Originally Posted by Gordon J
The certified Cummins mechanic told me that in my year engine that the company was using extended life coolant. Two years is how long you get off the green stuff. Current extended life coolant in stores claims to be good in cars for 120K miles or five years. I used to own a trucking company and learned to change fluids when the fluids were worn down/diluted or had some other issue. Testing can point you in the right direction.
While in the Army, we regularly tested oil in all diesel engines. Sometimes trucks would only get a couple thousand miles a year on them and with testing, we would learn that we could go often for years without changing.
I test oil now, but still change at the 250-hour interval as stated in the manual.
The difference between land based engine applications and marine is that the marine engine coolants can easily be contaminated by raw water leaks within the X-changer over time.
Even longer life coolants are not recommended for the same duration of service in marine diesels.
Please consult a Cummins engine manual and or take a look over at sbmar(dot)com.