Duramax 3.0: oil consumption and oil changes

[William Richardson]

We purchased a new 2020 Chevy Silverado 1500 crew cab LTZ 4x4 with the Duramax diesel over a month ago. I’m in my sixties but this is my first pickup truck and first diesel. We will use it primarily for towing a relatively light travel trailer (5500 lbs GVWR). During the research about this truck, I have read the opinions out there about the pros and cons of the Duramax 3.0. The straight six seems to be a positive for reliability and performance. There are concerns with the wet belt for the fuel pump and associated maintenance at 150K and that it uses 0w20 engine oil. Regardless, here are some things I have learned and a few additional questions.

 

In the short time I have owned it, I am impressed. It is smooth and quiet, tows with ease and gets wonderful mileage. I even like the way it looks, but of course, that is subjective. In terms of care, I followed the manufacturers break-in recommendations: first 500 miles at max 55 mph. They also recommend a break-in period for towing that specifies an additional 500 miles at no more than 50 mph. That was difficult to follow when you’re driving on the interstate, but we managed to do it. My apologies to those wondering why that idiot was going so slow.

 

After both break in periods, I have an additional 1900 miles on it. The owner’s manual says to check the oil level at every gas fill up or every 400 miles. Unfortunately, I didn’t do that. I finally checked it at approximately 2500 miles and guess what? The dip stick was dry. Panic set in! We were on the road and used our phone app to find the nearest place to get some motor oil. Of course, my research suggested the oil this engine uses (0w20, DexosD) is difficult to find. As I understand it, there are currently only two brands for this oil: AC Delco and Mobil 1. The AC Delco brand is available from your local Chevy or GMC dealer (if they have it in stock) and maybe your local auto parts store (NAPA) can order the Mobil 1 ESP X2 0W-20. What do you do when you’re on the road and need at least a quart or more? I looked for my closest Chevy or GMC dealer and luckily found one only a few miles away from where I checked it.  I went to the parts department of the GMC dealer I found in Loveland, Co and told them exactly what I needed: AC Delco 0w20 Dexos D . The parts person sold me two quarts and even walked out to my truck to help. He couldn’t believe my dipstick showed no oil at all. We added a quart and it brought it up to the middle of the cross hatches on the dipstick. I was relieved.  At least it wasn’t so low that damage was done.  We leave and arrive home 150 miles later and then I look closely at the oil he sold me. It was AC Delco 0w20 Dexos Gen 2. THAT IS NOT DEXOS D. That oil is for gasoline engines. Shoot. I assume it is close enough to not do much harm but now I feel like I need to drain and replace my entire crankcase. I decided to do it myself. I am not mechanically inclined, but I can usually handle an oil change. So here goes….

 

Now I had to find that “hard to find” oil with the correct specs. The Chevy dealers in and around Denver carried the AC Delco brand so I drove 95 miles (in my Subaru) to the nearest Chevy dealer and purchased 8 quarts (the 7 needed for the oil change and an extra quart for any future top off). There is one guy on YouTube that documented his oil change (though not in a real detail way) for the Duramax 3.0 and he pointed out it is helpful to have an oil filter cap for removing and reinstalling the oil filter. He was right. After draining the oil, I had a difficult time removing the oil filter. I went to the auto parts store and purchased a cap that goes over the filter where you can use a socket wrench to remove it. I went home but it wasn’t a great fit so the oil filter slipped through the cap and wouldn’t come off. So, back to the auto parts store with a replacement filter in hand and I determined the oil filter cap with the specs 75.6 mm, 14 flutes would work best. This close fit made a big difference and the filter came off without too much effort.

 

I’m sure there are instructions somewhere on the specifics for doing an oil change on the new Duramax 3.0. Does anyone know where I can find them? For example, what size socket / wrench do you use on the oil plug? How much do you torque it? Is the oil supposed to be warm before draining it? I guessed as to the answers to those questions.  I tried different standard and metric socket sizes and determined the metric 15 was the best fit for the plug. It worked fine but it would be nice to have definitive information.

 

The new oil filter I installed by tightening by hand and then three quarters to a full turn beyond using the filter cap and socket wrench. However, how tight do you tighten the oil plug? I tightened it with my socket wrench but I guessed at how tight to make it. I tightened it down snug and then just a little more. I’m pretty sure it’s tight enough but I think one needs to be careful not to over do it. Hopefully, I didn’t.

 

So….I’m looking forward to someone doing a detailed YouTube video on doing an oil and filter change on the Duramax 3.0. For me it would have been useful.

 

One last point. The manual says the truck needs to be level and the engine cold when using the dip stick to check the oil level. If the engine is not cold, you are suppose to wait a specific amount of time before checking it.  My experience is that the proper reading of the dipstick is sensitive to both recommendations.

 

That’s it. Kind of long and winded but hopefully helpful to someone out there. If you have answers to my questions, I thank you in advance! In the meantime, I really like this truck!

[Black02Silverado]

Welcome to the forum.

 

Sounds like you had quite the adventure.  The oil is going to hard to find for a little while until more units are sold.  I would stock up just in case.  Better to have than not.  The drain plug is 18 lbsft of torque.  The oil filter is just like the rest and you turn it on until the gasket contacts and then 3/4 to one full turn farther.  This can be done by hand, no need to use the filter wrench.

 

You don't have to have the vehicle warm to change the oil but it is best to do it with it up to operating temp.  Reason is that way the oil is all mixed up and anything that might have settled to the bottom of the pan will be in the oil and will drain out, not to mention it will drain out a little faster.

 

I would say the 15mm is the correct size but I don't have the written specs.  If that fit the best then make sure it is a 6 point socket.  That will give the best grip on the drain bolt.

[William Richardson]

1 hour ago, Black02Silverado said:

Welcome to the forum.

 

Sounds like you had quite the adventure.  The oil is going to hard to find for a little while until more units are sold.  I would stock up just in case.  Better to have than not.  The drain plug is 18 lbsft of torque.  The oil filter is just like the rest and you turn it on until the gasket contacts and then 3/4 to one full turn farther.  This can be done by hand, no need to use the filter wrench.

 

You don't have to have the vehicle warm to change the oil but it is best to do it with it up to operating temp.  Reason is that way the oil is all mixed up and anything that might have settled to the bottom of the pan will be in the oil and will drain out, not to mention it will drain out a little faster.

 

I would say the 15mm is the correct size but I don't have the written specs.  If that fit the best then make sure it is a 6 point socket.  That will give the best grip on the drain bolt.

Thank you very much for the information.  I didn't mention it but I did purchase a total of 15 quarts knowing how difficult it is to get.  I am a concerned about it being only 18 lbsft of torque on the drain plug. I hope I didn't over tighten it. That would be bad. I think I'm fine with how I tightened the oil filter since I could easily limit it to the three quarters to full turn after contact. It was certainly tighter than that based on the effort required to get it off. Unfortunately I didn't bring the engine to operating temperature but I did give it a lot of time to drain.  Since it only had a little less than 3000 miles on it, hopefully there was not too much "stuff" that settled on the bottom. Of course, who knows for sure since it was the first oil change and approximately half of the 3000 miles was towing. My primary motivation for the oil change was the quart plus of oil that I added that wasn't Dexos D approved. Since we get a free oil change in the year after purchase, the Chevy dealer will be doing my next one. At least I'll have good notes for doing it myself in the future. 

 

It would be nice if the information you shared was readily available in the owner's manual. My cynical side thinks they want the dealers to make money on maintenance and therefore they limit the information that would make it easy for owners to do the job themselves.

[Black02Silverado]

You can always go to AMSOIL's site and look up a vehicles lubrication needs and the drain plug torque spec's are listed.  AMSOIL gets the info from the manufacture.  Some times even the T case plug torque spec's are provided.  You can check it out here.

[steve841]

https://www.summitracing.com/parts/mob-125386?rrec=true

 

6 Bottles for $62.00 Mobil 1 ... Dexos D certified.

 

 

[William Richardson]

Thank you for the link. Will keep in mind next time I need DexosD oil. 

6 hours ago, steve841 said:

https://www.summitracing.com/parts/mob-125386?rrec=true

 

6 Bottles for $62.00 Mobil 1 ... Dexos D certified.

 

 

 

[steve841]

I actually emailed the folks at Mobil.

 

Their reply was - as soon as demand picks up, they'll package the 5qt jugs.  So, single unit pricing till then.

[Grumpy Bear]

3 hours ago, steve841 said:

I actually emailed the folks at Mobil.

 

Their reply was - as soon as demand picks up, they'll package the 5qt jugs.  So, single unit pricing till then.

Has anyone asked yet what the spec it for Dexos D? 

 

https://standards.globalspec.com/std/13137772/GMW18006

 

I don't own a Diesel so I wont be spending $36 to find out. But you might want to. Why?

 

Because we learned that Dexos2 spec meant only that the oil MUST be synthetic AND have a NOACK less that 13%. Yes just 2% lower than the SAE standard for the same 0W20, 5W20, 5W30 and most recently 10W40 gas oils. We also learned that about 80% of the oils manufactured already met the standard BEFORE buying the license. You note that in the link provide that 5W30 is also covered under this liceense. 

 

I would expect the first hurdle to be finding a 20W diesel oil. 

Edited June 16, 2020 by Grumpy Bear

[steve841]

No really sure what you're implying ...

 

But, here's the Mobil link

 

https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/products/mobil-1-esp-x2-0w-20/

 

As long as it meets the requirements for warranty, I could care less about the specs so long as it's synthetic.

[Grumpy Bear]

5 hours ago, steve841 said:

No really sure what you're implying ...

 

But, here's the Mobil link

 

https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/products/mobil-1-esp-x2-0w-20/

 

As long as it meets the requirements for warranty, I could care less about the specs so long as it's synthetic.

Imply? Nothing. Asking a question. Are there other oils not yet licensed that meet the spec as was the case with other Dexos licensed oils? Actually that goes to your last sentence. AS LONG AS....you have to know what it is to know if that is true. 

 

You do know that AC-Delco and Mobil 1 are the same oil, right? Different packaging and pricing. Exxon/Mobil is their supplier. 

 

 

[diyer2]

WOW

 

 

[jnissen]

My takeaway is check the oil level often till you can get a sense of the consumption rate. Next is that the oil is expensive and hard to find. I likely will take mine to the dealer for it’s first change as it was thrown in as an incentive for the first change.

Hoping GM will open up the choices for oil. I’d much prefer to use a standard 15W-40 for availability. Just concerned that with a belt that oil pump may not like it and then your screwed

[Grumpy Bear]

From what I can find in the commercial literature the dexos D has an elevated phosphorus 880 ppm and zinc level of 950 ppm with a middle of the 'new road' 100 C viscosity of 7.8 cSt and an HSTS of 2.6 cSt for a 0W20. Serves both SN and SL requirements but not SN-Plus. So without a lab test I know it has a nice dose of calcium as well. I'd be fairly certain this would be a Group III base oil. 

 

The only other street oil in Mobil's list of products with nearly alike additive is the ESP 0W40. If I needed some top off oil in a pinch this would be good. IMHO. 

[William Richardson]

1 hour ago, Grumpy Bear said:

From what I can find in the commercial literature the dexos D has an elevated phosphorus 880 ppm and zinc level of 950 ppm with a middle of the 'new road' 100 C viscosity of 7.8 cSt and an HSTS of 2.6 cSt for a 0W20. Serves both SN and SL requirements but not SN-Plus. So without a lab test I know it has a nice dose of calcium as well. I'd be fairly certain this would be a Group III base oil. 

 

The only other street oil in Mobil's list of products with nearly alike additive is the ESP 0W40. If I needed some top off oil in a pinch this would be good. IMHO. 

You must be a chemical engineer or similar. I appreciate your effort to find an alternative oil.  To summarize things I learned from my experience and inputs from folks on this thread:

 

1. Carry a couple of quarts in the truck of the "Dexos D" approved oil so I know I have the correct oil to top it off.  Dexos D approved oil is not carried by very many retailers at this time. My best bet is either a Chevy or GMC dealer, but not all dealers will have it. Be sure to check that it is Dexos D and not "Dexos 1, Gen 2" or Dexos 2.

2. Check the oil level often, especially if I'm towing.

3. Check the oil level under the right conditions: cold engine on a level surface. 

4. There is a difference between "Dexos D" and "Dexos 2" and "Dexos 1, Gen 2" and make sure whatever I purchase for the Duramax 3.0 diesel is "Dexos D" approved.

5. If I do an oil change myself on my 2020 Chevy 1500 Duramax:

    a. An oil filter cap makes it easy to remove the oil filter but only if it is the correct fit. I purchased a correct fitting oil filter cap that had specs of 75.6mm and 14 flutes. Tighten the new filter after contact an additional 3/4 to 1 turn. 

    b. These two oil brands are Dexos D approved: 

           -AC Delco Light Duty Diesel DexosD 0W-20  Part number: 19370138

           -Mobil 1 ESP X2 0W-20

     c. It's best to have the engine oil at operating temperature to get the best drain.

     d. The oil plug wrench / socket to use is 15 mm

     e. Do not over-tighten the drain plug. I will find out in the next oil change if I damaged it. I hope not. The torque spec is 18 ft/lbs per  this web site: https://www.amsoil.com/lookup/auto-and-light-truck/?zo=521390 . Replace the drain plug seal. 

 

Thanks all for the input and response to my original post. 

[Grumpy Bear]

Perfect!!