hey guys found some info for you with the zf 6 speed, it seems ford is allowing you to use 2 options for the zf 6 speed a cheaper mercon v oil or what i would seem to be a more long term investment the syn man trans oil for long life and high heat protection. my early 2009 owner manual states to use the syn man trans fluid and then abruptly ford changed the specs later that year, i checked on the motorcraft website on any updated editions of my owners guide, they went to mercon v instead don't know why or for what advantage this may be other than a more cost effective solution for the consumer? below is a link you may want to check out to see what i am talking about. by the way does anyone know where i can purchase the 1 qt bottles cheaper than the dealers 19.00/qt. price?