2021 GMC Sierra HD - Oil Type?

[2021GMCLP5]

So I am ready to do my first oil change on my 2021 GMC Sierra HD Denali.

Owners manual says to use dexos 1 5w-30 oil.

 

Every auto parts store is saying that doesn't fit my engine, and use 15w-40. I have the Duramax L5p.

 

 

Any guidance here? or anyone have some sort of experience on this, i know the weight can change, but i havent seen the 2nd number change. Also, why does the manual say 1 thing, and the auto parts stores say another.....

[hollywoodsle]

You should have received a duramax supplement to go along with the owners book.  The information is in there, the truck takes 15w40.

[gemarsh]

Your oil fill cap will agree with the auto parts store.

[gemarsh]

Edit to add. Is there a typo in the year? Or is this a new to you, truck?

[newdude]

2 hours ago, 2021GMCLP5 said:

So I am ready to do my first oil change on my 2021 GMC Sierra HD Denali.

Owners manual says to use dexos 1 5w-30 oil.

 

Every auto parts store is saying that doesn't fit my engine, and use 15w-40. I have the Duramax L5p.

 

 

Any guidance here? or anyone have some sort of experience on this, i know the weight can change, but i havent seen the 2nd number change. Also, why does the manual say 1 thing, and the auto parts stores say another.....

 

With the diesel there should be a second owners manual, the Diesel Supplement Manual.

 

Oil weight can be either 15w40 or 5w40 if you have really cold winters.  Shell Rotella is a popular choice, Amsoil, Chevron, Mobil Delvac, etc.  

[Pryme]

22 hours ago, 2021GMCLP5 said:

So I am ready to do my first oil change on my 2021 GMC Sierra HD Denali.

Owners manual says to use dexos 1 5w-30 oil.

 

Every auto parts store is saying that doesn't fit my engine, and use 15w-40. I have the Duramax L5p.

 

 

Any guidance here? or anyone have some sort of experience on this, i know the weight can change, but i havent seen the 2nd number change. Also, why does the manual say 1 thing, and the auto parts stores say another.....

5w30 is for the gasoline engine. 

[2021GMCLP5]

On 1/26/2023 at 12:31 PM, gemarsh said:

Edit to add. Is there a typo in the year? Or is this a new to you, truck?

new to me

[elcamino]

Edited March 2 by elcamino