Rotella T6; 12k miles; Dmax with 70k

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This is the longest I have stretched a change out in this truck, so I'm looking for some reassurance that I'm not pushing the oil too far. This oil is only 3 months old, but has had about 8,000 miles of hard towing the trailer pictured (about 10K loaded), including crossing the Rockies twice and towing into some miserable winds in Wyoming and Nebraska. The other 4,000 miles were daily commuting and around town. My plan is to leave the oil until spring, which is when I normally change it (spring and fall). Any feedback is appreciated. Thank you.

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Iron is low.
Fuel dilution is low.
Soot is low.
There is no water in the oil.
Viscosity hasn't broken down.

I think the oil is still good to go.
Maybe take another sample in 6k miles.
Can you have the lab check TBN on the next sample?
 
Nice results and nice photo! I wouldn't change a thing. T6 is a great oil.
 
Posted in the wrong forum.

Post title does not conform to BITOG guidelines.

Perhaps a moderator can move it to the correct forum, and edit the title of the thread.
 
wear numbers look good, really need to get TBN tested when trying to strech OCI... but knowing T6 I'm pretty confident that there is some TBN left @ 12k miles.
 
I would never chance an expensive engine on an inexpensive oil change. I would change it immediately. Once you go too far and ruin the tolerances in an engine you can't get them back without an expensive rebuild. I see this many times with customers who don't change oil often enough. Silly really.
 
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Looks good, but try and find a set of universal averages for the same engine and a similar OCI. One advantage of using Blackstones is that they have a very good data base and can list a set of averages for most engines, they also have a VOA for most types of oil which can be useful. The Copper figure might be of interest, but it has a number of sources apart from turbo bearings, like oil coolers and is also in some additives.
Towing is not hard on an engine if you drive in the correct gear, although it does reduce the life of the transmission, particularly if you don't change the oil often enough. The real engine oil killers are idling and dirty air. I'm impressed by how low the Silicon figure is, so the air filtration system is working very well.
 
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I agree with the Jake. For the cost of the oil at Walmart, a change is the way to go. Why risk an engine for a couple of bucks? You got great service out of the oil Do a change and move on.
 
Originally Posted By: skyship
Looks good, but try and find a set of universal averages for the same engine and a similar OCI. One advantage of using Blackstones is that they have a very good data base and can list a set of averages for most engines, they also have a VOA for most types of oil which can be useful. The Copper figure might be of interest, but it has a number of sources apart from turbo bearings, like oil coolers and is also in some additives.
Towing is not hard on an engine if you drive in the correct gear, although it does reduce the life of the transmission, particularly if you don't change the oil often enough. The real engine oil killers are idling and dirty air. I'm impressed by how low the Silicon figure is, so the air filtration system is working very well.


Towing only kills a transmission if your not properly setup and don't know how to drive when towing.
 
This UOA looks like it was subbed to Polaris.
TBN would be nice to know and Polaris throws it in as part of their standard UOA, so maybe the analysis service you used gets a discount for not having TBN done?
Anyway, everything looks good in this report.
Viscosity is close to virgin levels for this oil.
How many more miles do you anticipate before you drain it?
As of right now, it clearly looks to have some life left in it, maybe quite a bit.
 
Originally Posted By: cknaffle
This is the longest I have stretched a change out in this truck, so I'm looking for some reassurance that I'm not pushing the oil too far.
...
My plan is to leave the oil until spring, which is when I normally change it (spring and fall). Any feedback is appreciated. Thank you.


Ahh, the venerable Dirtymax once again proves that it's extremely easy on oil.

You've got low single-digit wear per kilomile for all the wear metals (Fe 2.75 ppm/kmile; Cu 1 ppm/kmile; everything else less than 1 ppm/kmile), plenty of active additives left, no fuel dilution to speak of, soot is low and the oil is still in grade. The only missing part of this UOA is a TBN/TAN but I certainly see no reason why you can't leave it in until spring. Maybe pull a sample then and decide if you want to leave it in even longer?

Nice truck, nice report! Glad you're getting your money's worth out of both the truck and the oil. Keep it topped up and motor on.

Originally Posted By: Brons2
Posted in the wrong forum.

Post title does not conform to BITOG guidelines.

Perhaps a moderator can move it to the correct forum, and edit the title of the thread.


Perhaps you should apply to be a moderator, or is your BITOG-ennui too crippling to moderate?
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Lighten up, Francis.

Originally Posted By: The_Jake
I would never chance an expensive engine on an inexpensive oil change. I would change it immediately. Once you go too far and ruin the tolerances in an engine you can't get them back without an expensive rebuild. I see this many times with customers who don't change oil often enough. Silly really.


Let's base oil changes on evidence rather than gut feeling. Did you bother to look at the OP's analysis? It looks fantastic and the Isuzu Duramax engines are well known to be extremely easy on oil and live long, healthy lives.

Originally Posted By: Boomer
Why risk an engine for a couple of bucks? You got great service out of the oil


What leads you to believe the engine is at risk? I'm honestly curious. What about the UOA or OP's post makes you think something's wrong?

He got great service out of the oil and it certainly appears to me (and the oil analysis company) that the oil is still providing great service.
 
The general limits are TBN < 2 or soot > 3 or iron > 75 or fuel > 2.5%. Some of these numbers vary by engine manufacturer.

Rotella T6 is excellent oil.

The UOA was a private label done by Polaris. You want TBN and oxidation and nitration are handy also.

Keep on going. Get TBN next time.
 
I dont see anything to flag. I do wish that there was a TBN value, as IME this is a major determinant before wear or additives come into play.

I assume that you have an OLM, right? What is it stating?

Nice pic, BTW.
 
Originally Posted By: scurvy

What leads you to believe the engine is at risk? I'm honestly curious. What about the UOA or OP's post makes you think something's wrong?

He got great service out of the oil and it certainly appears to me (and the oil analysis company) that the oil is still providing great service.


My point was that you go along fine until you cross the line of failure and then you do expensive irreversible damage. For what savings? The risk curve gets steeper the further you go into an oil change. So my point is why risk it?
 
Originally Posted By: The_Jake
My point was that you go along fine until you cross the line of failure and then you do expensive irreversible damage. For what savings? The risk curve gets steeper the further you go into an oil change. So my point is why risk it?


The 'line of failure' is not a defined point or a line in the sand. You get plenty of warning if you run oil analyses. The oil could be shearing out of grade, additive metals depleted, low TBN/high TAN, fuel dilution, wear metal deposition rate increasing (ppm/kmile), coolant contamination, etc...

But none of that is happening in this case.

The Duramax engine is notoriously easy on oil and the OP doesn't have anything else going on that would necessitate a change. Once again, what about his current condition of the oil is putting his engine at risk? Please cite specific data from this UOA.
 
Thank you everybody for the information and feedback. I will get the TBN next time. I normally just get the basic analysis tests.

Answering the question about the oil monitor on the dash, it went from 100% to 0, I reset it, then it was at 80% when I took this sample.

I expect 3000 - 4000 more miles until I change it. Spring and fall is just a convenience thing for me, and works out to be an interval that matches up well with the miles I drive.
 
Originally Posted By: daman
IMO i wouldn't put another 4k on but that's me,Anyway here's our '05 same oil with TBN at 11k. Only moderate towing.


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Why not its well below the limits set by the engine manufacturers.
 
Originally Posted By: Donald
Originally Posted By: daman
IMO i wouldn't put another 4k on but that's me,Anyway here's our '05 same oil with TBN at 11k. Only moderate towing.


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Why not its well below the limits set by the engine manufacturers.

I said thats what i would do,he can do what he wants.
 
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