Want to drain and fill the Sedona, but don't know what to use. Right now it has a dark green coolant(old, degraded maybe)in it and not sure if it is FF or regular green. It still runs cool and have had the vehicle since '06. Can I use Peak Global for it or Prestone 5/150,00? Should I flush till clear with distilled water and put whatever I want in it? Thanks in advance for the help.