Delo 400 vs. Delvac

Are there any studies out there that compare Chevron's Delo 400 to Mobile's Delvac diesel oils?

I usually run Delo, but in my last discussion about synthetic oils, someone mention Delvac. I am about to change my oil. I decided to stay with Delo or Delvac. Which is a better quality, or are they basically the same.

Thanks in advance.

Bob