So Duramax has approved Mobil 1 in 5W-40 for the D'Max. Problem is they have either all three of the below bottle package markings or they have finally changed to just the last one. I called Mobil in VA and was told they are all the same !! (make it simple guys)

There is some confusion about this oil as it has come in THREE different bottles with three different labels:

First: Mobil 1 for 'turbo diesels'
Second: Mobil 1 'Delvac'
Third: Mobil 1 'Trucks and SUV's'

ALL ARE THE SAME OIL; ALL ARE 5W-40 AND CARRY THE CI AND CH DIESEL CODES. ALL ARE IN SILVER BOTTLES (DELVAC 1300 IS IN A BLACK CONTAINER)

Just thought you would want to know . . my opinion of this insanity isCensored

Most likely you will only see Mobil 1 Turbo Diesels for now on.

Just waiting for the local wallyworlds to start stocking it again. Had to use Rotella synthetic last change & will go back to M-1 when I can find it...

When I looked at Mobil 1 Truck & SUV it said for "gasoline engines" on the bottle. It didn't used to, I know that for fact. I know Mobil changed the truck/suv line of oil in february - WallyWorld hadn't started stocking the Diesel version yet on my last oil change.

When I looked at Mobil 1 Truck & SUV it said for "gasoline engines" on the bottle. It didn't used to, I know that for fact. I know Mobil changed the truck/suv line of oil in february - WallyWorld hadn't started stocking the Diesel version yet on my last oil change.

Ya that's the 5w-30 you're talking about.

If it says 5W-40 and is approved for CI and CH on the bottle it is what you want for your truck.

Oil id cheap: trucks/cars/lawn movers are not cheap.

The Delvac oil from Mobile is not mobile 1. Mobile 1 are only synthetics and the Delvac is only a Mobile oil, so it's not synthetic. I'm not sure about the other oils but if the container only says Mobile I know that It's not synthetic so it's not the same as the others. You have to read the contianers carefully. Just like the extended range mobile oils for 5000 and 7500 miles they are standard oil but the Extended 10,000 mile oil Mobile 1 so it is synthetic but cost more then regular Mobile 1 because it says 10,000 mile on it. It's just to confuse people and make more money.

Mobil Delvac 1300 Super is 15W40 diesel dino oil (good dino oil)

Mobil Delvac 1 is 5W40 diesel synthetic oil (good syn oil)

Mobil 1 Truck & SUV USED TO BE 5W40 synthetic oil and good for diesel

NOW Mobil 1 Truck & SUV is 5W30 synthetic oil and NOT FOR DIESELS

Mobil 1 Turbo Diesel is the new synthetic for diesels

One of the Mobil 1 synthetics was marked DELVAC on a silver bottle: briefly!!

Why do these guys do these things?

One of the Mobil 1 synthetics was marked DELVAC on a silver bottle: briefly!!

Why do these guys do these things?

Actually for decades.

Actually for decades.
:exactly: Mobil Delvac 1 is the oldest of all the synthetic formulations and has been one of the best diesel synthetics for a LONG time. It wasn't readily available in retail, had to be purchased from a Mobil distributor or at a few truck stops.

Getting ticked that I cant find it on the shelf anywhere! Everyone has the 5W30 Truck/SUV I think many of the stores don't know of the change. If I don't find some soon maybe I'll try Royal Purple, they have a synthetic 15W40 for diesels and Year One sells it for $62.00 for a 12 Qt. case.

Getting ticked that I cant find it on the shelf anywhere! Everyone has the 5W30 Truck/SUV I think many of the stores don't know of the change. If I don't find some soon maybe I'll try Royal Purple, they have a synthetic 15W40 for diesels and Year One sells it for $62.00 for a 12 Qt. case.


And Royal Purple is great stuff.

I thought 5W40 for the Duramax was only for really cold temps? In the owners manual, it says that 15W40 is preferred, but 5W40 can be used when it gets around 32F. Did they change it?

5W40 is the rating on most synthetics. It is still 40 weight when hot, but flows like 5 weight when cold due to being synthetic. GM recommends lower viscosities for cold temps due to the high cold-start oil pressure. Synthetics are good year-round. There are only a few 40W synthetics available that *aren't* 5W on the cold rating.