A diesel engine is a fairly difficult lubrication application, mainly because of the fuel and soot loading. Good oils will use TAN boosters to alleviate the acidity of the partially burnt acidic fuel, dispersants and detergents for soot control, and antioxidants for high temperature and longevity. The base oil is nearly irrelevant for the application. Use a great quality petroleum base oil with a high VI and change your oil and filter often.
PS: I like synthetics, just not for this application.
PPS: The synthetic oil used in aero-derivative gas turbines is typically an organic ester due to high contact temperatures. Completely different animal. Frame gas turbines and steam turbines often run regular hydro cracked petroleum base oil.