I used BG SynchroShift in my 93 prelude SI... it made the shifting a lot smoother.. so I decided to put it in the supra... the supra was filled with an auto tranny fluid.. i guess for energy efficency... i drained that from my 6spd tranny and pumped in bg synchroshift into it.. it runs just fine for me, shifting is a little smoother compred to before, but that could be because of the new oil, 10k miles so far now i'm running at 91k total and it runs just fine.