My supply of Motorcraft 5w40 CJ-4 oil dried up, so I went with one of the first 5w40 oils listed on the Ford approved oils list. In my area Valvoline 5w40 is plentiful at NAPA for $19.99/gallon or on Amazon for same price when not on sale at NAPA. After my initial test of the Motorcraft reported running more miles, I started running it for 7500 miles. Since the Valvoline is much cheaper than the Motorcraft, I decided to run it about 5500 miles, test it and see if there were any major changes between the CJ-4 and the new CK-4 oils. You guys take a look, it looks good to me. Notice the oil stayed in weight for the entire 5500 miles so I'll probably run this next OCI out to at least 7500 miles or more. I also noticed fewer regens and the motor was quieter during the entire 5500 miles.
The oil was changed at 90,508 miles and did have about 2000 miles of towing my 10k lb fifth wheel camper on it.