Motor oil, engine oil, or engine lubricant is any one of various substances used for the lubrication of internal combustion engines. They typically consist of enhanced with various additives, particularly antiwear additives, detergents, , and, for multi-grade oils, viscosity index improvers. 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 ) and varnish (detergents). It also neutralizes acids that originate from fuel and from oxidation of the lubricant (detergents), improves the sealing of piston rings, and cools the engine by carrying heat away from moving parts.Klamman, Dieter, Lubricants and Related Products, Verlag Chemie, 1984,
In addition to the aforementioned basic constituents, almost all lubricating oils contain corrosion 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 are blended using base oils composed of petroleum-based , polyolefin (PAO), or their mixtures in various proportions, sometimes with up to 20% by weight of for better dissolution of additives.R.H. Schlosberg, J.W. Chu, G.A. Knudsen, E.N. Suciu and H.S. Aldrich, "High stability esters for synthetic lubricant applications", Lubrication Engineering, February 2001, pp. 21–26
Lubricating oil creates a separating film between surfaces of adjacent moving parts to minimize direct contact between them, decreasing frictional heat 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 oil pan, airflow through an Oil cooling, 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 of 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 . In diesel engines, the top ring can expose the oil to temperatures over . Motor oils with higher viscosity index thin less at these higher temperatures.[1] Piston Cooling | Hannu Jääskeläinen | DieselNet Technology Guide » Combustion Systems | piston Bowl rim (diesel engine, direct injection) 350–400°C
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 and 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.
Rubbing of metal engine parts inevitably produces some microscopic metallic particles from the of the surfaces. Such particles could circulate in the oil and grind against moving parts, tribology. Because particles accumulate in the oil, it is typically circulated through an oil filter to remove harmful particles. An oil pump, a vane or gear pump powered by the engine, pumps the oil throughout the engine, including 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 journal bearings (main bearings and big-end bearings) and connecting rod connecting the to the crankshaft. The oil collects in an oil pan, or sump, 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.
Motor oil may also serve as a cooling agent. In some engines oil is sprayed through a nozzle inside the crankcase onto the piston to provide cooling of specific parts that undergo high-temperature strain. On the other hand, the thermal capacity of the oil pool has to be filled, i.e. the oil has to reach its designed temperature range before it can protect the engine under high load. This typically takes longer than heating the main engine coolant or mixtures thereofup to its operating temperature. In order to inform the driver about the oil temperature, some older and most high-performance or racing engines feature an oil thermometer.
Continued operation of an internal combustion engine without adequate engine oil can cause damage to the engine, first by wear and tear, and in extreme cases by "engine seizure" where the lack of lubrication and cooling causes the engine to cease operation suddenly. Engine seizure can cause extensive damage to the engine mechanisms."https://www.sgi.sk.ca/motorcycle/-/knowledge_base/motorcycle-handbook/engine-seizure
Motor oil must be able to flow adequately at the lowest temperature it is expected to experience in order to minimize metal to metal contact between moving parts upon starting up the engine. The pour point defined first this property of motor oil, as defined by ASTM D97 as "...an index of the lowest temperature of its utility..." for a given application, but the cold-cranking simulator (CCS, see ASTM D5293-08) and mini-rotary viscometer (MRV, see ASTM D3829-02(2007), ASTM D4684-08) are today the properties required in motor oil specs and define the Society of Automotive Engineers (SAE) classifications.
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 Oil refinery, fractional distillation separates a motor oil fraction from other crude oil fractions, removing the more volatile components, and therefore increasing the oil's flash point (reducing its tendency to burn).
Another manipulated property of motor oil is its total base number (TBN), which is a measurement of the reserve alkalinity of an oil, meaning its ability 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 .
The Noack volatility test (ASTM D-5800) determines the physical evaporation loss of lubricants in high temperature service. A maximum of 14% evaporation loss is allowable to meet API SL and ILSAC GF-3 specifications. Some automotive OEM oil specifications require lower than 10%.
Table of thermal and physical properties of typical (SAE 20W ) unused engine oil:
0 | 899.12 | 1.796 | 4.28E-03 | 0.147 | 9.11E-08 | 47100 | 7.00E-04 |
20 | 888.23 | 1.88 | 9.00E-04 | 0.145 | 8.72E-08 | 10400 | 7.00E-04 |
40 | 876.05 | 1.964 | 2.40E-04 | 0.144 | 8.34E-08 | 2870 | 7.00E-04 |
60 | 864.04 | 2.047 | 8.39E-05 | 0.14 | 8.00E-08 | 1050 | 7.00E-04 |
80 | 852.02 | 2.131 | 3.75E-05 | 0.138 | 7.69E-08 | 490 | 7.00E-04 |
100 | 840.01 | 2.219 | 2.03E-05 | 0.137 | 7.38E-08 | 276 | 7.00E-04 |
120 | 828.96 | 2.307 | 1.24E-05 | 0.135 | 7.10E-08 | 175 | 7.00E-04 |
140 | 816.94 | 2.395 | 8.00E-06 | 0.133 | 6.86E-08 | 116 | 7.00E-04 |
160 | 805.89 | 2.483 | 5.60E-06 | 0.132 | 6.63E-08 | 84 | 7.00E-04 |
In engines, there is 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 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 wear. The oil filter removes many of the particles and sludge, but eventually, the oil filter can become clogged, if used for extremely long periods.
The motor oil and especially the additives also undergo thermal and mechanical degradation, which reduces the viscosity and reserve alkalinity of the oil. At reduced viscosity, the oil is not as capable of lubricating the engine, thus increasing wear and the chance of overheating. Reserve alkalinity is the ability of the oil to resist the formation of acids. Should the reserve alkalinity decline to zero, those acids form and corrode the engine.
Some engine manufacturers specify which Society of Automotive Engineers (SAE) viscosity grade of oil should be used, but different viscosity motor oil may perform better based on the operating environment. Many manufacturers have varying requirements and have designations for motor oil they require to be used. This is driven by the EPA requirement that the same viscosity grade of oil used in the MPG test must be recommended to the customer. This exclusive recommendation led to the elimination of informative charts depicting climate temperature range along with several corresponding oil viscosity grades being suggested.
In general, unless specified by the manufacturer, thicker oils are not necessarily better than thinner oils; heavy oils tend to stick longer to parts between two moving surfaces, and this degrades the oil faster than a lighter oil that flows better, allowing fresh oil in its place sooner. Cold weather has a thickening effect on conventional oil, and this is one reason thinner oils are manufacturer recommended in places with cold winters.
Motor oil changes are usually scheduled based on the time in service or the distance that the vehicle has traveled. These are rough indications of the real factors that control when an oil change is appropriate, which include how long the oil has been run at elevated temperatures, how many heating cycles the engine has been through, and how hard the engine has worked. The vehicle distance is intended to estimate the time at high temperature, while the time in service is supposed to correlate with the number of vehicle trips and capture the number of heating cycles. Oil does not degrade significantly just sitting in a cold engine. On the other hand, if a car is driven just for very short distances, the oil will not fully heat up, and it will accumulate contaminants such as water, due to lack of sufficient heat to boil off the water. Oil in this condition, just sitting in an engine, can cause problems.
Also important is the quality of the oil used, especially with synthetics (synthetics are more stable than conventional oils). Some manufacturers address this (for example, BMW and Volkswagen with their respective long-life standards), while others do not.
Time-based intervals account for the short-trip drivers who drive short distances, which build up more contaminants. Manufacturers advise to not exceed their time or distance-driven interval for a motor oil change. Many modern cars now list somewhat higher intervals for changing oil and filter, with the constraint of "severe" service requiring more frequent changes with less-than-ideal driving. This applies to short trips of under , where the oil does not get to full operating temperature long enough to boil off condensation, excess fuel, and other contamination that leads to "sludge", "varnish", "acids", or other deposits. Many manufacturers have engine computer calculations to estimate the oil's condition based on the factors which degrade it, such as RPM, temperature, and trip length; one system adds an optical sensor for determining the clarity of the oil in the engine. These systems are commonly known as s or OLMs.
Some quick oil change shops recommend intervals of , or every three months; this is not necessary, according to many automobile manufacturers. This has led to a campaign by the California EPA against the "3,000-mile myth", promoting vehicle manufacturer's recommendations for oil change intervals over those of the oil change industry.
The engine user can, in replacing the oil, adjust the viscosity for the ambient temperature change, thicker for summer heat and thinner for the winter cold. Lower-viscosity oils are common in newer vehicles.
By the mid-1980s, recommended viscosities had moved down to 5W-30, primarily to improve fuel efficiency. A typical modern application would be Honda motor's use of 5W-20 (and in their newest vehicles, 0W-20) viscosity oil for . Engine designs are evolving to allow the use of even lower-viscosity oils without the risk of excessive metal-to-metal abrasion, principally in the cam and valve mechanism areas. In line with car manufacturers push towards these lower viscosities in search of better fuel economy, in April 2013 the Society of Automotive Engineers (SAE) introduced an SAE 16 viscosity rating, a break from its traditional "divisible by 10" numbering system for its high-temperature viscosity ratings that spanned from low-viscosity SAE 20 to high-viscosity SAE 60.
Breakdown of VIIs under shear is a concern in motorcycle applications, where the transmission may share lubricating oil with the motor. For this reason, motorcycle-specific oil is sometimes recommended. The necessity of higher-priced motorcycle-specific oil has also been challenged by at least one consumer organization.
The API sets minimum performance standards for lubricants. Motor oil is used for the lubrication, cooling, and cleaning of internal combustion engines. Motor oil may be composed of only a lubricant base stock in the case of mostly obsolete 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.
Groups: 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. Poorly refined mineral oils that fail to meet the minimum VI of 80 required in group I fit into Group V. Group II base stocks are composed of fractionally distilled petroleum that has been hydrocracking 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 either Group II base stocks or hydroisomerized slack wax (a Group I and II dewaxing process by-product). Group IV base stock are (PAOs). Group V is a catch-all group for any base stock not described by Groups I to IV. Examples of group V base stocks include (POE), polyalkylene glycols (PAG), and Krytox (PFPAEs) and poorly refined mineral oil. Groups I and II are commonly referred to as , group III is typically referred to as synthetic (except in Germany and Japan, where they must not be called synthetic) and group IV is a synthetic oil. Group V base oils are so diverse that there is no catch-all description.
The API service classes have two general classifications: S for "service/spark ignition" (typical passenger cars and light trucks using ), and C for "commercial/compression ignition" (typical Diesel engine equipment). Engine oil which has been tested and meets the API standards may display the API Service Symbol (also known as the "Donut") with the service categories on containers sold to oil users.
The latest API service category is API SP for gasoline automobile and light-truck engines. The SP 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 SP, SN, SM, SL and SJ for gasoline engines. All earlier service categories are obsolete. Motorcycle oils commonly still use the SF/SG standard though.
All the current gasoline categories (including the obsolete SH) have placed limitations on the phosphorus content for certain SAE viscosity grades (the xW-20, xW-30) due to the chemical poisoning that phosphorus has on catalytic converters. Phosphorus is a key anti-wear component in motor oil and is usually found in motor oil in the form of zinc dithiophosphate (ZDDP). Each new API category has placed successively lower phosphorus and zinc limits, and thus has created a controversial issue of obsolescent oils needed for older engines, especially engines with sliding (flat/cleave) tappets. API and ILSAC, which represents most of the world's major automobile/engine manufacturers, state API SM/ILSAC GF-4 is fully backwards compatible, and it is noted that one of the engine tests required for API SM, the Sequence IVA, is a sliding tappet design to test specifically for cam wear protection. Not everyone is in agreement with backwards compatibility, and in addition, there are special situations, such as "performance" engines or fully race built engines, where the engine protection requirements are above and beyond API/ILSAC requirements. Because of this, there are specialty oils out in the market place with higher than API allowed phosphorus levels. Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. For example, in API SG rated oils, this was at the 1200–1300 ppm level for zinc and phosphorus, where the current SM is under 600 ppm. This reduction in anti-wear chemicals in oil has caused premature failures of camshafts and other high pressure bearings in many older automobiles and has been blamed for premature failure of the oil pump drive/cam position sensor gear that is meshed with camshaft gear in some modern engines.
The current diesel engine service categories are API CK-4, CJ-4, CI-4 PLUS, CI-4, CH-4, and FA-4. The previous service categories such as API CC or CD are obsolete. API solved problems with API CI-4 by creating a separate API CI-4 PLUS category that contains some additional requirements – this marking is located in the lower portion of the API Service Symbol "Donut".
API CK-4 and FA-4 have been introduced for 2017 model American engines. API CK-4 is backward compatible that means API CK-4 oils are assumed to provide superior performance to oils made to previous categories and could be used without problems in all previous model engines.
API FA-4 oils are formulated for enhanced fuel economy (presented as reduced greenhouse gas emission). To achieve that, they are SAE xW-30 oils blended to a high temperature high shear viscosity from 2.9 cP to 3.2 cP. They are not suitable for all engines thus their use depends on the decision of each engine manufacturer. They cannot be used with diesel fuel containing more than 15 ppm sulfur.
Cummins reacted to the introduction of API CK-4 and API FA-4 by issuing its CES 20086 list of API CK-4 registered oils and CES 20087 list of API FA-4 registered oils. Valvoline oils are preferred.
While engine oils are formulated to meet a specific API service category, they in fact conform closely enough to both the gasoline and diesel categories. Thus diesel rated engine oils usually carry the relevant gasoline categories, e.g. an API CJ-4 oil could show either API SL or API SM on the container. The rule is that the first mentioned category is fully met and the second one is fully met except where its requirements clash with the requirements of the first one.
A key new test for GF-4, which is also required for API SM, is the Sequence IIIG, which involves running a , GM 3.8 L V-6 at , 3,600 rpm, and oil temperature for 100 hours. These are much more severe conditions than any API-specified oil was designed for: cars which typically push their oil temperature consistently above are most Turbocharger engines, along with most engines of European or Japanese origin, particularly small capacity, high power output.
The IIIG test is about 50% more difficult Development of the Sequence IIIG Engine Oil Test ASTM Research Report 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. To help consumers recognize that an oil meets the ILSAC requirements, API developed a "starburst" certification mark.
A new set of specifications, GF-5, took effect in October 2010. The industry had one year to convert their oils to GF-5 and in September 2011, ILSAC no longer offered licensing for GF-4.
After nearly a decade of GF-5, ILSAC released final GF-6 specifications in 2019, with licensed sales to oil manufacturers and re-branders to begin in May 2020. There are two GF6 standards; GF-6A being a progression and fully backwards compatible with GF-5, and GF-6B specifically for SAE 0W-16 viscosity oil.
ACEA does not certify oils, nor license, nor register, compliance certificates. Oil manufacturers are themselves responsible for carrying out all oil testing and evaluation according to recognised engine lubricant industry standards and practices. Lubricants ACEA 28/11/2016
Popular categories include A3/B3 and A3/B4 which are defined as "Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline& Diesel Engines with extended drain intervals" A3/B5 is suitable only for engines designed to use low viscosities. Category C oils are designated for use with catalysts and particulate filters while Category E is for heavy duty diesel. ACEA EUROPEAN OIL SEQUENCES ACEA 2016 update 1/12/2018 ACEA EUROPEAN OIL SEQUENCES ACEA 2016 update 1/7/2020
For four-stroke gasoline engines, the JASO T904 standard is used, and is particularly relevant to motorcycle engines. The JASO T904-MA and MA2 standards are designed to distinguish oils that are approved for wet clutch use, with MA2 lubricants delivering higher friction performance. The JASO T904-MB standard denotes oils not suitable for wet clutch use, and are therefore used in scooters equipped with continuously variable transmissions. The addition of friction modifiers to JASO MB oils can contribute to greater fuel economy in these applications.
For two-stroke gasoline engines, the JASO M345 (FA, FB, FC, FD) standard is used, and this refers particularly to low ash, lubricity, detergency, low smoke and exhaust blocking.
These standards, especially JASO-MA (for motorcycles) and JASO-FC, are designed to address oil-requirement issues not addressed by the API service categories. One element of the JASO-MA standard is a friction test designed to determine suitability for wet clutch usage.Motorcycle Four Cycle Gasoline Engine Oil (JASO T 903:2011) Application Manual. JASO Engine Oil Standards Implementation Panel. May 2011. An oil that meets JASO-MA is considered appropriate for wet clutch operations. Oils marketed as motorcycle-specific will carry the JASO-MA label.
dexos1 was introduced in 2011, superseded by dexos1Gen2 in 2015, and later dexos1Gen3. dexos 2 was discontinued in 2025, replaced by dexos D for diesels, and dexos R for petrol (gasoline) engines.
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:
Some molybdenum disulfide containing oils may be unsuitable for motorcycles which share wet clutch lubrication with the engine.
Used motor-oil dumped on land reduces soil productivity. Improperly disposed used oil ends up in landfills, sewers, backyards, or where soil, groundwater and drinking water may become contaminated.
Synthetic oils are derived from either Group III, Group IV, or some Group V bases. Synthetics include classes of lubricants like synthetic esters (Group V) as well as "others" like GTL (methane gas-to-liquid) (Group III +) and polyalpha-olefins (Group IV). Higher purity and therefore better property control theoretically means synthetic oil has better 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 higher 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, synthetic oils need lower levels of 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, although the matter better suspends within the oil, 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 primarily due to reduced degradation by oxidation.
Tests show that fully synthetic oil is superior in extreme service conditions to conventional oil, and may perform better for longer under standard conditions. But in the vast majority of vehicle applications, mineral oil-based lubricants, fortified with additives and with the benefit of over a century of development, continue to be the predominant lubricant for most internal combustion engine applications.
The USDA National Center for Agricultural Utilization Research developed an Estolide lubricant technology made from vegetable and animal oils. Estolides have shown great promise in a wide range of applications, including engine lubricants. Working with the USDA, a California-based company Biosynthetic Technologies has developed a high-performance "drop-in" biosynthetic oil using Estolide technology for use in motor oils and industrial lubricants. This biosynthetic oil American Petroleum Institute (API) has the potential to greatly reduce environmental challenges associated with petroleum. Independent testing not only shows biosynthetic oils to be among the highest-rated products for protecting engines and machinery; they are also bio-based, biodegradable, non-toxic and do not bioaccumulate in marine organisms. Also, motor oils and lubricants formulated with biosynthetic base oils can be recycled and re-refined with petroleum-based oils. The U.S.-based company Green Earth Technologies manufactures a bio-based motor oil, called G-Oil, made from animal oils.
Biodegradable motor oils based on esters or hydrocarbon-ester blends appeared in the 1990s followed by formulations beginning in 2000 which respond to the bio-no-tox-criteria of the European preparations directive (EC/1999/45).Directive 1999/45/EC of the European Parliament and of the Council concerning the approximation of the laws, regulations and administrative provisions of the member states relating to the classification, packaging and labeling of dangerous preparations, Official Journal of the European Communities L200/1, 30 July 1999, ISSN 0376-9461 This means, that they not only are biodegradable according to OECD 301x test methods, but also the aquatic toxicities (fish, algae, daphnia) are each above 100 mg/L.
Another class of base oils suited for engine oil are the polyalkylene glycols. They offer zero-ash, bio-no-tox properties, and lean burn characteristics.M. Woydt, No /Low SAP and Alternative Engine Oil Development and Testing, Journal of ASTM International, 2007, Vol. 4, No.10, online ISSN 1546-962X or in ASTM STP 1501 "Automotive LubricantsTesting and Additive Development", 03.-05. December 2006, Orlando, , eds.: Tung/Kinker/Woydt
Motor oils were sold at retail in , metal cans, and metal-cardboard cans, before the advent of the current polyethylene plastic bottle, which began to appear in the early 1980s. Reusable spouts were made separately from the cans; with a piercing point like that of a can opener, these spouts could be used to puncture the top of the can and to provide an easy way to pour the oil.
Today, motor oil in the US is generally sold in bottles of and on a rarity in as well as in larger plastic containers ranging from approximately due to most small to mid-size engines requiring around of engine oil. In the rest of the world, it is most commonly available in 1L, 3L, 4L, and 5L retail packages.
Distribution to larger users (such as drive-through oil change shops) is often in bulk, by tanker truck or in drums, in Europe and drums are common.
ASTM
The rapid growth of non-Newtonian multigraded oils has rendered kinematic viscosity as a nearly useless parameter for characterising "real" viscosity in critical zones of an engine... There are those who are disappointed that the twelve-year effort has not resulted in a redefinition of the SAE J300 Engine Oil Viscosity Classification document so as to express high-temperature viscosity of the various grades ... In the view of this writer, this redefinition did not occur because the automotive lubricant market knows of no field failures unambiguously attributable to insufficient HTHS oil viscosity.
Manufacturer Specifications
GM
BMW
Other additives
Environmental effects
Synthetic oils
Bio-based oils
Future
Re-refined motor oil
Packaging
in obsolete cardboard cans with steel lids]]
Dangers
See also
External links
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