I'm going to get told I am crazy and my tranny will blow up by some, but I run the Redline MTL in mine.
I bought this T5-Z in August 2002. Put it in with regular ATF, then changed it out at about 1500 KMs. NOTCHY is an understatement. Put in Mobil 1 synthetic ATF, for a couple thousand KMs.. still NOTCHY as all hell, can't speed shift let alone powershift, I thought something was wrong with the tranny to be honest.

And so.... in April 2003 I went to the Perf store about 1/2 hour from here and they had Redline MTL and and the other one that was the D4 I think everyone is mentioning. I ended up buying the MTL. Cause.. for a long time I remember MTL being "the stuff" to run in the T5s back in the Stang mags in the late 90s and stuff.
I remember a few people, can't remember which, either here or Corral telling my I was going to fry the trans cause I bought the wrong stuff etc. I did call a few places... and talked to a guy at D&D and he said that the MTL was fine and lotsa people had used the stuff. I can't remember which other places I called [jus grabbed a Stang mag] but every other place said it was fine. D&D I remembered cause thats all they do is trannies..
Even though its numerically rated a gear oil, it looks like & pours out at about the same consistency as ATF. It's a tad thicker but barely noticable. Infact I filled my T5 up using a oil squirting can with a vac hose on the end stuck up in the fill hole [I know, pretty ghetto

] and kept filling the oil can with this stuff and pumping it in... thats how thin it was.
Anyways, soon as I put the Redline MTL in mine I noticed about a week later it was real nice to shift just driving it, and I was able to speedshift and powershift. Another thing I notice, when I just had regular ATF in all my other Stangs [89 GT and 91 LX.. 5.0 5 spds.], on a hot summer day after alot of driving, they would become notchy when they got real hot. I notice with the MTL in this one, it is a little notchy if I have to move the car in the winter on a VERY cold day [dont winter drive it though] but from 48* early April spring weather to HOT summer days I can drive all day long and no notchiness or anything and I think thats because the oil doesnt break down and get thinner like the ATF used to.
I wont run anything else now. For a car that see winter use I might use the Redline D4 that is actually rated as ATF and not a gear oil. BUt summer only T5 i'll use the Redline MTL.
