First, my car has 23K miles on it and is 19 months old. What is the maintence interval for both the transmission and differential fluids? Lastly, what's everyone using?

Thanks, Jason

 

Scheduled maintence guide suggests 150,000miles for diff. fluid and automatic transmissions, nothing for manual tranny's. The guide stops at 150,000 so not sure about the manual tranny's interval, obviously it's way longer than you need to worry about right now.
As far as what to use, just use the motorcraft stuff, it's fully synthetic...good stuff.

 

Excellent advice. I used to own a 94 Supra Turbo, the owners of which cars are even more mod-obsessed than Mustang owners. I don't know how many dozen transmissions, including mine, were ruined by deviating from the factory recommended lube (which was also synthetic) and using Redline synthetic gear lube in the hopes of some magical transformation in "feel" or performance.

 

Exactly. The engineers who designed these parts spent countless hours designing these parts to be used with certain lubrication qualities. If the stock oil was crap, you'd have tons of failures, and Ford would be spending even more $$ on expensive warranty work. Sometimes "better" oil can be worse...