mixing transmission fluid types

I never had any trouble with type F in any car. But putting Dexron in a Ford could result in disaster. I think type F Was formulated for C-4 and C-6 trannys because they opperate at a higher temp than 727's, and turbo-hydromatics. I never mix synthetic and non synthetic gear lubes together in heavier equiptment and probably only do it in my car in an emergency type situation.