Within Idemitsu there are two branches, one dealing with OEM fluids and one with aftermarket. Due to contracts, the OEM branch is not allowed to share the chemistry of this OEM fluid with the aftermarket till after three years. After those three years pass, they can then “unlock” the formulation and then the aftermarket side can develop an aftermarket fluid to meet the spec. So, the only option we 2020+ users have at this point is Subaru’s Type III fluid, which is made my Idemitsu’s OEM branch. He says in a couple years Idemitsu should have a fluid compatible with the OEM Type III fluid. He does not even know if the two fluids are compatible or even the differences. When asked if it could be simply for fuel economy, he said it could very well be, but we don’t know. He said -if- the two fluids are different viscosities, there may be a difference in the CVT transmission itself. Therefore putting the wrong fluid in may cause issues with the “shifting”.
