New oils with less ZDDP.

The last couple of years, the zink packages have been scaled back, because it hurts emmissions. That's in gasoline powered engines. The secret is, it's not the case for deisels. The fleet type oils are still keeping the zink in them. Also, they tend to be much cleaner in terms of internal gunk..So, run deisel rated oils, or add a can of GM (i know..but they have it and mpar doesnt..lol) Engine Oil Supplement with each oil change. Todays faster rate cams and stiffer springs are battering the lifters even harder than normal, and they cut back what keeps them alive.