Oil tcw3 Prem. Qt Certified TC-W3 designed to meet the unique requirements of marine engines. Gain engine life and performance with this specially formulated 2 cycle outboard oil. The special Quicksilver formula allows for this oil to be used in a wide variety of non-marine 2 cycle engine applications when mixed at manufacturer's recommended ratios. Oil tcw3 Prem. Qt Certified TC-W3 designed to meet the unique requirements of marine engines. Gain engine life and performance with this specially formulated 2 cycle outboard oil. The special Quicksilver formula allows for this oil to be used in a wide variety of non-marine 2 cycle engine applications when mixed at manufacturer's recommended ratios.