I know that there are different schools of thought on oil visocities....straight versus multiweight...

But I always figured that straight 30 weight is not the ticket for winter use......in a slant 6.

Thoughts?

I use a Good Name brand 10W 30 or Sometimes Mobil 1 0W30

I am sure there are Lots of Varying Facts and Opinions with this subject.

I Perfer the 0w30 in the cold as it has more consistent Oil Press. from Cold start to warm up to full operating temp.

10W30 tends to have super High Oil Pressure when its Below 20*

Greg

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http://www.youtube.com/hyperpack

On the subject of engine oil, there's an enormous amount of ignorance, misinformation, and baseless or thoroughly obsolete advice handed down from dad's dad's dad's dad's dad.

Straight-weight oil has no place in your engine until it is past worn out and you are trying to squeeze every last half-mile out of it.

For a newly-built engine, once it's run in (broken in, bedded in), a reputable major brand of 5W-30 oil year round, preferably synthetic, and a good quality filter. Both changed every 5,000 to 10,000 miles, depending on what kind of driving you do and the results of periodic oil analysis. No additives.

For that same engine in very good shape, driven in very cold temperatures, 0W-30, otherwise same as above. No additives.

For an engine in good but not new shape, 10W-30, otherwise same as above. No additives.

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

Had 0W-30 full synthetic for couple years in a \6 in the past.

Engine has had full rebuild, no major leaks and minimal oil consumption.

Lost one rocker shaft and rockers as the surfaces went bad and valve train become noisy. After 25'000 miles full disaster when the camshaft gear for (high volume) oil pump was totally worn out and broke.

Have used thicker oil since. Usually the same weight with Harley-Davidson.

And no more high volume oil pump either.

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1966 Dart. 170 cu.in. 200 rwhp.

Yeah that is basically what my gut was saying -- didnt want to spoil the "survey" with my opinion...LOL

I have always figured that whatever the manual says as far as weights is what you should go with , as long as the engine is new or in good shape.....for our situation the manual says we can go 10w30 or 5w30 for c older seasons......

I always figured that the "10w" meant that the oil acts like a sae 10 oil when cold and then acts like a 30 weight when warmed up.

Reason I was asking is that we had our car to the shop that rebuilt our engine this summer, to fix the oil leak.

The fellow replaced the main seal and the pan gasket and so far no more oil leak. One small drop dangling, and one on the ground when we had stopped after about 15 minutes of driving on the highway....but none dripped as I stared at it while it was running for a good 30-45 seconds....then my back hurt so I got up off the ground...LOL

We got home and no leaks yet.....so I think he got it.....time will tell. But I know its not leaking anywhere near like it was.

Anyways, I had asked him what oil he put back in it and he said straight 30 weight.

He didnt realize that we plan to drive this all winter.....so we will be swapping the oil out tomorrow for 5w or 10w30.
Thanks to you both!!!!!

I began using synthetic oil since I got my first car in tenth grade, and have been ever since. I always run the grade of oil the factory recommends, since the engineers probably know something I don't.

Exception: when an engine is on its last legs, I'll dump it full of 20W-50 to nurse it along until it expires.

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If it was easy, everybody would be doing it.

Can't really go too far wrong that way, but build yourself in some more lattitude than the manual allows, because this isn't 1980 any more (or 1970, 1960, etc) and today's oils are much better than yesterday's in every way.

The most common mistake is too high a viscosity grade...SAE 30, 20W50, 10W40, 15W40, 9W77, I made that last one up, etc…in the mistaken belief that it "protects better", which it does not. Most engine wear occurs just after startup because the oil has not yet reached all the friction points. Lower viscosity grade = faster oil travel to those points = less engine wear = longer engine life. Also less pumping drag, so less wear and tear on the oil pump and camshaft and timing chain and sprockets, and better fuel economy and engine output.

Anecdotes ("In the past I used such-and-such an oil weight and such-and-such a part on my motor broke, so now I use thicker oil") are not useful for making decisions like this, for a collection of sturdy reasons.



This is dumb mistake number I've-lost-count by this guy, and that's just the ones you've described. Start avoiding him as soon as you can. For now, you're wise to get that grease out of the sump in a hurry and put in appropriate oil. We ought to ask what filter he put on...



Doesn't matter. SAE 30 doesn't belong in it even at the height of summer.

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

I run 5W-30 year round in all my motors, synthetic when I can afford it. I live in a climate that varies from 25-105 degrees fahrenheit (extremes).

My advice is consult the temperature range viscosity chart and pick the oil that matches your conditions. No additives, no overly thick oil, basically go as thin as you can. Always use oil with the API logo on it.

I have never run straight weight oils.....

That said , what I get hung up on is this:

if the "10W" or "5W" portion of a multigrade oil means that it acts like a 10 weight or 5 weight respectively oil in the winter (ie, below 40 degrees) for startup, but the second half means that it acts like a 30W oil once the engine has warmed up anyways, why is a straight weight 30 any different than say a 10w30 in the summer?

Unless the "10W" applies even in the summer when its 80 degrees out for the initial startup?

We are gonna go 5w30 for the winter I think since the engine is new and tolerances are tight, etc and its being driven on 20-30 degree days......then maybe switch to 10w30 in the spring/summer.....

I've been running Mobile1 since the break in was over on my unit and when I took it apart to do the head gasket a couple of weeks ago, there was very little crap inside it. A quick wipe with a rag and it was clean inside.

I run 5-30 only...
I rebuilt this thing about 13 and a half years ago now? About that anyway...

My unit runs roughly 50+ lbs of oil pressure constantly - although when it's hot and sitting at a light in gear, it drops to 45...

Anyway, just my .02 input...

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"I may be slow, but at least I'm not very fast!"
'69 A108 - 225, 727, 3.55, MSD6AL, a.k.a.-the brick

That's a quick 'n' simple way of talking about it, but in real life it's not that simple.



Pumpability, flow on engine startup...the reasons already covered.

We are not talking about a product that goes "Oh, gosh, it's getting colder out; I'd better behave just like a 10-weight oil" or "Yay, summer's here, it's warm out; I'm going to act just like 30-weight oil".



Yep, that's much closer.



0W30.



5W30.

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

Well, yeah it actually kinda does.

My understanding is that the product flows like a 10 weight when "cold" and like a 30 w when "warm".

While not as animated as your suggestion, it IS responding to temperature via its flowabiity......

So I guess what is considered "cold" is the key here.

Because if "warm" is 180-195-200 degrees , as a normal engine would run, seems to reason that at 85 degrees (outside temp) it would flow slower/be harder to pump and at 25 degrees even more slowly/harder and at 10 below even more slowly/harder.........

I agree that oil has changed over the years.....additives etc...and of course synthetics....

But they still use the "W" rating.....and straight oil is still straight oil......and I am using straight oil as they did back when this engine was first built (at least for now)....so why would the factory recommendations (when using regular oil) be any different?

I guess if I lived in an area where its 20 below all the time I would be more worried....and actually probably not driving the old Volare to begin with......but my area normally sees mid 20s to 30s in the winter..... seeing spells of 10s and a few single digits to the positive now and then......and winter cold is only really 2 or 3 months......and usually with warm breaks thrown in for good measure.

0W30 is too alien to me.....as is the straight 30 weight to be honest......never ran either in any vehicle ever.....most vehicles I have owned have called for 10w30......5w30 synthetic we use on the imports and now the Ram hemi.....but those are much tighter engines......even in its rebuilt form, I doubt my slant 6 is as tight tolerance wise as my modern Hemi or the import 4 bangers.......or maybe it is...... who knows.

I figure 5w30 will be a safe bet for the winter around my neck of the woods in our newly redone slant.

Well, no, it kinda really doesn't.



That's a quick 'n' easy description, but by itself it's not enough unless we're just chatting with our gradeschool-age kid, explaining how things work. If we want to understand what's really going on, it doesn't suffice. Your idea of "cold" and "warm" appear to still be getting in the way of your understanding.



Where's that written?



Oil doesn't require faith or belief. You're seriously going to reject an oil grade out of hand, facts notwithstanding, just because you've never used it before, which in turn is probably because it's a recent innovation, and that makes you uncomfortable? Um...does your phone have pushbuttons on it, or are those just a little too alien and you prefer to use a rotary dial?



Yes, it will.

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

Sure seems like you are inferring that I have a grade school understanding of the topic. Trying very hard here to NOT be offended --- and written word can sometimes be misconstrued....so please do explain, then, why its much more complicated than that. Because, the way I see it, in my apparently grade-school like way, is that the basics of it IS in fact that the temperature is the main variable affecting flow when comparing 0w30 oil, 5w30 oil and 10w30 oil and that more flow is "better" Instead of telling me I am wrong, please, the, explain WHY.




Oh...they had synthetic oil widely available in 1980? I remember Arco graphite oil -- but not much else.




I haven't "rejected" anything based on it being alien to me.

It may not require faith or belief, but it DOES require using the proper tool for the job. Just what tool is the "BEST" I guess is the question here.

Show me somewhere--- anywhere --- a body of scientific study that proves that 0W30 oil is now the correct oil to run in a 1980 slant six engine in the winter and that running 10w30 (as prescribed in the documentation that came with the vehicle when originally built) is shown to reduce the life of that engine.

Consider, for a moment, that I am caught between the opinions of two experts.......you, with your decades (40+ I would assume?) of slant six experience....and my builder, with 40+ years of engine building experience.

If experience is the ultimate decision maker, how can it be that you are both at opposite ends of the spectrum?

YOUR OWN PERSONAL EXPERIENCE is what you are BOTH basing your recommendations on.

As am I, albeit that my experience is not as deep as either of you.

I am always willing to learn. So please, teach.

Otherwise, just saying "its the best" is just an opinion, right?

If my idea that temperature is the core issue is too simplistic, why wouldn't 0W30 be the "best" oil for ALL vehicles in ALL sorts of weather?

Just because something is "new and improved" doesn't mean it is necessarily "improved" and "right" for a given situation........there may be absolutely nothing wrong with the "old and unimproved" version.

If you are sitting in a room with 10 other people and you all have cell phones (to use your phone analogy), is it "better" to group-text each other to hold an important conversation or is speaking face to face (the old fashioned way) the "right thing" to do? You will accomplish a conversation either way. And the damn kids do it all the time.....I just laugh at them......but hey, its "new and improved" so they must be right....and in THEIR eyes, it is better, somehow, I guess. For them, maybe it is. For me, not so much.

0W30 wasn't around- or at least not widely available - when the slant 6 was designed, was it? 10w30 and 5w30 was. The engine was designed around THEN current technology.

And by your own argument, oils in general -- including 10W30 and 5W30 oils -- have been improved since then.

So how can you honestly say that 0w30 weight is the "best" way to go for me for winter?

Or are you suggesting that the "W" rating scheme has been substantially revamped since 1980 and that it no longer directly correlates to what was recommended back then?

You argue that it is because 0w30 has the best flowability and lubricity......perhaps it does.....but in what specific sets of variables?

What is the cutoff for using 5w30 versus 0w30 for "winter" use? Someone in the arctic circle, with air temps of -30 degrees and me, with average air temps in the winter of +30 should use the same 0W30?

The slant 6 engine has been called "bulletproof" , "impossible to kill", "runs forever" etc etc etc...and that was established well before synthetics or 0w30 oils were the big thing. Hell, I would bet that there were a LOT of slant 6s that were run on sae30 year round simply because of the "old school, misinformed" folks hanging on to that. My guess is most have run on 10W30 year round.

Something may be "better" but if there is not measurable proof to show that, it really doesn't matter a lot IMHO.

We had a similar discussion around the reusable K&N filters.....K&N filters are not a "new" concept....reusable, oiled filters have been around forever......I believe you argued or at least inferred they will destroy an engine over time....my experience using them in all the vehicles says otherwise. So who is "right"? If you have had an engine destroyed because you used a K&N I guess you can say you are. And since I have never had an engine destroyed because of a K&N I guess I can say I am.

The empirical data in a given situation is where its really at at......and so far my use of K&Ns has saved me a lot of money over the years. So its my tool of choice.

I am all for using the best tool for the job. I would switch to 0W30 on all my vehicles in a heartbeat if there was a proven body of evidence proving that I should ignore the owners manual recommendations and use it.

But I have been around on the interweb long enough to know that "what is the best oil" is just like trying to talk politics or religion....everyone has a closely held opinion that is "right" based on what they have experienced.

Still one has to ask......If 0W30 were the be -all, end all --- if it was the ideal oil for all engines in all scenarios and it made 5W and 10W obsolete.......why would there be anything else available on store shelves the world over?

From my 1980 Volare owner's manual:





And my 2012 Ram manual




Neither even mention 0W30 as being appropriate for any situation. The RAM manual doesnt even have the "range" chart.....5W20 for my hemi year round.

Seeing as manufacturers warranty a vehicle based on using these recommendations, probably a safe bet that they are the safest oil grades/viscosities to use, even if there are "new and improved" options out there.

As with everything on the WWW, "YMMV".

I wont be going to a 0W oil anytime soon. I just am not convinced that it WILL provide any substantial benefits or that it will NOT introduce risk.

Always open to proof though! And I always want the most bang for my buck....... Show me!

Proof is for mathematics. Evidence is found in the scientific and legal arenas. The distinction is important.

If you want evidence of lubrication performance you can start reading here: https://bobistheoilguy.com/forums/ubbth ... -_Gasoline

To find evidence you may be willing to accept you'll probably need to do oil analysis on your own engines and be willing to experiment.

At operating temperature our engines want SAE 30. At lower temperatures a lower viscosity oil flows better and provides better lubrication. Just about any xW-30 available off the shelf will provide greatly increased lubrication performance than what was available at the end of slant 6 production let alone at the beginning.

Your Ram specifies 5W-20 due to the cylinder deactivation system and the SAE 20 is adequate for the rest of the engine. As you show in your owners guide 5W-30 is recommended for heavy duty use. The SRT8 vehicles (no MDS) specified Mobil 1 0W-40 under Chrysler LLC then 5W-40 Pennzoil (FCA) until Shell developed Pennzoil Platinum 0W-40. It's not about the oil clearances, but the duty cycle.

0W-x oils are synthetics so a 0W-30 will cost you more than a 5W-30. It also costs the OEMs more so you find 5W-30 recommended even though 0W-30 is almost always a superior product. Does that superior 0W-30 perform markedly better? Generally no as 5W-30 flows well in most all cases and provides full hydrodynamic lubrication in all the bearings. If the bearings and crank don't touch then they don't produce wear metals.

My Nissan Frontier specifies 5W-30, but I had some left over 0W-40 from BMW ownership so that's in it now. As a 0W-x the oil flows well when cold, but as a 40 when hot the mileage is a little off so I'm going back to 5W-30. I have fuel economy records for the last 25k of driving so I should be able to see the change when going back to xW-30. I'm actually going to mix 1:1 Mobil 1 5W-20 and the rest of my 0W-40 to end up awfully close to 5W-30.

I have used oil analysis results from both conventional and synthetic 5W-30 oils showing negligible difference in wear metals. With the warranty mandated 5k mile oil changes synthetic oil didn't do enough better on wear to justify the expense. The warranty ended at 30k. I am now using synthetic and have extended the oil changes to 7500 miles.

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Joshua