I have (if I didn't delete it) an email from Terry that doesn't match what you have. His most recent comment to me when specifically asked about Ford Honey and friction modifier was something to the effect of use it on an as needed basis. Try it without and then add the friction modifier if needed.
Most any tribologest will tell you that you are usually better off getting the right fluid in the first place rather than trying to do your own. That is fair enough advise, but Ford had already muddied the water with it's earlier manuals showing that additional friction modifier was needed and the habits were somewhat entrenched.
This whole thing about adding friction modifier to the MTX75 started with Ford. In their earlier Contour shop manuals, they specified using Mercon ATF with added Ford friction modifier. A popular fluid for that application for some time was using Mobil 1 synthetic ATF (which meets Mercon specs) and adding 2 oz of Ford friction modifier. This combination works reasonably well by the way.
And then Ford introduced the new fluid, called Ford Honey. It is specified to be used whenever it was factory fill and is appropriate for top off as well as refill for all earlier MTX75 transmissions. I have changed a few cars over to it. I have also observed that the shift quality is improved when adding Ford friction modifier. Presently I have Ford Honey with 2 oz of Ford XL-3 friction modifier in my own car and it works very well.
I am lightly concerned that Ford Honey seems to be more like a synthetic motor oil and not much like a gear oil. I am greatly concerned that Ford wants $20.00 a quart for the stuff.
The ideal fluid would be a synthetic that is specifically blended for use in a manual trans. If properly done, the GL4 or GL5 would be a benefit as well as an apppropriate level of the right friction modifiers.
As MolaKule already posted earlier in this thread, the correct Specialty Formulations product for this trans is MTL-R.
