I'm a UPS semi mechanic. I also work on the yard shifter trucks. Those are the trucks that move semi trailers around sort hubs. They have a Cummins 6.7 in them with a lower output engine vs whats in a Ram truck and an Allison automatic. Delo 15W40 is what those trucks get. I've seen one last over 30K HOURS on the original engine. 25K hours is the norm.
Worry about the emissions system. Don't be old school thinking you need to let your diesel sit and warm up before driving it.
And don't let it sit and idle for prolonged periods.
In fact, the newest yard shifter trucks only run X minutes without a butt in the seat because prolonged idling makes more soot and
that mucks up the emissions components much faster than driving under load.