I just pit Valvoline synpower in mine,with 72K on it the original PS fluid was about as dark as Rotella with 5K on it,yuk,I sucked it out with a turkey baster,ran it for 20 minutes,flushed it again,Much cleaner this time,and filled it again,now its clear like new. I didnt notice any difference in power steering effort,or braking performance. I really need a little more asssit with my plow on the truck,Im getting fore arms like Popeye turning this truck.