Royal Purple HPM – High Performance Synthetic Marine Oil 10W-30 11582 - Royal Purple High Performance Marine Oil (HPM) is specifically formulated for 4-stroke marine engines. HPM is high performance synthetic oil that maximizes the performance and fuel economy of inboard and outboard motors while providing superior protection. Specifically engineered for marine environments, HPM is certified NMMA FC-W Catalyst Compatible® and exceeds the stringent warranty requirements. HPM motor oils provide exceptional anti-wear protection with a load-carrying capacity multiple times that of ordinary mineral or synthetic marine lubricants. Its advanced synthetic solvency reduces engine deposits and keeps engines much cleaner than other high performance synthetic oils. And because of its proprietary Synerlec® additive technology, HPM’s advanced film strength delivers cooler operating temperatures while increasing engine efficiency and maximizing horsepower and torque.