Yes, switch from the cheap ATF fluid to the expensive CHF 11S. I have a newer 335i that specs CHF 11s and a daily driver '03 530i that specs "ATF"; aka Dex III. I'm well aware of the Dex VI being newer, and mainly thinner. And some manufactures going to it for p/s fluid. However, I'd like to take it a step further and completely flush my ATF ps system out and run the super thin CHF 11S and stock 1 product for both cars. And maybe free up some power/MPG's while I'm at it. Is that possible or am I going to completey ruin my old ATF p/s system bying flushing it over to CHF 11s? I could play it safe and just flush it over to Dex VI. Middle of the road on visc.