I don't know if you ever dropped an oil pan, before (doesn't sound like it, all talk) but that process only drains 50 percent with the remaining in the valve body, torque converter, cooler lines and cooler. That is not empty by no means. I and many others have not had to perform any special procedure to fill just the sump back up other than what is spelled out in their owners or Ford service manual, not Haynes.. You can continue to use whatever fluid you want. Millions of others do not use OEM ( Connoco- Phillips) fluid and know the word "Mercon V" on their fluid container will perform as well or better than the OEM fluid. I am not saying Motorcraft is not a good product. I am saying there are other more affordable and acceptable options out there. I doubt Ford would "CERTIFY TO USE" any fluid in their transmissions if it was not acceptable to use which is what I read on Castrol's product sheet.. You can continue to play your word games and try to get others to drink your kool aid. It is time to move on.

 

Oils and fluids have certainly evolved and improved over the last 40 years. Most people have developed loyalty to particular brands of oil / fluids for one reason or another, in many cases it is just blind loyalty with no facts or reasons to back that up.

All oils / fluids must pass tests by independent labs in order to be able to be an Approved fluid meeting the specifications for that category. Note the ASTM test #'s listed in the Castrol link above. If you want some dry reading start reading ASTM test language.

Motorcraft fluids must pass the same ASTM tests. Further batch to batch consistency is undoubtedly required by the contractual agreements to supply & label those products with the Motorcraft name.These are premium products. Ford uses these products in their vehicles and sells them in their stealerships. Ford makes a profit off these from every Sale, thus the Recommended status. These products are used by Ford engineers & technicians and become trusted, and for good reason as they provide consistent performance. You can't go wrong using Motorcraft fluids.Loyalty here is not blind loyalty, the trust has been built over a long period of time with good results. They are not the only good choice.

You also can't go wrong using brands that meet the ASTM tests for the category they are Approved for. The quality can be the same or higher. No royalty dollars going to Ford either.

Having always kept my vehicles long term and kept up the maintenance with quality fluids approved for the application I have never had a lubrication related failure. A whole lot of Motorcraft fluids went into those vehicles, and so did some other brands. Using Approved fluid is the key, not the brand. Not everyone will agree.

 

High quality fluids have their place. I am a fan of castrol for engine oil(full synthetic) and I use a very cheap group III store brand oil for my non-road applications like my snowblower, plow truck(1980 GMC K25), cars I flip that can take conventional, etc. I used amsoil in my car, its definitely a good oil but Im not sure if it was *that* good considering what I put it in. Was an experiment for sure. When it comes to trans fluid, Ive used.. uh.. I think it was prestone..? maybe it was penzoil? for my Gm applications and power steering systems. Ive also used supertech.

In my f150, I used some seafoam hydra trans tune and that helped quiet my pump a lot and made it much easier to turn, and I flushed it out and filled it with supertech Merc III fluid, which also goes for Dex III according to the bottle.

Ive heard of guys running type F in these trucks... half of my trans is full of that.. not sure what to think on that.

I would like to use a nice synthetic ATF when I do trans fluid in my car, truck, and eventually other 2 cars. Only ford in my fleet is my f150, i used to have a 77 LTD. currently have a 2001 mercury, but its for sale. So I will be needing Dex VI fluid. F150 I think Ill use merc V

 

Mercon V replaces Mercon when not available if you want synthetic, I would not use Dex 6 in a Ford. Viscosity on Dex 6 is much thinner.

 

Oh no I was saying Dex 6 for my GM and mercon 5 for my Ford. I don't have much Ford's I have a lot of GMs

 

Even though Dex 6 is a better fluid than the old Dex 3, I would still use Dex 3 in an older GM transmission. I discovered that my old 4T60E trans. started to shift little harsher when real warm with the Dex 6 because of the viscosity. Dex 3 may be hard to find. I will kept it brief before the forum cop scolds me for talking G.M. here in this Ford truck forum.

 

My trans was rebuilt in 2016 by previous owner with 20k miles on it, they used dex 6 after rebuild so fortunately i think thats one application it will be okay lol

 

Dex 6 is fine for G-Motors not a Ford.