Royal Purple HPS series engine oils are specifically formulated to meet the demands of vintage, late-model and modified high performance engines. Whether the challenge is increased valve-train load due to aggressive camshafts or big engine power because of forced-induction or other power adders, HPS provides more than enough protection for the most severe street car and light competition applications. Royal Purple HPS oils are fortified with a high level of zinc/phosphorus anti-wear additive and a generous dose Synerlec. Synerlec is Royal Purple’s proprietary additive chemistry that greatly increases the protective film strength of the oil, reducing metal to metal contact, friction and wear. This unique and highly effective additive technology greatly enhances wear protection above and beyond that achievable in any other commercially available engine oil. Synerlec also increases the oil’s resistance to thermal degradation, enhancing lubrication at extreme engine temperatures, reducing deposit formation and lengthening the oil’s useful life. The oxidation resistance, synthetic solvency and varnish control contribute to incredible cleanliness inside the engine. These unique formulations enable HPS oils to outperform leading synthetic and conventional lubricants in both gasoline and diesel engines. All HPS viscosities are formulated for gasoline and diesel engine use, including those that are turbocharged or supercharged. As a performance-upgrade engine oil, HPS is recommended for vehicles no longer under manufacturer warranty and for those seeking a higher level of performance and protection for any engine. HPS meets ACEA E9-16 performance requirements.