The GT oil cooler is water cooled by 2 coolant hoses connected at the lower radiator hose and the oil filter screw on itAir is used to cool the oil, I believe. If the coolers were water cooled, there would be double the lines and the associated opportunities for problems.
Thanks. Much appreciatedThe official GT vs Mach 1 comparison image from Ford says that it has "air engine oil cooler".
https://i.pinimg.com/originals/41/2e/83/412e837839b139bba92c50045a712343.jpg