A. -An automatic transmission is a hydraulic system, transmissions use pressurized fluid (Hydraulic pressure) applied to pistons which then apply pressure to a clutch pack/packs to force gears to transfer power to the driveline. A power steering system uses pressurized fluid directed by a valve to one side or the other of the piston in the rack and pinion which steers the front wheels, both systems are very similar. Before Amsoil came out with a power steering fluid it recommended ATF for the power steering systems. Amsoil came out with a power steering fluid to keep up with the “specialized” power steering fluids the auto makers have come out with to drive business back to the auto dealerships. The automakers are engineering for profits, they make smaller and smaller power steering systems that run hotter and expose the oil to significantly higher shear stresses on the oil, thus requiring much better quality fluids to stand up to what is being put to it.
The automakers are resistant to pulling out the stops when formulating lubricants, they like to stick with the cheapest product that will allow the vehicle to make it out of warranty. This accomplishes 2 things for the automakers, first it keeps lubricant costs down which increases profit margin, second if the vehicle makes it out of warranty the consumer foots the bill for any repairs after the warranty expires.In all reality the Amsoil ATF is nearly identical to the Multi vehicle power steering fluid, any differences are in specific additives that each auto manufacturer adds to its lower quality fluids to make them perform better, in order for Amsoil to meet these specs for vehicles that are under manufacturers warranty they are required to add, or in some cases subtract beneficial additives to meet a specific vehicle manufacturers specifications. I use the Amsoil multi vehicle ATF because it outperforms any power steering fluid on the market, it is a chemically engineered fluid that runs 20 to 50 Degrees cooler than petroleum based fluids, and flows to nearly 70 below zero to prevent wear to the pump & rack and pinion in cold startup situations. It also handles twice the heat of petroleum based fluids. It also quiets down many of the power steering systems I have installed it in over the last 12 to 15 years, I have had absolutely no issues whatsoever with the hundreds of power steering flushes I have performed . Another reason Amsoil came out with a power steering fluid is marketing, most people do not understand lubricants or lubrication, it makes no sense to them to put a transmission fluid in a power steering system, so from a marketing standpoint you will pick up more power steering customers if you have a product labeled “power steering fluid”, even though the Amsoil Automatic transmission fluid performs exactly the same, it’s sort of a psychological phenomenon.