Mercury - Power Trim and Steering Fluid Universal Marine Hydraulic Formula 858075K01. Overview. Every boater knows the feeling - that effortless glide when the wheel turns smooth, the trim responds instantly, and everything just feels right. That's not luck or coincidence; that's good maintenance, and Mercury Power Trim and Steering Fluid is a big part of it. Whether you're cutting across open water or easing into a quiet dock, you'll appreciate the precision and calm control it brings to every