Any petroleum diesel oil is satisfactory for the CTD engine parts wear-in because there is enough friction developed to heat the piston rings under high torque operation. With 100% synthetic diesel oils the lubrication is so superior that there is little friction to develop heat that facilitates quick break-in or seating of the engine piston rings. A lighter grade of petroleum oil will also help develop more heat. My engine came with factory 15W-40 petroleum engine oil and after my first oil change at 2303 km I put in ESSO 10W-30 petroleum to continue the break-in period. When the engine was new I first checked my fuel mileage and it was 16.6 mpg. After about 875 km the mileage was 19.06 mpg. While doing some towing pulling 10,000 lbs the mileage obtained was 18.5 mpg. After the towing it was 22.6 mpg. I drive with a very light foot and accelerate easily. That is not good practice for quick wear-in, but that is how I drive. You can not teach and old dog new tricks.

 

I am also part of the AR crowd. I changed my oil the first time right at 1000 miles then again at 2500 miles and try to keep with a 2500 mile interval. If I had stuck with the mileage that the manual states, I would have changed the oil only about 3 times since I had bought the truck in 04. On the bright side for me is that I also change the fuel filter at the same time as I change oil, with the filters being cheap enough I think it is a good idea.