill, and they don't get as thin as they heat.

This might sound like just another way of saying the same thing, but it isn't quite.



That is true and correct.



They did, but how does that come in? Oh, did you mean dinosaur juice (conventional oil) when you said "straight oil"? I thought you meant straight-weight oil, since that was the main thing we were talking about.



Formulate a reasonable question about it, and you might get more copies of the reasonable answer you've already had to this question. (Also, you didn't react too well the last time you asked for and received scientific study that poked a hole in one of your pet ideas. I showed you rigourously-collected evidence that K&N "filters" don't filter very well, and you basically stuck your fingers in your ears and went la-la-la-I-can't-hear-you.)



And a real nice history (as you've documented here) of making dumb errors and bad recommendations.



You'll have to go with your gut. Let the record show I have never advised that an oil leak I caused by carelessly assembling an engine should be fixed by whacking the oil pan with a hammer.



Well, no. He's basing his recommendation on what he's been saying and doing for __ years. I'm basing mine on understanding of the science involved. Be careful not to fall into the "I've never had a problem" pit (I've been using 30-weight oil for forty years and I've never had a problem, I've been smoking for 50 years and I'm still here, I've been driving without a seatbelt for my whole life and I've never been in a crash, etc). Why is that a pit? Because I've been swinging my left hand in a horizontal figure-8 four times at 7:17pm every odd Thursday since I was seven, and I haven't been bitten by a crocodile. The one doesn't follow from the other. The guy who's been smoking for half a century has trashed his lungs whether or not he's been diagnosed yet with lung cancer or emphysema. The guy who doesn't believe in seatbelts is playing chicken with fate. The guy who's been using straight-weight oil hasn't measured or noticed the accelerated wear to his engine, but it's still happening. And I haven't been keeping the crocodiles away with my figure-8 swinging.



Nobody ever said that, at least not that I'm aware of. 5W20 is the spec for my daily driver, a 2007 model, all year round. Does that strike me as strange, having driven older models with older specs for many years? Yep, it does. Do I use the 5W20 anyhow? Yep, for a few reasons: (1) the car is new enough that today's oils closely resemble the ones available when the car was engineered and built, and (2) used-oil analysis shows very low wear. So clearly this is the right thing to do.

5W20 and 0W30 didn't exist when your car was new, and the behaviour of 10W30 and other oils at that time was markedly different to that of today's oils of that same grade, in a lot of ways. That's why I said you can't really go wrong following the owner's manual, but build yourself in some more latitude because this is no longer 1980. You have options today that you didn't have in 1980, some of which will do a better job of protecting your engine than could be done in 1980.



You might be interested to read this veteran Chrysler engineer's account of some of the real-world limitations of the oils of the early 1980s.



That's true. And today's gasoline is very different, and today's spark plugs, and we've got much better oil filters, and tires are far better than they used to be, mufflers are available that are much more durable, we've got much better chassis grease, much better engine coolant, much better brake fluid, much better transmission fluid...headlamps...wiper blades...belts...hoses...air filters, etc. As a result, it is possible (and easy) to make our old cars work better than they were able to work back when they were new cars.



You've already demonstrated that you know and understand the answer to this question (flow).



See!



Cold.



Depends on the specific oils in question. It'd be smart to take a good 5W30 over a poor 0W30, for example. But if we're talking about those two grades of the same reputable brand of oil, and an engine in good/new/tight condition, effectively there wouldn't be a cutoff. Again, most engine wear occurs at startup before sufficient oil reaches the critical points. The shorter that grind-time, the less the engine wears, the longer it stays in new/tight condition, the longer you can keep using thinner-weight oils and enjoying the other benefits already mentioned (and some not yet mentioned -- oil pumpability has a large effect on ease of cold-engine startup, and not just at subzero temperatures).



That is true -- and that's what makes their reputation particularly notable: these massively-overbuilt engines managed to last unusually long despite the low-performing oils and dirty-burning gasolines and other primitive technology of the time. These days we expect (and get) Slant-6 type durability from just about any engine and car. The average age of a car on American roads in 1979 was 5.7 years, and that was up from a lower figure in 1969. The 2015 average-age-of-car-on-the-road figure is 11.5 years, that is a little over double the 1979 figure. That's because today's cars are better engineered and built, and because todays' oils (etc) are so much easier on the engines they're used in. . What's unusual and notable these days is the ones that don't hold up well over 100,000 miles without issue.



I presented evidence that they're basically useless as filters. You preached faith. In the end, it's your car to do with as you please. You ask questions, you're gonna get answers. Don't like an answer? Don't use it.



For the same reason they make flat and Philips and Robertson and Torx and Allen and tri-lobe screwdrivers, I reckon.

/out

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Whoa! Some serious misunderstandings here. The "W"weight is entirely
independent of the std. weight, they are two different scales measured
at two different temperatures. The facts of the characteristics are basic
'tho, the farther apart the two weights are, the more thermally stable the
oil is. I've run 0W-40 MobileOne in the turbo cars I drive year 'round, and
15W-50 in the "summer only" ones, regardless of wear/mileage. We're
talking fresh rebuilds to 205K engines here.
As you might have guessed, now cars are running extremely thin oils in
an attempt to wring every 1/10th of a mile per gallon,both to satisfy CAFE
BS & win customers. 0W-20 is the common weight of choice now, but a
few issues have cropped up, mainly an intolerance for anything that ain't
just right. As stated above, straight weight oils belong in nothing these days
except maybe the old lawn tractor,maybe. If you've got an engine so
loose that you've got to run 20W-50 in it to keep the smoke & the leakage
down, it's time for a rebuild dude!

Been following this thread, and would like to ask a question to further my own understanding of the subject.
What does the term "viscosity" use as a referance, as applied to oils?
The flow characteristsics of water, with water being zero? (Although that sounds like comparing apples to oranges.)
And is there a chart somewhere that shows "cold", "mild", or "hot", as applied to recommended viscosities-to-temp ranges?

Roger

The number represents the time that it takes the fluid to flow through a tube a fixed distance through a fixed orifice.
The W does not stand for Weight. It's "Winter."

CJ

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Part of Tyrde-Browne Racing

It is standardization of the measurement of the frictional factor of the fluid
in question compared to others. Water is the -0- standard for specific gravity
/density of other fluids at std. atmosphere & temperature per unit/volume.
Water has the specific gravity of -1.0-, less dense fluids are less than-1-,
denser fluids above-1-. The winter viscosty & std. viscosity are the rel-
ative performance indicators per temp., as I stated above, the farther apart
the numbers are the more stable the lubricant is. As far appropriate for
which temp., each individual application determines what is needed. Keep in mind that oils reach full operating temps as long as the engine does,
regardless of how cold the starting temps are. Thus my preference for
the oils I use.

When we talk about viscosity in engine oils we talk about resistance to flow, pumpability and something called HTHS. All of these are important and all must be addressed individually. Let's touch on pumpability in this post.

Pumpability is tested and certified at different temperatures for different W grades. 20W at -15°C, 15W at -20°C, 10W at -25°C, 5W at -30 C, and 0W at -35°C. So if you live in Atlanta, GA where the average January low temp is 1°C and the historic low of -22°C was reached once in 1985 you really don't need to worry about pumpability of any API certified xW-30 engine oil as they are all 10W or lower. But if you live in North River, ND where the average January low is -19, and it regularly gets colder, then the pumpability starts looking much more important.

So what's available in the real world? Mobil 1 is widely available and so is Arnold Palmer's favorite, Pennzoil.

Looking at a couple of PQIA tests...

Mobil 1 5W-30: http://www.pqiamerica.com/March2013PCMO/mobil1.htm

Pennzoil conventional 5W-30: http://www.pqiamerica.com/Pennzoil.htm

Viscosity @ -30ºC mPa s (cP) 6,600 Max, 4,487 average, 3,937 Mobil 1

Viscosity @ -30ºC mPa s (cP) 6,600 Max, 5,775 average, 6,077 Pennzoil

The conventional 5W-30 is almost twice as viscous at -30°C, but it's still under the limit for a 5W. And the Mobil really is exceptional here. Looking at the 2013 synthetic round up: http://www.pqiamerica.com/March2013PCMO ... final.html We see that only 2 synthetic oils marginally beat the Mobil 1 and both are thinner at 100° C. Mobil did a fantastic job with their 5W-30 as it pumps well and has a very good viscosity index. If 5W-30 were specified for my vehicle and I lived in a cold climate I would probably go right to the Mobil 1 as it's going to give much better cranking performance than the conventional Pennzoil.

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Joshua

Okay, so I was going to write more, but I'd rather be doing other things. Read about viscosity at length here: http://www.kewengineering.co.uk/Auto_oi ... lained.htm

In closing I suggest you look at product data sheets and PQIA tests to see what you're getting. As shown earlier there can be vast differences in cold performance of different 5W-30 oils. And a 0W-30 could very well be more viscous at operating temperature than a conventional 5W-30.

https://mobiloil.com/en/viscosity/0w-30
https://mobiloil.com/en/motor-oils/mobi ... obil-super

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Joshua

Thanks for clarifying-- the way it was written, it seemed pretty condescending.



Errrr....pretty sure I said this.....when I said that a "w" oil "acts like a X weight oil when cold and an X weight oil when warm....they ar gloing for maximum flow across the two operating ranges -- "warm" and "cold".

Of course the question of "how cold is cold" comes back.




No, the "studies" you pointed me toward appeared to be biased, to me, as I had said then.

There are studies that show that certain brands of oil (Amsoil for example) are better than others for whatever reasons. Same with different brands and types of air cleaners.

How did I react? I called BS.

You disregarded my real life usage facts as anecdotal and irrelevant but stand behind studies that many look at as biased, or at least that have results that do not bear out in real world use.

I dont have anything to gain by saying the K&Ns I have used have saved me money and have not resulted in any issues.....whereas some of those "experts" are paid for their "expert opinions". So, excuse me if I don't throw away my real world experience for those folks' opinions.



Now, that's not QUITE fair Dan.

First off you dont know the guy at all.

I had an oil leak. Caused by a problem with the pan gasket or main seal. Poke around on the interweb and there are SCORES of folks who talk about different engine being known for certain things......Yes, I do feel that an engine, freshly and properly assembled, will not leak. That said, he (like you) is human and mistakes happen. And he fixed the problem (replaced the pan gasket and rear main seal).

tell me you never assembled something and had issues or made a mistake.

The only other things I can figure you are talking about is his theory behind using sae3 weight oil and the "tap the oil pan" concept.

The sae 30 thing is nothing new....I have seen many other old timey gear head types say the same thing. They are going on their own personal experience.You condemn them and fools and tout yourself as the professional who knows better. That may be. But there is a point at which the results of "studies" are not relevant in real world situations.

Just like K&N touting that their studies show a horsepower gain by using their product.......I know its marketing hype...no one will feel 2 hp, even if it is true. I use K&N because it saves me money. Period. If by chance there are extra HP for "free", well why not. But I'm not holding my breath.

As for the "tap the pan seal" idea......two other well revered (by me) long time car guys suggested the same thing....."worth a shot, though could make it worse too..." -- that latter part was MY issue.

There are a lot of "tricks of the trade" out there that mechanics use everyday that are not "by the book" and work perfectly fine to solve issues.



Nor did my engine guy. He suggested tapping (different than whacking) along the sealing surface with a hammer, thinking that there could be some area of the pan that could benefit from it, sealing the leak. It might have worked. It might not have.

But if the end result is replacing the pan gasket anyways, why not try it?

We cannot let "doing things right" make us so closed minded that we ignore the "KISS" method as well.




The key there is "what he has been DOING for years".

Science also said many years ago that using leeches on a person would cure almost every malady known to man at the time. The last time I was in the hospital, there wasn't a bucket o' leeches any where to be found.

The same science said that the oil in 1980 was superior to that of the oil in 1930.......probably was....science evolves based on PRACTICE and what the results are in the real world, not just studies. That is why any drug that is developed first must be tested on mammals and then human being trials before the drug is allowed to be sold.....otherwise the "studies" would say the drug works great and we would ALL be guinea pigs from the start (though we probably are to a degree anyways).




Apples to oranges.

The two things have to be related and possible to begin with. Every scientific experiment or conclusion has to take all variables into consideration to be valid. Remove a variable and then you can longer say that it proves or disproves the results.

If you waved your arms in a figure 8 four times at 7:17pm every odd Thursday since you were seven AND you lived on a crocodile farm AND you did so in the croc enclosure, you COULD say that INDEED it worked (or not).

As it stands, you DON'T live anywhere NEAR a crocodile and HAVENT been doing it four times at 7:17pm every odd Thursday since you were seven........soooooo....that "study" is moot.

The folks who did the "K&N filters are bad" "studies" , in my opinion, were biased going in....they were LOOKING for a result and they worked at it till they found it.

My real world usage, so far, supports the manufacturer claims that it filters at least as well as a paper filter when brand new.

That, or EVERY engine I have ever used them on for the past 20+ years LIKES to ingest copious amounts of dirt.

Yeah maybe that's it.




FATE has NOTHING to do with scientific evidence, I agree.

The smoker has MORE OF A CHANCE to get cancer......the guy who doesnt wear seat belts has MORE OF A CHANCE of dying in a car wreck......neither may happen. I have personally seen people die in car wrecks WITH belts on and pack-a-day smokers live to be 100.

The oil argument is not the same animal, at least from my vantage point.

I concede that a study or 100 studies may say that "0w20 oil flows better"....and one COULD extrapolate that better flow= better protection=better engine longevity.

Makes sense.

But one could ALSO extrapolate from those running sae 30 for 40 years in the same engine in the same car ( I personally know a couple of these guys) results in no more wear THAT MATTERS than running 0w20. Of course, their specific variables all factor in.....andTHAT is my point in all this.

I also ride a motorcycle and participate in a motorcycle equivalent of slantsix.org......the "what oil is better" argument is no less ferevently argued there than here.

There are also people who claim to get 40mpg+ and 15,000 miles per set of tires with the same bikes I have been running for 20 years. I get around 30 mpg and more like 8,000 miles per set of tires...........tank after tank of gas, and set after set of tires....consistent real-world data for MY set of variable for 20 years. Who is "wrong"?

As an aside, don't forget that "scientific studies" also are responsible for the "estimated fuel consumption" stickers on new cars.....have bought plenty of those over the years and NEVER have bought a car that gets what the sticker says.....I guess it's my K&N doing that, right? LOL

Scientists also said we would be driving flying cars and living on Mars by now.

Science can be wrong or at least not 100% right.



You recommended 0w30 for cold weather and 5w30 for warm , in my slant 6, in an earlier post.

Going by the "more flow is better" stand you are taking, and if 0w30 flows better when "cold", where "cold" is not defined, then one could extrapolate that 0w30 oil is the cat's meow for ALL situations.

Rather than tell me "it's not that simple", please explain why.



I read it....and I assume you are pointing me towwards the issue of parafins (waxes) in oils and how they related to hydraulic lifters pumping up on non-roller engines.

He also talks about how the design of the engine itself was an issue.....the oil had been around for eons and was fine for older vehicle designs.

New designs for equipment sometimes require new designs for support materials for that equipment.

That's not really news.



The words "make old cars work better" is the issue.

You are mixing durability items --- like spark plugs, wiper blades, tires --- with items that are tougher to prove real world merit for ......the "studies" show that these new fluids are "better" than 40 years ago, but most of the studies are done with new equipment......

Our slant sixes were designed to work fine with the oils and fluids that were available back then.

New engines have way different tolerances and oil systems --- they NEED the "thinner" oils etc. and they have been designed to work that way.

I said it before and will again, I wont just buy, wholesale, the "data" that oil companies or even "independent study groups" put out there.....EVERYTHING is marketing these days.

You talk about oil analysis.

I did this several times on my motorcycle.......at best all they could say was that "there are some higher levels of this" or "low levels of that"......and the kicker at the end of the study was ALWAYS "continued regular oil analysis is recommended to be certain".

At $20 a test, it's no surprise that they recommend further continued testing. LOL

After doing 4 or 5 of these in a row and realizing they were not telling me anything that could help REAL WORLD, I stopped wasting my money. The way I figured it was this.....if by chance I *DID* get a result back saying that I was toasting a bearing, what good would it do me, real world? Not a damn thing. The end result would be "ride it til it dies, then rebuild" either way.



Oh come on Dan.

Yeah, I am saying "what is better -- a crappy 0w30 or a better 5w30". Really? LOL




We are.



Yes



Then why WOULDNT "0W30" or "0W20" be THE ONLY recommendation to make?



No, I said that over numerous vehicles over 20 years, I never had an engine go south due to it sucking dirty air.

That is not "faith". That is "fact".




SO...the "right tool for the job" ? Right?

I can tell someone to use a jewelers hammer to hammer a penny nail....it will work.....but a carpenter's claw hammer would be better, and is tried and true and real world, works best.

Even if a study came out and said that a jewelers hammer could hammer a nail just as well as a hammer in certain situations?

I would keep on using the claw hammer because it is doing what is designed to do, until I was in the provable, real world situation where the jewelers hammer worked better.

The oils of today probably DO in fact offer "better everything" compared to the oils of 1980 or 1960.

But the "W" rating system hasnt changed since 1980. The manual called for 5w when it was really cold, 10w for when it was warmer.

Newer engines NEED the newer abilities of the oil......older engines may benefit from them, or there may be damage done.

Who knows for sure without in depth real world case study?

So, until I see a scientific , multi-case study that compares the various oils in a slant 6 engine long term, I am going the safe route of running 5w30 for the winter and probably switch to 10w30 in the spring , just as the manual says.


As yet another aside, I just looked back at my current post and your last....I just KNOW someone will think "these guys have way too much time on their hands"....LOL .......Truth be told I had an hour to kill. You and I are probbaly the only two reading these,.....LOL :D:D:D:D:D

I like to discuss. As long as it stays civil and no one fancies themself the be-all/end-all expert, it's all in fun. And for the record, I am NO EXPERT.....just a guy who likes to tinker and has had his share of ups and downs....and learning every day from everyone I run across. When we stop learning, we truly deny ourselves growth. No one is the omniscient being but God himself. The rest of us mere mortals have room to learn.

Good stuff!

But.........Not sure I get the math here......Mobil One is 3,947, Pennzoil is 6,077....thats not twice....thats 50% higher......and still within the range of what the 5W30 rating calls for.....or did I miss something?

I think your best point was that WHERE YOU OPERATE THE VEHICLE is key to what makes sense.

Better flow, less wear etc of synthetic is well known.....not just for Mobil 1....for synthetic in general....at least in modern engines.

I have run Mobil 1 in certain newer vehicles for ever.......

Waiting for break in for a while on the slant 6 and may consider running synthetic at some point.....ran it in my Barracuda's 318 and found I had more seepage than with dino oil. Obviously the synthetic finds the nooks and crannies better.

This is what I have been saying....taken from the link at kew engineering....



Or , summed up, "what is your situation?"

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

hi uncle d and other sages- without a doubt this is the longest running car question. been living in se fla for a long time now. daily temp at least 75 mos t days. heres my take on this threads recommendations. figure my uncles(moe and sl6d are mostly correct and on point. have been using conventional name brand 10w30 oil in my fleet. have no complaints. all are well over 100k miles. however if and when i get a new(er) car i may switch to 5w30 or 10w30 in a synthetic name brand b/c not only the words of moe and dan but also the many surveys which have been done say repeatedly that this oil has better flow, pumploading, cleaning ability, longevity and overall lubricating ability than the conventional oils. i only have one concern which i have also heard many times to wit that synthetic oils create leaks in engines in otherwise good shape but which have been used to conventional oils. moe says not to worry about this concern unless engine is already shot and sludged up. would like to hear dans and others critiques of my statement. thanks tons bob f

Synthetic oil I feel is a good choice if the engine in question doesn't contaminate the oil too quickly. The fuel and ignition systems need to be spot on and the engine in good mechanical condition. Otherwise you will need to change the oil based on contamination long before a synthetic has paid for itself in most daily driver scenarios. Conventional oils are better than ever and you can get great results with nothing more exotic than Chevron Supreme.

If sludge and varnish are keeping the oil in the motor then you're risking oil leaks by running detergent oils. Synthetic will seep more than conventional, but it rarely causes leaks.

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Joshua

hi joshie- think your comments are good advice on synthetic earls. if synthetics loosen up sludge from a shot and sludged engine that would lead to a leak, doom the engine and cause a po man to ride # 7 bus to work from stinking creek. think i will start using synthetic 10w30 in the next new car her in fla. today oddly it is 50 degrees in se fla., a rarity. leaning toward a corolla or sonata w/ 3 floor pedals. is my judgment flawed? regards bob f

Bob,

About 2 years ago I bought a new Nissan Frontier with a 4 cylinder and 3 pedals. It had to be brought in from out of state. Anyhow... With this truck I have used both conventional oil and synthetic and received one oil analysis for each type as part of a Pennzoil promotion. For the warranty mandated 5k mile oil change interval (OCI) the conventional oil did great. Now that the 30k mile warranty is in the past I have switched to synthetic and extended the oil change interval to 7,500 miles. I will probably stay with a 7.5k OCI unless I start driving the truck a lot more (as of 12/5 I have a company truck and so the Frontier sits too much) and see with oil analysis that a 10k OCI is fine. I've already switched the wife's '04 Corolla to a 10k OCI with Mobil 1 Extended Performance. My '03 Miata is on a short (~3k mi) OCI with conventional as it's new to me. It will probably then get the same diet as the Corolla. What do these vehicles all have in common? They are all EFI, OBD II and distributor-less. All use 5W-30. Clean combustion and good cylinder seal reduces oil contamination a lot.

If I ever get my '54 Dodge, with manual choke and point ignition, on the road I'll probably change the oil with 15W-40 Delo 400 every 3k or annually.

10W-30 synthetic will probably be hard to find at quick lubes and dealers and 5W-30 is more than fine. Modern automatics are generally excellent, but buy what you want. I did. Thankfully my Nissan didn't have to be ordered so I didn't have to pay full sticker price.

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Joshua