Since there is no history of maintenance on my 96 Explorer, I am going to get it flushed by a local shop that has a flush machine and replace the green coolant with G-05. My question is, Is distilled water really needed or would tap water be fine? Not sure about the local shops water, but my water at my house is in the middle between Hard and Soft. I highly doubt the shop is gonna use distilled water and that's why i am asking if the tap will be ok. If you do demand distilled water to be used, do you bring a bunch of gallons of distilled with you to the shop that is doing the flush? thanks for the help