6.7 Powersteoke Oil requirement
 

Not sure how many folks out there know Ford has slowly been adding oils to their approved list of oils for the powerstroke after the whole switch from CJ4 to CK4 standard fiasco. I have been occasionally looking at the list, and now Rotella T6 is back on the approved list. Motorcraft 5W40 synthetic has been hard to find locally since the new standard came out, so for the last 3 changes I have been using Carquest CJ4 5W40 synthetic heavy duty diesel oil by Warren Oil Co with motorcraft filter. But now that Rotella T6 is Ok per Ford I will begin using it as well. By the way it was on sale for 19.99 a gallon today at Advance Auto Parts.

Just make sure when you are getting oil to make sure it's either CJ4 only standard, not CK4, or if you use CK4 make sure its on this list.

https://www.fcsdchemicalsandlubricants.com/main/product.asp?product=Diesel%20Motor%20Oils%20Meetin g%20Ford%20WSS-M2C171-F1&category=Motor%20Oil