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Was told today at the dealer that the free oil changes are full synthetic? was it full synthetic from the factory? I am so confused with which brand GM uses, called several different dealers with several different answers, delvac, delvac semi syn, rotella, mobil 1. any input would be greatly appreciated! Thanks

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All of the major brands are good choices. I would use any of them. I primarily use Schaeffer oils, but have used Delvac on occasion and like it. Rotella is good, and Delo is good. Even the new CK-4 oils are pretty good. I did a test run of Delvac Extreme CK-4 10w30 syn blend this last winter in my commercial truck and it delivered very good results. Actually a couple points lower wear numbers and such than the previous CJ-4 rated oils I had used. Get a brand you are comfortable with and you can get at a good price. There is no perfect oil that beats everyone else.

 

I have been a syn blend advocate for quite a while. Best of both worlds at conventional oil prices and very good results. I have a Detroit Series 60 that now has 683,000 miles on it, has gotten 10w30 syn blend in winter / 15w40 syn blend in summer, and it still doesn't use more than 2 qt of oil in 20-22,000 mile oil changes. Wear numbers are as good as they were when the engine had less than 100K on it. No major repairs, original turbo, etc. Syn blends are a great value. If I were operating in very extreme cold like Alaska, I would consider a full syn. Otherwise, the best overall bang for my buck with excellent results has been syn blends for my diesels.

 

You don't have to overthink the deal. There are a lot of great oils on the market at very good prices. Try one and see if your engine agrees with it. If not, go with another. In over 4 decades of tracking engines and oils, I have found that they relate to each other in different ways, even within the same brands. Kind of like .22 rifles and ammunition. I can take two fine crafted, superior .22 rifles and feed them both a high quality ammo. I will get different down range results from each rifle. I can then take another high quality ammo and repeat the test and get different results, sometimes even reversed, with the best shooter now being the worse shooter of the two. Nothing wrong with either rifle or either ammo, just one rifle gets best results from a particular brand of ammo over another. One of those little mysteries of life that a particular rifle gets best results from a particular ammo. Engines are no different. One engine may really do well on a Delvac, another one do better on Rotella, with neither engine failing on either oil.

Edited by Cowpie

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I am looking at the 2017 Duramax Diesel Supplement to the owners manuals and it makes no mention of requiring synthetic oil. 5W-40 below 0°F and 15W-40 above.

 

 

 

Use only engine oils that have the designation CJ-4 for the diesel engine. Failure to use the recommended oil can damage the DPF and result in engine damage not covered by the vehicle warranty
Engine oils with the letters CJ-4 are required for your vehicle. The CJ-4 designation can appear either alone or in combination with other American Petroleum Institute (API) designations, such as API CJ-4/SL. These letters show API levels of quality. To determine the preferred viscosity for your vehicle's diesel engine, see Engine Oil ► 93.
Edited by elcamino

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That supplement was written before the new CK-4 oils came on the market at the first of the year. The new CK-4 oils are specifically designed to protect the emissions stuff beyond what CJ-4 oils were ever designed for. CJ-4 spec came about back when the first DPF's showed up. SCR/DEF hadn't been used yet. CK-4 is backward compatible with CI-4, CI-4+, and CJ-4. You want to stay current on specs and CK-4 is the latest. And I have already done some actual runs on CK-4 and it is more than up to the task compared to CJ-4. No worries.

 

You are correct, synthetic oil is not required. It may be beneficial in some situations, but not required. 5w40 is always going to be a full syn though. No conventional oil or syn blend HDEO can meet the cold flow / operating spread of a 5w40. I just use a 10w30 in winter and a 15w40 in summer. I travel multiple states and deal with Minnesota and the Dakotas in the winter and have not come across any situation that I felt a 5w40 full synthetic would be the only option. Like I stated, it could be beneficial in some regards, but not required.

 

GM is really a little behind the curve on this one. All of the heavy diesel engine manufacturers are factory filling with CK-4 10w30 and recommending 10w30 for all applications from 4L all the way up to 15L engines, from the Rio Grande to Canada. Cummins (yes, even the pickup version), Detroit, Volvo/Mack, Navistar, Paccar, etc. The Ecodiesel in the Ram also is getting factory fill of 10w30 HDEO. Even Ford allows 10w30 in the Pstroke. 10w30 actually does a stellar job in modern diesels and even shows better shear performance and NOACK (burn off) performance than the 5w40 and 15w40 oils. Stick with a 40w if you feel better doing so and it helps you to sleep well at night. For normal use, a 15w40 syn blend will be fine. For extreme cold, yeah, go to a 5w40. In that case, full syn is your only option.

Edited by Cowpie

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Was told today at the dealer that the free oil changes are full synthetic? was it full synthetic from the factory? I am so confused with which brand GM uses, called several different dealers with several different answers, delvac, delvac semi syn, rotella, mobil 1. any input would be greatly appreciated! Thanks

 

 

Factory fill on a 6.6 Duramax is Mobil Delvac 1300 15w40 CJ-4 (GM specs CJ-4). Conventional.

Edited by 15HDriver

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Just food for thought.

 

Ford is not recommending the use of the CK-4 oil in any of its diesels. Inadequate wear protection. The bulletin is below:

 

https://jobbersworldblog.files.wordpress.com/2016/05/ford-motor-company-ck-4-position-statement.pdf

 

GM as far as I know, hasn't said anything.

 

Mark

Edited by HeliMark

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Well, not quite true. Ford is allowing many CK-4 oils. You need to look at the current Ford list. Ford has complicated all of this to an extreme degree. They DO allow CK-4 oils, as shown on their approved oil list, BUT, they do not recommend CK-4 oil that ALSO have a gasoline engine API SN specification. Oils that have API SN spec along with the CK-4 spec tend to have ZDDP additive levels lower than Ford likes. Problem is, Ford is being a little myopic in this regard. They claim lower ZDDP levels mean increased wear. There are many alternative additives that can be used that more than make up for lower ZDDP levels.

 

This list is current as of Friday 4/28/2017. Today is 4/30/2017. Can't get much more current than that. Look thru the list and you will find several CK-4 oils.

 

https://www.fcsdchemicalsandlubricants.com/main/additionalinfo/dieseloilsWSSM2C171F1.pdf

 

 

Ford is the only OEM that has thrown a monkey wrench into this. Every HD engine OEM in the nation not only recommends CK-4 oils, but it factory filling with them. Some even factory filling with the alternative FA-4 which in no way should ever be used in a Dmax engine! You have to watch things more closely. Look for a CK-4 that is not also API SN rated, and avoid FA-4 rated oils like they are the plague. Owners are going to have to be more diligent in their making sure they read the spec label on the back of the jug.

 

Either way, the new CK-4 oils are specifically designed to out do performance of CJ-4 oils, and they do, and provide much better emission system component protection, which they do. We went all thru this nonsense back when CJ-4 came along. Oh the hue and cry that went out across the land that CJ-4 would not provide adequate protection as CI-4+ did. Bull Hockey to all of this sky is falling nonsense. CK-4 has gone thru probably more industry level testing than any previous HDEO specification. And only Ford wants to play games about it. Either they are just causing grief for the sake of having a corporate laugh at everyone out here in the cheap seats how we will react, or they are making substandard engines. Cummins (yes even in the Ram pickups), Volvo/Mack, Detroit Diesel, Navistar Engine Division, Paccar Engine, and the list goes on have all jumped on board CK-4 and are factory filling. CK-4 was developed in unison with OEM engine requirements. Lots of development articles out line this if one wants to look it all up.

Edited by Cowpie

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This makes me happy to have a gasser. Almost any 5 or 10w30 oil will work in the 6.0 no matter what brand. I also doubt that the average owner looks at the details when purchasing oil or having a service done. Similar to the uproar when the oil manufacturers reduced the zinc to protect catalytic converters from damage. Since newer engines have roller lifters the zinc isnt needed as much. The classic car guys had many camshaft failures that was speculated to be caused directly by the reduction of zinc which is needed for normal flat tappet camshaft life. Ask any classic car guy what oil he uses- most use a diesel blend or add a zinc additive to the new oil blends. I use a racing oil just for this reason and change it regularly in my old Pontiac. New vehicle owners shouldn't have to deal with these issues. How many diesel engine failures will happen due to this and how will GM or the other manufacturers deal with warranty? They really can't hold the general public liable for damage if the public let alone service providers are not aware of the changes. It's ridiculous.

Edited by 4x4Pete

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Yeah, easier for me regarding my 2500 6.0L. I use a 5w30 in winter and 10w30 in summer. Not always the same brand. But I have diesel engines in my commercial stable and I have to be on top of all this goofy stuff. I have run the new Delvac CK-4 10w30 in my factory remanned legacy Detroit 60 12.7L and on the UOA it showed performing quite admirably. all wear numbers across the board were down a couple of points, TBN retention was very good, and viscosity change over 20,000 miles was nonexistent. Doesn't get much better than that, especially on an engine that was originally built last century, and currently has 683,000 miles on the reman. Only uses 2 qt of oil in 20,000 miles. Some folks are just suffering from and enlarged paranoia gland and they must be gently guided along.

Edited by Cowpie

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Factory fill on a 6.6 Duramax is Mobil Delvac 1300 15w40 CJ-4 (GM specs CJ-4). Conventional.

 

 

This is a confirmed fact?

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This is a confirmed fact?

 

When they launched yes. I would imagine though by now (2018 model year) they've gone to CK-4.

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Interesting that GM recommendation for the 2.8L 'baby duramax' is different than for the 6.6L.

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It's my understanding that Mobil Delvac 1300 Super 15W40 is the Duramax factory oil fill.  Past formulations (e.g. CJ4, CI4+) of Mobil Delvac 1300 Super have performed very well based upon various Internet used oil analysis (UOA) postings and customer testimonials.  Fast forward to today, and GM is using the current CK4/SN Mobil Delvac 1300 Super formulation as the factory fill in the Duramax. 

 

As many of you know, the CK4/SN formulation of Delvac 1300 Super is a reduced phosphorus (800 PPM) heavy-duty engine oil (HDEO) that Mobil designed as a universal oil for mixed fleet applications (diesel and gasoline engines).  The reduction of phosphorus raises a question about wear protection.  According to Mobil, the CK4/SN formulation provides a 20% improvement in wear protection over the previous CJ4 formulation and 50% more wear protection as required by API CK4 testing standards...which is good.  However, I have yet to see any (UOA) postings of Mobil Delvac 1300 Super 15W40 CK/SN that confirms that the various metallic wear rates which verifies the new formulation is providing good wear protection.  Again, my interest in UOA data for Delvac CK4/SN 15W40 is to make sure the reduction of phosphorus in the formulation has not compromised good wear protection.

 

I, personally, have been using the previous formulations of Delvac 1300 Super 15W40 for many years with good success, but I would like to see some UOAs of the new Delvac CK4/SN formulation. I have checked the BITOG website, and there are not any Delvac 1300 Super 15W40 UOAs posted.   Do any members here have any UOAs of Delvac CK4/SN that can be shared?  

 

On another note, the  Duramax runs fine on API approved 15W40 conventional heavy-duty diesel oil.  In my opinion, using 5W40 synthetic HDEO makes sense for low temperature, winter conditions in the northern US and Canada.  And, for use in extended drain oil change intervals (OCIs) applications; however, most diesel owners dump synthetic oil far too early never capturing the long-drain value of synthetic oil.  

 

 

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It's an old thread but to add to this.  GM is calling for 0w-20 dexos 2 diesel oil in the new Dmax coming to the 1500 Silverado and GMC.

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Posted (edited)
2 hours ago, Black02Silverado said:

It's an old thread but to add to this.  GM is calling for 0w-20 dexos 2 diesel oil in the new Dmax coming to the 1500 Silverado and GMC.

Be careful with applying spec for a new engine to older ones.

 

In the same (2018, the newest I've found) Duramax supplement, GM recommends different oil for the 6.6l in the HD's than what they recommend for the 2.8L 4 cyl in the Canyon/Colorado. 

Dexos2 is NOT the recommended oil in the L5P. 

6.6L 15W-40 CJ/CK-4

2.8L Dexos2 5w-30 

(lighter options are listed for continuous operation below 0*F)

 

Similarly, with the gassers, the new 5.3 and 6.2L have a different oil recommendation that the older design 6.0.

 

 

Edited by redwngr

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