Originally Posted by wstar

Yeah it's pretty common. ATF and Power Steering Fluid are basically the same stuff, same generally desirable properties. In our car's case, in the Service Manual they only recommend a special Nissan ATF for the auto transmission itself, but they recommend either Nissan's own brand of power steering fluid, or as an alternative any "Dexron VI" -compatible ATF (which probably means Nissan's fluid is roughly equivalent to that anyways).

I'm really not up on whether there are better aftermarket alternatives. I just used whatever random Dexron VI ATF they had at the auto parts store.