Marine Lubricants & Oils

Marine lubricants are the consumable oils that keep a vessel's propulsion and machinery running — and choosing the wrong one is one of the costliest mistakes in the engine room. The main classes are cylinder oil and system oil for slow-speed two-stroke crosshead engines, trunk-piston engine oil for medium- and high-speed four-stroke engines, and the hydraulic, gear, turbine and compressor oils that serve auxiliary systems. The decision that dominates this category is base number (BN) selection for two-stroke cylinder oil, because BN must be matched to the sulphur content of the fuel being burned: too little base and sulphuric-acid corrosion attacks the liner, too much and hard deposits and bore polishing follow. Since the IMO 2020 sulphur cap pushed most of the fleet onto VLSFO and LSFO, operators now switch between high-BN and low-BN grades and tune feed rates accordingly. This hub indexes the data-backed decision guides that answer those questions, and frames every recommendation against the engine OEM's approval and the lubricant supplier's own technical advice — which always take precedence over general guidance.