Is Prestone Cor-Guard compatible with 2013 Ford Fiesta? The display at the store said it was for Ford. There is nothing on the bottle to say what color it is or if ford compatible. (I bought the Prestone several months ago) No ASTM or other number either. Is it an OAT or HOAT type? Which type does my car require? I know it's supposed to be orange. Car is 5 years old w/43000 Miles. Coolant looks very clean. Ford says to change coolant every 100, 000 miles but coolant has been in there 5 years. I am only getting .07 VDC reading from coolant to ground so I do not think I have an electrolysis problem.