psfred makes a great point regarding soot. This is why Universal grade oils, which are designed for diesels do a much better job of helping these engines live a long life.

The additive package is designed to disperse the soot and minimize it's ill effects. I'm not trying to sell any one brand, there are many that will help your diesel live a long life. The most common are: Chevron Delo 400, Mobil Delvac, Mobil Delvac One and Shell Rotella T. Any of these oils will do a better job in your diesel to combat the problems psfred describes, better than a regular oil with a "C" rating.

Have a great day,