My question is how will you get all of the green coolant out of the block and heater core as to make sure it will not have any in it to mix with the Dexcool? I would never use Dexcool in a Nissan, personally. Blue coolant will mix with the green coolant without issues and, of course, yellow or "one color works with all" like Prestone will mix with the green, as well.
