LMM Duramax 400k mi; Delo 5w-40 20k mi

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Vehicle 2009 Chevy 3500 cutaway chassis. In service date Aug 2011 Engine: Duramax LMM Oil: Chevron Delo 5W40 Full Syn CJ4 for whole life. NO Additives! Filter: Fleetguard LF16102 Service Interval: 20,000 miles for oil and filter Below is a data summary report for this unit. On the right side are the averages and the max values for each measured item. TAN was not tested at every sample..hence only 12 counts vs 20. [Linked Image from bobistheoilguy.com] Filters are cut open at every service and checked. Will post pics if anyone interested. Unit has one more service interval on CJ4 and then will switch to CK4 Delo 5W40 syn.
 
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This is incredible. Also incredibly good. I'm not an expert on Duramax engines but it seems like this is one with a "9th injector" and therefore no fuel dilution due to regeneration. What a difference between this engine and previous ones with up to 6% fuel dilution. The main difference of the CK4 seems to be less Zn/P. Will be interesting if wear #s go up.
 
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What a great sheet of information that is. If that's something that Polaris offers, that would be a good reason to use them. Thanks for sharing this with us!
 
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Originally Posted By: leje0306
Ummm bypass filter?
No...no bypass filter...just the full flow Fleetguard. I bought a bypass system (Racor)...but never installed it once I saw the numbers were what they are.
 
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Originally Posted By: dustyroads
What a great sheet of information that is. If that's something that Polaris offers, that would be a good reason to use them. Thanks for sharing this with us!
Dusty - it is included in the Polaris service. There is a Management Reports menu that has various reports you can run, one of them being the Data Analysis Report:
 
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After doing a little reading around the site I think I should maybe add a few comments. I use synthetic not because it is "better"...this particular unit lives in Canada and the upper midwest most of it's time. The unit does not get plugged in...and has no engine pre-heater. This unit is on-call on demand type of service...the phone rings and wheels roll within 15 minutes and, it has to GO..not putter along for a nice smooth warm up...the engine usually gets maybe 5 minutes and it has to hit the interstate. Cold flow properties are therefore pretty critical...so that's why it uses a 5w40 syn. In summer, it would likely perform fine with a conventional 15w40...but in the interest of simplicity it stays on 5w40. the other oils in this unit are also synthetics..and they are such for the same reasons. (although the Dex6 in the transmission was changed to syn because of our original Dex6 oil not holding up). I use Chevron products because I like my distributor, I can get the oil at any Wal-Mart on the road and, their stuff seems to have worked for me over the years. If that all went away I wouldn't hesitate to use Shell or Mobil stuff...just as good. And...no fancy filtration of any kind..just a full flow cellulose media from Fleetguard..a good filter but not a fancy box welded nut or any of that stuff. We will get to see if that makes a difference soon...my Fleetguard pricing has gone waaay up (volume disc gone) so the last box of filters I bought were Wix XP.
 
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Originally Posted By: 2015_PSD
Originally Posted By: dustyroads
What a great sheet of information that is. If that's something that Polaris offers, that would be a good reason to use them. Thanks for sharing this with us!
Dusty - it is included in the Polaris service. There is a Management Reports menu that has various reports you can run, one of them being the Data Analysis Report:
Thanks for that! thumbsup I had just decided to go with Cat SOS. I like the idea of just dropping off the samples and quick reports with Cat, but I do like that Polaris report as seen above.
 
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dnewton3

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Doing the math; 20 OFCIs at 20k kms each - that's 400k kms (give or take a little). That engine is on death's doorstep, and probably won't last much more than an additional 600K kms! LOL! (I am presuming kms because it's in Canada). Averaging less than 1ppm FE per 1k kms; nice! All other metals so low they are inconsequential. (put's it about 1ppm / 1k miles "ish") I do take exception to the std dev values they post; technically speaking anything less than 30 samples makes for too much error in calculations. But that is the statistical quality control engineering in me speaking ... OTOH - it's a Dmax; would we expect anything other than boring (stellar) results? And, this is an LMM; it does have in-cylinder regens! Hard to tell it though. It was the subsequent LML that introduced the downstream 9th injector.
 
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He said mi, not km. Amazing that the fuel dilution is so low with in cyl regens. Must have a proper duty cycle vs the other recent Dmax post (1-2 mile runs) Remember when the Duramax came out and all the Ford people were belittling it because of the Al heads? Look how it turned out vs the Ford 6.0/6.4.... Charlie
 
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Originally Posted By: m37charlie
He said mi, not km. Amazing that the fuel dilution is so low with in cyl regens. Must have a proper duty cycle vs the other recent Dmax post (1-2 mile runs) Remember when the Duramax came out and all the Ford people were belittling it because of the Al heads? Look how it turned out vs the Ford 6.0/6.4.... Charlie
Except now the current Ford diesel has aluminum heads. LOL
 
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It's miles...not km. Bought it in the US. To be fair and open...this engine's emission system has been modified. It does return to stock form if it goes to California or other emission hyper locations (about 45 mins to change it back over). About 15% of these miles are with the unit doing regens etc but the rest are more like an LBZ...just EGR and DOC...no DPF. It was ugly oil samples (and fuel mileage) from another LMM that convinced me this unit needed to be modified. Based on those samples I would have used conventional oil and likely 10k mi oil changes...and found other ways to deal with the cold start n go situatuons. I'd have no problem treating the newer DEF Duramax's the same as this one...20k. That all said..still happy with the results and I think it's decent proof the Dmax does not need short "oil is cheap" type service intervals.
 

dnewton3

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So my mistake; apology for presuming it was kms. However, that only make it more impressive. You're at/near 400k miles (20 OFCI x 20k miles each). And still getting great wear. Hard to argue with your success; here a syn and Dmax are working well. I'd not change a thing, unless you'd consider adding a BP filter and then extending the OCIs out further.
 
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I did push one service out to 31,000 miles...just to see..and that sample's values are included in the list above...and it did really well...even out that far. It was summer however..so I backed it back down to 20,000 to make myself feel better about winter and idling and what that can do..and 20k is easy math for my feeble brain! The worst oil sample to come from this truck was a short change interval to get things back on the perfect 20k interval...8000 miles.. it was not as nice as the rest. In an earlier post you mentioned std deviation values..and how you liked 30 samples plus. If it is easy to explain....what is the standard deviation value and what is it's usefullness in these reports?
 

dnewton3

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I can certainly give some "top level" viewpoint in regard to my comments. Just please realize that the world of statistical analysis (I do statistical process quality control for a living), is not something one will understand fully in a short web-session. But I believe I can make it consumable for most in just a post or two. In simple terms, standard deviation (aka stdev, or "sigma") is the magnitude of variation of a set of numbers, that which represents the "normal" variation away from the average value of those numbers. Consider the following ... think of these 10 numbers: 6,4,6,4,6,4,6,4,6,4 ... the "average" of those is "5", and the variation away from "5" is very low. think of these 10 numbers: 10,0,10,0,10,0,10,0,10,0 ... the average of those is still "5", and the variation is MUCH greater. Averages (aka the "mean") are not the same as standard deviation (aka "variation"). So that explains what stdev is. Now we need to understand why we need some many samples to get an ACCURATE value for stdev ...Look at the graph below ... it represents the 95% confidence interval of the value of 1 for any given sample size. What you see are the two response curves (upper and lower) for the considered deviation away from the value of "1", in terms of standard deviation. Standard deviation is the "variation" of a data stream (typically a process measurable). The "Y" axis (vertical) is the amount of variation away from the value of 1. The "X" (horizontal axis) is the quantity of samples taken. As you can see, the amount of std deviation variance gets VERY broad as the sample size gets smaller. Typically 30 is a minimum, and 50 is preferred. Anything much over 50 does not greatly increase the accuracy; anything past 100 does nothing to refine the data in pragmatic terms. Having only 20 samples does not truly give a good indication of std dev; too much inaccuracy in the math below 30 samples. At 100 samples, the actual value of "1" could be as low as .85 and as high as 1.17; the difference being .32 or about 1/3 the value of "1". At 50 samples, the actual value of "1" could be as low as .825 and as high as 1.25; the difference being .425 or less than 1/2 of the value of "1". At 30 samples, the actual value of "1" could be as low as .8 and as high as 1.35; the difference being .55, or about 1/2 of the value of "1". At 20 samples, the actual value of "1" could be as low as .75 and as high as 1.5; the difference being .75, or about 3/4 the value of "1". At 10 samples, the actual value of "1" could be as low as .7 and as high as 1.8; the difference being 1.1, or more than the actual value of 1 itself! As you can see, the accuracy of stdev falls off sharply below 30 samples. It does not increase dramatically over 50 samples. That range (30-50 samples) is the "sweet spot" where you get the best bang for the buck. You can take a LOT more samples, but you'll not get a huge increase in accuracy for the efforts. You can take a bit fewer than 30 samples, but your accuracy falls of horridly. I have thousands upon thousands of UOAs in my database. I don't really need that many, but it does help see trending year over year. But the accuracy of the data really is just as good when I look at 50 samples, versus 500 samples. Once I have 50 samples, I have a very good understanding of the typical (normal) process variation. Knowing the mean (aka the "average" valve) is only half of the story. You must also understand the variation (standard deviation) away from the mean. This is just an application of what most would understand to be called "Six sigma" control. Mathematically, you can get an "average" using as few as two numbers. Mathematically, you can get a "standard deviation" using as few as three numbers. But for them to be accurate, you need a lot more than that. So my comment regarding your data sheet is that they certainly can give you a stdev value for 20 samples, but it's not an accurate trustworthy value. You need 10 more samples AT A MINIMUM to really get a decent stdev value. This is why I tell folks to quit looking at one or three or five UOAs and think that they understand how the equipment is performing. You can look at one or two UOAs, compared to macro data, and have a very good understanding. You CANNOT look at even 20 UOAs, of micro data, and yet know what is "normal". When you get a chance, please read the article about UOA normalcy; it will help you understand stuff better. It is critically important to understand the differences between macro and micro data sources. https://bobistheoilguy.com/used-oil-analysis-how-to-decide-what-is-normal/ There's a LOT more to it than just this, but this is at least where most folks can get a decent understanding of why I complain so much about understanding "variation" of UOAs. Too few people here understand, but think they know it all. I'm not a chemist; I cannot explain tribology in those terms and I must defer to those who have chemical backgrounds. But results-driven data (like UOAs), I know really well; it's what I do for a living. I cannot tell you what goes into a lube bottle and how it interacts with all the other chemicals in the bottle. But I can darn well tell you what happens when those bottles come out of the crankcase!
 
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Originally Posted By: PiperOne
Originally Posted By: leje0306
Ummm bypass filter?
No...no bypass filter...just the full flow Fleetguard. I bought a bypass system (Racor)...but never installed it once I saw the numbers were what they are.
Wow, amazing results then
 
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Dnewton3....first off...thanks for the explanation. So basically...once I get a decent sample pool size...I could look at the std deviations and when I see values outside that...it can flag a problem for me? For example...if my average viscosity was say 14 and the std deviation was 3...I would be concerned only if the number was lower than 11 or higher than 17 (very hypothetical numbers!)?
 

dnewton3

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"Normal" is considered being 3 sigma off of the mean or less. In your example, only being "3" off (11 or 17) would be completely normal and expected. In your example, non-normal would be a low of 5 and a high of 23. It it also normal (not statistical, but the vernacular use) to occasionally see a spike that is due to a particle streak; these will jump up suddenly and then settle over an OCI or two, as the residual is drained successively. It happened to my Dmax; got a spike in Pb that dropped upon the next OCI. In UOAs, it's very important to watch for trending. Try to discern if the means are going up. Knowing the stdev is important, but not the whole story. Need to know the mean, the stdev, and trending. Which is why a few UOAs are just not nearly enough to know about your individual equipment performance. Micro data is just really hard to come by due to the time and money it takes to get there. Macro data is useful in that you get a decent view of overall market response. But you are far and away much further along than most folks! Hope that helps.
 
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Originally Posted by dnewton3
Doing the math; 20 OFCIs at 20k kms each - that's 400k kms (give or take a little). That engine is on death's doorstep, and probably won't last much more than an additional 600K kms! LOL! (I am presuming kms because it's in Canada). Averaging less than 1ppm FE per 1k kms; nice! All other metals so low they are inconsequential. (put's it about 1ppm / 1k miles "ish") I do take exception to the std dev values they post; technically speaking anything less than 30 samples makes for too much error in calculations. But that is the statistical quality control engineering in me speaking ... OTOH - it's a Dmax; would we expect anything other than boring (stellar) results? And, this is an LMM; it does have in-cylinder regens! Hard to tell it though. It was the subsequent LML that introduced the downstream 9th injector.
so was the whole "that engine is on death's doorstep" a sarcastic comment dnewton3?
 
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Originally Posted by oakaro68
so was the whole "that engine is on death's doorstep" a sarcastic comment dnewton3?
Originally Posted by dnewton3
Doing the math; 20 OFCIs at 20k kms each - that's 400k kms (give or take a little). That engine is on death's doorstep, and probably won't last much more than an additional 600K kms! LOL! (I am presuming kms because it's in Canada).
What do you think?
 
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