Synthetic Tranny Oil for 2003 Ford Ranger?

[NH73]

Based on what? How do you know will not thicken? Or stay the same?
I did exchanges of Mercon V at 30k miles and it looked almost new. Transmission shifted the same.

Oil usually thins out as it gets used at first. Looks can be deceiving, but Mercon V can last longer than 30,000 miles. My Sport Trac which specs Mercon V has an ATF exchange interval of 150,000 miles.

 

[stanlee]

Stick with Mercon V. Doesn't have to be Motorcraft. Castrol, Supertech, STP, Fram, Proline (pep boys), Amalie, Kendall, Ravenol, oem Mazda Merc V and who knows who else all offer licensed or unlicensed Mercon V. Why are we trying to outsmart what's already proven in millions of Ford transmissions. (Yeah some have issues which are rarely fluid related).

 

[SoNic67]

My Sport Trac which specs Mercon V has an ATF exchange interval of 150,000 miles.

Good luck with that.
I never left the Mercon V more than 50 k miles and never had any issues with my Ford transmissions. I actually changed the sump pans with the ones that has a drain bolt (Dorman makes them).
I didn't need the bragging rights that "I never changed my transmission oil", just the ones that my transmissions lasted 200k miles and still going strong when the cars got totaled (rust and a teenager driver).