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LUBRICANT LEXICON
 

SAE values ///
Together with SAE (SAE International) values, they are represented by the standardized viscosity grades of automotive lubricants. Example: SAE type 0W is an extremely thin liquid winter oil. In contrast, SAE 40 indicates a thick summer oil. A multigrade oil, for example SAE 0W-40, behaves in cold weather like SAE 0W and in heat like SAE 40. Thus, the criteria required for cold starting at low temperatures as well as for hot highway driving at temperatures high are covered.

API ratings ///
API = American Petroleum Institute (American standard). This institute defines the worldwide quality requirements and the corresponding test criteria for motor oils. The classification is made separately for gasoline and diesel engines. S class gasoline engines (duty classes and spark ignition). C class diesel engines (commercial and compression ignition grades). The second letter stands for quality. For example, SM LL (from 2004) contains high quality oil for gasoline engines. CJ identifies diesel passenger car oils from 2006.

ACEA specifications ///
Since January 1996, the Association of European Automobile Manufacturers (ACEA) has defined the quality of motor oils in accordance with European requirements. Car gasoline engines have the designations A1-A5, passenger car diesel engines B1-B5. The symbols E1 to E5 apply to diesel engines of commercial vehicles and machines in general.

Example: (*xx is the year of introduction)

A1-xx = oils with fuel saving properties
A3-xx * = heavy duty engine oils
A4-xx * = GDI and FSI engine oils
A5-xx * = latest high performance engine oils
B = low oil consumption class for car diesel engine (B1-xx*, B3-xx*, B4-xx*, B5xx*)
C = car gasoline and diesel engine oil with particulate filter (C1-xx*, C2-xx*, C3-xx*, C4*xx)
E = commercial vehicle engine oil (E4-xx*, E6 xx*, E7 xx*, E9 xx*)


Mineral Oils ///
Mineral oils are the longest known and used base oils. Mineral oils are inherently unique quality oils and can be produced relatively easily and inexpensively by distillation and petroleum refining. However, these oils have limited performance. Viscosities: 15W-40, 20W-50.

Semi-synthetic oils ///
Since mineral oils and synthetic petroleum oils are produced, only the manufacturing process (synthesis) is complex and expensive. Synthetic oils already naturally provide a multigrade characteristic, which allows them to be processed much more economically with the use of viscosity index improvers. Due to their uniform structure, they respond better to the effectiveness of additives, resulting in better performance. Known viscosities for semi-synthetic oils: 10W-40, 5W-30.

100% synthetic oils ///
Fully synthetic motor oils can be used in gasoline and diesel engines and offer advantages over mineral oils, including: improved cold start performance at low temperatures, optimized wear protection due to faster power delivery lubrication points, easy tracking and excellent engine cleanliness. These oils generally meet the quality standards of API, ACEA and the corresponding versions of the company. Known viscosities: 0W-30, 0W-40, 5W-40.

Additives ///
When additives are oil soluble, active ingredients that target base oils are added to modify or improve (chemically and/or physically) the properties of lubricants. The distinction between additives is divided into two categories, polar and non-polar additives.

Polar Additives ///
Many additives are known as surfactants or surfactants, the structure of which can be compared in principle to a match: like the head of a match, the active ingredients are concentrated, they are called the "polar group". It is as if water, acids and/or metals are attracted to the soot particles. This is likely to form on the substances mentioned, causing certain effects (thereby preventing packing and recovery, protecting against wear and corrosion, neutralizing acids). In comparison, the match rod is made of a hydrocarbon radical and only allows solubility of the additive in the base oil.

Non-polar additives ///
Other types of additives consist only of hydrocarbons with a special high molecular weight structure, they are non-polar. They are not attracted to water, acids, soot particles or metals, but only affect oil.

Surface protection additives ///
Surface protection additives include: detergents, dispersants, anti-wear, corrosion and rust inhibitors, friction modifiers.

Detergents ///
High operating temperatures lead to deposits (varnish, oil, carbon), especially in the piston area. This can cause the piston rings to seize and thus increase the amounts of leak gas. Additionally, deposits can also cause the piston to slip on the cylinder bore. The result is a mirror surface formation, also called "bore polish" or a plate shape. Detergents prevent / reduce varnish deposits and carbon deposits and additionally have a cleaning effect.

Dispersants ///
Maintain oil-insoluble impurities finely distributed in the oil through a liquid suspension, thus avoiding lumps of sludge particles.

Defoaming additives ///
Intense mixing of oil and air during operation causes foaming which leads to oil leakage from the system (eg via ventilation points). In addition, it increases the rate of oil aging, thereby reducing viscosity and compressibility. These can in particular affect hydraulic control operations. Antifoam additives (eg silicone, oil) prevent foaming and reduce the foaming tendency of the oil. Foam significantly alters the properties of lubricants.

Anticorrosive additive ///
Corrosion is generally the chemical or electrochemical attack on metallic surfaces. For corrosion protection there are preferably surfactant additives which can be ashless or ash reducing.

Anti-wear additives ///
Thanks to suitable additives, extremely thin layers can be built up on sliding surfaces, the shear strength of which is significantly lower than that of metals. Even under normal conditions of wear (pressure, temperature), the parts remain lubricated, which prevents excessive wear (seizing or welding).

Antioxidants ///
Lubricating oils tend to oxidize (age) under the influence of heat and oxygen. The decomposition process is further accelerated by products reacting with acid during combustion and trace metals causing the catalytic effect (abrasive or corrosive wear). The addition of antioxidants leads to significantly improved aging. Although you can't completely eliminate the aging process, you can successfully slow it down.

Oxidation ///
Aging oil forms acids, varnish, resin and sludge-like deposits, most of which are insoluble in oil, such as carbon. Antioxidants can act in three ways:

Elimination of radicals (main antioxidants)
Removal of peroxide (secondary aging substances)
Metal ion passivators/deactivators
 

Pour point ///
Identifies the lowest temperature in degrees Celsius where oil will continue to flow. The "status quo" of the oil is determined by the crystallization present in base paraffin oils at low temperatures. Lower values are obtained by adding flow improvers.

Viscosity ///
Viscosity (flow behavior) is the property of a liquid to oppose a resistance to its reversible deformation. This plays an important role especially in engine oil. It is influenced by the temperature, the pressure exerted on the lubricating film and the shear rate, i.e. the speed interval between the moving surface and the fixed surface of a lubrication interval, for example in a warehouse.

Viscosity index improvers ///
Allows the production of multigrade engine oils. Increase viscosity improvers to stretch oil viscosity and thereby improve viscosity-temperature behavior. Figuratively speaking, they are molecules of very long shape compressed in cold oil, where the movement of the oil molecules opposes a relatively weak resistance. With increasing temperature, they uncoil, occupy a larger volume and form a mesh network, which slows down the movement of oil molecules and delays too rapid "thinning" of the oil.

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