Interesting about ATF in the p/s! I know quite a few people who used Mobil-1 ATF and had no problems. You are correct though, better to use stuff designed for p/s systems. The MB fluid is pricey, near $10/qt I believe. The Valvoline is under $4/qt and so far is working fine in my cars. And I agree, the p/s should be flushed periodically... I just did this for the first time since I bought my '84, and WOW was there some nasty stuff in there! I wonder if it had ever been changed in 220kmi...!