Has anyone used Peak Fleet Charge antifreeze? I plan on draining,flushing and refilling the coolant in our 8.3 Cummins. I have no idea what is in it now except that it is green and looks clean. I have always used the "green stuff" and want to know if the "pink" is a good extended life coolant for diesels. By "flushing" I mean filling once with distilled water only and...