never used any Amsoil product but if it meets MBZ power steering fluid specs. then perhaps it'll work.

FYI, as per MBZ, if you switch from regular non synthetic to synthetic, you must completely flush out all of the old power steering fluid.

if you feel you must go synthetic, MBZ does make a synthetic PS fluid but it's pricey.

if you're only considering Amsoil because you can get it for free, i'd play it safe and spend a little for the correct fluid that came with the car.

just my 2 cents...