Mercury - High Performance Oil Filter MerCruiser Sterndrive & Inboard Series Synthetic High-Efficiency Media 858004Q. OverviewA dependable oil filter doesn't just keep your engine running-it lets you enjoy your time on the water without thinking twice about what's happening under the hatch. When you're cruising a long stretch of open lake or easing into a busy marina, you want to feel that smooth, steady hum that only comes from an engine protected the right way. The Mercury Marine part number 8