5W-40 All year round?

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Originally Posted By: Swift101
I appreciate all the input, I'm assuming if they list that oil than it must be safe to use in my engine. They even went so far as to recommend 5W-40 for improved vehicle performance it in the 2011 Manual, see the second to last paragraph.

My manual doesn't have this paragraph but still lists 5W-40, I honestly think it's a fuel economy issue. Remember Hyundai had that MPG fiasco over a year ago, they had to drop the Elantra to 38 from 40MPG. I'm not say it's directly related, but it might have something to do with why the manual was changed. Perhaps they didn't want customers complaining to them about fuel economy.

oil1e.jpg




Straight from Hyundai. Thinner for fuel economy,thicker for protection. Go with the 5W40.
 
Originally Posted By: Swift101
I'll see how 5W-40 feels & performs, If anything I'll run a shear stable/thick 30 grade. It looks the M1 5W-30 is on the thicker side ,at least thicker than more competitors.

http://www.pqiamerica.com/March2013PCMO/Marchsyntheticsallfinal.html



While M1 5W30 is a fine oil, it has an HTHS of ~ 3.0-3.1 I believe (that's off the top of my head, but likely close). Thus, it would not be known as a "thick" 30-grade oil.

All of the thick or Euro 30-grade oils will have HTHS values of >= 3.5 cP, which is significantly thicker than any store-bought North American style synthetic 5W30 or 0W30 oil. GC (now Belgian Castrol) 0W30 is likely one of the only easily obtainable Euro style 30-grade oils with an HTHS of > 3.5 cP that also meets most of the requisite European specs such as MB 229.5, BMW LL-01, etc.

If you want a thick 30-grade, you will have to shop for an oil that meets the Euro specs or carries an ACEA A3 rating. Also, any 0W40 or 5W40 API-SN will work as well.

To be clear, I'm strictly speaking of higher SAPS oils here, as there are other selections (M1 ESP 5W30) that are quite thick, but have a low SAPS level and thus a low starting TBN.
 
Originally Posted By: il_signore97

To be clear, I'm strictly speaking of higher SAPS oils here, as there are other selections (M1 ESP 5W30) that are quite thick, but have a low SAPS level and thus a low starting TBN.


Low starting TBN wouldn't be an issue given the conservative OEM OCI recommendation. 5K mile Max for the 2.0T
 
Originally Posted By: wemay
Originally Posted By: il_signore97

To be clear, I'm strictly speaking of higher SAPS oils here, as there are other selections (M1 ESP 5W30) that are quite thick, but have a low SAPS level and thus a low starting TBN.


Low starting TBN wouldn't be an issue given the conservative OEM OCI recommendation. 5K mile Max for the 2.0T



Yes, I agree. I just didn't want to assume that the OP was going to follow the factory recommendation for OCI length
smile.gif


On another note, the low-SAPS oils might have some benefit in DI applications (along with conservative OCI's) in that they could possibly reduce the tendency of valve deposit build-up. One of the additive companies suggested that this might be the case... The link is somewhere in the Euro forum I think.
 
Originally Posted By: il_signore97
On another note, the low-SAPS oils might have some benefit in DI applications (along with conservative OCI's) in that they could possibly reduce the tendency of valve deposit build-up. One of the additive companies suggested that this might be the case... The link is somewhere in the Euro forum I think.


^^Agreed^^
 
Originally Posted By: OVERKILL
So I don't agree with your premise that the pump relief is open most of the time. Perhaps on certain engine families that is the case (we've discussed this before on here and IIRC there were certain Mopar engines, running the spec viscosity oil that were on the relief frequently) but at least in my experience, running something in the neighbourhood of the spec viscosity on a warmed up engine, relief events only happen at the top of the RPM scale. So unless you are cruising down the highway at 6,000RPM, the relief is probably closed most of the time, LOL!



No I don't think so. You're thinking of it as a safety relief. It's really a pressure regulator that operates most of the time. Otherwise as an engine wears there would be no reserve capacity. Do you understand?

Here's a little primer from Melling. http://www.youtube.com/watch?v=7IpJlYssvkM
 
The above is dependent on many factors. Basic engine design and spec for OEM pump, bearing clearances, wear and tear, oil viscosity, filter type/design, etc.

No blanket statements are possible unless you confine yourself to one specific engine design. And even within that are huge variations.

For example, despite the fact they are nearly identical, the 5.7 and 6.1 Mopar V8's have very different oil pumps with different relief settings.

Both Overkill and TV are correct but they must be qualified statements as all engines are very different.
 
Originally Posted By: turtlevette

No I don't think so. You're thinking of it as a safety relief. It's really a pressure regulator that operates most of the time. Otherwise as an engine wears there would be no reserve capacity. Do you understand?

Here's a little primer from Melling. http://www.youtube.com/watch?v=7IpJlYssvkM



No, I'm thinking of it as a pressure regulator and I believe I defined its function quite clearly.
 
Originally Posted By: OVERKILL

No, I'm thinking of it as a pressure regulator and I believe I defined its function quite clearly.


It's ok to be wrong. After all you're an IT person who plays with computers all day. Not a guy working in the auto industry.

What kind of pressure regulator only works at the very high end limit. You said it only opens at very high rpm. Not true. It's a graduated pressure relief that controls pressure throughout the rpm range.

And again by nature of a good design it must be bypassing extra oil most of the time. Otherwise as clearances increase during the life of the engine, it wouldn't be able to maintain pressure.

Quit back peddling, admit you're wrong, and move on.
 
Mine si around 75-80 psi. It will open at lower rpms when the oil is cold but once warmed up it is near redline when it hits 75 lbs.
 
Originally Posted By: turtlevette

It's ok to be wrong.


Unless you are you of course right? Must be quite the life being the guy that is never wrong and has a chip on his shoulder so heavy he walks on an angle.

Quote:
After all you're an IT person who plays with computers all day. Not a guy working in the auto industry.


I have a fair deal of experience tearing down and modifying engines. I was an active member in the Mustang community for years and have a great deal of experience. My grandfather also owned a fleet of antique boats powered by a variety of engines, all with oil pressure gauges and many of which I've been inside.

Quote:
What kind of pressure regulator only works at the very high end limit.


Where did I state it was designed to work only at a very high end limit? I said it was designed to regulate the pressure at or below a specific point. In the case of an SBF, the spring-loaded valve begins to open at around 65psi. It will open more when volume requires it to open more to maintain that pressure. Of course it is also, as I noted in my original reply, possible to overrun the valve and system pressure will subsequently go higher than the intended regulated pressure.

Quote:
You said it only opens at very high rpm. Not true. It's a graduated pressure relief that controls pressure throughout the rpm range.


Nope, where did I say that? I said it will, on a HOT engine, DEPENDING ON THE ENGINE FAMILY, open only at HIGHER RPM. Not HIGH RPM. I don't consider 4,500RPM high, do you? That's where it began to open on my SBF with 0w-40. With 0w-20, that point was higher. Heck, I even gave you examples!!!

And I ALSO noted that with cold, THICK OIL, that the relief begins to open much earlier, sometimes, on my engines, as low at 1,500RPM.

It is a pressure actuated valve that begins to open at a set pressure that it is designed to regulate the maximum pressure to.

This is of course excluding the variable displacement pumps currently employed by BMW and the like.

Quote:
And again by nature of a good design it must be bypassing extra oil most of the time. Otherwise as clearances increase during the life of the engine, it wouldn't be able to maintain pressure.


you've never seen a worn out SBC or SBF with low oil pressure?


Quote:
Quit back peddling, admit you're wrong, and move on.


Says the pot calling the kettle black. You are always looking for a fight aren't you? You ever notice that's not how we post on here? That's not how we discuss things?

I find your posting style abrasive and tiresome. It causes me to not want to visit this site, which is unfortunate, because I normally enjoy posting here. It isn't that your topics aren't interesting or that you don't make valid points, it is the fact that everything has to be a fight, everything has to be a put down or carry some sarcastic tone to it. I don't want to know what it is like to be that angry all the time and I dislike having to vicariously do so through your posts. I'm sure there are others here who share that sentiment.
 
Originally Posted By: A_Harman
Originally Posted By: Shannow
Specific heat of oil is pretty well a constant...pumps are positive displacement...how does a thinner oil move more heat ?

Just asking...


Thinking about the environment inside of an oil cooler:
Lower viscosity means higher Reynolds number --> better convective heat transfer.


Yep, got me on that one, don't see many oil coolers 'though...although the same premise will apply to the stuff swirling in the sump waiting to head back to the pump.

edit...from (an apparently washed out Westinghouse Inspector)..+1 to what they said ^^^
 
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Originally Posted By: Gokhan
As I said, 7% improvement was for "gentle" driving, almost hypermiling. For more regular driving or fast driving, improvement would be a lot less. Also, as you said, 15W-40 has an HTHSV ~ 4.3 cP vs. 5W-40 HTHSV of ~ 3.9 cP, and the fuel economy correlates mostly with HTHSV.

There is also the VI issue. Nonetheless, while I don't dispute that lighter oils have fuel economy advantages and can essentially pay for themselves, we should take 7% with a grain of salt. I'd have great difficulty accepting an error bar of less than 10% in fuel economy calculations, so 7% falls easily within statistical noise.
 
Originally Posted By: OVERKILL


Where did I state it was designed to work only at a very high end limit? I said it was designed to regulate the pressure at or below a specific point. In the case of an SBF, the spring-loaded valve begins to open at around 65psi. It will open more when volume requires it to open more to maintain that pressure. Of course it is also, as I noted in my original reply, possible to overrun the valve and system pressure will subsequently go higher than the intended regulated pressure.

I said it will, on a HOT engine, DEPENDING ON THE ENGINE FAMILY, open only at HIGHER RPM. Not HIGH RPM. I don't consider 4,500RPM high, do you? That's where it began to open on my SBF with 0w-40. With 0w-20, that point was higher. Heck, I even gave you examples!!!

And I ALSO noted that with cold, THICK OIL, that the relief begins to open much earlier, sometimes, on my engines, as low at 1,500RPM.

It is a pressure actuated valve that begins to open at a set pressure that it is designed to regulate the maximum pressure to.

This is of course excluding the variable displacement pumps currently employed by BMW and the like.




Hi overkill,

Not that you need any confirmation or anything, but I've personally seen the same bypass behavior that you have noted above. Not surprising of course
wink.gif
 
Originally Posted By: OVERKILL
Originally Posted By: turtlevette

It's ok to be wrong.
Says the pot calling the kettle black. You are always looking for a fight aren't you? You ever notice that's not how we post on here? That's not how we discuss things?

I find your posting style abrasive and tiresome. It causes me to not want to visit this site, which is unfortunate, because I normally enjoy posting here. It isn't that your topics aren't interesting or that you don't make valid points, it is the fact that everything has to be a fight, everything has to be a put down or carry some sarcastic tone to it. I don't want to know what it is like to be that angry all the time and I dislike having to vicariously do so through your posts. I'm sure there are others here who share that sentiment.

You are right that he is angry. I can't think of any other member I've seen in my time on this site who is so angry. Don't let him affect your desire to post on here. When you see his posts, just ignore them and take satisfaction in knowing that he is already suffering for whatever reason(s) and by ignoring him he still loses and you haven't wasted any time on him nor has his anger spread to you. His goal is to make others emotionally suffer because he is suffering. As Shannow pointed out, if you Google his username, you will see evidence of his past train-wrecking. You are an excellent contributor to this site, so I, and I'm sure many others, want to see you post here!
 
Originally Posted By: Garak
Originally Posted By: Gokhan
As I said, 7% improvement was for "gentle" driving, almost hypermiling. For more regular driving or fast driving, improvement would be a lot less. Also, as you said, 15W-40 has an HTHSV ~ 4.3 cP vs. 5W-40 HTHSV of ~ 3.9 cP, and the fuel economy correlates mostly with HTHSV.

There is also the VI issue. Nonetheless, while I don't dispute that lighter oils have fuel economy advantages and can essentially pay for themselves, we should take 7% with a grain of salt. I'd have great difficulty accepting an error bar of less than 10% in fuel economy calculations, so 7% falls easily within statistical noise.

It depends on how you do the experiment. I compared them under almost identical conditions and driving, using the same gas pump. Of course, there is going to be an error. Again, 7% was for very gentle driving. Fuel-economy benefits are less for regular driving style. ~ 4% should be normal for 15W-40 to 5W-30 and ~ 2 - 3% for 5W-40 to 5W-30, ~ 1.5% for 5W-30 to 0W-20, and ~ 1% for 5W-30 to 5W-20. It's mostly correlated with HTHSV and then with VI to a smaller degree.
 
Originally Posted By: Swift101
Originally Posted By: Realtech214
5w40 is fine. If your car calls for 5w30? why not use that?


They manual recommends both grades, my logic is if i use a 40 weight it will shear down to a 30 weight. If I use a 30 I'll get a 20 weight, I'd rather have as much protection as possible.

It is very much a newbie error to automatically assume, just because you may think you drive your car hard that a heavier oil grade would be somehow beneficial. Running the lightest oil specified still provides a large viscosity reserve if high oil temp's are encountered.
If your concern is as much protection as possible then install oil gauges including a oil pressure gauge, that's the only way you'll know if the oil is getting too thin at maximum oil temp's (very unlikely since you don't apparently track your car).

All running a heavier oil grade will guarantee is less fuel economy, power and driveability when cold. And if you drive aggressively when the engine is cold you'll increase the possibility of increased engine wear.

Stick with a 5W-30 synthetic and enjoy your ride.
 
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