I plan on performing a transmission and differential fluid change this weekend. The vehicle is a 2000 Ford Ranger 2.5L 4 cylinder, 2WD, 5 speed manual. The owner's manual calls for Mercon ATF in the transmission and SAE 80w-90 gear oil in the differential. I plan on sticking with those specs. Currently, there are no problems with either the transmission nor differential. As long as I get Mercon ATF and SAE 80w-90 API GL-5 gear oil, I should be okay, correct? The name brand doesn't really matter? I won't notice a difference between Super Tech and Mobil 1?