Question for oil experts here...

[Thax]

Originally Posted By: SnogardE55AMG
Thax@ O.K. i respect your advice, but anyway could you tell me why should i not use Mobil 1 5W-50? It is OEM oil for SLR (which have almost the same engine as my E55)and i run my cars hard. I also avoid shiort trips and on top of that temperatures here are not that low not even in the winter. Plus, Mercedes did recomend 15W-50 oils few years ago for AMG engines, but after "ECOmania" comes out, it went down to 0W-40 obvios for eco reasons (not because it is better for engine itself). So can you give me your opinion about that please?

Either Mobil 1 oil or any oil for that matter that meets the spec for your car will work fine.Me personally have always put what oil the manufacturer recommends/requires. I do this for A.) peace of mind B.)I know that the engineers who built these motors tested many oils and they have recommended a oil in this case 0w-40 for the fact it will perform well in areas of performance,fuel economy and emissions output as well as protecting your motor.Just my opinion

 

[CATERHAM]

Originally Posted By: Spyder7
Originally Posted By: SnogardE55AMG
Originally Posted By: Gearhead113
Now whether the improved fuel economy minimums come from a lower High Temperature/High Shear rating, the addition of more friction modifiers, higher quality base stock etc. or a combination I don't know...


I thought that fuel economy minimums comes only and specificyly from lower viscosity?? Was i misleaded?



The oil's HTHS isn't going to affect fuel economy. Its viscosity at operating temp is the largest factor, though better base stocks (I'm thinking esters specifically) and friction modifiers (moly, etc) may play a role as well. That doesn't mean the thinnest oil is the best choice, just that the oil should be no thicker than it needs to be.

-Spyder

All things being equal, such as an oil's chemistry and antiwear composition, an oil's fuel economy is DIRECTLY related to the HTHS viscosity of an oil.

 

[Spyder7]

Originally Posted By: CATERHAM
Originally Posted By: Spyder7
Originally Posted By: SnogardE55AMG
Originally Posted By: Gearhead113
Now whether the improved fuel economy minimums come from a lower High Temperature/High Shear rating, the addition of more friction modifiers, higher quality base stock etc. or a combination I don't know...


I thought that fuel economy minimums comes only and specificyly from lower viscosity?? Was i misleaded?



The oil's HTHS isn't going to affect fuel economy. Its viscosity at operating temp is the largest factor, though better base stocks (I'm thinking esters specifically) and friction modifiers (moly, etc) may play a role as well. That doesn't mean the thinnest oil is the best choice, just that the oil should be no thicker than it needs to be.

-Spyder

All things being equal, such as an oil's chemistry and antiwear composition, an oil's fuel economy is DIRECTLY related to the HTHS viscosity of an oil.


Either of you guys want to explain how, as I'm not seeing a direct relationship between the two; I can see an indirect relationship in that an oil with a lower HTHS score will sheer and thereby thin faster than one with a higher HTHS, and the change in viscosity in the sheered oil, being thinner, will at that point positively affect FE.

Its only that indirect relationship that I'm aware of, and only after the oil has sheered down, which may be pretty far or near the end of the OCI.

BTW I'm not asking for the explanation to challenge you on that point, I'm just not seeing the direct relationship you guys are and would therefore like it explained as to how/why.

-Spyder

 

[d00df00d]

AFAIK:

HTHS viscosity is the best widely-used indicator of viscosity in the hottest, fastest-moving parts of the engine, including piston rings, various bearings, etc. Viscosity-related drag in these areas will have a strong effect on fuel efficiency.

Kinematic viscosity is a low-shear measurement, which means it doesn't really relate to much of what's going on in the engine. It might give you an idea of windage losses (which may or may not even exist), but that's about it.

 

[CATERHAM]

The reason likely has to do with the fact that the HTHS method of measuring viscosity under stress (pressure) is more representative of the actual operational viscosity in an IC engine.
The very simple kinematic method of measuring viscosity does not correlate well with the operational viscosity at any temperature.
HTHS vis is best thought of as the true measure of an oil's viscosity and this effect has been found to apply at normal operating oil temperatures. Consiquently for a given HTHS viscosity measure, it will have a range of possible KV100 spec's but they will all have the same actual operational viscosity.
And that in a nut shell is why fuel economy correlates with HTHS vis and not the KV100 spec'.

For more info' on the relationship between HTHS and KV100 check out my post below:
https://bobistheoilguy.com/forums/posts/2018835/

 

[Spyder7]

Thanks for clarifying that point guys, it was an interesting (and enlightening) read.

-Spyder

 

[buster]

I really think M1 0w40 is your best choice. It's latest product data sheet shows improved VI, HT/HS and Tbn. This is one of their best oils IMO.

VI 188
HT/HS 3.8
Tbn 11+

 

[SnogardE55AMG]

Originally Posted By: JHZR2
It concerns me that it appears that you like certain responses only because they tell you what you want to hear. That isn't really being objective and listening to reason.


I came here to collect opinions (and learn new facts), because without any doubt, you users here are by far the most knoledgefull people on the internet about engine oils. That is the fact for me.
And as i can see, each of you have his own opinion about oil (which is exactly what is suposed to be, wright?). And of course, i agree with some of them more then with others (like we all do). But that does not meen that i dont respect every each of the opinion i get here. Including yours.
So if i go to OT again; I can not get temperature/viscosity chart for my engine model from Mercedes, that is the problem. You see, i know that what factory recomends, should be best for our vehicles, but on the other side, that same factory did recomend other type of oil for the same engine (Mobil1 15W-50) just a few years ago. In the matter of fact, it did actualy construct,build and test that same AMG engine with 15W-50 oil. And nowadays they wont us to use 0W-40. And that fact is making me ask what oil shoul i use (if i dont care for ECO reasons and DO care about engine protection itself). Plus, as i already told, SLR use 5W-50 oil still today. And i run my cars as hard, if not harder than most SLR owners. The engine is the same.
And that are 2 strong erasons for me to doubt that 0W-40 is the best oil for that engine. And because of that i come here to collect opinions.
On top of that i wonder if i will do any (measurable) good if i will go from GC 0W-30 (which i use at that moment in that engine)to Mobil1 0W-40, which we all know that it have almost the same 100 degree viscosity characteristics as GC. So a lot of doubts and a lot of questions for me. Now with all that help that i get from you guys in last 24 hours, things are getting more clear for me, but at the end i think it is all on me to decide wether to left GC in , or change it with M1 0W-40 or with M1 5W-50 or maybe some good 5W-40 from other brand.
My biggest question still remains; Why did AMG went from 5(15)W-50 to 0W-40 few years ago? Is it just because ECO reasons or did they really discovered that AMG engine do not need that thick oil?

 

[SnogardE55AMG]

Originally Posted By: d00df00d
Noise is not a good guide to whether an oil is good for your car, nor is switching to a thicker oil a good solution for most problems. Thicker oil may deaden sound, but it will compromise heat transfer and reduce flow rates on cold starts. Not a good trade-off.


I know that, but like i said, mercedes used to use thicker oil in the beggining for AMG engines (15W-50). Just a few years ago it went to thinner (0W-40 demand).It actuially developed that same engine with thicker (15W-50)oil. So will it really be trade of for me if i went from 0W-30 GC to 5W-50 (or even 10W-60) which both of them have almost the same characteristics like the oil which was in the first place in the engine when the engine was developed end tested? That is the main question for me (and for a lot of AMG owners). Maybe those AMG engines start to become noisy when mercedes decide to put in thinner oil? Maybe that was trade off for them for better ECO results? If that is the case, then there is no question for me about what oil to use in AMG.

 

[SnogardE55AMG]

Originally Posted By: chubbs1
Take care and WELCOME


Thanks man!

 

[CATERHAM]

I believe you are over thinking this.
I agree with others here that M1 0W-40 is the oil of choice.
The current formulation is heavier (HTHS vis of 3.8cP) along with a higher VI than than it has ever had.
If you still have concerns that the oil may still be too light when the oil gets hot, there is one sure fire way to find out, and that is to install an oil pressure gauge, assuming your car doesn't have one already. If you still have adequate OP, as specified by Mercedes Benz, when the oil is at it's maximum oil temperature, then the oil is not too light and there is no benefit in running a heavier oil.

 

[d00df00d]

Originally Posted By: SnogardE55AMG
I know that, but like i said, mercedes used to use thicker oil in the beggining for AMG engines (15W-50). Just a few years ago it went to thinner (0W-40 demand).It actuially developed that same engine with thicker (15W-50)oil. So will it really be trade of for me if i went from 0W-30 GC to 5W-50 (or even 10W-60) which both of them have almost the same characteristics like the oil which was in the first place in the engine when the engine was developed end tested? That is the main question for me (and for a lot of AMG owners). Maybe those AMG engines start to become noisy when mercedes decide to put in thinner oil? Maybe that was trade off for them for better ECO results? If that is the case, then there is no question for me about what oil to use in AMG.

I sincerely doubt Mercedes AMG switched to a thinner oil for fuel economy reasons.

You may notice that there isn't a single xw-50 oil with MB229.50 approval any more. They are all xw-30 and xw-40. The fact that they removed all heavier oils from the list should tell you something.

Thicker oil doesn't cool as well, and it doesn't flow as quickly at start-up. Both of these things are bad for the engine. This is why you always want the oil to be as thin as possible, and only as thick as necessary. Mercedes is telling you that you can have the same high-temp protection, but with better cooling and quicker cold flow. I guess I can't speak for you, but I would be quite happy about that.

Mercedes AMG isn't the only company to do this, by the way. BMWs used to come with a 15w-40. Now BMW recommends LL-01 approved oils for almost all of them, including the performance models, and many LL-01 oils are 0w-30 and 5w-30.

I see no reason to suspect that thicker oil is better just because that's what the car came with. It's kind of like saying a horse-and-carriage is better than a car because that's how people originally moved around.

 

[SnogardE55AMG]

Originally Posted By: CATERHAM
If you still have concerns that the oil may still be too light when the oil gets hot, there is one sure fire way to find out, and that is to install an oil pressure gauge..


Actually i did just that last weekend because my car doesnt have OP gauge, neather warning light for oil pressureas (can you imagine that on 100k$ car?). My conclusion after testing OP with GC 0W-30 was that pressure is well within mercedes demands. But that is not my concern. My concern is the fact that there have been many engine catastrophic failurs after mercedes went to thinner grade. Also my concern is why SLR still use thicker oil (which doesnt even meet 229.5 specs!!!) with not a single known catastrophic engine failure. My concern is why did our engines become noisy (that is our speculation) after mercedes went to thinner oil? You see, i bought my car with engine with catastrophic failure too. So i had to bought new low millage engine and instaled it into the car. And last thing that i wont is to have another engine catastrophic failure. But maybe i really AM over thinking....and should just follow mercedes recomendation. Before that i think i will try SLR spec oil (5W-50) and see how will it react...

 

[SnogardE55AMG]

Originally Posted By: d00df00d
[You may notice that there isn't a single xw-50 oil with MB229.50 approval any more...


...and yet mercedes SLR with same engine still use one after mercedes recomendation (229.3 Mobil1 5W-50). Can you explain that. I can not.

Like i said, first i will try with SLR oil to see engne reaction , and then according to test (oil pressure, temp.,noise...)decide whether to use that one or mercedes recomended one.

So thank you and thank you all guys for helping me understand more4 clearly some oil facts.

 

[d00df00d]

Originally Posted By: SnogardE55AMG
...and yet mercedes SLR with same engine still use one after mercedes recomendation (229.3 Mobil1 5W-50). Can you explain that. I can not.

I offered an explanation earlier. Are you actually reading what people are saying to you?

 

[SnogardE55AMG]

Originally Posted By: d00df00d
Originally Posted By: SnogardE55AMG
...and yet mercedes SLR with same engine still use one after mercedes recomendation (229.3 Mobil1 5W-50). Can you explain that. I can not.

I offered an explanation earlier. Are you actually reading what people are saying to you?


Yes i am (as far as my bad English is letting me), but sorry, with all respect to you, i can not find direct explanation in that thread for use of thick 5W-50 oil (which is not even 229.5 aprooved, which itself is kontradictory from mercedes itself) in mercedes flagship sport car SLR? All you are saying is that mercedes have good reasons to use thinner oil in last years. But if that is true, then why do they still use thick oil in SLR? I guess you are the one who did not read all that i wrote...Mistery which i am trying to resolve here is mistery from many AMG owners, that is why i am trying to solve it in the long, understandabke way. if you think i (we) are really overthinkig this, then thank you very much for your help and just ignore me in the future. But we are onto something and we are going to resolve that no matter what. As a matter of fact, for few months some of euro dealers in Europe are started to recommend ESSO 5w-40 oil instead of Mobil1 0W-40. So there must be something (bad) in the use of thin 0W-40 anyway...My prediction is that in in the matter of months mercedes will go again to thicker oil (at least 5W-40 if not 5W-50) for that AMG engine type (just like BMW did for M3,M5 and Z8 car engines when it went from thinner (which fas factory aprooved from beggining) to thicker 10W-60 oil few years ago, which is still today the only aprooved oil for that M engines). So the other round away comparing to what Mercedes did for AMG engines. But we will see, and in the mean time i will try to get to the bottom of thin oil saga in AMG.
As i said before, thank you all again.

 

[SnogardE55AMG]

Originally Posted By: d00df00d

Mobil 1 5w-50 is used in the SLR because that car will generate higher oil temperatures than yours will....


If that is your only explanation then let me again clear it to you. As i already said, many of us non SLR (but ordinary AMG) users with same engines like SLR drive our cars as hard, if not harder then most of SLR owners. And yes, maybe because of that, we are seeing many catastrophic engine failures (with thinner oil), then SLR owners with thicker oil. So will i be better with catastrophic engine failure or with less protection at start and slightly higher oper.temp.? That is the whole point of that thread. And i come here to get opinions if thin oil is really the culprit of all our engine problems / or in your oil expert guys eyes-how much more is engine prone to catastrophic failure because of too weak oil film with 0W-40 comparing to 5W-50.

 

[A_Harman]

A big difference in the SLR is that it makes 600+HP, and your car makes 469. It runs higher boost pressure and rpm, both of which stress the oil more.

If money is no object, and if you can find it, my recommendation is Redline 5w40.

 

[Merkava_4]

From reading this whole thread, the OP is saying that Mobil 0W-40 is not making his engine run as quiet as he wants; nor is German Castrol 0W-30. And from what I'm reading, the OP seems to think that a thicker oil is what's needed to quiet the engine. My question is this: what if a different brand of 0W-40 was tried other than Mobil; could that possibly dampen the engine noise like the OP wants?

 

[Propflux01]

Why don't the OP just put in M1 5w-50(or 15w-50 if its available) and run it. If it blows up, He'll know it wasn't the right choice.

That aside, I think Mercedes probably went to the thinner type oils because they feel they are more robust nowadays than they were a few years ago, and can handle what the engine can give the oil, with the added benefit of one or 2 more horses gained with the use of that thinner oil. I seriously doubt the use of either oil would affect longevity of the engine.