I change mine annually (roughly 20,000 miles for me). The first change was Mobil 1 by itself (no friction modifier). The current change is Redline D4 (with the 2 0z. of friction modifier). The shifting action since the last change has sometimes been a little 'notchy' (but it has smoothed out condiderably).

Next December (approximately when I will do the next change) I think I'll use Mobil 1 ATF again. The Redline is good, but I don't think it's worth 60% more money in this application.

Just my .02 wink

Mike

1996 SE MTX, Desert Violet
Blaupunkt Munchen, Dunlop
Sport 5000s, Ray
McNairy's THFix, custom air filter,
Magnecor wires,
Redline D4 tranny cocktail,
9005 lo-beams
SVT-size front rotors, EBC Greenstuff pads all around