oil

An oil is any substance that is in a viscous liquid state ("oily") at ambient temperatures or slightly warmer, and is both hydrophobic (immiscible with water, literally "water fearing") and lipophilic (miscible with other oils, literally "fat loving"). This general definition includes compound classes with otherwise unrelated chemical structures, properties, and uses, including vegetable oils, petrochemical oils, and volatile essential oils. Oil is a nonpolar substance.

Whale oil is the oil obtained from the blubber of various species of whales of the genus Balaena, such as B. mysticetus, Greenland or Right Whale (Northern whale oil), B. australis (southern whale oil), Balaenoptera longimana, Balaenoptera borealis (Fin oil, Finner whale oil, Humpback oil). The Orca and the Beluga also yield whale oils. Train oil proper is the northernwhale oil, but this term has been applied to all blubber oils, and in Germany, to all marine animal oils: fish oils, liver oils, and blubber oils. The most important whale oil is sperm or spermaceti oil, yielded by the Sperm Whales.
Whale oil varies in colour from a bright honey yellow to a dark brown, according to the condition of the blubber from which it has been extracted. Stearin and spermaceti may be separated from whale oil at low temperatures; at under 0°C these constituents may be almost completely crystallized and filtered out. When removed and pressed, this deposit is known as whale tallow, and the oil from which it is removed is known as pressed whale oil; yet is sometimes passed as sperm oil.
The first principal use of whale oil was as an illuminant in lamps and as candle wax. Whale oil later came to be used in oiling wools for combing and other uses. It was the first of any animal or mineral oil to achieve commercial viability. It was also used to heal soldiers' wounds in war.[citation needed]
However, with the 1986 International Whaling Commission (IWC) moratorium on commercial whaling, whale oil has all but ceased to be viable, as substitutes have been found for most of the uses of whale oil, most notably jojoba oil.

Motor oil is a type of liquid oil used for lubrication by various types of internal combustion engines. While the main function is to lubricate moving parts, motor oil also cleans, inhibits corrosion and cools the engine by carrying heat away from the moving parts. The majority of motor oils are derived from petroleum.
Synthetic motor oil, consisting of artificially-synthesized compounds, currently has a majority share in the motor oil market place because, while more expensive, it offers enhanced performance.
Semi-synthetic motor oil was introduced in 1966.

Use of motor oil
Motor oil is used as a lubricant in internal combustion engines, typically found in automobiles and other vehicles, boats, lawn mowers, trains, airplanes. In engines there are parts which move very closely against each other at high speeds, often for prolonged periods of time. Such motion causes friction, absorbing otherwise useful power produced by the motor and converting the energy to useless heat. Friction also wears away the contacting surfaces of those parts, which could lead to lower efficiency and degradation of the motor. This increases fuel consumption.
Lubricating oil makes a film between surfaces of parts moving next to each other so as to minimize direct contact between them decreasing friction, wear, and production of excessive heat, thus protecting the engine. Motor oil also carries away heat from moving parts, which is important because materials tend to become softer and less abrasion-resistant at high temperatures. Some engines have an additional oil cooler.
In petrol (gasoline) engines, the top compression ring can expose the motor oil to temperatures of 320 F. In diesel engines the top ring can expose the oil to temperatures over 600 F. Motor oils with the higher viscosity(thickness)indexes tend to thin less at these higher temperatures.
Coating metal parts with oil also keeps them from being exposed to oxygen, which inhibits their oxidation at elevated operating temperatures (basically preventing them from rusting) Corrosion inhibitors may also be added to the motor oil. Many motor oils also have detergent additives to help keep the engine clean and minimize oil sludge buildup.
Rubbing of metal engine parts inevitably produces some microscopic metallic particles from the wearing of the surfaces. Sludge also accumulates in the engine. Such particles could circulate in the oil and grind against the moving parts, causing erosion and wear. Because particles inevitably build up in the oil, it is typically circulated through an oil filter to remove harmful particles. An oil pump, a gear pump powered by the vehicle engine, pumps the oil through the oil filter. Oil filters can be a full flow or bypass type.
In the crankcase of a vehicle engine, motor oil lubricates rotating or sliding surfaces between the crankshaft journals, bearings, and rods connecting the pistons to the crankshaft. The oil collects in an oil pan at the bottom of the crankcase. In some small engines such as lawn mower engines , dippers on the bottoms of connecting rods dip into the oil at the bottom and splash it around the crankcase as needed to lubricate parts inside. In modern vehicle engines, the oil pump takes oil from the oil pan and sends it through the oil filter into oil galleries from which the oil lubricates the main bearings holding the crankshaft up at the main journals and camshaft bearings operating the valves. In typical modern vehicles, oil pressure-fed from the oil galleries to the main bearings enters holes in the main journals of the crankshaft. From these holes in the main journals, the oil moves through passageways inside the crankshaft to exit holes in the rod journals to lubricate the rod bearings and connecting rods. Some simpler designs relied on these rapidly moving parts to splash and lubricate the contacting surfaces between the piston rings and interior surfaces of the cylinders. However, in modern designs, there are also passageways through the rods which carry oil from the rod bearings to the rod-piston connections and lubricate the contacting surfaces between the piston rings and interior surfaces of the cylinders. This oil film also serves as a seal between the piston rings and cylinder walls to separate the combustion chamber in the cylinder head from the crankcase. The oil then drips back down into the oil pan. To see these details on a crankshaft, see "How Car Engines Work" at HowStuffWorks or "Types of Lubricating Systems" at Integrated Publishing.
Automatic transmission fluid is a separate fluid. It is typically colored red to distinguish it from the motor oil and other fluids in the vehicle.

Non-vehicle motor oils
Other kinds of motors, such as internal combustion engines in motorcycles, mopeds, outboard motors (for boats), snowmobile, ATV's, personal watercraft, scooters, and go-carts, etc., also use motor oil, as well as engines that are not in vehicles such as those for electrical generators. Examples include 4-stroke or 4-cycle internal combustion engines such as those used in many lawn mowers and other engines, and special 2-cycle oil used in 2-stroke or 2-cycle internal combustion engines such as those used in various smaller engines like snow throwers (blowers), chain saws, toy engines like those in model airplanes, certain gardening equipment like weed/grass trimmers, leaf blowers, soil cultivators, etc. Often, the applications are not exposed to as wide a temperature range in use as vehicles, so these oils may be single grade or have less viscosity index improver. 2-cycle oil is used differently than other motor oils in that it is pre-mixed with the gasoline or fuel, often in a gasoline : oil ratio of 50 : 1, and burned in use along with the gasoline.
In addition to the 2-cycle oil used if they have gasoline engines, chain saws also separately use "bar and chain oil" for lubricating the surfaces where the cutting chain moves around bar. Other examples of mechanical equipment often using oil include oil-driven compressors, vacuum pumps, diffusion pumps, sewing machines and other devices with motors, oil-driven hydraulic equipment, turbines, and mechanisms using gears such as gear differentials for rear wheel-drive vehicles. The oil properties will vary according to the needs of these devices.

Properties of motor oil
Most motor oils are made from a heavier, thicker petroleum hydrocarbon base stock derived from crude oil, with additives added as needed to improve the properties. One of the most important properties of motor oil in maintaining a lubricating film between moving parts is its viscosity. In layman's terms, the viscosity of a liquid can be thought of as its "thickness" or a quantity of resistance to flow. The viscosity must be high enough to maintain a satisfactory lubricating film, but low enough that the oil can flow around the engine parts satisfactorily to keep them well coated under all conditions. The viscosity index is a measure of how much the oil's viscosity changes as temperature changes. A higher viscosity index indicates the viscosity changes less with temperature than a lower viscosity index.
Motor oil must be able to flow at cold winter temperatures to lubricate internal moving parts upon starting up the engine. Another important property of motor oil is its pour point, which is indicative of the lowest temperature at which the oil could still be poured satisfactorily. The lower the pour point temperature of the oil, the more desirable the oil is when starting up at cold temperature.
Oil is largely composed of hydrocarbons which can burn if ignited. Still another important property of motor oil is its flash point, the lowest temperature at which the oil gives off vapors which can ignite. It is dangerous for the oil in a motor to ignite and burn, so a high flash point is desirable. At a petroleum refinery, fractional distillation to separate crude oil fractions removes the volatile components, which more easily ignite, from the motor oil fraction; thereby increasing the oil's flash point.
Another test done on oil is to determine the Total Base Number (TBN), which is a measurement of the reserve alkalinity of an oil to neutralize acids. The resulting quantity is determined as mg KOH/(gram of lubricant). Analogously, Total Acid Number (TAN) is the measure of a lubricant's acidity. Other tests include zinc, phosphorus, or sulfur content, and testing for excessive foaming.
Different motor oils are sold for Diesel fuel engines, with many claimed to contain a higher level of detergents to keep fine combustion soot in suspension. However, for some brands only the packaging varies (the oil is the same), and in general a diesel engine can use any good quality oil of the correct grade.

Grades of motor oil
Single-grade motor oil
The Society of Automotive Engineers, usually abbreviated as SAE, has established a numerical code system for grading motor oils according to their kinematic viscosity. For single-grade oils, the kinematic viscosity is measured at a reference temperature of 100 °C (212 °F) in units of mm²/s or the equivalent older non-SI units, centistokes (abbreviated cSt). Based on the range of viscosity the oil falls in at that temperature, the oil is graded as an SAE number 0, 5, 10, 20, 30, 40, 50, 60 or 70. The higher the viscosity, the higher the SAE grade number is. These numbers are often referred to as the weight of a motor oil. The reference temperature is meant to approximate the operating temperature to which motor oil is exposed in an engine.
The viscosity of single-grade oil derived from petroleum unimproved with additives changes considerably with temperature. As the temperature increases, the viscosity of the oil decreases logarithmically in a relatively predictable manner. On single-grade oils, viscosity testing can be done at cold winter (W) temperature (as well as checking minimum viscosity at 100 °C or 212 °F) to grade an oil as SAE number 0W, 5W, 10W, 15W, 20W, or 25W. A single-grade oil graded at the hot temperature is expected to test into the corresponding grade at the winter temperature; i.e. a 10 grade oil should correspond to a 10W oil. For some applications, such as when the temperature ranges in use are not very wide, single-grade motor oil is satisfactory; for example, lawn mower engines.

Multi-grade motor oil
The temperature range the oil is exposed to in most vehicles can be wide, ranging from cold ambient temperatures in the winter before the vehicle is started up to hot operating temperatures when the vehicle is fully warmed up in hot summer weather. A specific oil will have high viscosity when cold and a low viscosity at the engines operating temperature. The difference in viscosities for any single-grade oil is too large between the extremes of temperature. To bring the difference in viscosities closer together, special polymer additives called viscosity index improvers are added to the oil. These additives make the oil a multi-grade motor oil. The idea is to cause the multi-grade oil to have the viscosity of the base number when cold and the viscosity of second number when hot. The viscosity of a multi-grade oil still varies logarithmically with temperature, but the slope representing the change is lessened. This slope representing the change with temperature depends on the nature and amount of the additives to the base oil.
The API/SAE designation for multi-grade oils includes two grade numbers; for example, 10W-30 designates a common multi-grade oil. The first number associated with the W (again 'W' is for Winter, not Weight) is not rated at any single temperature. The "10W" means that this oil can be pumped by your engine as well as a single-grade SAE 10 oil can be pumped. "5W" can be pumped at a lower temperature than "10W". "0W" can be pumped at a lower temperature than "5W", and thins less at temperatures above 99°C (210°F). The second number, 30, means that the viscosity of this multi-grade oil at 100°C (212°F) operating temperature corresponds to the viscosity of a single-grade 30 oil at same temperature. The governing SAE standard is called SAE J300. The motor oil grade and viscosity to be used in a given vehicle is specified by the manufacturer of the vehicle.
Many new vehicles are marked to use 5W-20 oil (Honda, Ford and more recently Toyota). Some ultra fuel efficient and hybrid vehicles are marked to use 0W-20 oil.

Common multi-grade oils
Some of the common multi-grade oils are:
0W-20
0W-30
0W-40
5W-20
5W-30
5W-40
5W-50
10W-30
10W-40
10W-50
10W-60
15W-40
15W-50
20W-40
20W-50

Turbine motor oil
Turbine motor oils are designed somewhat differently than reciprocating engine oils traditionally used in automobiles. Deposit control and corrosion are not significant issues when formulating a turbine oil, and the shear stresses that turbine oils are exposed to are minimal in light of the fact that turbines are naturally balanced rotating machines unlike reciprocating engines. Turbine oils tend to have the ISO VG range 32, 46, and 68 (cSt at 40°C), and make extensive use of polyolester, polyalphaolefin, and Group II as base stock due to the high temperatures they must endure. Varnish is the most problematic contaminant, which can only be detected accurately with the Ultra Centrifuge test resulting in the "UC value".
In most aviation gas turbine applications, peak lubricant temperatures are not reached during engine operation, but after shutdown, when heat has been able to migrate from the combustor cans and the compressors into the regions of the engine with lubricated bearings and gearboxes. The gas flow associated with running the turbine provides significant convective cooling that disappears when the engine is shut down, leaving residual heat that causes temperatures within the turbine to rise dramatically, an often-misunderstood phenomenon.

American Petroleum Institute
Motor oil used for vehicle engines is commonly called engine oil in American Petroleum Institute (API) documentation. Engine oil is used for the lubrication, cooling, and cleaning of internal combustion engines. Motor oil may be composed of a lubricant base stock only 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. Lubricant base stocks are categorized into five groups by the API. Group I base stocks are composed of fractionally distilled petroleum which is further refined with solvent extraction processes to improve certain properties such as oxidation resistance and to remove wax. Group II base stocks are composed of fractionally distilled petroleum that has been hydrocracked to further refine and purify it. Group III base stocks have similar characteristics to Group II base stocks, except that Group III base stocks have higher viscosity indexes. Group III base stocks are produced by further hydrocracking of Group II base stocks, or of hydroisomerized slack wax, (a byproduct of the dewaxing process). Group IV base stock are polyalphaolefins (PAOs). Group V is a catch all group for any other synthetic and mineral base stocks. Examples of group V base stocks include polyol esters, polyalkylene glycols (PAG oils), and perfluoropolyalkylethers (PFPAEs). Groups I, II, and III are sometimes referred to as mineral oils and groups IV and V as synthetic oils. However, most manufacturers have labeled their group III based oils as synthetic in the US for reasons of economy and marketing.
Motor oils are further categorized by their API service class[1]. The API service classes have two general classifications: S for Service (typical passenger cars and light trucks using gasoline engines) and C for commercial applications (typical diesel equipment). Note that the API oil classification structure has eliminated specific support for wet-clutch motorcycle applications in their descriptors, and API SJ & newer oils are referred to be specific to automobile and light truck use. The latest API service standard designation is SM for gasoline automobile and light-truck engines. The SM standard refers to a group of laboratory and engine tests, including the latest series for control of high-temperature deposits. Current API service categories include SM, SL and SJ for gasoline engines. All previous service designations are obsolete, although motorcycle oils commonly still utilize the SF/SG standard. There are seven diesel engine service designations which are current: CJ-4, CI-4, CH-4, CG-4, CF-4, CF-2, and CF. All others are obsolete. It is possible for an oil to conform to both the gasoline and diesel standards. Engine oil which has been tested and meets the API standards has the API starburst symbol with the service designation on containers sold to oil users. The latest guide to API oil certifications can be found at [2].
The International Lubricant Standardization and Approval Committee (ILSAC) also has standards for motor oil. Their latest standard, GF-4[3] was approved in 2004. A key test is the Sequence IIIG [4] , which involves running a 3.8L, GM 3.8L V-6 at 125 horsepower, 3600 rpm, and 150°C oil temperature for 100 hours. These are much more severe conditions than any passenger car would see: cars typically average a few dozen horsepower and 80°C. The IIIG test is about 50% more difficult [5] than the previous IIIF test, used in GF-3 and API SL oils. Engine oils bearing the API starburst symbol since 2005 are ILSAC GF-4 compliant. [6]
The ACEA A3/A5, and MB 229.5 tests used in Europe are even tougher, it is debatable whether this matters for normal drain intervals (5,000-7,000 miles). CEC (The Co-ordinating European Council) is the development body for fuel and lubricant testing in Europe and beyond, setting the standards via their European Industry groups; ACEA, ATIEL, ATC and CONCAWE.
The Japanese Automotive Standards Organization (JASO) has come up with their own set of standards for 4-stroke gasoline motorcycle engines (JASO-MA), for 4-stroke automotive engines (JASO-MB) and 2-stroke gasoline engines (JASO-FC). These standards, especially JASO-MA and JASO-FC are designed to address oil-requirement issues not addressed by the API service categories.

Maintenance
In engines, there is inevitably some exposure of the oil to products of internal combustion, and microscopic coke particles from black soot accumulate in the oil during operation. Also the rubbing of metal engine parts inevitably produces some microscopic metallic particles from the wearing of the surfaces. Such particles could circulate in the oil and grind against the part surfaces causing erosion and wear. The oil filter removes many of the particles, but eventually the oil filter becomes clogged. The motor oil and especially the additives also undergo thermal and mechanical degradation. For these reasons, the oil and the oil filter need to be periodically replaced.
The vehicle manufacturer specifies which grade of oil should be used for the vehicles it produces. The manufacturer also specifies how often the oil changes should be made. Historically this has been 3,000 miles . Many modern cars list higher intervals for changing of oil and filter. There are many types (or sizes) of oil filters for vehicle engines. Vendors of oil filters have information on which type of oil filter is compatible with a given vehicle.
When an engine is not running, the oil collects in an oil pan or sump at the bottom of the crankcase. There is at least one oil drain plug normally screwed into a drain hole at the bottom of the oil pan which is accessible from underneath the vehicle. To change the oil in a vehicle's engine, the drain plug is unscrewed to let the oil drain out of the oil pan. After the used oil drains out, the plug is screwed back into the drain hole. Some drain plugs have a replaceable washer to prevent leakage due to corrosion, rust or worn threads in the drain hole. The removable oil filter can be unscrewed at this time, often with the help of an oil filter removal tool. Then a new oil filter is screwed back in after applying fresh oil to the sealing surface of the new filter. Then new oil is poured in through an otherwise capped opening at the top of the engine. For many cars, 4 to 5 quarts or liters of oil are needed to fill the engine. In the engine, there is a removable dipstick, accessible from above the engine, to check the oil level while the engine is not running. (In contrast, automatic transmission fluid level is checked with a separate dipstick while the engine is running.) Traditionally, lubrication at various joints in the vehicle is also done at the time of an oil change. Mechanics often call this maintenance routine "oil change and lube" or "LOF" (lube, oil, and filter).
For a detailed how-to guide to changing motor oil in a car, see How to Change the Oil in Your Car - WikiHow.
Changing a vehicle's oil should lead to slightly improved fuel efficiency, lower temperature, and less wear since friction is reduced. Because changing a vehicle's oil could be messy and inconvenient for the owner since he/she must drain from under the vehicle, vehicle owners often have mechanics change the oil for them because they can hydraulically lift the vehicle to easily access the oil pan. Many quick oil change shops have appeared in the USA to conveniently provide this service to owners. Many of these shops have rooms below ground level for a mechanic to access the underside of a vehicle. Used motor oil can be taken to recycling centers, auto parts stores and oil change locations for recycling. In addition, some states mandate that any location selling motor oil must also accept waste motor oil at no charge.

Other additives
In addition to the viscosity index improvers, motor oil manufacturers often include other additives such as detergents and dispersants to help keep the engine clean by minimizing sludge buildup, corrosion inhibitors, and alkaline additives to neutralize acidic oxidation products of the oil. Most commercial oils have a minimal amount of zinc dialkyldithiophosphate as an anti-wear additive to protect contacting metal surfaces with zinc and other compounds in case of metal to metal contact. The quantity of zinc dialkyldithiophosphate is limited to minimize adverse effect on catalytic converters.
There are other additives available commercially which can be added to the oil by the user for purported additional benefit. Some of these additives include:
Zinc dialkyldithiophosphate (ZDDP) additives, which typically also contain calcium, are available to consumers for additional protection under extreme-pressure conditions or in heavy duty performance situations. ZDDP and calcium additives are also added to protect motor oil from oxidative breakdown and to prevent the formation of sludge and varnish deposits.
In the 1980s and 1990s, additives with suspended PTFE particles were available to consumers to increase motor oil's ability to coat and protect metal surfaces. There is controversy as to the actual effectiveness of these products as they can solidify and clog the oil filters.
Some molybdenum-containing additives to lubricating oils are claimed to reduce friction, bond to metal, or have anti-wear properties.
Various other extreme-pressure additives and antiwear additives

Synthetic oil and synthetic blends
Synthetic lubricants were invented initially for high-temperature gas turbine/jet engine applications, where traditional mineral-derived lubricants provided inadequate performance. In the mid 1970s, synthetic motor oils were formulated and commercially applied for the first time in automotive applications. The same SAE system for designating motor oil viscosity applies to synthetic oils also.
Instead of making motor oil with the conventional petroleum base, "true" synthetic oil base stocks are artificially synthesized. ("Commercial" synthetic oils are in fact Group III mineral base oils.) True synthetics include classes of lubricants like synthetic esters and polyalpha-olefins. Higher purity and therefore better property control means synthetic oil has good mechanical properties at extremes of high and low temperatures. The molecules are made large and "soft" enough to retain good viscosity at higher temperatures, yet branched molecular structures interfere with solidification and therefore allow flow at lower temperatures. Thus, although the viscosity still decreases as temperature increases, these synthetic motor oils have a much improved viscosity index over the traditional petroleum base. Their specially designed properties allow a wider temperature range at higher and lower temperatures and often include a lower pour point. With their improved viscosity index, true synthetic oils need little or no viscosity index improvers, which are the oil components most vulnerable to thermal and mechanical degradation as the oil ages, and thus they do not degrade as quickly as traditional motor oils. However, they still fill up with particulate matter at the same rate as the conventional oils do, and the oil filter still fills and clogs up over time. So, periodic oil and filter changes should still be done with synthetic oil; but some synthetic oil suppliers suggest that the intervals between oil changes can be longer, sometimes as long as 10,000 - 15,000 miles.
With improved efficiency, synthetic lubricants are designed to make wear and tear on gears far less than with petroleum-based lubricants, reduce the incidence of oil oxidation and sludge formation, and allow for extended drain intervals. Today, synthetic lubricants are available for use in modern automobiles on nearly all lubricated components, potentially with superior performance and longevity as compared to non-synthetic alternatives. Some tests [citation needed] have shown that fully synthetic oil is superior to conventional oil in many respects, providing better engine protection, performance, and better flow in cold starts than petroleum-based motor oil. However, a test by Consumer Reports showed that taxi-cabs exhibited the same amount of engine wear regardless of which oil was used.[citation needed]

Future of motor oil
Future of motor oilA process to break down polyethylene, a common plastic product found in many consumer containers, is used to make wax with the correct molecular properties for conversion into a lubricant, bypassing the expensive Fischer-Tropsch process. The plastic is melted then pumped into a furnace. The heat of the furnace breaks down the molecular chains of polyethylene into wax. Finally, the wax is subjected to a catalytic process that alters the wax's molecular structure leaving a clear oil. (Miller, et al., 2005)
Esso
Motul
Royal Dutch Shell
Total S.A.