I hate that I have to buy specific power steering fluid as like with coolant/antifreeze. IMO it's a 'dumb' hydraulic system but some OEM systems are picky with fluids.
Redline PSF for GM products. Something about hydroboost brake boosters not liking ATF.
Honda PSF for Hondas.
CHF fluid for the German stuff.
Maxlife ATF in vehicles that call for ATF.
For American and GM specifically I'll rank the 5 best PSF in order of best, excellent, excellent, very good, good: Idemitsu, Amsoil, Red Line, Valvoline Professional Series, Lucas. That list and ranking is based solely on datasheets, not official recommendations. Idemitsu greatly exceeds official requirements for American and GM and exceeds the performance of other oils listed. The other 4 oils listed exceed GM requirement, but to a lesser extent than Idemitsu. The other 4 are officially recommended for American cars.
For Asian cars (excluding Honda) I'll rank PSF in order of best, excellent, very good, probably good: Idemitsu, Amsoil, Valvoline Professional Series, Red Line. That's based on datasheets. All of those (except Red Line) are officially recommended for Asian cars.
For Honda, I'd rank PSF in order of best, good: Honda, Idemitsu. Honda PSF is the ideal choice for Honda. Idemitsu is a distant 2nd best choice due to viscosity difference, IMO. That's based on datasheets and recommendations I got at a CR-V forum. Idemitsu officialy claims to be good for Honda and Asian cars in general.
For Euro cars I'd rank PSF in order of best, good: Pentosin, Lubeguard Complete
The above are my opinions. Yours may vary. Please read the datasheets in post 61 and decide for yourself.
