A relative just purchased a new F450, 7.3 PSD. He wants to run synthetic motor oil. It has 3000mi on it now. Is it broken in or should he run another 3k before switching?

Looks like Delvac 1 or Rotella T are the most common choices for diesel synthetics.

Comments Please

 

I would stick with oil made frome dead dinosaurs. However, if I were going to switch to synthetics and the truck had 3000 miles on it I would switch now.

 

Is it broken in? That's going to depend on how he has used it. With the advent of CNC machining equipment, precision casting and new means of machining, measuring, finishing and selective assembly, break in is not so critical as it once was. When a part is machined, the metal removed is actually torn off from the metal that remains. This tearing left the surface with a series of peaks and valleys. The degree of finish on the part dictated the relative heigth of these peaks and valleys. Break in was the period during which these peaks wore against each other and were either torn off, or battered down to fill in some of the valleys. The pieces torn off dictated early and frequent oil changes during this period. Today, the difference in heigth between those peaks and valleys has been reduced so that new engines can be better described as prarie. However, some break in will still occur in any engine.

As for today's diesel's, If you load them up to capacity and work them, your engine will be fully broken in within 3-5000 miles. If you simply drive it around as a passenger car, babying it like your aunt Myrtle drives, you can figure on 30.000 miles before it is fully broken in. All that said, many new engines come from the factory with synthetic oil, including the VW Diesel vehicles. (actually they use a dino'synthetic blend.)