LML Duramax Oil Recommendations

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Originally Posted By: userfriendly
You cannot connect the dots as you wish, then adjust engine oil viscosity to suit your logical fallacy.
Light truck Diesels are putting out 400 hp @ 3,500 RPM with 6.5 liter engines and 10L oil sumps.
You are comparing that, to a 13L engine producing 550 hp @ 2,200 RPM and a 40L sump?
This has nothing to do with UOA's, history or comfort zones.
There is nothing stopping someone with a 3500 fully loaded pulling a 5 ton trailer,
from going up a mountain pass with their foot on the floor all the way.
Now consider a tuned light truck Diesels @ 550 hp and the same 10L sump.
But this time empty, going up the same mountain pass blowing by everybody @ 100 mph.
Neither examples are "jerking 80,000 lbs", but they are not going up that hill with 10w30.


But my small ag tractor with a smaller engine than the Dmax also gets a 10w30 and works it hard on some pretty hot days. Same deal. Works great. I get less shearing from 10w30 HDEO in all my applications than I ever got with a XXw40.

And while it is true that the older engines like the Detroit 60 are getting their max HP at 2100, they also are getting max torque at 1200. Many HD diesels in commercial trucks are doing all their work between 1300 and 1500 RPM. That is substantially lower than the Dmax is doing stuff and that can really stress components. GM with it's pickup Dmax is about the only holdout that hasn't moved to a XXw30 as both a factory fill and recommended vis nowadays.
 
My 06 Dmax listed 10w30 as an option, but not in the new higher powered LML.
Personally I've used XW30 in my own LML, 0w30 for 7,000 miles last winter.
I have an unopened pail of Mobil 1330 HTHS 3.7 which will go in from Aug-Nov.
But, I stop short of recommending others to follow, not knowing their driving habits and other variables.
Rumor has it GM is rolling out a new Dmax either in 17 or 18, maybe it will be a 5w30 engine.
With any luck, they will also drop the 6.0L gasoline engine and put the more economical 5.3L in the HDs.
In fact, the 4.3L V6 in a 3500 would suit me just fine.
 
Originally Posted By: redneck47441
What oil filter or you folks using on the LML?


I have used the Mobil 1 filters but next OCI I'm changing to Fram Ultra $6 dollars cheaper and I don't think I'm giving anything away in quality.
 
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All the Dmax engines take the same filter; there's no change I know of from 2001 on up to current.

Pick the one you want. The engine itself could not care less. I've seen no data that indicates a practical ability to discern any different in wear control from one brand to another. As long as you use a quality brand name, properly spec'd for your vehicle, it will be fine.
 
Dnewton thank you. I just lover analyze it and start thinking about flow rates, filter media holding capacity, material used for anti drain back valve. There seems to be a lot of opinions on this stuff.
 
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On a similar but different note. After reading the UOA threads and listening to what DNewton has to say, I like raw data to guide me and I like to be different. I just started running PetroCan semi synthetic 10w30 Duron in my new Cummins. I looked at data, cost, availability, cold flow etc to come to a choice.

I want to start doing some UOA on this engine/oil combo in the near future but I only have 26,000km on so far so break in metals will still be prevalent.

Sure the manual calls for a synthetic 40 weight oil but the caveat is that it can also use a Cummins CES 20081 now 20086 oil. Reading further that allows any oil that Cummins allows. PetroCan Duron SHP 10w30 meets that spec.

So I found an oil that cost me 4.5$ a liter, has good cold flow properties, easily obtainable in my small town.

Further, Burbanite, just anecdotally, out here on the prairies, I know many people who run Dmaxes, Cummins and even various Powerstrokes that run conventional 15w40 year round. No engine related failures. In our harsh climate you simply just plug in prior to starting in the cold. Engines are just fine. Many of these guys run their rigs hard. Perhaps not often on mountain passes but I can say for certainty that many run well over their stated limits. This is just how it is when a guy is trying to make a living out here. These guys run their rigs hard and run them a long time.

Why did I deviate from the norm of 15w40? I wanted to run a 30 and be different and I might be able to find conventional 15w40 for perhaps a 1$ a liter cheaper. Cost difference is minimal.
 
Originally Posted By: BrianF
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Further, Burbanite, just anecdotally, out here on the prairies, I know many people who run Dmaxes, Cummins and even various Powerstrokes that run conventional 15w40 year round. No engine related failures. In our harsh climate you simply just plug in prior to starting in the cold. Engines are just fine. Many of these guys run their rigs hard. Perhaps not often on mountain passes but I can say for certainty that many run well over their stated limits. This is just how it is when a guy is trying to make a living out here. These guys run their rigs hard and run them a long time.

Why did I deviate from the norm of 15w40? I wanted to run a 30 and be different and I might be able to find conventional 15w40 for perhaps a 1$ a liter cheaper. Cost difference is minimal.



I, too, started running 10w-30 HDEO (dino) almost 10 years ago now in my Dmax. Just wanted to do something different; to prove that thinner does not mean less wear control. By now, I think it's becomming much better accepted, but certainly I (and a sparse few others) were "daring heretics" at the time. RR1 did so in his 6.0L PSD. Both he and I never had a bad UOA. I ran Rotella; he ran Deere. The thinner grade 10w-30 does every bit as well in wear control. It is not "better", but it's certainly not "worse". IOW - the grade is a wash in terms of wear. But there are other benefits such a fuel economy and ease of starting with a thinner grade. Thinner lubes and syns do give an advantage in uber cold temps. They help the diesels crank over a bit quicker; this can be an benefit if you're on that feathery edge of start/no-start with a compression ignition engine when it's silly cold outside. But even that "benefit" has diminished somewhat now that we have common rail direction injection, intake grid heaters, etc. Diesel are MUCH more reliable in cold starts now.
 
Well dnewton, it was your posts among others to use data in dispelling the myths about oil grade/group. Just make sure you keep it hush so one does not get burned at the stake.

Obviously Cummins tested a 30 weight and approved a few for use in the 6.7.
 
I live way south of BC and I use Mobil Delvac 1300 15w-40 I buy at Wally World for $26.97/2.5 gal. You want good oil at a good price that is very hard to beat, 22% of the cost of using Red Line.

I also do the same as
Originally Posted By: Burbanite


I used an Mobil M1-303 or a Baldwin B1441...
 
I used 15W40 on my 13’ LML Duramax for 307,000 miles of stricly hauling loads up to 28,000Lbs.8-9k oil change intervals with ACDELCO oil filter or Baldwin.
 
I've said if before, and I'll say it again :

1. Certain engines and apps have demonstrated 10/30 to be an exceptional lube.

2. 10/30 is a bit of a spooky situation because of the higher specific output of the pickup engines. I'm at 450 HP out of 6.7 litres.

3. Destroying a diesel engine in magnificent condition is one heck of a Sword of Damocles to have swinging over your head.

Cummins says 30 did well in the 6.7, but which one? The factory 385HP one? The toned down 245HP one?

I love to experiment, but losing a high-ticket engine is a tough game to play. My engines are doing beautifully on 40. Hard to bring myself to try and screw that up.
 
Well in the Ram diesel supplement they indicate one should use a 40 weight but their caveat is that you could also use an oil that meets 20081. Well this has been superseded by 20086. In looking into what oils meet 20086 from Cummins, PetroCan 10w30 semi synthetic is on the list.

Not reading between the lines but rather following the trail they left in the manual, certain 30 weight oils are acceptable in the 385hp/900ftlb engine.

If I was running a tuner and well above stock power levels, then I would reconsider this oil selection if there was some actual data to support the change.
 
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