Every 100,000 miles, or when ever it looks excessively burnt

 

What about being flushed?

 

That's how the anti-freeze is changed; it's flushed out, and replased with a minimum of 50/50 mix, depending on your location.

If you don't have an owners manual that outlines Ford's recommended maintenance schedule, you can download a .PDF version for free at the official Ford web site. Here's the link (enter your make/model/year):

https://www.flmowner.com/servlet/Con...aining-vehicle