I need to change my oil soon and not sure what to use, I have been use Delo 15-40 for years, but is not on the list. Have been thinking about using a synthetic, but is T6 with the new rating on the list? Just wanted to know what you are all using, thanks.

 

Triax 5w/40 full synthetic. 3900 miles so far, still has a slight caramel look to it, the Rotella would have been jet black by now, couldn't be happier, @ 5K miles I'll send in a sample for testing.

 

"The List" is for the newer engines, I believe, which means you can still use the Delo if you can find it.

 

I use Mobil delvac 5-40 full synthetic. have some cj4 and ck4. When someone says it is a problem for the 7.3 engines that has done testing in them and had something to do with making them ill worry about it. I buy it on sale and send in the rebates ends up about 35 dollars for 5 gallons with tax.

 

I still use Motorcraft 15w-40 Super Duty oil. Always have.

 

Shell Rotella T6

 

Delo is fine. Don't waste your money on synthetic oil unless you live somewhere that gets super cold then synthetic could be helpful during the winter months.

 

Thanks for the responses, so those using T6 and Delo, are you just using the new formula ck4?

 

I started using Motorcraft 15W-40 oil also.

 

I believe the CK-4 stuff is fine to run in the 7.3. Fords statement was about the 6.7 Powerstroke. Rotella t4, Delo, Delvac, Valvoline, Motorcraft, or any other 15w40 diesel oil is fine to run. I have been running Motorcraft but I picked up about 9 gallons of Castrol 15W40 at Walmart on sale for $5 a gallon a few months ago, I also have a few gallons of Delo.

 

T6 is on the “approved” Ford list: https://www.fcsdchemicalsandlubrican...SSM2C171F1.pdf

 

That list has 30-40 brands that no one has ever heard of, I wonder if they really tested all of those oils.

 

Well, I doubt Ford gives a flying , umm, fudge, about 7.3L problems/issues at this point. They are all long since out of warranty. So, just because they don't report 7.3L problems with the new oils doesn't mean there aren't any. In fact, I would suspect that the older motors are more vulnerable to excessive wear from newer oils, as the newer oils have less and less anti-wear additives, in order to protect the DPF/cats on newer diesels.

Umm, that doesn't seem right.
A.) I don't recall ever seeing a Castrol DIESEL RATED oil at Walmart.
B.) I have never seen any DIESEL RATED oil sell for $5/gallon.
C.) $1.25 /qt is a plausible sale price for regular NOT DIESEL RATED, conventional automotive 15w40 Castrol.

See the theme/pattern here? I highly doubt that Castrol oil is for diesels, in which case you definitely should not put it in your 7.3L

 

I used to use Rotella T6, but the engine always seemed to run weird after the first couple thousand miles.
I have since switched to this Lucas High TBN ( anti-wear additives) CI-4 oil
https://lucasoil.com/products/lucas-...h-tbn-ci-4-oil
Along with switching to a larger FleetGuard venturi oil filter ( which has a built in bypass filter section), I will be aiming for 10k mile oil changes.

 

Valvoline(red bottle) synthetic 15/40...10.98gal/walmart👍