PS-If you want a truck the doesn't smell, you shouldn't have bought a diesel.

actually I love the smell of diesel just not the smell of oil every time I shut my truck down

 

You may want to go over to BITOG (bob is the oil guy.com) & check the medium duty diesel engine oil forum. There are many really informed people over there. It's a lubrication related site.

Probably the most popular conventional (dino) oil on BITOG is the Chevron Delo-400, 15X40. It starts with a great base stock with a robust additive package, including moly & boron, in the CI-4+ rated oil.

I've been using Delo & my last oil change had 8303 miles on the oil. Did an oil analysis which showed the oil still had a lot of life left in it. I usually changed at 5000 miles but, after reading of extended oil change intervals, I thought I'd try it. The 8303 was with some towing, also.

The newer oils (CI-4+) are quite a bit stronger because of the higher emission standards.

You should be OK with any of the Major Heavy-Duty Rated diesel engine oils.
I remember reading, on the TDR, of a couple that towed trailers for a living with a '94 Dodge/Cummins. They had over 1,153,000 miles on the truck without an engine rebuild. That was using Rotella with 5000 mile oil change intervals & Fleetguard filters. The oils, now, are better than they were back then.

Joe F.(Buffalo)