Just wondering what some of your feelings are about using full synthetic oil in a turbo diesel engine. I have been using Castrol Syntech for over 15 years in all the Toyotas I have driven, well over 600,00 miles. I have been hearing some good things about Amsoil, don't have any personal friends who have used it yet, so I don't have any direct feedback ontheir product. Any and all comments are welcome and appreciated greatly!