Which Mobil oil for my 7.3

[JavierH19]

If you’re trying to start an UNHEATED diesel of any kind, with 15W40, at -33F, oil flow is likely to be the least of your problems. That’s seriously into 0W30, block & pan heater territory!

That's true. If I was in such uninhabitable temps a 0w-30 or 0w-40 and pan heaters would be my pick but in general there is still some benefit to having better cold flow even in 30f temps as you get slightly better initial fuel economy within the first 5 minutes of driving until it warms up enough for the gap to close.

 

[Surfram]

This was copied and pasted from Mobils website. Under products description. This is under Mobil delvac 1300 super 15w40 If it was recommended for turbo's, They wouldn't have said this!

• Diesel applications using older and naturally aspirated conventional designs

That is one line from the website stating that Delvac is backwards compatible for older diesels. Here is the complete version:

"Developed in close collaboration with OEMs, Mobil Delvac 1300 Super 15W-40 engine oil is recommended for use in a wide range of heavy-duty applications and operating environments in the trucking, mining, construction, agricultural and marine industries. Accordingly, this oil also meets or exceeds the requirements of API CK-4, CJ-4, CI-4 PLUS, CI-4 and CH-4 service categories, as well as key OEM requirements. Mobil Delvac 1300 Super 15W-40 engine oil is universal, meaning it may also be used in gasoline engines requiring the API SN specification.

Mobil Delvac 1300 Super 15W-40 diesel engine oil is recommended by ExxonMobil for use in:

• The latest heavy-duty diesel engines, including those equipped with aftertreatment systems and EGR
• Diesel applications using older and naturally aspirated conventional designs
• On-highway heavy-duty trucking and off-highway applications including trucking, mining, construction, agriculture and marine
• On-highway applications operating in both high speed/high load and short haul pick-up/delivery service
• Off-highway applications operating in severe low speed/heavy load conditions using up to 500 ppm sulfur fuels
• High-performance gasoline engines requiring API SN and mixed fleet operations
• Diesel-powered equipment from American, European and Japanese OEMs"

I probably ran Delvac 15-40 for 100k plus in my 2004 5.9 Cummins Ram 2500. It does not smell horrible like Rotella 15-40 after an oil change. I have also used it in my 2018 6.7 Cummins Ram 2500. I would not hesitate to use Delvac 15-40 in any diesel at temps above 0F that calls for 15-40 oil. Below 0F, 5-40 should be used.

 

[4WD]

This was copied and pasted from Mobils website. Under products description. This is under Mobil delvac 1300 super 15w40 If it was recommended for turbo's, They wouldn't have said this!

• Diesel applications using older and naturally aspirated conventional designs

It’s used in turbo’s all over the planet -
DMax is N/A ? Long list of HD OEM’s - not going to find many diesels that are not turbo - that’s a given … Millions of gallons from a CAT drum … (we run in 3516’s) They are just saying “also” blah, blah …
If it’s not recommended by Ford - Jimmy cracked corn - but you are not on to something …
BTW: My boss brings Delvac 1 to the dealership and it goes in his F250 … has done that for years …

 

[CleanSump]

"I have been using Mobil delvac 1300 super 15w40 in my 1997 F250 7.3 since I purchased in new. Now has 270,000 on the clock...."

After 270,000 miles, do you really think you need to change to avoid catastrophic failure due to the "incorrect" oil?

 

[blufeb95]

Keep using Delvac 1300 Super or use Delvac HDEO 15W40 if you can find it.

 

[bullwinkle]

In TX, any Big Three HDEO will work just fine-Delo, Rotella, or Delvac 15W40. You NEED the 40 weight in summer-I’ve been to TX, it gets pretty warm down there…

 

[Creekside]

Delvac is factory fill for Detroit Diesel or at least was for the Series 60. There has been hundreds of millions of miles run on it. My Series 60 didn’t like rotella and was a different truck after switching to Delvac. I see no reason to change now.

 

[SteveG4]

Delvac is factory fill for Detroit Diesel or at least was for the Series 60. There has been hundreds of millions of miles run on it. My Series 60 didn’t like rotella and was a different truck after switching to Delvac. I see no reason to change now.

I'll have to agree with you here. Why change now? What's the point at going on 300,000 miles? That cart is chock full of fine apples.

 

[wpod]

Can't say this is scientific by any means but it's still worth something. Starts at 5:20

Does it get -50* in Mississippi?