Motor oil is used to lubricate the moving parts of an engine to minimize wear and protect against rust and corrosion. As of 2015, motor oils and synthetic motor oils also contain detergent additives that prevent sludge buildup and dirt deposits in the engine.
Motor oil is also used to keep 4-stroke engines, which power most cars, trucks and motorcycles, from overheating. The oil transfers heat away from high-temperature areas, such as the piston rings, and disperses it around the engine. Motor oils minimize engine wear by forming a protective layer over the engine components, reducing drag and friction, and allowing the engine to operate smoothly and quietly. Motor oil traps potentially harmful loose dirt and debris until it is removed with an oil change.
Some motor oils contain antioxidants, which are used to slow down the aging of the oil and keep engines cleaner for longer. Anti-foam additives are also components in motor oils and are used to inhibit air bubble formations that slow down oil circulation through an engine.
Motor oils designed for motorcycles, such as the Lucas High Performance Motorcycle Oils, are formulated to raise oil pressure, improve performance and reduce engine noise. The brand also produces motorcycle oils with clutch-saving technology, designed for motorcycles with air-cooled and water-cooled 4-stroke engines.