I lost a perfectly working transmission to Redline MTL and would never personally touch the stuff. Many others reported the same problem and every 3000gt and Stealth owner knows to stay away from that stuff. They all discovered Syncromesh was the best product for their trannys. Not to mention that MTL is WAY thicker than what we have in there. The Xfire manual calls for 5w-20 meeting API SL or GF3. I would not deviate from that until other club members experiment later on. I plan on putting in synthetic fluid meeting those specs this spring.