Motor oil

Motor oil, engine oil, or engine lubricant is any of various substances comprising base oils enhanced with additives, particularly antiwear additive plus detergents, dispersants and, for multi-grade oils viscosity index improvers. Motor oil is used for lubrication of internal combustion engines. The main function of motor oil is to reduce friction and wear on moving parts and to clean the engine from sludge (one of the functions of dispersants) and varnish (detergents). It also neutralizes acids that originate from fuel and from oxidation of the lubricant (detergents), improves sealing of piston rings, and cools the engine by carrying heat away from moving parts. In addition to the basic constituents noted in the preceding paragraph, almost all lubricating oils contain corrosion (GB: rust) and oxidation inhibitors. Motor oil may be composed of only a lubricant base stock in the case of non-detergent oil, or a lubricant base stock plus additives to improve the oil's detergency, extreme pressure performance, and ability to inhibit corrosion of engine parts. Motor oils today are blended using base oils composed of petroleum-based hydrocarbons, polyalphaolefins (PAO) or their mixtures in various proportions, sometimes with up to 20% by weight of esters for better dissolution of additives. On September 6, 1866 American John Ellis founded the Continuous Oil Refining Company. While studying the possible healing powers of crude oil, Dr. Ellis was disappointed to find no real medicinal value, but was intrigued by its potential lubricating properties. He eventually abandoned the medical practice to devote his time to the development of an all-petroleum, high viscosity lubricant for steam engines – then using inefficient combinations of petroleum and animal and vegetable fats. He made his breakthrough when he developed an oil that worked effectively in high temperatures. This meant no more gummed valves, corroded cylinders or leaking seals. Motor oil is a lubricant used in internal combustion engines, which power cars, motorcycles, lawnmowers, engine-generators, and many other machines. In engines, there are parts which move against each other, and the friction wastes otherwise useful power by converting the kinetic energy to heat. It also wears away those parts, which could lead to lower efficiency and degradation of the engine. This increases fuel consumption and decreases power output and can lead to engine failure. Lubricating oil creates a separating film between surfaces of adjacent moving parts to minimize direct contact between them, decreasing heat caused by friction and reducing wear, thus protecting the engine. In use, motor oil transfers heat through conduction as it flows through the engine. In an engine with a recirculating oil pump, this heat is transferred by means of airflow over the exterior surface of the , airflow through an oil cooler and through oil gases evacuated by the Positive Crankcase Ventilation (PCV) system. While modern recirculating pumps are typically provided in passenger cars and other engines similar or larger in size, total loss oiling is a design option that remains popular in small and miniature engines. In petrol (gasoline) engines, the top piston ring can expose the motor oil to temperatures of 160 °C (320 °F). In diesel engines, the top ring can expose the oil to temperatures over 315 °C (600 °F). Motor oils with higher viscosity indices thin less at these higher temperatures. Coating metal parts with oil also keeps them from being exposed to oxygen, inhibiting oxidation at elevated operating temperatures preventing rust or corrosion. Corrosion inhibitors may also be added to the motor oil. Many motor oils also have detergents and dispersants added to help keep the engine clean and minimize oil sludge build-up. The oil is able to trap soot from combustion in itself, rather than leaving it deposited on the internal surfaces. It is a combination of this, and some singeing that turns used oil black after some running.