im looking into substitutes for my Toyota Tacoma truck with a T-IV required ATF, my biggest issue would be to introduce a ATF that wouldn't be compatable with the OEM T-IV and start issues, so I called AISIN corporate in Torrance,CA and talked to a nice Technical guy named Clark and asked them where they sourced their ATF-0T4 (T-IV) he said they have 3 different ATF fluids for Toyota Transmissions and they all are sourced from the OEM suppliers for Toyota although he wouldn't give me the names of the sources since its all Hush hush about divulging that info, so I mentioned would Mobil be a source because I know the OEM T-IV or JWS 3309 is a Mobil product but he wouldn't come clean on it. He basically says that they ask the source for the exact? same formula to be also made for them and assured me by using their ATF im basically will be using the exact same formula as whats sold under the Toyota T_IV emblem and assured me of no issues with using thiers, he also added its the same system that Idemitsu and Beck Arneley uses to source their ATF for Japanese transmissions . Anybody have experience using the AISIN ATF T-IV in their Toyotas or input please comment.