What oil does the dealer use? I don't think he knows...

gmatx · July 1, 2021

I have a fairly new Sierra 2500 HD with Duramax engine. My first oil change was today, provided free by the dealer. I went there hoping they would put in Mobil DELVAC 1 ESP 5W-40 which is fully synthetic. When I asked what they would use, my service advisor said "Dexos". I said are you sure? So he went and asked somebody and came back and said "Delco". I started laughing. Then he said maybe it's "Delo". I looked up Delo -- Chevron Delo 400 comes in Fully Synthetic and in a Synthetic blend. He assured me it was the full synthetic, but I was less than confident. The receipt had part # 88862497. When I looked that up, the parts websites say that it's DELVAC 1300 which I'm 99% sure is a synthetic blend. I'm calling the service manager tomorrow to find out what's what. Maybe if they used a blend I'll get a full refund.

elcamino · July 1, 2021

They get the oil in bulk from GM approved low bid vendors, It come in a truck and they pump it into a tank. Around this area you will see Halron trucks at the dealers. Even the Furd and Rum dealers. Its the lowest price oil that meets the spec, the dealer is not going to buy expensive oil is there is a cheaper one that meets spec. The dealer could care less what brand it is. The part number is generic to them, its what ever they put in there, no matter the brand. If you want a special brand then you need to supply it.

Edited July 1, 2021 by elcamino

diyer2 · July 1, 2021

Dream on gmatx.

KARNUT · July 1, 2021

Iv been using the dealer during the warranty period for many years. When I had my 06 trailblazer ss I watched them using mobile one by the qt not bulk. It was what was specified. Expensive but the light usually came on at 12K. Honestly if someone was pulling a trick it would be known. My dealer when I was getting my truck inspected told me they use only synthetic now. Even in vehicles calling for blends. It’s just easier. My Honda dealer said the same.

nards444 · July 1, 2021

1 hour ago, diyer2 said:

Dream on gmatx.

lol yup. The guys that spend the effort on this blow my mind.

It's Tim · July 1, 2021

12 hours ago, gmatx said:

My first oil change was today, provided free by the dealer.

Maybe if they used a blend I'll get a full refund.

They'll be sure to refund your free... pronto.

gmatx · July 1, 2021

The service manager just sent me a pic of the oil they used. Mobil Delvac 1300 Super 15W-40 in quart sized bottles, which I'm sure you all know is a very high quality synthetic blend. I know it's more than sufficient for my truck, I just wish the advisor had known they were using a blend when I was there yesterday and asked for full synthetic, and was assured I was getting full synthetic.

KARNUT · July 1, 2021

19 minutes ago, gmatx said:

The service manager just sent me a pic of the oil they used. Mobil Delvac 1300 Super 15W-40 in quart sized bottles, which I'm sure you all know is a very high quality synthetic blend. I know it's more than sufficient for my truck, I just wish the advisor had known they were using a blend when I was there yesterday and asked for full synthetic, and was assured I was getting full synthetic.

Back when I had my trailblazer during my second oil change at 24K miles on mobile one. The second of 5 that year. Yes I drove a lot. The service writer scolded me on the extended oil changes. Of course he was oblivious to the maintenance schedule on that vehicle. During that time I was exclusively using Amsoil (after warranty) telling him that it was less half of what I was use to. I handed him my maintenance manual. While telling him it’s better to be silent and thought a fool. Then to speak and remove all doubt. Most service writers have no clue. Get everything in writing.

newdude · July 1, 2021

GM dealers 99% buy on the GM oil program. All GM program oils are supplied by Mobil, including factory fills. GM factory fill on the 6.6 Duramax is Mobil Delvac 1300 in 15w40 weight. Its what GM dealers stock (we stock it here at work in quarts and gallons).

There is two versions of Delvac GM dealers have access to on the GM oil program, Delvac 1300 15w40 and Delvac ESP 5w40.

All the ones around me stock the Delvac 1300. If you want full synthetic, I would pursue changing your own self in the future.

Edited July 1, 2021 by newdude

C/K Man · July 1, 2021

It looks like most of the ACDelco lubricants are supplied by ConocoPhillips. I was looking at their MSD sheets and noticed that the ACDelco Dexos full synthetic 5W-30 comes in the same bottle as Phillips 66 Shield Valor 5W-30.

gmatx · July 1, 2021

22 minutes ago, newdude said:

All the ones around me stock the Delvac 1300. If you want full synthetic, I would pursue changing your own self in the future.

I will most likely start changing it myself once I'm out of free oil changes. I think I still get one more more for free, but after that I'll switch to Delvac 1 or Rotella T6.

newdude · July 1, 2021

21 minutes ago, C/K Man said:

It looks like most of the ACDelco lubricants are supplied by ConocoPhillips. I was looking at their MSD sheets and noticed that the ACDelco Dexos full synthetic 5W-30 comes in the same bottle as Phillips 66 Shield Valor 5W-30.

Hmmm. They must be switching then? Or its because of the oil shortages? Our June oil supply update they mentioned Exxon Mobil as their supplier.

newdude · July 1, 2021

20 minutes ago, gmatx said:

I will most likely start changing it myself once I'm out of free oil changes. I think I still get one more more for free, but after that I'll switch to Delvac 1 or Rotella T6.

Unless your dealer agreed to give you more free ones, only the first service is free from GM.

C/K Man · July 1, 2021

7 minutes ago, newdude said:

Hmmm. They must be switching then? Or its because of the oil shortages? Our June oil supply update they mentioned Exxon Mobil as their supplier.

Phillips appears to be what's coming in the ACDelco bottles, what the dealers are buying in bulk may be different.