Personally I would be searching for the F1 spec Ford requires.

I’ve been waiting to see delo on the list but it wasn’t there last time I checked.

https://www.fcsdchemicalsandlubrican...ry=Motor%20Oil

The 400 LE 5w-40 in the grey jug is still CJ-4, dont know how much longer it will be available.

I wouldn’t run that Chevron oil until Ford approves it and it shows up on the list. I don’t know why Chevron is holding out so long. They must be the last big name hold-out where their CK-4 oils aren’t approved, since the CK-4 spec change?

Here’s the breakdown of some Chevron CK-4 SDE 15w/40. Looks like the phosphorus is below the 1000 ppm threshold to get Fords blessing? Some other anti-wears look low as well, such as zinc, but boron seems higher than most.

Chevron Delo 400 SDE SAE 15W-40 Heavy Duty Diesel Engine Oil API CK-4/SN

I stockpiled quite a bit myself lol

Why would anyone try to justify using a motor oil that doesn’t fall within FoMoCo’s F-1 specs? I get it that some folks have a favorite brand, due to either commercials, favorite spokespersons, NASCAR racers, what daddy used, etc. But why would anyone risk damage or voiding a warranty just to be brand loyal?

i have not heard any scientific explanation to justify a non-F-1 oil as better for the 6.7 power stroke engine than a certified F-1 oil.

Just use what’s on the list, and don’t worry about it.

We ran Delo in our trucks for years but switched over to Rotella T6 full syn when Ford added it to the aproved oil list .

i was reading that the phosphorus needs to be between 1000 and 1200 PPM to be acceptable, any older CJ-4 formula is acceptable as long as it does not share the CK-4 in the API donut.
If it's a newer oil formulation do not use it unless it's on Fords list!