I've used Royal Purple Max ATF with good results in several older vehicles that specify a standard viscosity ATF (Dexron III, Mercon V, etc), and I use AMSOIL SS FE ATF in my 2010 Ford Escape that specifies a low viscosity ATF (Mercon LV). Both are good quality fluids, and depending which one in suitable for your application, you can't go wrong either way! Royal Purple's product is readily available in retail locations while AMSOIL's has to be ordered off their website in most cases... it just depends what better meets your needs.