Well, finding Zerex around here is a PITA. Checked 2 Advance Autos. Autozone and Pepboys are too far for me to waste my time. Walmart doesn't have it either. Seems Prestone and Texaco are available. I checked the label on the Advance Auto extended drain antifreeze, and it is made by Prestone. Container stated it was compatible with everything else out there, and is the 5/150k stuff. I don't know that much about which coolant to use, but I figure with a proper flush the AA stuff will work okay. I bought 10 gallons of distilled water and a bottle of RMI-25 as well.