2011 LML duramax oil

[skyship]

Originally Posted By: daman
What I'm getting at is any named brand CJ-4 5w40 will be a synthetic not a blend or conventional, CF is an old spec Obsolete no? and would hardly work in a modern diesel.


The old specs oil work better than some of the new ones because they had an add pack designed to protect the engine not the new go green exhaust system.
The OP has said this Duramax has had the EGR & DPF removed, so there is no need for him to use a CJ-4 spec oil. In my opinion the higher the API group oils are worth avoiding if you don't have to use them because of a DPF.
The Duramax does have a tough block that seems to be OK with many different oils, but that is not always the case for other diesels and there was a series of UOA results for a VW TDI posted that showed a clear improvement after a Zinc additive was used to augment the low Zinc level of a DPF approved oil.
Some of the EU oils carry older API specs because no one in the EU pays much attention to the new API designations apart from Castrol, because the car manufacturers just list the ACEA designations (B4 is the best diesel oil) as a requirement.

 

[CONMCK]

My OP states that my 2011 LML does not have a functional EGR valve (turned off) and has no SCR/DEF/DPF.

So the question is whether or not my LML still requires CJ-4 oil..that is what this thread should be addressing, that and a viscosity recommendation.

I believe in my case that a earlier API oil, (CH, CI) may even be beneficial vs a CJ.

Thanks everyone, so far.. [/quote]
I know you have no working EGR but the fact still remains that todays CJ-4 oil is so much better then previous used lubes for soot handling capability's and more,then your CF,CH,etc.

take some time and read this thread dnewton has some good info on why CJ-4 is a great fluid compareded to even CI-4.


https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2206986#Post2206986

thats just one post he has more with some searching. [/quote]

Yes, good reading and thx.

 

[CONMCK]

Originally Posted By: m37charlie
Originally Posted By: daman

I know you have no working EGR but the fact still remains that todays CJ-4 oil is so much better then previous used lubes for soot handling capability's and more,then your CF,CH,etc.



What is the point? Especially without EGR does it matter that CJ4 can handle 6.0% soot and CI4+ only 4.5%, when he won't even get to 1.0%?
ANY decent CH4, CI4 or CJ4 oil will work perfectly well in his application.
But on a -35C morning it might be nice to have 5W40 rather than 15W40.

Charlie


I'm thinking in my case, choose the correct viscosity, and whether I use a CH, CI or CJ-4 oil, any one of those will work fine, if i change the oil/filter at the correct intervals the motor will probably outlast the rest of the truck!!!!

This post has been a good read for myself, this is my 1st diesel I have owned (driving over 30 years now), learning what I can!!!

Thanks again every one.

 

[skyship]

Originally Posted By: CONMCK
My OP states that my 2011 LML does not have a functional EGR valve (turned off) and has no SCR/DEF/DPF.

So the question is whether or not my LML still requires CJ-4 oil..that is what this thread should be addressing, that and a viscosity recommendation.

I believe in my case that a earlier API oil, (CH, CI) may even be beneficial vs a CJ.

Thanks everyone, so far..

I know you have no working EGR but the fact still remains that todays CJ-4 oil is so much better then previous used lubes for soot handling capability's and more,then your CF,CH,etc.

take some time and read this thread dnewton has some good info on why CJ-4 is a great fluid compareded to even CI-4.


https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2206986#Post2206986

thats just one post he has more with some searching. [/quote]

Yes, good reading and thx. [/quote]

The average figures might have improved, but the major brand oil companies do change base stock quality and even adjust add packs of older type pre DPF oils. For example my own UOA/VOA shows an improvement in LM synthoil and Castrol GTX changed completly over the years, that is one reason I would only use an oil from Castrol, Liqui Moly, Mobil or Shell. Some of the other companies have been back specing their oil to a lower standard for supermarket oils in particular (ZF oil analysis lab data) to cut costs. This was one reason why Castrol GTX 5w30 produced better wear figures than any other fully synthetic oil (Apart from Edge) in the BMW forum group averaged UOA results. Oil performance is more about quality than actual type or approvals, although obviously if you have an EGR, fussy KAT or DPF life is more complicated in oil selection terms.

 

[mobilaltima]

two of my friends have LML Dmaxes, both of which we deleted, 5 inch straight pipe, and EGR unplugged. one runs Rotella 15W40, an the other runs Delvac 15W40, i recommend Delvac. Although they will try T6 5W40 for the winter. Alligator Diesel now makes an EGR Delete kit for the LML's.

 

[skyship]

Originally Posted By: dnewton3
This so overblown; typical of a BITOG response.

Guys - the Dmax simply does not care what lube you use. There is no data that shows any signficant statistical difference when it comes to brand/grade/base stock.

I fully understand and agree that in extreme cold areas, such as the OPs location, that cold starts are a likely event that would manifest into starting concerns.

Let me be clear here; it is not an issue of wear, but an issue of starting.

Compression-ignition engines (diesels) need to be able to spin the engine quick enough to create the heat for ignition. When it's uber-cold, every rpm matters for starting. In that regard, thinner lubes can be an aid.

But I also content that good, strong batteries also help here. Not just because of the starting torque needed, but also to run the intake-heaters that are common in all modern diesels.

He may need a thinner lube; that would something that he can be the judge of, when it comes to starting ease. But it will NOT make any darn difference in wear.

I will note that the Rotella T5 in 10w30 has the same cold-crank performance as their 5w-40 T6. So, don't get completely hung up on the grades listed on the bottle. Look at the actual performance stats, especially the mRV rating if you can find one.

Pan heaters are a great aid, but they are only good if you're near power. Where I live, that would be great for me at home, but not at work after sitting for 10-12 hours with no outlet. Strong batteries and a thinner lube are how you start any diesel in the uber-cold.


Important part I disagree with:
He may need a thinner lube; that would something that he can be the judge of, when it comes to starting ease. But it will NOT make any darn difference in wear.

I asked the senior geek in the ZF oil analysis lab out cold start wear, as I know him from visiting the R&D section every month and although they do mostly transmission fluid analysis, he did work for VW engine R&D before and is one of the leading bearing wear and oil analysis experts in Germany. His answer was based only on UOA results for VW diesels, so might not be applicable to truck engines.
The data file he quoted from was for a comparison of test rig data based UOA figures comparing a good quality 10/40 conventional with a full synthetic 0/40 doing multiple cold starts cycles with only 5 minute runs (The engine was in a freezer). The results were better with the 0/40 and when fed into a software program to figure out the TBO of a typical cars engine in central EU, it translated to a difference of just under 10%. BUT he would not comment on whether that was because one oil was synthetic and the other conventional or because one was an 0W. Both oils had the same Zinc and add pack contents, so it had to be one of the two factors. The only real conclusion I could get from him was based on his own old diesel van, as I asked him which oil he used and it was 15w40 in summer and 0/40 in winter.

 

[SteveSRT8]

Dmax is a bit unusual among large high output diesels used in cars and trucks as it is VERY EASY on oil.

In my eyes it's an inherent superiority of the design, but either way it's still great to own one and be free of "oil anxiety"!!!

 

[m37charlie]

Originally Posted By: dnewton3
This so overblown; typical of a BITOG response.



I fully understand and agree that in extreme cold areas, such as the OPs location, that cold starts are a likely event that would manifest into starting concerns.

Let me be clear here; it is not an issue of wear, but an issue of starting.

Compression-ignition engines (diesels) need to be able to spin the engine quick enough to create the heat for ignition. When it's uber-cold, every rpm matters for starting. In that regard, thinner lubes can be an aid.

But I also content that good, strong batteries also help here. Not just because of the starting torque needed, but also to run the intake-heaters that are common in all modern diesels.

He may need a thinner lube; that would something that he can be the judge of, when it comes to starting ease. But it will NOT make any darn difference in wear.



I beg to differ. In an SAE article "Preventing catastrophic camshaft lobe failures in low emission diesel engines" at -15C it took 50sec for 15W40 to reach 30psi at the rocker arms; it took 15 sec for 5W40. God only knows what the difference would be at -30 or -35C; my guess is an ORDER OF MAGNITUDE greater! There were all sorts of electron micrographs of roller follower failure due to inadequate lubrication in the article. I have seen 2nd hand the results of forcing an engine to start in cold weather with a heavy oil; not pretty.

Charlie

 

[scurvy]

Originally Posted By: m37charlie
I beg to differ. In an SAE article "Preventing catastrophic camshaft lobe failures in low emission diesel engines" at -15C it took 50sec for 15W40 to reach 30psi at the rocker arms; it took 15 sec for 5W40.


Similar information here from a presentation by Liqui-Moly.

I know which one I choose to run. While the Duramax is remarkably 'easy' on oil, it still helps to have an appropriate lubricant in the crankcase for unaided deep cold weather starts!

 

[dnewton3]

Charlie - please cite the the SAE paper you reference; I'd like to read it before I comment on it.

 

[m37charlie]

http://papers.sae.org/2000-01-2949/

Sometimes I have difficulty understanding your point. You have strongly recommended in the past that people in southern tier of states try 10W30 instead of 15W40. Yet for someone in Alberta, you somehow seem to imply that 15W40 is harmless even in winter conditions - just might be hard to start.
According to Widman's calculator, the viscosity of a typical 15W40 at -40C is about 150,000 cP. Way thicker than SAE's upper limit of pumpability of 60,000cP.

Charlie

 

[dnewton3]

Originally Posted By: skyship
Important part I disagree with:
He may need a thinner lube; that would something that he can be the judge of, when it comes to starting ease. But it will NOT make any darn difference in wear.

I asked the senior geek in the ZF oil analysis lab out cold start wear, as I know him from visiting the R&D section every month and although they do mostly transmission fluid analysis, he did work for VW engine R&D before and is one of the leading bearing wear and oil analysis experts in Germany. His answer was based only on UOA results for VW diesels, so might not be applicable to truck engines.
The data file he quoted from was for a comparison of test rig data based UOA figures comparing a good quality 10/40 conventional with a full synthetic 0/40 doing multiple cold starts cycles with only 5 minute runs (The engine was in a freezer). The results were better with the 0/40 and when fed into a software program to figure out the TBO of a typical cars engine in central EU, it translated to a difference of just under 10%. BUT he would not comment on whether that was because one oil was synthetic and the other conventional or because one was an 0W. Both oils had the same Zinc and add pack contents, so it had to be one of the two factors. The only real conclusion I could get from him was based on his own old diesel van, as I asked him which oil he used and it was 15w40 in summer and 0/40 in winter.


Interesting, but not really easy for me to disect.
I do have some thoughts though:

1) whatever study this was, I really don't put much stock into it unless I can read it. I'm not saying you're wrong or being untruthful. I'm saying there is WAY too much left out to really understand the criteria of the German study. Plus, they often focus on models and lubes specific to their part of the world; perhaps not directly applicable to a Dmax in NA.
2) repeated cold starts with run times no more than 5 minuets? Several Q's here:
a) was the rig allowed to completely cool between starts?
b) was this a full engine, or just a sympathetic test rig?
c) what controls were in place?
d) what other characteristics were nullified as controllables?
e) the "results were better"? How defined? a 10% reduction in wear I presume? Over a period of what projected lifecycle? (IOW - if planned life is 400k miles, then would we expect 40k less miles of lifecycle? Should that matter to someone who only keeps a vehicle for 150k miles?) In essence, how does the projected lifecycle degredation compare/contrast to ROI?
f) Was there a manifestation of wear-rate shift tested at different OCI durations? (IOW - at what exposure duration was the test run at? Was it affected by OCI duration, if even tested at all as part of the DOE?) We know that nearly all lubes will be "better" when aged; so could the 10% difference be enhanced or diminished with shorter/longer OCIs? Many times these studies are run with "new" oils; that does NOT reflect a real world difference. As lubes age, the performance differential grealy shrinks; the perceived advantage of one lube over another reduces as they all beging to homogenize with OCI extensions.
g) does a 5 minute run time really reflect real world experiences for most of us? I understand that it might be significant to the study, but how many of us have this experience as the "normal" operational pattern for our engines?

Get the point? I'm not saying you're wrong, but I have a lot of questions about what the DOE was, how the test was set up and controlled, etc.



Here's my point to you, and to Charlie:
the real world application of these different lubes does not manifest into longevity issues in a Dmax.

I point to the data in my "normalcy" article. Consider the SAE paper (2007-01-4133) that shows lube wear rates drop all the way out to 15k miles. What that paper shows is that oil changed frequently has approximately a 33% higher wear rate towards the front of an OCI (certainly dependent upon lube and engine). Now, 33% sounds shocking, but you have to keep that in perspective. It is essentially the difference of wear rates dropping from 3ppm to 2ppm. And we MUST look at the exposure duration for those ppm counts to really understand wear rates. Folks - that just does NOT make any real difference in the lifecycle of an engine; at least not relative to the typical ownership lifecycle. As the OCI lingers on, the wear rates drop, pracitcally to zero in some manner. I point this out because there may be some German study that does show that a thinner lube makes a "10%" reduction in wear at uber-cold temps. But often those wear rates are so incredibly low already, that a 10% reduction means NOTHING in real world ownership criteria. The shift is basically moot; it's a fraction of an already miniscule wear rate. And what does one pay for that 10% gain in wear reduction? 2x+ more money, for a 10% reduction, resulting in a shift of total lifespan of equipment that the owner likely never hold onto long enough to realize?

The SAE study I reference shows that the tribochemical anti-wear layer is the number one thing that contributes to wear reduction, and that wear rates can be positively affected by running a longer OCIl. I agree that vis may or may not play a small part, but it simply pales in contrast to the other contributors, when the totality of wear is considered. Why is this? Because before pressure gets to float a part in a bearing, there is NOT much metal to meatl contact. It is essentially the two metal parts pressing their chemical-barriers together. As long as that anti-wear layer is intact, it retards wear until the pressure can float the parts on the hydrodynamic wedge. So, if a thicker lube does take a bit longer to get where it's going, you won't see wear escalate in the same magnitude relative to the time shift. IOW - it may take a thicker lube 3x longer to get to the upper end, but that 300% greater time may only make a 10% shift in wear. And that differential does not even show up in all engines; the Dmax seems nearly immune to wear. So that 10% German study may only reveal a 1-2% shift in a Dmax (I'm picking out ficticious numbers for an example here). Get the point?

I'm being specific to this engine family; it does not see much wear at all, and it really does not shift wear rates greatly based upon lube choice. A thinner lube here might well make the Dmax start a bit quicker, but it's not going to make the engine last much longer. The OP would have to run this rig out way past 500k miles to likely see any shift in the wear rates great enough to affect his ownership lifecycle. Is that REALLY going to happen?

I'm not saying you two wrong; I'm saying you haven't convinced me until I get to read, disect and understand the study you claim to support your position.

I agree that the OP is likely to benefit from a thinner fluid. But I stand by my statements that wear reduction isn't going to be one of them; not relative to the overall lifecycle of the Dmax engine, and the likely projected ownership duration. I've got about 600 UOAs of Dmax engines, running all kinds of lubes in all kinds of temps. I've seen the data much deeper and broader than most of you. My claims are backed up by my UOA macro data, SAE study, and the direct knowledge of this engine family.

I welcome your challenges, but please be specific and show how your data would usurp mine as it directly relates to a Duramax.

 

[m37charlie]

Originally Posted By: dnewton3
I've got about 600 UOAs of Dmax engines, running all kinds of lubes in all kinds of temps. .


Do you have one UOA, let alone a set of them, involving cold soaked starts with 15W40 at -35C or lower?

Charlie

 

[durallymax]

Seems theres a lot of things a bit overthought in this thread.

Bear with me im new to being an oil geek, but have turned a wrench or two on the Dmax's.

The number one thing I've noticed over the years is that nearly all of the oil related "failures" have not been due to the oil itself, rather they have been from outside contributing factors.

[censored] even logging thousands of miles with nothing but fuel in the crankcase doesn't seem to bother the Dmax. Theres plenty of trucks I've drained over 5 gallons out of the crankcase. A couple I drained just to get them through plowing the next day only to have them come back and have a trail a diesel following them in the snow and filling another 5 gallon pail.

The bottom line is simply this, you will not run the engine out past its service life in stock form. The rest of the truck will nickel and dime you and fall apart well before you ever reach the day the engine itself is worn out. You may replace turbos, and the CP4 system will probably give you some issues, but the short block is stout and although it was only engineered for 350,000 miles, its proving it can hold its own much longer than that.


Warranty is obviously a non-issue to this guy as he already has all of the emissions devices deleted.

I saw a couple of others posted they had their systems removed as well. Who's tuning are you using? Many tuners suspended their sales as the EPA threats have materialized and are beginning to get real.

Question of the day to those of you who deleted the system. I am by no means a "greenie" in favor of the systems, however I don't hate them because I believe they can work. I would like to know how you figured your savings after deleting. The early results were barely showing 1mpg improvement. That doesn't add up very fast. Many have cited DEF costs as being the reason, however if you figure the average consumer price of a 2.5 jug of DEF at $12 and the consumption of one gallon per 1000 miles average (which is higher than GM predicted but closer to real world), you would spend less than $500 on DEF. Maybe its the availability for you, DEF is easily available near me. With the amount of equipment we have running it we buy it for $2.20/gallon. That makes the cost even lower. You can stockpile a years supply in your garage with no concerns.

Add to all of that the fact that you warranty is gone. While the Duramax has an impressive record, there's still plenty of things to go wrong, most notably the CP4 injection system. Not a cheap fix at all.

Was it your fear of downtime related to the system? Aside from a few early calibration issues, the SCR systems have been running very well.

Did you simply just want more power than was already on tap? For a purpose or just for fun?


The reason I ask these questions is because I get asked by a lot of LML owners if I can remove their SCR/DPF systems and I always ask them first, "why". Most have a blank stare, like why would I even question them. The reality is that there are far too many people buying these trucks with the impression that they need to delete the evil SCR because it uses DEF and the evil DPF because on EGR/DPF only trucks it caused issues. The main issue is peoples lack of understanding of the SCR system and how it allows to engine to be tuned so much differently and actually have power while creating few particulate emissions which leads to better MPG's and fewer DPF issues. They think that DEF is the worst thing in the world until you show them that nearly every auto store, gas station and farm store has it as well as the truck stops and oil supply companies bulk storage. Then you break the price down per mile and they see it only costs $0.005/mile to keep the DEF tank full while in return you get a fuel economy gain and more power.

In the end, I have yet to delete a system. There is one thing I wont argue, power. Some people just want more for whatever reason. I used to, still do love power, but I think the 397hp coming out of the Dmax now is enough for 99% of the people out there. My LB7 Dmax was a lot of fun at 450hp but once the big turbo went on and things got pushed closer to 600hp it turned into unmanageable power that wasn't fun anymore, needing 4x4 to pass a car, replacing tires non-stop, freshening the trans up, just got old. Fun for a toy, not for a $50,000 daily driver.


Not criticizing you just curious, sorry for the hi-jack.

 

[CONMCK]

durallymax;
H & S tuner, set on wild.
Total cost $1800.00
GM dealer install, warranty is still intact unless warranty claim is due to my abuse/neglect. I'm covered, lets just leave it at that.
I bought the truck new, had just over 25,000 KM and never reset the mileage on the DIC. Mileage was 15.9L/100km, 17.85 MPG canadian, hand calc is 17.8 mpg actual..
Since the delete, reset the DIC, programmer set on wild, never changed, almost 10,000 km and now the mileage is at 13.6L/100 km, 20.83 MPG off the DIC, hand calc is 13.7 L/100km, 20.71 actual.

So I'm almost 2.2L/100km, or 3 mpg better, (the regen itself used (averaged) approx .6 to .7L/100km, about 1 mpg, the programmer I guess is good for approx 1.5 to 1.6 L/100 improvement, another 2 mpg.

So, my fuel savings alone is approx 2.2L/100km, or 220 L/ 10,000 km. $250.00 savings + def $25.00. Total savings $275.00 every 6200 miles or 10,000km.
The cost of the delete kit will be recovered in 65,000 km, 41,000 miles, not including resale I get for the parts (DEF tank, entire exh system)some day. I brought all that stuff home from the shop.

Now for actual driving, it is night and day different,
turbo lag (dead pedal) is pretty much non existant.
Approx 100 more HP + 150 ft/lbs more torque at peak, which is now available if I choose to use it.
Zero issues, no codes, nothing (touch wood),
With the egr off the oil definately stays cleaner longer, whether or not that will allow me to extend my oil changes further (more cost savings) is still to be determined.
With the present setting on the H & S tuner, it has the adaptive learn on the transmission, and I'm convinced the transmission actually shifts smoother, definately does slowing down downshifting.

FYI, I went with a 4" exhaust from the turbo back, with a muffler, yes it is a bit noisier than the factory set up but once up to highway speed you hear nothing.


The whole idea for me doing the delete was not for the power, it was for the mileage gains. I hope not to shorten the life of the truck by adding the programmer, and I will admit at my age, I do not drive with a heavy foot. Jack rabbit starts are a thing of the past for me, and pretty much travel the highway close to the speed limit. I can see where an abusive driver could create havoc on the power train, hope thats not me ....ever, although the wild setting pretty much keeps things within the limits of the truck. There is one higher setting (hot), which is not recommended for the abusive type drivers....Shop foreman suggested wild setting is as high as I go as he has not had any issues yet (touch wood again) on wild or any lower setting.

 

[durallymax]

Originally Posted By: CONMCK
durallymax;
H & S tuner, set on wild.
Total cost $1800.00
GM dealer install, warranty is still intact unless warranty claim is due to my abuse/neglect. I'm covered, lets just leave it at that.
I bought the truck new, had just over 25,000 KM and never reset the mileage on the DIC. Mileage was 15.9L/100km, 17.85 MPG canadian, hand calc is 17.8 mpg actual..
Since the delete, reset the DIC, programmer set on wild, never changed, almost 10,000 km and now the mileage is at 13.6L/100 km, 20.83 MPG off the DIC, hand calc is 13.7 L/100km, 20.71 actual.

So I'm almost 2.2L/100km, or 3 mpg better, (the regen itself used (averaged) approx .6 to .7L/100km, about 1 mpg, the programmer I guess is good for approx 1.5 to 1.6 L/100 improvement, another 2 mpg.

So, my fuel savings alone is approx 2.2L/100km, or 220 L/ 10,000 km. $250.00 savings + def $25.00. Total savings $275.00 every 6200 miles or 10,000km.
The cost of the delete kit will be recovered in 65,000 km, 41,000 miles, not including resale I get for the parts (DEF tank, entire exh system)some day. I brought all that stuff home from the shop.

Now for actual driving, it is night and day different,
turbo lag (dead pedal) is pretty much non existant.
Approx 100 more HP + 150 ft/lbs more torque at peak, which is now available if I choose to use it.
Zero issues, no codes, nothing (touch wood),
With the egr off the oil definately stays cleaner longer, whether or not that will allow me to extend my oil changes further (more cost savings) is still to be determined.
With the present setting on the H & S tuner, it has the adaptive learn on the transmission, and I'm convinced the transmission actually shifts smoother, definately does slowing down downshifting.

FYI, I went with a 4" exhaust from the turbo back, with a muffler, yes it is a bit noisier than the factory set up but once up to highway speed you hear nothing.


The whole idea for me doing the delete was not for the power, it was for the mileage gains. I hope not to shorten the life of the truck by adding the programmer, and I will admit at my age, I do not drive with a heavy foot. Jack rabbit starts are a thing of the past for me, and pretty much travel the highway close to the speed limit. I can see where an abusive driver could create havoc on the power train, hope thats not me ....ever, although the wild setting pretty much keeps things within the limits of the truck. There is one higher setting (hot), which is not recommended for the abusive type drivers....Shop foreman suggested wild setting is as high as I go as he has not had any issues yet (touch wood again) on wild or any lower setting.



Being in Canada does have its perks. One of the reasons I'm still a GM fan. Customer service.

Ford immediately puts out all kinds of bulletins banning everything everywhere, GM does what it takes to keep people happy.


H&S isn't selling in the US for now.

Your mileage gains are much higher than most. Possibly due to the fact that when most people do all of the work and have the added power, they always use it.

The LML still isnt going to show the gains of the LMM due to it being tuned so much better, however its nice to see some improvement.


The transmission TAPs relearn can be done with many programs or at the dealer, it resets to default and relearns your driving and the power from the ground up smoothing out the shifts as it goes. The Full relearn is a Tech II only thing, but only needed after rebuilding or installing a rebuilt transmission as it allows the TCM to learn the clearances.


Glad to hear yours is doing so well.

 

[m37charlie]

The people in the service dept of the Detroit Diesel dealer I use for service on the Unimog were very enthusiastic that I removed the EGR on my 902.912 6.37L Mercedes diesel. "Best modification you can do!" "The engine will last forever!" etc etc. Plus the cooler had failed once already (coolant leak into intake).
And it is definitely good for the oil, especially since MB was kind enough to install a centrifuge on its' EGR 906s which I did NOT delete!

Charlie

 

[durallymax]

Originally Posted By: m37charlie
The people in the service dept of the Detroit Diesel dealer I use for service on the Unimog were very enthusiastic that I removed the EGR on my 902.912 6.37L Mercedes diesel. "Best modification you can do!" "The engine will last forever!" etc etc. Plus the cooler had failed once already (coolant leak into intake).
And it is definitely good for the oil, especially since MB was kind enough to install a centrifuge on its' EGR 906s which I did NOT delete!

Charlie


I encourage the removal of EGR only systems. EGR is a backwards approach. SCR is an alternative to EGR, however many OEMs left some EGR on their engines, although NOX compliance can be met without it, the off-road sector proved that with John Deere being the only OEM with plans to use EGR for meeting Tier IV Final. Their PM emissions limit is slightly higher than the on road, but their NOX limit is the same.

I am strictly referring to the latest breed of SCR/EGR/DPF systems which are allowing the engines to run much better, have fewer issues and get better mpgs.

In the off road sector our SCR equipped tractors get the best fuel efficiency out of any of them, they also have the cleanest oil and longest OCI's. Not to mention you can run them in the shop if needed and not feel nauseated.

 

[m37charlie]

Originally Posted By: dnewton3
Originally Posted By: skyship
Important part I disagree with:
He may need a thinner lube; that would something that he can be the judge of, when it comes to starting ease. But it will NOT make any darn difference in wear.

I asked the senior geek in the ZF oil analysis lab out cold start wear, as I know him from visiting the R&D section every month and although they do mostly transmission fluid analysis, he did work for VW engine R&D before and is one of the leading bearing wear and oil analysis experts in Germany. His answer was based only on UOA results for VW diesels, so might not be applicable to truck engines.
The data file he quoted from was for a comparison of test rig data based UOA figures comparing a good quality 10/40 conventional with a full synthetic 0/40 doing multiple cold starts cycles with only 5 minute runs (The engine was in a freezer). The results were better with the 0/40 and when fed into a software program to figure out the TBO of a typical cars engine in central EU, it translated to a difference of just under 10%. BUT he would not comment on whether that was because one oil was synthetic and the other conventional or because one was an 0W. Both oils had the same Zinc and add pack contents, so it had to be one of the two factors. The only real conclusion I could get from him was based on his own old diesel van, as I asked him which oil he used and it was 15w40 in summer and 0/40 in winter.


Interesting, but not really easy for me to disect.
I do have some thoughts though:

1) whatever study this was, I really don't put much stock into it unless I can read it. I'm not saying you're wrong or being untruthful. I'm saying there is WAY too much left out to really understand the criteria of the German study. Plus, they often focus on models and lubes specific to their part of the world; perhaps not directly applicable to a Dmax in NA.
2) repeated cold starts with run times no more than 5 minuets? Several Q's here:
a) was the rig allowed to completely cool between starts?
b) was this a full engine, or just a sympathetic test rig?
c) what controls were in place?
d) what other characteristics were nullified as controllables?
e) the "results were better"? How defined? a 10% reduction in wear I presume? Over a period of what projected lifecycle? (IOW - if planned life is 400k miles, then would we expect 40k less miles of lifecycle? Should that matter to someone who only keeps a vehicle for 150k miles?) In essence, how does the projected lifecycle degredation compare/contrast to ROI?
f) Was there a manifestation of wear-rate shift tested at different OCI durations? (IOW - at what exposure duration was the test run at? Was it affected by OCI duration, if even tested at all as part of the DOE?) We know that nearly all lubes will be "better" when aged; so could the 10% difference be enhanced or diminished with shorter/longer OCIs? Many times these studies are run with "new" oils; that does NOT reflect a real world difference. As lubes age, the performance differential grealy shrinks; the perceived advantage of one lube over another reduces as they all beging to homogenize with OCI extensions.
g) does a 5 minute run time really reflect real world experiences for most of us? I understand that it might be significant to the study, but how many of us have this experience as the "normal" operational pattern for our engines?

Get the point? I'm not saying you're wrong, but I have a lot of questions about what the DOE was, how the test was set up and controlled, etc.



Here's my point to you, and to Charlie:
the real world application of these different lubes does not manifest into longevity issues in a Dmax.

I point to the data in my "normalcy" article. Consider the SAE paper (2007-01-4133) that shows lube wear rates drop all the way out to 15k miles. What that paper shows is that oil changed frequently has approximately a 33% higher wear rate towards the front of an OCI (certainly dependent upon lube and engine). Now, 33% sounds shocking, but you have to keep that in perspective. It is essentially the difference of wear rates dropping from 3ppm to 2ppm. And we MUST look at the exposure duration for those ppm counts to really understand wear rates. Folks - that just does NOT make any real difference in the lifecycle of an engine; at least not relative to the typical ownership lifecycle. As the OCI lingers on, the wear rates drop, pracitcally to zero in some manner. I point this out because there may be some German study that does show that a thinner lube makes a "10%" reduction in wear at uber-cold temps. But often those wear rates are so incredibly low already, that a 10% reduction means NOTHING in real world ownership criteria. The shift is basically moot; it's a fraction of an already miniscule wear rate. And what does one pay for that 10% gain in wear reduction? 2x+ more money, for a 10% reduction, resulting in a shift of total lifespan of equipment that the owner likely never hold onto long enough to realize?

The SAE study I reference shows that the tribochemical anti-wear layer is the number one thing that contributes to wear reduction, and that wear rates can be positively affected by running a longer OCIl. I agree that vis may or may not play a small part, but it simply pales in contrast to the other contributors, when the totality of wear is considered. Why is this? Because before pressure gets to float a part in a bearing, there is NOT much metal to meatl contact. It is essentially the two metal parts pressing their chemical-barriers together. As long as that anti-wear layer is intact, it retards wear until the pressure can float the parts on the hydrodynamic wedge. So, if a thicker lube does take a bit longer to get where it's going, you won't see wear escalate in the same magnitude relative to the time shift. IOW - it may take a thicker lube 3x longer to get to the upper end, but that 300% greater time may only make a 10% shift in wear. And that differential does not even show up in all engines; the Dmax seems nearly immune to wear. So that 10% German study may only reveal a 1-2% shift in a Dmax (I'm picking out ficticious numbers for an example here). Get the point?

I'm being specific to this engine family; it does not see much wear at all, and it really does not shift wear rates greatly based upon lube choice. A thinner lube here might well make the Dmax start a bit quicker, but it's not going to make the engine last much longer. The OP would have to run this rig out way past 500k miles to likely see any shift in the wear rates great enough to affect his ownership lifecycle. Is that REALLY going to happen?

I'm not saying you two wrong; I'm saying you haven't convinced me until I get to read, disect and understand the study you claim to support your position.

I agree that the OP is likely to benefit from a thinner fluid. But I stand by my statements that wear reduction isn't going to be one of them; not relative to the overall lifecycle of the Dmax engine, and the likely projected ownership duration. I've got about 600 UOAs of Dmax engines, running all kinds of lubes in all kinds of temps. I've seen the data much deeper and broader than most of you. My claims are backed up by my UOA macro data, SAE study, and the direct knowledge of this engine family.

I welcome your challenges, but please be specific and show how your data would usurp mine as it directly relates to a Duramax.


Is use of 50 wt oil a good idea in ANY engine a smart thing at -20F? If not then use of 15W40 is not a smart thing for cold soaked starts (except for block heater) at -40F. The viscosities are about the same.
You are smithing a lot of words, I think it verges on sophistry, in order to avoid the "embarrassment" of saying that someone who lives in a climate with significant exposure to -40C/F should use 0W30/40 or 5W30/40 in the winter - these are usually synthetics! Your anti synthetic bias has seemingly overwhelmed common sense; the OP asked a simple question that deserved simple answers. He can/should use CH4/CI4/CJ4 0 to 5w30 or 40 in the Alberta winter.
Sorry for the rant.

Charlie

 

[CONMCK]

Originally Posted By: durallymax



Being in Canada does have its perks. One of the reasons I'm still a GM fan. Customer service.

Ford immediately puts out all kinds of bulletins banning everything everywhere, GM does what it takes to keep people happy.


H&S isn't selling in the US for now.

Your mileage gains are much higher than most. Possibly due to the fact that when most people do all of the work and have the added power, they always use it.

The LML still isnt going to show the gains of the LMM due to it being tuned so much better, however its nice to see some improvement.


The transmission TAPs relearn can be done with many programs or at the dealer, it resets to default and relearns your driving and the power from the ground up smoothing out the shifts as it goes. The Full relearn is a Tech II only thing, but only needed after rebuilding or installing a rebuilt transmission as it allows the TCM to learn the clearances.


Glad to hear yours is doing so well.


H & S is not selling product in Canada at the moment either.
durallymax, are you a licensed diesel mechanic?? Curious what your experience and expertise is on the lml's. I may have a few questions to ask!