Motorcraft chart (link below) says your factory fill was normal green. You may use Motocraft Gold (G0-5) if you fully flush the system. Your choice. If you don't know what has been done in the past, a good water flush probably should be done. The Zerex equivalents may be cheaper and easier to find.
G-05 can mixed with old green, but you will not get the benefit of an extended life coolant until the system is all G-05 via a flush or complete (block, radiator, heater core) drain and fill.
What color is the stuff currently in there? Unless you want to do a full flush for something else I would stick with what is currently in there. If there has been any prior work done on the cooling system I wouldn't be surprised if it was am/am but personally I would flush everything with distilled and fill with G-05. Whatever brand you can find.
G-05, Motorcraft Gold. There's a plastic intake on these, so I'm leery of Prestone and most "universal" all makes/all models based on Dex-Cool chemistry. This includes SuperTech/Prime and anything except for Peak Global Extended Life.
Originally Posted By: Bgallagher
What color is the stuff currently in there? Unless you want to do a full flush for something else I would stick with what is currently in there. If there has been any prior work done on the cooling system I wouldn't be surprised if it was am/am but personally I would flush everything with distilled and fill with G-05. Whatever brand you can find.
Probably crud brown. People never change coolant and then it turns crud brown.