I heard the diesel oil with its additives was only bad for gas powered pollution controlled vehicles, something about the cat getting clogged. For me, this has been proven wrong. My work truck, a 1999 F**D F150 has 185,000 miles on it and has taken Chevron Delo 15W40 exclusively. I have put 130,000 of the miles on it myself and have had no problems emission or motor wise with it.
When my 56 gets road-worthy, I'm going to run Delo 30 weight in it.
