oil choice for diesel

I use Mobile Delvac 1300 in my 2001 Dodge Cummins. I tried Rotella TTT, but the numbers weren't as good as they were with Delvac according to Blackstone Labs, so I went back to Delvac and have lived happily ever after. I do change it every 5,000 miles or so, sometimes a little over, just depends. It's only about $12 per gallon so a little more frequent oil changes aren't that big of a deal. And usually a Wix filter, or Bosch, or Fleetguard.