From reading mileage reports, lab test results, MSDS sheets on the contents of oil packages I 've come to the conclusion that there really is not much difference between the top manufacturers diesel engine oils. Chevron, Mobil, Shell, Amsoil, etc except the price.
It also appears there is not much protection package difference between the Synthetic oil and regular oil. The main benefit to synthetic is it's cold temperature flowability and higher temperature limit prior to breakdown.
So... I decided that ease of buying and cost is the only big differences. During the winter I chose to run a synthetic (Rotella Syn) and the summer a regular oil (Chevron Delo or Rotella).Edited by: JohnnyO