Originally Posted By: DaveL
I just didn't know whether there was anything radically different about the Honda PSF that would make it be a problem.
For many makes, Ford, Nissan, and Subaru to name a few, power steering fluids and ATFs are interchangeable. Honda is probably the best known exception in this regard.
Still, even for Honda, as far as I know, the main difference is its PSF is thinner than its ATF. Somehow Honda's power steering systems have a tendency of foaming the fluid so it requires a thinner fluid.
In addition to viscosity, there may be additional differences in the additives.
But by and large, PSFs and ATFs are very similar because they are both hydraulic fluids. While engine oil's main function is to lubricate so it is different.