Quicksilver 25W-40 4-Stroke Synthetic Marine Oil Maintaining your engines health is a vital part of engine maintenance, the synthetic blend by Quicksilver is a great option for reducing friction and preventing damages. This Quicksilver synthetic oil is specifically formulated and developed to meet the needs of high-output sterndrive and inboard engines. This formula was developed to provide all the protection needed for your engines when dealing with all the rigors of marine environments. Quicks