Mineral based 4-Stroke engine oil that's an approved NMMA® FC-W® formulation with our exclusive additives that meet or exceed the industry standards. FC-W® sets the standards for Outboard engine lubrication, corrosion protection and oil dilution (w/fuel) all of which are important when choosing an oil for your outboard engine an Automotive engine oil will not pass the rigors of the FC-W® test. In fact most automotive engines cruise at 2500 rpm where as an outboard engine will cruise from 4500 rpm to 6000 rpm and don't forget the hardest engine stress occurs when getting the boat up on plane all the while injesting moisture rich air unlike an automobile, simply put an automotive oil is not designed or formulated to provide the protection required by an Outboard
