# Engine oil dexos 2



## Speedbuff (Mar 24, 2021)

I have some mobil 1 full synthetic oil left from my cadillac that got tottalled just prior to buying the 2015 dwiesel cruse . The mobil 1 full synthetic oil is a high quality oil I was debating using it up in the cruze during the next service . Its not dexos2 synthetic . What do you guys think its hardly a conventional oil neither though. Where do they differ?


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## Diesel4Ever (May 30, 2018)

As long as it is a diesel rated oil that has an HTHS > 3.5 cP it will be fine in the Cruze. I run 10w30 and 10w40 synthetic CJ-4 oils in my Cruze diesel and VW TDI and it hasn't blown up yet. Anything below 3.5 HTHS is not sufficient to protect the bearings on a diesel engine and should not be used. (Any API "S" Rated 5w30 and most 10w30 will be lower than 3.5 HTHS)

I wouldn't run any oil that has an API rating for gas engines, that would probably be like a modern SM or SN rated oil. There aren't enough dispersants and detergents in "S" oils to manage soot loading seen with diesel combustion. It would probably be OK if you changed it at 5k miles but no longer than that.


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## boraz (Aug 29, 2013)

as long as its acea c3 go ahead, otherwise dont


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## Diesel4Ever (May 30, 2018)

Here is my Oil analysis report for 12K miles. Oil is 10w40 CJ-4 Bio-Based synthetic. I ended up running this stuff for another 1k, so 13K miles before it was changed and re-filled with the same stuff.


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## Tomko (Jun 1, 2013)

Remind us again why you’re a former GM tech?


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## snowwy66 (Nov 5, 2017)

I wouldn't use.


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## shimmy816 (Aug 22, 2020)

for those looking for dexos 2, advanced auto has a fram oil that is listed as dexos 2.


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## BDCCruze (Jul 12, 2017)

Speedbuff said:


> I have some mobil 1 full synthetic oil left from my cadillac that got tottalled just prior to buying the 2015 dwiesel cruse . The mobil 1 full synthetic oil is a high quality oil I was debating using it up in the cruze during the next service . Its not dexos2 synthetic . What do you guys think its hardly a conventional oil neither though. Where do they differ?


You have to use Dexos2 or ACEA C3 oil unless the car is deleted. Not using mid-SAPS oil (Dexos2/ACEA C3) will kill your emissions system. Could you 'top up' on something else and be ok for the rest of that change? Probably, but I wouldn't make a habit out of it.



Diesel4Ever said:


> As long as it is a diesel rated oil that has an HTHS > 3.5 cP it will be fine in the Cruze. I run 10w30 and 10w40 synthetic CJ-4 oils in my Cruze diesel and VW TDI and it hasn't blown up yet. Anything below 3.5 HTHS is not sufficient to protect the bearings on a diesel engine and should not be used. (Any API "S" Rated 5w30 and most 10w30 will be lower than 3.5 HTHS)
> 
> I wouldn't run any oil that has an API rating for gas engines, that would probably be like a modern SM or SN rated oil. There aren't enough dispersants and detergents in "S" oils to manage soot loading seen with diesel combustion. It would probably be OK if you changed it at 5k miles but no longer than that.


Is your car deleted?


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## Speedbuff (Mar 24, 2021)

No the car is completely stock ordered some pennsoil synthetic dexos 2 oil better safe than sorry. Were the 2014 cruze diesels specd out with dexos 2 as well from new ? Just curious? Was dexos always full synthetic from its introduction or was it initially a conventional oil with major chemicals added? I guess that would make it a semi synthetic?


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## Tomko (Jun 1, 2013)

Speedbuff said:


> No the car is completely stock ordered some pennsoil synthetic dexos 2 oil better safe than sorry. Were the 2014 cruze diesels specd out with dexos 2 as well from new ? Just curious? Was dexos always full synthetic from its introduction or was it initially a conventional oil with major chemicals added? I guess that would make it a semi synthetic?


All of these RPO LUZ engines left assembly in Rüsselsheim Germany with dexos2. While new to GMNA, dexos2 was well established in overseas markets where light-duty diesels are common. At introduction in 2009, the dexos2 standard could be met with a semi-synthetic. But since then it has been upgraded to full synthetic.

dexos1 is gasoline-specific oil. It replaced the former GM4718M and GM6094M standards in summer 2010.

The licensing and use of the dexos1, dexos2, and dexosD, wordmarks are intended to make it easier to identify the correct engine oil to comply with engine design and warranty requirements.



dexos® Licensed brands | General Motors


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## Speedbuff (Mar 24, 2021)

Thank you that has cleared it up for me except for the actual physical improvements. I understand these engines will require a dexos 2 spec but what is it in the oil that theve actually done ? Is it just the ability to absorbs acidic byproducts of combustion detrimental to the lube oil . Is it perhaps the ability of the oil to burn when it gets pumped through the engine by means of the egr system or through the intake to relieve crankcase pressure.
Just curious I am sure it would be addressed in dealer training in the classroom or via remote learning as it was offered back in my day or perhaps even handed out to the technical staff on cd's which is what they used to do


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## Tomko (Jun 1, 2013)

Speedbuff said:


> Thank you that has cleared it up for me except for the actual physical improvements. I understand these engines will require a dexos 2 spec but what is it in the oil that theve actually done ? Is it just the ability to absorbs acidic byproducts of combustion detrimental to the lube oil . Is it perhaps the ability of the oil to burn when it gets pumped through the engine by means of the egr system or through the intake to relieve crankcase pressure.
> Just curious I am sure it would be addressed in dealer training in the classroom or via remote learning as it was offered back in my day or perhaps even handed out to the technical staff on cd's which is what they used to do


I recall a pretty detailed article in TechLink - but that was eons ago and I couldn’t find it when I searched.

The key difference with dexos2 is that it is low sulphated ash, phosphorous and sulfur (SAPS) that serve to prevent the emissions equipment from fouling.


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## Diesel4Ever (May 30, 2018)

BDCCruze said:


> Is your car deleted?


No I live in CA we can’t do that here . I have the OZ tune though. Got it before they shut down.

I’m gonna go to 13k miles on this oil then sample, then change it at 14k. I want to gradually get to 15k by testing and eventually changing it at 2x the normal interval. Since I’m using CJ-4 10w40 it will last longer before it needs to be changed.


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## Speedbuff (Mar 24, 2021)

Tomko said:


> I recall a pretty detailed article in TechLink - but that was eons ago and I couldn’t find it when I searched.
> 
> The key difference with dexos2 is that it is low sulphated ash, phosphorous and sulfur (SAPS) that serve to prevent the emissions equipment from fouling.


Hey thank you for the insite I appreciate it! Some days I miss the the gm days it was a lot of fun working in a medium sized gm dealership for 25 years with a great bunch of tech's. Seems like a 100 years ago now The only thing I dont miss are the cadillac's and their whiney customers. Its not near as bad in the hd world


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## Tomko (Jun 1, 2013)

Speedbuff said:


> Hey thank you for the insite I appreciate it! Some days I miss the the gm days it was a lot of fun working in a medium sized gm dealership for 25 years with a great bunch of tech's. Seems like a 100 years ago now The only thing I dont miss are the cadillac's and their whiney customers. Its not near as bad in the hd world


Yep. First time Cadillac owners who drive the least expensive or stripper model - but demand the Royal treatment. Or those who buy a used Caddy and become drama queens once they‘re faced with Cadillac parts and labour charges. Don’t get me started, LOL.


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## BDCCruze (Jul 12, 2017)

Diesel4Ever said:


> No I live in CA we can’t do that here . I have the OZ tune though. Got it before they shut down.
> 
> I’m gonna go to 13k miles on this oil then sample, then change it at 14k. I want to gradually get to 15k by testing and eventually changing it at 2x the normal interval. Since I’m using CJ-4 10w40 it will last longer before it needs to be changed.


I have to admit, I'm a bit skeptical. I understand CJ-4 oil is designed for modern diesel emission systems, but in trucks. How long have you been using this oil in your Cruze? GM has a bulletin out that specifically says CJ-4 and Dexos2 are not interchangeable oils. CJ-4 has a higher SAPS content than Dexos2.


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## Diesel4Ever (May 30, 2018)

BDCCruze said:


> I have to admit, I'm a bit skeptical. I understand CJ-4 oil is designed for modern diesel emission systems, but in trucks. How long have you been using this oil in your Cruze? GM has a bulletin out that specifically says CJ-4 and Dexos2 are not interchangeable oils. CJ-4 has a higher SAPS content than Dexos2.


I did the 1st service on the Cruze when I got it at 50K miles and it got filled with 10w30 CJ-4. 2nd Oil change was early because the water pump started leaking so it got the full TB replacement, also suspension rebuild including Bilstein B12 Pro-kit installed and OZ remap with another oil change with 10w40 at 56K. It now has 69K and just got the Polish oil pickup sleeve and fresh 10w40 CJ-4.

I use CJ-4 instead of Dexos 2 in my 2017 2.8 Duramax Canyon 4x4 as well. Since it's first oil change at 1,500 miles.

I also use 10w30 CJ-4 in my 2010 VW TDI.


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## BDCCruze (Jul 12, 2017)

Diesel4Ever said:


> I did the 1st service on the Cruze when I got it at 50K miles and it got filled with 10w30 CJ-4. 2nd Oil change was early because the water pump started leaking so it got the full TB replacement, also suspension rebuild including Bilstein B12 Pro-kit installed and OZ remap with another oil change with 10w40 at 56K. It now has 69K and just got the Polish oil pickup sleeve and fresh 10w40 CJ-4.
> 
> I use CJ-4 instead of Dexos 2 in my 2017 2.8 Duramax Canyon 4x4 as well. Since it's first oil change at 1,500 miles.
> 
> I also use 10w30 CJ-4 in my 2010 VW TDI.


That's interesting. How many miles on the truck?


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## Diesel4Ever (May 30, 2018)

BDCCruze said:


> That's interesting. How many miles on the truck?


40k


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## Detrious (Jul 5, 2017)

I think it's something like .8% max allowed SAPS for the C3/Dexos2 oils and 1.0% max on CJ-4. Negligible difference overall but yea, I suppose over time it could add more ash to the DPF causing earlier than designed plugging. I'd guess it really wouldn't be a larger issue unless the engine is burning a ton of oil but at that point the DPF is gonna foul from oil contamination before the ash gets to it. CJ-4 is a more robust oil though, additive and wear protection wise, since it's really designed for HD application and long OCI. Personally I just stick with Dexos2 Pennzoil.


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## Speedbuff (Mar 24, 2021)

I think a thick oil like that cant be good for the variable displacement oil pump? That being said I think there is a lot of stuff the manufacturers dont tell us.eg . My brother works is a mine where they run a lot of different equipment . Spec'd out with all types of diesel oils . They only use 1 to avoid the wrong oils beng put in by operators.They spend a lot of money with those manufacturers and its amazing how they have gotten the ok from all the oe manufactures to use the oil.
Please dont missunderstand me there is no way in hell I would put 15w40 in my little 2.0 liter.can you imagine the flow rates at -25 or 30. I have seen what those thick oils can do to gasoline engines. The oil starvation at start up due to it being so thick is not good . To the guy using 40 weight I hope you live in florida! If not stick some oil in the feezer and pour it out of the container even at -10 or 15 right out of youre freezer and see how it pours .Get back to us on that or plug the oil pan heater in year round . Working with a lot of hd equipment I see the value of a thicker heavier film of oil on bearing journals. By definition viscocity means an oil's ability to resist flow . It is very important to use a good quality oil .If it wasnt for all the dpf crap I would likely use a different oil and maybe even a 40 weight in the summer but most likely a 5w30 as recomnended to work with the variable displacement pump . This light oil works very well how many crankshaft failures are we having ? Thexthick oil would tend to make nake the pick up seal fail sooner as well. Mine will get the polish update soon as wel but no 40 weight oil for me


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## Detrious (Jul 5, 2017)

Oh yea I didn't even touch on weights, just the additive packages and SAPS. I personally wouldn't consider a x-40w in this engine, but I would swap to 10w-30 if I thought I needed to. I don't know if the heavier oil would damage the pump but I guess it would just create a bit more drag on the engine and increase fuel usage a bit.


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## Diesel4Ever (May 30, 2018)

You guys make a lot of assumptions without looking at the data I presented. it’s not a thick 10w40. I blend it myself from BioSyn HD 10w30 and 15w40.

The blends’ baseline viscosity @ 40c and 100c is shown on the oil report because I had it tested. At 100c it’s 13.3 cSt. Max viscosity for a 5w30 is 12.5 cSt so it’s just slightly above, into the 40wt range. As you can also see, it dropped down to a 30wt at the end of my 12k miles due to the fuel dilution and aging of the oil. The reason I blend is because 10w30 and 15w40 are more shear stable and have lower volatility. The slightly heavier viscosity allows the oil to stay in grade on the extended interval as well.

I live in CA where it doesn’t get below 20F. I don’t need a 0w or 5w oil so I don’t use them.



Speedbuff said:


> I think a thick oil like that cant be good for the variable displacement oil pump? That being said I think there is a lot of stuff the manufacturers dont tell us.eg . My brother works is a mine where they run a lot of different equipment . Spec'd out with all types of diesel oils . They only use 1 to avoid the wrong oils beng put in by operators.They spend a lot of money with those manufacturers and its amazing how they have gotten the ok from all the oe manufactures to use the oil.
> Please dont missunderstand me there is no way in hell I would put 15w40 in my little 2.0 liter.can you imagine the flow rates at -25 or 30. I have seen what those thick oils can do to gasoline engines. The oil starvation at start up due to it being so thick is not good . To the guy using 40 weight I hope you live in florida! If not stick some oil in the feezer and pour it out of the container even at -10 or 15 right out of youre freezer and see how it pours .Get back to us on that or plug the oil pan heater in year round . Working with a lot of hd equipment I see the value of a thicker heavier film of oil on bearing journals. By definition viscocity means an oil's ability to resist flow . It is very important to use a good quality oil .If it wasnt for all the dpf crap I would likely use a different oil and maybe even a 40 weight in the summer but most likely a 5w30 as recomnended to work with the variable displacement pump . This light oil works very well how many crankshaft failures are we having ? Thexthick oil would tend to make nake the pick up seal fail sooner as well. Mine will get the polish update soon as wel but no 40 weight oil for me





Detrious said:


> Oh yea I didn't even touch on weights, just the additive packages and SAPS. I personally wouldn't consider a x-40w in this engine, but I would swap to 10w-30 if I thought I needed to. I don't know if the heavier oil would damage the pump but I guess it would just create a bit more drag on the engine and increase fuel usage a bit.


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## Speedbuff (Mar 24, 2021)

Personally my thinking always was change it every 5000km or 3000 miles clean oil is better and oil is cheap . That however is no longer the case. I see you have researched youre reasoning quite extensively. My thinking remains the same though when this engine was designed they had to come up with a spec for the oil to-deal with the variable displacement oil pump and the rest of the internals .I would be comfortable putting in some full mobil 1 synthetic oil that I have used for many years and changed at 6-7 thousand kilometers . The oil-remains fairly clean . The issue I have now is the dpf system and its contamination and thus I use their spec'd out oil. We have hd diesels at work with dpf systems and they run rotella oil which I believe to be a decent oil . There must be a reason engineering wouldnt let us use 15w40 .
As was stated before I might consider moving up to a 10w30 but that would be it for me and I see no reason to unless things were running hotter than normal . Different kind of engine = different kind of oil. Why strech oil changes on youre diesel ? When you dump it out at the recommended interval all the contaminants are gone and you start over with a clean sheet . 
If you have an engine failure and gm declines you waranty I for 1 believe they would have a valid case. The specification is there and they dont force you to buy their brand but do force you to use their spec Why stray from there unless there is some gain?


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## BDCCruze (Jul 12, 2017)

Detrious said:


> I think it's something like .8% max allowed SAPS for the C3/Dexos2 oils and 1.0% max on CJ-4. Negligible difference overall but yea, I suppose over time it could add more ash to the DPF causing earlier than designed plugging. I'd guess it really wouldn't be a larger issue unless the engine is burning a ton of oil but at that point the DPF is gonna foul from oil contamination before the ash gets to it. CJ-4 is a more robust oil though, additive and wear protection wise, since it's really designed for HD application and long OCI. Personally I just stick with Dexos2 Pennzoil.


Yeah, that's why I was asking about mileage.

I put almost 100% freeway miles on my car so I imagine my DPF is likely very healthy and I could get away with a bit more SAPS, considering GM designed the car for city driving as well.

My car also does not burn a drop of oil at 160k miles so I'm very hesitant to change oils at this point. I run the Pennzoil exclusively except in winter I switch to the 0W-30 ESP stuff by Mobil.


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## Diesel4Ever (May 30, 2018)

5w30 at 40c is thicker than 15w60 at 100c. Oil is very thick when it’s cold. Look at the numbers if you don’t believe me, they don’t lie.

The myth that a thicker oil “can’t flow” or somehow can overwhelm the VDOP doesn’t make any sense, as it deals with thick oil every time you cold start it. As long as you’re within the cold temp operating range (w-rating) it doesn’t matter.

Modern oils are like vitamins. The additives are slowly released over time, through heat cycles and age. Fresh oil mostly has a detergent effect, the anti-wear, anti-friction effects come later as it ages. It sounds crazy but it’s actually true. The old philosophy of changing oil every 3k is archaic and outdated with modern formulations. You get better performance with aged oils, but they must be changed before they start to thicken and oxidize. That is the purpose of oil analysis.



Speedbuff said:


> Personally my thinking always was change it every 5000km or 3000 miles clean oil is better and oil is cheap . That however is no longer the case. I see you have researched youre reasoning quite extensively. My thinking remains the same though when this engine was designed they had to come up with a spec for the oil to-deal with the variable displacement oil pump and the rest of the internals .I would be comfortable putting in some full mobil 1 synthetic oil that I have used for many years and changed at 6-7 thousand kilometers . The oil-remains fairly clean . The issue I have now is the dpf system and its contamination and thus I use their spec'd out oil. We have hd diesels at work with dpf systems and they run rotella oil which I believe to be a decent oil . There must be a reason engineering wouldnt let us use 15w40 .
> As was stated before I might consider moving up to a 10w30 but that would be it for me and I see no reason to unless things were running hotter than normal . Different kind of engine = different kind of oil. Why strech oil changes on youre diesel ? When you dump it out at the recommended interval all the contaminants are gone and you start over with a clean sheet .
> If you have an engine failure and gm declines you waranty I for 1 believe they would have a valid case. The specification is there and they dont force you to buy their brand but do force you to use their spec Why stray from there unless there is some gain?


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## Cruz15 (Mar 17, 2016)

Engine oils with 1500 ppm or more calcium can cause more LSPI which wrecks pistons. I would not use that oil.
Both those oils have 4000 ppm sulper which will not play nice with the dpf.


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## Diesel4Ever (May 30, 2018)

Cruz15 said:


> Engine oils with 1500 ppm or more calcium can cause more LSPI which wrecks pistons. I would not use that oil.


Ha nice advice, LOL this is a diesel engine smart guy. LSPI is a phenomenon with mostly GM and Subaru small displacement turbocharged GASOLINE engines likely caused by poor engineering or a design flaw. Other manufacturers utilizing SMTID engine technology have not had these problems and are not required to use Dexos 1 Gen 2.


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## Cruz15 (Mar 17, 2016)

So maybe not what you call lspi. Oil with to much calcium causes abnormal ignition in the cylinder. Big rigs get chunky pistons and is called normal wear. Chunks of the piston are missing normally at the edges, I definitely don't want that happening in my engine not even a small chunk.
Any engine can have detonation, abnormal pressure waves in the cylinder and calcium is one of the big problems. So ya High Calcium engine oils are a problem in any engine with high temps and compression. It can happen to diesel and gasoline engines.


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## Speedbuff (Mar 24, 2021)

Well thats an interesting way to look at things.with the oil starvation due to a pick up air leak . I feel without the polish mod yours would be first to fail because the oil is thicker? As far as thickning the oil to compensate for "when the 5w30 starts to lose its lub quality" wouldnt that be when I would be replacing all my oil with fresh oil while you trying to come up with some better than factory formula?
All the while you are plugging up youre dpf with additional emmisions .You stated that the amount of extra soot goin into the dpf was minimal. I tend to think any gains with you mix of engine oils would be minimal. To me it would seem all the extra money you are wasting on oil anallasys might be better spent on doubling youre oil changes with factory spec oil and let the lub engineers do rhe required testing for you by design. That is just my view as merely a mechanic and certainly no chemist
If these engines were failing with bottom ends going out of them that could be pinned on any kind of lube issue short of the pick up seal leak I would take you more seriously but that doesnt seems to be the case.we cant even compare how long our engines last as due to climatic conditions mine sees a much harsher operating enviroment than yours . Otherwise I would say the proof is in the pudding


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## Diesel4Ever (May 30, 2018)

Cruz15 said:


> So maybe not what you call lspi. Oil with to much calcium causes abnormal ignition in the cylinder. Big rigs get chunky pistons and is called normal wear. Chunks of the piston are missing normally at the edges, I definitely don't want that happening in my engine not even a small chunk.
> Any engine can have detonation, abnormal pressure waves in the cylinder and calcium is one of the big problems. So ya High Calcium engine oils are a problem in any engine with high temps and compression. It can happen to diesel and gasoline engines.


Your'e full of do-do to put it nicely. CI-4+ diesel oils can over 3000+ ppm of Calcium. CJ-4 oils like what I'm using typically come with 2400-2500 ppm of calcium or a hybrid mix of calcium and magnesium. Make up some more BS nonsense about how calcium is bad for a diesel engine, when it's actually the BEST detergent and soot dispersant additive there is. Period.



Speedbuff said:


> Well thats an interesting way to look at things.with the oil starvation due to a pick up air leak . I feel without the polish mod yours would be first to fail because the oil is thicker? As far as thickning the oil to compensate for "when the 5w30 starts to lose its lub quality" wouldnt that be when I would be replacing all my oil with fresh oil while you trying to come up with some better than factory formula?
> All the while you are plugging up youre dpf with additional emmisions .You stated that the amount of extra soot goin into the dpf was minimal. I tend to think any gains with you mix of engine oils would be minimal. To me it would seem all the extra money you are wasting on oil anallasys might be better spent on doubling youre oil changes with factory spec oil and let the lub engineers do rhe required testing for you by design. That is just my view as merely a mechanic and certainly no chemist
> If these engines were failing with bottom ends going out of them that could be pinned on any kind of lube issue short of the pick up seal leak I would take you more seriously but that doesnt seems to be the case.we cant even compare how long our engines last as due to climatic conditions mine sees a much harsher operating enviroment than yours . Otherwise I would say the proof is in the pudding


Actually the contrary. Higher viscosity fluids like oil reduce slip in positive displacement pumps. That is one of the reasons you get higher pressure with thicker oil.

As I said before, which you didn't bother to read or didn't understand. Fresh oil has a detergent effect and it's primary purpose is cleaning. The AW/AF additives are released later. *Wear metals always spike up after an oil change, THEN TREND DOWNWARDS AS THE OIL AGES*. I wrote it in CAPS so maybe you can understand it. This is elementary information, basic knowledge.

One of the benefits of oil analysis is DATA. I have many pages of data, some of which I have shared with you. All you have are archaic outdated beliefs that you must change your oil every 3K miles. So in a typical 15k mile time frame, you've changed your oil 5x, while I've changed mine ONCE. You've used over 20 liters of oil and 5 oil filers. I've used 4 liters and one oil filter. And you're lecturing me about "extra money" LOL. I think your math skills are worse than your reading comprehension. 

The DPF gets plugged with ASH, not emissions. Soot is burned of either in a passive or active regeneration.

I have the proof, and not the pudding. I have many oil analysis reports from different vehicles over the last 10 years. That is how I know what I'm doing and can prove it. I can also prove that I have less metallic wear at nearly 2x the normal oil change interval that GM recommends. All with a higher viscosity un-approved lubricant, made from vegetable oil, designed for HD diesel trucks.


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## Speedbuff (Mar 24, 2021)

I bet gm still voids any waranty on the engine that you have because the oil simply doesnt meet their specs.
I can certainly tell you have spent a lot of time researching this . Perhaps thats why the specific bulletin was put out that the 2 oils are not interchangeable .My point is what is wrong with going with the factory service interval or shorter. I have never seen engine failure from excessive oil changes.I have seen many from incorrect oil use lack of changes etc . I am not going to test my oil until the engine gets more miles on it. I will put that money towards clean fresh oil of good quality at or before the changes are due .I am not gambling away my warranty . 
We can agree on 1 thing this is not a hd diesel and to be honest I was surprised to see such a thin oil used. All that being said I maintain my view point that you would have been much more likely to have seen the seen the oil pump seal failure due to the the fact the vacuum created at the pick up tube will be much higher due to the incorrect thicker oil you use. Its a good thing you live in california and not in the northern states or Canada. I think mother nature might make you see the error of youre ways


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## BDCCruze (Jul 12, 2017)

Speedbuff said:


> I bet gm still voids any waranty on the engine that you have because the oil simply doesnt meet their specs.
> I can certainly tell you have spent a lot of time researching this . Perhaps thats why the specific bulletin was put out that the 2 oils are not interchangeable .My point is what is wrong with going with the factory service interval or shorter. I have never seen engine failure from excessive oil changes.I have seen many from incorrect oil use lack of changes etc . I am not going to test my oil until the engine gets more miles on it. I will put that money towards clean fresh oil of good quality at or before the changes are due .I am not gambling away my warranty .
> We can agree on 1 thing this is not a hd diesel and to be honest I was surprised to see such a thin oil used. All that being said I maintain my view point that you would have been much more likely to have seen the seen the oil pump seal failure due to the the fact the vacuum created at the pick up tube will be much higher due to the incorrect thicker oil you use. Its a good thing you live in california and not in the northern states or Canada. I think mother nature might make you see the error of youre ways


GM would have to run an oil analysis to determine that though. If they tear your engine down and determine there is no sludge buildup, as long as the issue is not emissions related I doubt they will invest much time in looking in to your oil.


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## Tomko (Jun 1, 2013)

@XtremeRevolution I think we’d all benefit from your tribology in this thread.


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## Speedbuff (Mar 24, 2021)

In my dealership experience if you had a engine failure due to something that could be attributed to the lube circuit the first thing they will do is ask for youre service records . If you havent followed them by extending youre oil change intervals past the gm requirements the dealership would simply say we cant warrant this for you . They will then advise you of further options . Which will be contact customer care and plead youre case . My guess is that when you tell them youre using a mixed form of oil that they spell out as not meeting their dexos 2 diesel spec in a product service bulletin . 
They will refer you to their Dsm (district service manager).That guy will hear youre argument and likely point out that you have exceeded the service intervals using a unaproved mixture of oil and youre engine waranty is void . At that point youre going to court and Gm has deep pockets . Good luck !! Seen this sort of thing before! Its been interesting getting youre views on this and I certainly am not trying to upsrt or offend you in any way shape or form . This is about all I care to add to this thread as I think weve covered it all perhaps more then once . As I said good luck


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## Tomko (Jun 1, 2013)

One thing I’d like to point out is that there are probably few CTDs still under warranty.

I’ve managed to tease mine out to nine years. But I think that I’m in the minority.


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## MP81 (Jul 20, 2015)

Tomko said:


> One thing I’d like to point out is that there are probably few CTDs still under warranty.
> 
> I’ve managed to tease mine out to nine years. But I think that I’m in the minority.


Yep, ours has been out by both mileage and time for a couple years now (time) - it was pretty close in mileage at that point too. 

We have a "data point" at the dealer regarding our transmission's behavior, so if it ever just totally shits the bed, I'm hoping that can be used to at least bargain for some reduced costs, as it'll be from the same issues they couldn't reproduce.


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## Diesel4Ever (May 30, 2018)

One man's synthetic oil-life study, Interesting read:





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Synthetic Oil Life Study


This page examines the actual service life of synthetic motor oil.



www.brianschreurs.org









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Mobil 1 Test Results


This page examines the actual service life of Mobil 1 synthetic motor oil.



www.brianschreurs.org









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Amsoil Test Results


This page examines the actual service life of Amsoil synthetic motor oil.



www.brianschreurs.org


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