Originally Posted By: Thingfish
Other than viscosity, what are the differences between the ATF and the ATD?
The difference is really pretty subtle. Slightly more AW/EP type additives in ATD, but both have very similar frictional properties. Neither contain ANY VI, so they are both VERY shear stable, they just use different base oil to get there.
Amsoil's published answer is interesting:
Quote:
How does Torque-Drive™ compare to AMSOIL Synthetic Transmission Fluid (ATF)?
Torque-Drive™ was created to satisfy the concerns of customers currently using TranSynd®, and it carries with it the confidence to be used for the intervals established by Allison. AMSOIL ATF is a more advanced product with universal applications such as Mercon V and ATF +4. AMSOIL does not recommend draining or switching to Torque-Drive™ unless the Allison customer intends on following the extended drain interval recommendations of Allison.