Between 1993 - 1999 BMW recommends ATF in there manual transmissions, that are in the M3's. I use Lubro moly gear oil. I have used both the MTLl and MT-90. I have been the happiest with the Lubro moly. Even though BMW recommends ATF in some of there manual transmissions, I will not use ATF in mine. It's your chioce. MT-90 is a bit thicker than the MTL.