Quart Synthetic SAE 10W-30 Outboard Engine Oil. Lucas synthetic outboard engine oil is specially formulated for the harsh conditions of high-speed watercraft. Designed for 4-stroke applications, Lucas marine oil is catalyst-compatible and will also perform well in inboards and personal watercrafts. Their outboard engine oil is long-lasting and safely blends with synthetic and non-synthetic oils. Plus, it's fortified with a special blend of synthetic additives that coat all moving parts to guard against rust and moisture during long periods of storage. They're excellent for use with supercharged, turbocharged, or nitrous oxide high performance engines. Lubricate your marine engine for performance with Lucas synthetic 4-stroke outboard engine oil.