top of page
Servicehefte

The manual for proper lubrication

Specifications in the world of lubricants are extremely important in a jungle of lubricants.

Correct lubrication provides a longer service life, prevents breakdowns, and improves the economy on the bottom line. Therefore, we have made a small list of the most used specifications.

Laboratory

American Petroleum Institute

API Gear Oil Specifications

GL-1

The designation API GL-1 denotes lubricants intended for manual transmissions operating under such mild conditions that straight petroleum or refined petroleum oil may be used satisfactorily. Oxidation and rust inhibitors, defoamers, and pour depressants may be added to improve the characteristics of these lubricants. Friction modifiers and extreme pressure additives shall not be used.

GL-2

The designation API GL-2 denotes lubricants intended for automotive worm-gear axles operating under such conditions of load, temperature, and sliding velocities that lubricants satisfactory for API GL-1 service will not suffice.

GL-3

The designation API GL-3 denotes lubricants intended for manual transmissions operating under moderate to severe conditions and spiral-bevel axles operating under mild to moderate conditions of speed and load. These service conditions require a lubricant having load-carrying capacities exceeding those satisfying API GL-1 service but below the requirements of lubricants satisfying API GL-4 service.

GL-4

The designation API GL-4 denotes lubricants intended for axles with spiral bevel gears operating under moderate to severe conditions of speed and load or axles with hypoid (see note) gears operating under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications where MT-1 lubricants are unsuitable. The manufacturer's specific lubricant quality recommendations should be followed.

GL-5

The designation API GL-5 denotes lubricants intended for gears, particularly hypoid (see note) gears, in axles operating under various combinations of high-speed/shock load and low-speed/high-torque conditions.

GL-6

The designation API GL-6 denotes lubricants intended for gears designed with a very high pinion offset. Such designs typically require protection from gear scoring in excess of that provided by API GL-5 gear oils.

MT-1

The designation API MT-1 denotes lubricants intended for non-synchronized manual transmissions used in buses and heavy-duty trucks. Lubricants meeting the requirements of API MT-1 service provide protection against the combination of thermal degradation, component wear, and oil-seal deterioration, which is not provided by lubricants in current use meeting only the requirements of API GL-1, 4, or 5.

API Engine Oil Service Category Charts

Gasoline Engines

SN PLUS

Licensed from May 1, 2018, API SN Plus is a new API classification that can be used alongside API SN, API SN with Resource Conserving and ILSAC GF-5. It was developed in accordance with OEMs request for motor oils that can protect from the potentially catastrophic effects of Low-Speed Pre-Ignition

SN

Introduced in October 2010 for 2011 and older vehicles, designed to provide improved high temperature deposit protection for pistons, more stringent sludge control, and seal compatibility. API SN with Resource Conserving matches ILSAC GF-5 by combining API SN performance with improved fuel economy, turbocharger protection, emission control system compatibility, and protection of engines operating on ethanol-containing fuels up to E85.

Sm

Category SM oils are designed to provide improved oxidation resistance, improved deposit protection, better wear protection, and better low-temperature performance over the life of the oil. Some SM oils may also meet the latest ILSAC specification and/or qualify as Energy Conserving. They may be used where API Service Category SJ and SL earlier categories are recommended.

SL

Category SL was adopted to describe engine oils for use in 2001. It is for use in service typical of gasoline engines in present and earlier passenger cars, sports utility vehicles, vans and light trucks operating under vehicle manufacturers recommended maintenance procedures. Oils meeting API SL requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SJ and earlier categories are recommended.

SJ

Category SJ was adopted in 1996 to describe engine oil first mandated in 1997. It is for use in service typical of gasoline engines in present and earlier passenger cars, vans, and light trucks operating under manufacturers recommended maintenance procedures. Oils meeting API SH requirements have been tested according to the American Chemistry Council (ACC) Product Approval Code of Practice and may utilize the API Base Oil Interchange and Viscosity Grade Engine Testing Guidelines. They may be used where API Service Category SH and earlier categories are recommended.

SH - For model year 1996 and older engines.

SG - For model year 1993 and older engines.

SF - For model year 1988 and older engines.

SE - For model year 1979 and older engines.

SD - For model year 1971 and older engines.

SC - For model year 1967 and older engines.

SB - For older engines. Use only when specifically recommended by the manufacturer.

SA - For older engines; no performance requirements. Use only when specifically recommended by the manufacturer.

Diesel F Category

FA-4

API Service Category FA-4 describes certain XW-30 oils specifically formulated for use in select high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway greenhouse gas (GHG) emission standards. These oils are formulated for use in on-highway applications with diesel fuel sulfur content up to 15 ppm (0.0015% by weight). Refer to individual engine manufacturer recommendations regarding compatibility with API FA-4 oils. These oils are blended to a high temperature high shear (HTHS) viscosity range of 2.9cP–3.2cP to assist in reducing GHG emissions. These oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. API FA-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low- and high-temperature properties, and soot-related viscosity increase. API FA-4 oils are not interchangeable or backward compatible with API CK-4, CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 oils. Refer to engine manufacturer recommendations to determine if API FA-4 oils are suitable for use. API FA-4 oils are not recommended for use with fuels having greater than 15 ppm sulphur. For fuels with sulfur content greater than 15 ppm, refer to engine manufacturer recommendations.

Diesel C Categories

CK-4

API Service Category CK-4 describes oils for use in high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 ppm (0.05% by weight). However, the use of these oils with greater than 15 ppm (0.0015% by weight) sulfur fuel may impact exhaust aftertreatment system durability and/or oil drain interval. These oils are especially effective at sustaining emission control system durability where particulate filters and other advanced aftertreatment systems are used. API CK-4 oils are designed to provide enhanced protection against oil oxidation, viscosity loss due to shear, and oil aeration as well as protection against catalyst poisoning, particulate filter blocking, engine wear, piston deposits, degradation of low- and high-temperature properties, and soot-related viscosity increase. API CK-4 oils exceed the performance criteria of API CJ-4, CI-4 with CI-4 PLUS, CI-4, and CH-4 and can effectively lubricate engines calling for those API Service Categories. When using CK-4 oil with higher than 15 ppm sulfur fuel, consult the engine manufacturer for service interval recommendations.

CJ-4

Introduced in 2006 for high-speed four-stroke engines. Designed to meet 2007 on-highway exhaust emission standards. CJ-4 oils are compounded for use in all applications with diesel fuels ranging in sulfur content up to 500ppm (0.05% by weight). However, use of these oils with greater than 15ppm sulfur fuel may impact exhaust after treatment system durability and/or oil drain intervals. CJ-4 oils are effective at sustaining emission control system durability where particulate filters and other advanced after treatment systems are used. CJ-4 oils exceed the performance criteria of CF-4, C-4, AH-4 and C-4.

CI-4 Plus

Used in conjunction with API C-4, the "CI-4 PLUS" designation identifies oils formulated to provide a higher level of protection against soot-related viscosity increase and viscosity loss due to shear in diesel engines. Like Energy Conserving, CI-4 PLUS appears in the lower portion of the API Service Symbol "Donut."

CI-4

The CI-4 performance requirements describe oils for use in those high speed, four-stroke cycle diesel engines designed to meet 2004 exhaust emission standards, to be implemented October 2002. These oils are compounded for use in all applications with diesel fuels ranging in sulfur content up to 0.05% by weight. These oils are especially effective at sustaining engine durability where Exhaust Gas Recirculation (EGR) and other exhaust emission components may be used. Optimum protection is provided for control of corrosive wear tendencies, low and high temperature stability, soot handling properties, piston deposit control, valve train wear, oxidative thickening, foaming and viscosity loss due to shear. CI-4 oils are superior in performance to those meeting API CH-4, CG-4 and CF-4 and can effectively lubricate engines calling for those API Service Categories.

CH-4

These service oils are suitable for high speed, four-stroke diesel engines designed to meet 1998 exhaust emission standards and are specifically compounded for use with diesel fuels ranging in sulfur content up to 0.5% weight. CH-4 oils are superior in performance to those meeting API CF-4 and API CG-4 and can effectively lubricate engines calling for those API Service Categories.

CG-4

This category describes oils for use in high speed four-stroke-cycle diesel engines used in both heavy-duty on-highway (0.05% wt sulfur fuel) and off-highway (less than 0.5% wt sulfur fuel) applications. CG-4 oils provide effective control over high temperature piston deposits, wear, corrosion, foaming, oxidation stability, and soot accumulation. These oils are especially effective in engines designed to meet 1994 exhaust emission standards and may also be used in engines requiring API Service Categories CD, CE, and CF-4. Oils designed for this service have been in existence since 1994.

CF-2

Service typical of two-stroke cycle diesel engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designed for this service have been in existence since 1994 and may be used when API Service Category CD-II is recommended. These oils do not necessarily meet the requirements of API CF or CF-4 unless they pass the test requirements for these categories.

CF

Service typical of indirect-injection diesel engines and other diesel engines that use a broad range of fuel types, including those using fuel with high sulfur content; for example, above 0.5% wt. Effective control of piston deposits, wear and copper-containing bearing corrosion is essential for these engines, which may be naturally aspirated, turbocharged or supercharged. Oils designated for this service have been in existence since 1994 and may be used when API Service Category CD is recommended.

CF-4

Service typical of high speed, four-stroke cycle diesel engines. API CF-4 oils exceed the requirements for the API CE category, providing improved control of oil consumption and piston deposits. These oils should be used in place of API CE oils. They are particularly suited for on-highway, heavy-duty truck applications. When combined with the appropriate S category, they can also be used in gasoline and diesel powered personal vehicles i.e., passenger cars, light trucks and vans when recommended by the vehicle or engine manufacturer.

CE

Service typical of certain turbocharged or supercharged heavy-duty diesel engines, manufactured since 1983 and operated under both low speed, high load and high speed, high load conditions. Oils designed for this service may also be used when API Service Category CD is recommended.

CD-II

Service typical of two-stroke cycle diesel engines requiring highly effective control of wear and deposits. Oils designed for this service also meet all performance requirements of API Service Category CD.

CD

Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines where highly effective control of wear and deposits is vital, or when using fuels with a wide quality range (including high-sulfur fuels). Oils designed for this service were introduced in 1955 and provide protection from high temperature deposits and bearing corrosion in these diesel engines.

CC

Service typical of certain naturally aspirated, turbocharged or supercharged diesel engines operated in moderate to severe-duty service, and certain heavy-duty gasoline engines. Oils designed for this service provide protection from bearing corrosion, rust, corrosion and from high to low temperature deposits in gasoline engines. They were introduced in 1961.

CB

Service typical of diesel engines operated in mild to moderate duty, but with lower quality fuels, which necessitate more protection from wear and deposits; occasionally has included gasoline engines in mild service. Oils designed for this service were introduced in 1949. They provide necessary protection from bearing corrosion and from high temperature deposits in naturally aspirated diesel engines with higher sulfur fuels.

ABOUT

Service typical of diesel engines operated in mild to moderate duty with high quality fuels; occasionally has included gasoline engines in mild service. Oils designed for this service provide protection from bearing corrosion and ring-belt deposits in some naturally aspirated diesel engines when using fuels of such quality that they impose no unusual requirements for wear and deposit protection. They were widely used in the 1940s and 1950s but should not be used in any engine unless specifically recommended by the equipment manufacturer.

ACEA Engine Oil Sequences

Oil for the car

A/B: gasoline and diesel engine oils

 

ACEA A1/B1 Category is removed with the ACEA 2016 Oil Sequences. From ACEA 2012: Stable, stay-in-grade oil intended for use at extended drain intervals in gasoline engines and car & light van diesel engines specifically designed to be capable of using low friction low viscosity oils with a high temperature / high shear rate viscosity of 2.6 mPa*s for xW/20 and 2.9 to 3.5 mPa.s for all other viscosity grades. These oils are unsuitable for use in some engines. Consult the owner's manual or handbook if in doubt.

ACEA A3/B3 Category is removed with the ACEA 2022 Oil Sequences. From ACEA 2016: Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & Diesel Engines and/or for extended drain intervals where specified by the engine manufacturer, and/or for year-round use of Low Viscosity Oils, and/or for severe operating conditions as defined by the Engine Manufacturer.

ACEA A3/B4 Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & DI Diesel Engines, but also suitable for applications described under A3/B3.

ACEA A5/B5 Stable, stay-in-grade Engine Oil intended for use at extended Drain Intervals in Passenger Car & Light Duty Van Gasoline & Diesel Engines designed to be capable of using Low Viscosity Oils with HTHS Viscosity of 2.9 to 3.5 mPa*s. These Oils are unsuitable for use in certain Engines - consult the vehicle OEM's owner's manual/handbook in case of doubt.

ACEA A7/B7 Stable, stay-in-grade engine oil intended for use at extended oil drain intervals in passenger car and light-duty gasoline and DI diesel engines designed for low viscosity engine oils with HTHS viscosity of 2.9 to 3.5 mPa*s. Relative to A5/B5, these engine oils also provide low-speed pre-ignition and wear protection for turbocharged gasoline DI engines, as well as turbocharger compressor deposit (TCCD) protection for modern DI diesel engines. These engine oils are unsuitable for use in certain engines – consult manufacturers' owner manual/handbook in case of doubt.

C: Catalyst compatible oils

Note: These oils will increase the DPF/GPF and TWC life and maintain the vehicle's fuel economy.
Warning: Some of these Categories may be unsuitable for use in certain Engine Types – consult the vehicle-OEM's owner's manual/handbook in case of doubt.

 

ACEA C1 Category is removed with the ACEA 2022 Oil Sequences. Stable, stay-in-grade Engine Oil with Lowest SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Low Viscosity Oils with a minimum HTHS Viscosity of 2.9 mPa*s.

 

ACEA C2 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Low Viscosity Oils with a minimum HTHS Viscosity of 2.9 mPa*s.

 

ACEA C3 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Oils with a minimum HTHS Viscosity of 3.5 mPa*s.

 

ACEA C4 Stable, stay-in-grade Engine Oil with Low SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Oils with a minimum HTHS Viscosity of 3.5 mPa*s.

 

ACEA C5 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, for further improved Fuel Economy, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable and OEM-approved for use of Low Viscosity Oils with a minimum HTHS Viscosity of 2.6 mPa*s.

 

ACEA C6 Stable, stay-in-grade engine oil for improved fuel economy, with mid-SAPS level, for aftertreatment system compatibility. Intended for use at extended oil drain intervals in passenger car and light-duty gasoline, and DI diesel engines designed and OEM-approved for engine oils with HTHS viscosity of minimum 2.6 mPa⋅s. Relative to C5 these engine oils also provide low speed pre-ignition and wear protection for turbocharged gasoline DI engines as well as turbocharger compressor deposit (TCCD) protection for modern DI diesel engines.

E: Heavy Duty Diesel engine oils

ACEA E4 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer's recommendations. It is suitable for engines without particulate filters, and for some EGR engines and some engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so Driver Manuals and/or Dealers shall be consulted if in doubt.

 

ACEA E8 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly-rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under very severe conditions, eg significantly extended oil drain intervals according to the manufacturer's recommendations. It is suitable for EGR engines, with or without particulate filters, and for engines fitted with SCR NOx reduction systems. E8 quality is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low-sulphur diesel fuel. However, recommendations may differ between engine manufacturers, so driver manuals and/or dealers must be consulted if in doubt.

 

ACEA E7 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer's recommendations. It is suitable for engines without particulate filters, and for most EGR engines and most engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so Driver Manuals and/or Dealers shall be consulted if in doubt.

 

ACEA E11 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under severe conditions, eg extended oil drain intervals according to the manufacturer's recommendations. It is suitable for engines with or without particulate filters, and for most EGR engines and for most engines fitted with SCR NOx reduction systems. E11 is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low-sulphur diesel fuel. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.

ACEA = Association des Constructeurs Europèens d`Automobiles

A/B : For petrol and diesel engines. Ex. A1/B1, A3/B3, A3/B4, A5/B5.

C : For aftertreatment of exhaust gases (DPF). Ex. C1, C2, C3

E : For heavier vehicles. Ex. E2, E4, E6, E7, E9.

A1/B1 High-quality oil with low HTHS (High-Temperature High-Shear), due to fuel-saving properties. Only approved for special engines based on the manufacturer's specifications.

A3/B3 Oil of high quality "stay-in-grade" for modern high-performance engines also intended for extended change intervals.

A3/B4 As described for A3/B3, but also intended for passenger/van diesel engines with direct injection.

A5/B5 High quality oil with lower HTHS, only approved for special engines based on the manufacturer's specifications.

C1 Low content of SAPS with lower content of HTHS 2.6 - 2.9 mPas, sulphate ash  max. 0.5%, sulfur max. 0.2% w/w, phosphorus max. 0.05%, performance equivalent to ACEA A5/B5 and proven fuel saving as ACEA A1.

C2 Medium SAPS oil with a lower content of HTHS 2.9 mPas, sulphate ash max. 0.8% sulfur max. 0.3%, phosphorus max. 0.08%, performance equivalent to  ACEA A5/B5 and proven fuel-saving as ACEA A1.

C3 Medium SAPS oil without lower HTHS 3.5 mPas, sulphate ash  0.8%, sulfur max. 0.3%, phosphorus max. 0.08%, corresponds to performance ACEA A5/B5.

E2 Universal engine oil for heavy diesel for normal use, but not for extended change intervals.

E4 Universal adapted oil for heavy diesel that meets emission requirements standard EURO 1 and EURO 2. For use under heavy loads and approved for the longest change intervals according to the manufacturer's specifications. Compared to E3, E4 has a better ability to clean and absorb soot from the engine.

E6 Euro 4 engines with exhaust recirculation and diesel particulate filter (EGR/DPF) with performance equal to ACEA E4/E5 with reduced additives such as sulphate ash 1.0%, phosphorus max. 0.08%, sulfur max. 0.3%. Preferred SAE grades 10W-40

E7 Euro 4 engines with exhaust gas recirculation (EGR) without diesel particulate filter and without chemical restriction of the additives (P, S, SA), Preferred SAE grade 15W-40.

E9 Is close to ACEA E7, but is a Low SAPS oil for engines with an exhaust cleaning system. The specification also contains the strictest requirements for American engines such as API CJ-4.

E3/E5 Released in 2004.

 

API = American Petroleum Institute 

API has the classification S (service) for petrol engines, and the classification C (commercial) for diesel engines.

The following classifications therefore apply to petrol engines:

SH - Withstands great stress and gives high performance.

SL - Tougher engine test compared to API SH.

SM - For engines with improved wear and oxidation properties, with improved pump pressure and limited phosphorus level.

For diesel engines, these classifications apply:

CF - Turbo tested, withstands high stresses. Can also be used where CD classification is required.

CF-4 - For high-speed diesel engines, with low emissions, with anti-wear, oxidizing, anti-rust and anti-soot properties.

CF-4 classification surpasses CD and CE oils, and can be used where these classifications are required. CG-4 - For high-speed diesel engines, with low emissions, with anti-wear, oxidizing, anti-rust and anti-soot properties. Replaces API CF-4.

CH-4 - Too heavy diesel.

CI-4 - Engines with low sulfur (0.05%) content adapted to the emission requirements from 2004.

 

API Gear oil specifications

 

The API system does not only describe engine oil quality - it also describes gear oil quality (Auto)
Fortunately for us, only this system is used today, and it is used by all oil producers. The API system for gear oil is very simple, with the help of a number/letter code they tell us the amount / type of high pressure additives found in the oil. The letters "GL" after API show us that it is a gear oil - in addition, there is always a number. The number shows us the amount of high-pressure additives in the oil.

API GL  1                 - Gear oil with little high-pressure additives
API GL  4                 - Gear oil with moderate high-pressure additives
API GL  5                 - Gear oil with special high-pressure additives - also called hypoid oil
API GL 4 / 5             - Gear oil with moderate to special high-pressure additives
API GL 5 LS            - Gear oil as GL 5 shown above, but in addition anti-friction additives for differential brakes etc.

The API codes always appear on the labels on the oil packaging and in instruction books/recommendation tables  for vehicles. In other words - if you are in doubt about which engine oil to choose, look up the instruction book / recommendation table for the vehicle and check against the label on the oil packaging.

SAE = Society of Automotive Engineers

This is the minimum requirement for the temperature range the respective viscosities must maintain. For example  5W-40  i from the recognized manufacturers  has pour point   below - 40 degrees. SAE value is described on the container with two numbers and a letter, e.g.: 5w-40 or 0w-30. ((W = Winter) oil viscosity/flowability)). This means that the oil's consistency changes from the first to the second number as the temperature of the engine rises, - and at the same time preserves its lubricity.

The lower the first number, the thinner the oil when cold. This makes it easier to start at low temperatures without impairing lubrication.

By definition, viscosity is  an "Expression of a liquid's resistance to flow". The viscosity of one and the same oil will vary with the temperature to which it is exposed.

At low temperatures, the oil will normally be viscous -  having a high viscosity.

At high temperature, the oil will normally flow easily - have a low viscosity

The extent to which the viscosity changes depends on the properties of the base oil (Ref. mineral versus synthetic) and the additives.

Viscosity index is an expression or measure of how much an oil's viscosity changes with temperature changes. High VI (Viscosity Index) of an oil, e.g. 150 tells us that this oil changes less with temperature changes than an oil with a VI of, say, 100.

Indication of the viscosity takes place in accordance with international standards.

There are two types of viscosity, dynamic and kinematic, and it is the latter that we are most concerned with.

Kinematic viscosity has the designation mm2/s,   (Centistokes, often abbreviated to cSt.) and is a measure of a liquid's resistance to flow under the influence of gravity. It is common to measure this at 40 and 100 °C.

The ISO-VG system (International Standardization Organization - Viscosity Grade)

 ISO standard 3448 divides industrial oils into ISO-VG classes. The standard states which viscosity the oil must have at 40 °C, as well as which deviations are permitted within each class.

The lower the ISO class, the thinner the oil. The lowest class is ISO-VG 2, with a viscosity of 2.2 mm²/s at 40 °C. In comparison, regular diesel oil has a viscosity of around 2.5 mm²/s at 40 °C.

The lowest classes ("Thinnest" oils = ISO-VG 2 to 10) are typically spindle oils for machine tools etc. The most used classes are 15 to 220, where hydraulic oils, turbine/circulation oils and compressor oils are usually in the classes up to 100, while gear oils usually go up in the grades to 220.

For the classes above 220, we find a large number of exchange and circulation oils for slightly more special applications.

FAT AND NLGI NUMBER

Grease, like most other lubricants, consists of a base oil mixed with various additives. The additives are much the same as those used in lubricating oils. The base oil can be mineral, synthetic or semi-synthetic.

The very special thing about fat is that you have to use a so-called thickener (Metal soap) in the base oil to achieve the desired consistency. The amount of thickener is quite small, approx. 10% is sufficient to turn a thin oil into a fat consistency.

The most common types of soap are lithium, potassium, sodium and gel. The types of soap are often made "complex", (a multi-step manufacturing process) to increase the range of use. Fats that are built up as "complex" are more expensive than other fats, but usually have a wider range of use, e.g. on the temperature side.

As mentioned, additions, additives,   are mixed into the fat to give it special properties. One of the special high pressure additives for grease can be molybdenum disulfide. In this case, you will be able to read this from the product name.

A very common question concerns the consistency, or firmness, of the fat. It is always indicated by a so-called NLGI number. NLGI is an abbreviation for National Lubricating Grease Institute.

According to the NLGI system, there are 9 classes - from the very soft and almost liquid 000 - fat to the almost completely solid 6 - fat. It is worth noting that most of the grease used within the industry and transport sector is in NLGI class 2.

NLGI classifications:

NLGI  000       - almost liquid

NLGI   00      - as above

NLGI     0      - somewhat firmer

NLGI     1        - somewhat firmer

NLGI     2      - the most commonly used firmness

NLGI     3      - somewhat firmer

NLGI     4           *

NLGI     5           *

NLGI     6      - almost completely fixed

All oil companies use the NLGI system, and as a rule the NLGI number appears in the number after the product name.

In addition to consistency, a number of other requirements are set for a grease's properties, all of which are tested according to international standards such as DIN, ASTM, ISO, SKF, Timken, FAG etc.

Another important property is the fat's dropping point. The dropping point is at the temperature where the fat melts and emits droplets. When choosing a grease, you must therefore check in advance what temperatures the grease will work under - and choose a grease that can withstand the temperature in question.

You should also be aware that not all types of fat are miscible with each other, this applies especially to synthetic types of fat.

OEM = Original Equipment Manufacturers

Here are some examples of original specifications:

DAIMLER CHRYSLER, MB 228.1, 228.3, 228.5, 228.51, 229.1, 229.3, 229.31, 229.5, 229.51

VOLKSWAGEN, 500.00, 501.00, 502.00, 503.00/01, 504.00, 505.00/01, 506.00/01, 507.00

MAN, M3275 / M3277 / MAN 3477 (LOW SAP PRODUCT)

MACK, TWO API CG-4, CH-4

VOLVO, VDS, VDS-II, VDS III

MTU, FOR CF OR CF-4 OR ACEA E-CLASS

RENAULT RVI, BMW, PSA, FORD, LANCIA, FIAT, ALFA, PORSCHE, RENAULT, ROVER

Dictionary

API American Petroleum Institute. Specifies the quality level for engine oils and gear oils.

Ash content The ash residue that remains after the oil has been completely burned. The ash content is stated as a percentage of the mass, and the ash consists of inorganic salts, oxides and minerals.

ASTM American society for testing and materials.

Bentonite Clay used as a thickener in high-temperature grease.

Bottom waste Deposits of impurities, especially in engines.

CCMC / ACEA Alliance consisting of European car manufacturers within the EU.

CP CentiPoise, unit of measurement for dynamic viscosity - mPa.s.

cSt centiStoke, unit of measurement for kinematic viscosity.

Detergent Addition to motor oil that increases the oil's sludge-dispersing ability.

Dispersant Surface-active substance that is added to finely distribute particles.

DIN Deutsche Industrie Normen.

Dropping point The temperature at which the oil can no longer be poured.

Emulsifiable oil Oil that mixes with water and forms a stable emulsion.

Angels (*E) Outdated unit of measure for viscosity.

EP Extreme pressure, high pressure additive for oil and grease.

Fatty oil Animal and vegetable oils. Used as a film-strengthening additive.

Grease with lithium complex Lubricating grease that has been thickened with a lithium soap complex, so that it can be used at higher working temperatures.

Flash point The temperature of the oil when the gases released are ignited by an open flame. Measured with the COC method (Cleveland Open Cup) or the PMCC method (Pensky-martens Closed Cup).

Pour point The lowest temperature at which the oil still flows (during cooling).

Friction Resistance to movement.

Glycol A type of alcohol that is widely used in lubrication technology.

Graphite A solid lubricant used as an additive in oil and grease.

HD oil Heavy Duty - Old term for motor oil with cleaning properties.

IR Infrared spectrophotometer for analyzing lubricants.

JASO Japan Automobile Standards Organization.

Colloids Very small particles that are added to some lubricants.

Corrosion protection Additive that counteracts rust and corrosion.

Cracking Molecular cracking, heavy oil molecules are broken to form light molecules.

MIL-L xxx US military specifications. (MIL-L-2105C = API GL-5) (MIL-L-46152D = API SG)

Molybdenum disulphide (MoS2) A fixed additive for oils and fats.

MVMA Motor Vehicle Manufacturers Association.

Naphthenic oil Mineral oil with good flow properties at low temperatures.

NMMA National Marine Manufacturers Association, origin of BIA - Boating Industry Association.

NLGI Classification system for lubricating greases according to consistency.

OEM Original Equipment Manufacturers, manufacturers of technical equipment (with components from subcontractors).

Oxidation protection Addition to prevent the oil from oxidising, thus ensuring that it can be used for longer.

PAO Polyalphaolefins, a type of synthetic base oil that can be mixed with mineral oil.

Paraffin-based oil Mineral oil which is the most commonly used base oil in lubricants.

Polymer Long molecular chains Synthetic additive to improve the fluidity of the oil.

Pumpability The lowest temperature at which it is possible to pump the oil.

SAE Society of Automotive Engineers. The SAE system is used to grade motor and transmission oil according to viscosity.

Silicone Water-repellent polymers.

Synthetic oil Lubricating oils where the base oil is produced using a chemical process. The basis is usually crude oil or gas.

TBN Total Base Number. Shows the oil's ability to neutralize acids.

Additive Substances that are added to lubricants, fuels to improve certain properties.

Tribology The study of lubrication, friction and wear.

VI Viscosity index, an expression of the oil's resistance to changing viscosity due to temperature variations.

Viscosity Indicates the thickness and/or buoyancy of a liquid.

Helvetica Light is an easy-to-read font, with tall and narrow letters, that works well on almost every site.

bottom of page