I have a 2SDK8 with the 2J diesel engine. It is 40 yrs old. When purchase back in the late 1980's the company informed me that the engine should use 10w40 oil. The manual recommended 10w30. This was conventional oil. I've been wondering if I should or can use synthetic diesel oil now. Anyone have any info or suggestions/experiences. I've done some research and suggestions state it's ok to use synthetic as long as I watch the zinc content in the oil (should be 1200 to 1400 ppm). Suggestions stated its ok to use 5w40 T6 Rotella, anyone have any experience or thoughts?
Why synthetic now? It's more important to do regular oil changes than switching to synthetic. Save your money.
I was just in a couple discussions referring to the use of which oil to use in situations similar to yours and would advise continuing the use of conventional oil unless you are having issues that may or may not be changed by changing to synthetics of synthetic blends and in some cases this change can make issues even worse. Also take into consideration the cost differences since synthetics are now many times more than conventional. I'm sticking with conventional oil in my engines that started with it but using synthetics in my newer things that require synthetic.