Engine Oil Classification

engine oil classification

API ENGINE SERVICE CLASSIFICATION

API (American Petroleum Institute), ASTM (American Society for Testing and Materials) and SAE (Society of Automotive Engineers) set up the American Petroleum Institute (API) engine oil classification system as a joint effort. The letter classification system is a method of classifying engine oils according to their performance characteristics, and relating this to their intended type of service.

The API system currently includes service classifications for service stations. Spark ignition engines ("S" Series) for commercials applications/compression ignition engines ("C" Series) and for energy conserving engine oils ("EC" Series). It is an "open-ended" system, which allows for the addition of new designations with little change to existing ones.

"S" Service Station/Spark Ignition Engine Classifications:
Only four API "S" service Classifications, categories SJ, SH, SL and SM (restricted usage) are currently existing. The API decided to move directly from API Service Classification SH to SJ in order to avoid confusion with the abbreviation Sl, which is used for the System International d'Unites (International System for Units) and "spark ignition". The remaining categories are obsolete due to the introduction of higher performance categories, or the non-availability of test methods.

SA formerly for Utility Gasoline and Diesel Engine Service (Obsolete)
Oils for such mild service category had no performance requirements. Oils of API Service Category SA should not be used in any engine unless specifically recommended by the manufacturer.

SB for Minimum-Duty Gasoline Engine Service (Obsolete)
Oils meeting this service provided only mild anti scuff capability and some resistance to oil oxidation and bearing corrosion. Oils of API Service Category SB should not be used in any engine unless specifically recommended by the manufacturer.

SC for 1964 Gasoline Engine Warranty Maintenance Service (Obsolete)
It is applied for typical service of gasoline engines in 1964 through 1967. It is of little relevance to modern gasoline engines. It is superseded by API Service Category SD in 1968.

SD for 1968 Gasoline Warranty Maintenance Service (Obsolete)
Service typical of gasoline engines is beginning with 1968 models. It is of little relevance to modern gasoline engines and superseded by API Service Category SE in 1972.

SE for 1972 Gasoline Engine Warranty Maintenance Service (Obsolete)
Service typical of gasoline engines passenger cars and some trucks were beginning with 1972 and certain 1971 models operating under manufacturers' recommended maintenance procedures. The oils is designed for this service provided more protection against oil oxidation, high temperature engine deposit, rust and corrosion in gasoline engines than oils that met API Engine Service Categories SD or SC and may be used when either of these categories is recommended.

The lowest specification of lubricant products in Indonesia is marked with API Service SE. In the mean time, few number of lubricant manufacturers remain to produce this kind of lubricant aimed to serve engine at hight operating conditions. Whilst API itself no longer provides engine tests for certification of API Service SA, SB, SC, SD, SE, SF, SG & SH.

SF for 1980 Gasoline Engine Warranty Maintenance Service (Obsolete)
Service typical of gasoline engines in passenger cars and some trucks are beginning with 1980 models operating under manufacturers’ recommended maintenance procedures. The oils is developed for this service provided increasing oxidation stability and improving antiwear performance relative to engine oils that meets the minimum requirements for API Service Category SE. These oils also provided protection against engine deposits, rust and corrosion. Oils meeting API Service Category SF may be used when API Service Categories SE, SD or SC are recommended.

SG for 1989 Gasoline Engine Warranty Maintenance Service (Obsolete)
Service typical of gasoline engines in passenger cars, van, and light duty trucks and some diesel engines, were beginning with 1989 models operating under manufacturers’ recommended maintenance procedures, Oil developed for API Service Classification SG provided improved control of sludge and varnish, oil oxidation and engine wear relative to engine oils developed for previous categories. These oils also provided protection against rust and corrosion. Oils meeting API Service Category SG may be used when API Service Categories SF, SE and earlier categories are recommended.

SH for 1994 Gasoline Engine Warranty Maintenance Service (obsolete)
Service typical of gasoline engines in current and earlier passenger car, van, and light truck are in operation under vehicle manufacturers' recommended maintenance procedures. First available 1 January 1994, oils in this category exceed the minimum performance requirements of API Service Category SG in the areas of deposit control, oil oxidation, wear, rust and corrosion.

Engine oils meeting API Service Category SH have been tested in accordance with the Chemical Manufacturers Association (CMA) code of Practice, and may be used where API Service Category SG and earlier categories have been recommended.

SJ for 1996 Gasoline Engine Warranty Maintenance Service
Service typical of gasoline engines in current and earlier passenger car, van and light truck are in operation under vehicle manufacturers’ recommended maintenance procedures. First available from 15 October 1996, oils of this category exceeded the minimum performance requirements of API Service Category SH with a slightly different simulated distillation and evaporation loss. Plus met the requirements of bench tests for wet filterability, gelation index, high temperatures foaming, and high temperature deposits. API Service Category SJ also introduced a limit on phosphorus content of 0.10 mass %. API Service Category SJ may be used where API SH, SG, and earlier categories have been recommended.

SL-2001 Gasoline Engine Service
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, sport 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.

SM 2004 For all automotive engines currently in use. Introduced November 30, 2004, 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.

“EC” Energy Conserving Classifications:
Only one Energy Conserving "EC" Classification is current.

Energy Conserving is conjunction with API
Service Category SJ
API Service Category SJ oils categorized as energy conserving are formulated to improve the fuel economy of passenger cars, sports utility vehicles, van and light-duty trucks powered by gasoline engines. These oils have produced a fuel economy improvement of 1.4% or more (0W-20 and 5W-20 viscosity grades), 1.1% or more (other 0W-xx and 5W-xx viscosity grades) or 0.5% or more (10W-xx and all other viscosity grades) in the sequence VIA test, when compared with the standard reference oil used in the test.

Energy Conserving II in conjunction with API
Service Category SH
API Service Category SH engine oils categorized as Energy Conserving II are formulated to improve the fuel economy of passenger cars, sports utility vehicles, vans and light trucks powered by gasoline engines. These oils have produced a fuel economy improvement of 2.7 % or more in the Sequence Vl test, compared with the standard reference oil used in the test.

“C” Commercial Classification:
Four API "C" Service Classifications are current. A new proposal is being prepared for the heavy-duty engine oils, which will be required for engines meeting 1998 emission requirements.

CA for Diesel Engine Service (Obsolete)
Service typical of diesel engines was operated in mild to moderate duty with high-quality fuel. Oils was designed for this service provided protection from bearing corrosion and from ring belt deposits in some naturally aspirated diesel engines when using such quality fuels that they imposed no unusual requirements for wear and deposit protection. Oils of API Service Category CA should not be used in any engine unless specifically recommended by the manufacturer.

CB for Diesel Engine Service (Obsolete)
Service typical of diesel engines was operated in mild to moderate duty. Oils was designed for this service provided necessary protection from bearing corrosion and high-temperature deposits in normally aspirated diesel engines with lower quality fuels. Oils of API Service Category CB should not be used in any engine unless specifically recommended by the manufacturer.

CC for Diesel Engine Service (Obsolete)
Service typical of certain naturally aspirated and lightly supercharged diesel engines operated in moderate to severe service and certain heavy-duty gasoline engines. Oils designed for this service provided protection from high-temperature deposits and bearing corrosion in these diesel engines, and from rust, corrosion and low-temperature deposits in gasoline engines. These oils were introduced in 1961.

CD for Diesel Engine Service (Obsolete)
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 of 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.

CD II for Severe-Duty Two Stroke-Cycle Diesel Engine Service (Obsolete)
Service typical of two-stroke-cycle diesel engines was requiring highly effective control over wear and deposits. Oils designed for this service also met all the requirements of API Service Category CD

CE for 1983 Diesel Engine Service (Obsolete)
Service typical of certain turbocharged and have supercharged heavy-duty diesel engines manufactured since 1983 and were operating under high-load conditions for both low and high-speed operation. Oils designed for this service may be used where API Service Category CD is recommended for diesel engines.

CF for Indirect-lnjected Diesel Engine Service
API Service Category CF denotes service typical of indirect-injected diesel engines, and other diesel engines which use a broad range of fuel types including those using fuel with higher sulfur content, for example over 0.5% weight. 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 also be used when API Service Category CD is recommended.

CF-2 Two-Stroke-Cycle Diesel Engine Service
API Service Category CF-2 denotes service typical of two-stroke-cycle engines requiring highly effective control over cylinder and ring-face scuffing and deposits. Oils designated 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 CF-4 unless passing test requirements of these categories

CF-4 for Severe-Duty-4 Stroke-Diesel Engine Service
Service typical of certain high-speed, turbocharged, four-stroke-cycle diesel engines since 1990. API Service Category CF-4 oils exceed the requirements of API Service Category CE, and provide improved control of oil consumption and engine deposits. Oils meeting API Service Category CF-4 may be used when API Service Categories CE and CD are recommended for diesel engines.

CG-4 for Severe-Duty, Four-Stroke Cycle Diesel Engine Service
API Service Category CG-4 describes oils for use in high speed, four-stroke-cycle diesel engines used in both heavy-duty, on-highway (0.05% weight sulfur fuel) and off-highway (less than 0.5% weight sulfur fuel applications). CG-4 oils provide effective control over high temperature piston deposits, wear, corrosion, foaming, and oxidation stability and soot accumulation. These oils are specifically effective in engines designed to meet 1994 U.S.A. exhaust emission standard and may also be used in engines requiring API Service Categories CF-4, CE and CD.

CH-4
Introduced December 1, 1998. For high-speed, fourstroke engines designed to meet 1998 exhaust emission standards. CH-4 oils are specifically compounded for use with diesel fuels ranging in sulfur contents up to 0.5% weight. Can be used in place of CD, CE, CF-4, and CG-4 oils.

Cl-4-2002
Severe-Duty Diesel Engine Service-The Cl-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 component 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. Cl-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.

ILSAC ENGINE SERVICE CLASSIFICATION

The American Automobile Manufacturers Association (AAMA) and the Japan Automobile Manufacturers Association (JAMA), through an organization called the International Lubricant Standardization and Approval Committee (ILSAC), jointly developed and approved a "Minimum Performance Standard for Passenger Car Motor Oils". The standard, known as ILSAC GF-1, was issued in October 1990 and revised in October 1992. An upgraded standard, known as ILSAC GF-2, was commercially released in October 1996.

Engine oils meeting ILSAC GF-2 may be licensed to be labelled using the ILSAC "Starburst" certification mark on packaging.

ILSAC GF-1
Comprises all of the requirements of API Service Category SH, plus bench test for volatility, filterability, foaming, flash point, high temperature/high shear viscosity, shear stability and phosphorus content. As well, ILSAC GF-1 requires a minimum of 2.7 % fuel economy in the Sequence Vl test and is restricted to oils which met the low temperature viscosity grades 0W, 5W and 10W.

ILSAC GF-2
Comprises all of the requirements of API Service Category SJ, plus bench test for high temperature/high shear viscosity, volatility, filterability, foaming, flash point, shear stability, high temperature deposits and phosphorus content. As well, lLSAC GF-2 requires an Energy Conserving rating from the Sequence VIA test.

ACEA / CCMC EUROPEAN OIL SEQUENCES FOR SERVICE-FILL OILS

The ACEA (Association des Constructeurs Europeen d'Automobiles) released new European performance levels for lubricants, which came into effect at the start of 1996. These new standards will replace the outdated CCMC Sequences previously used to define European gasoline and diesel engine oil quality.

The ACEA Sequences consist of nine designations within three main categories. The three categories are Passenger Car Gasoline Engine Oil, Passenger Car Diesel Engine Oil and Heavy-Duty Diesel Engine Oil, known respectively as A, B and E. There are three oil performance levels within each category: Gasoline Engines (A1-98, A2-96 Issue 2, A3-98), Passenger Car Diesel Engines (B1-98, B2-98, B3-98) and Heavy-Duty Diesel Engine oil (E1-96 Issue 2, E2-96 Issue 2, E3-96 Issue 2, E4-98).

ACEA SEQUENCES
Passenger Car Gasoline Engine Oils:
A1 - 98 :
Similar to API SH or SJ, but with better high temperature properties. Some properties, such as high-temperature/high-shear (HTHS) viscosity, have maximum limits, and oils meeting A2 and A3 cannot also meet A1.

A2 - 96 Issue 2 :
Simliar to ACEA A1, but with a higher minimum shear stability, lower evaporative loss for some viscosity grades, and a higher minimum HTHS viscosity specified for bearing protection under high temperature operating conditions. A2 lubricant cannot meet all the requirements of A1, some of which have maximum values set below the minimum value set for A2.

A3 - 98 :
Similar to ACEA A1 and A2, but with stay in grade shear stability, and tighter limits on evaporative loss and high temperature oxidation and piston varnish. A3 lubricant cannot meet all the requirements of A1, some of which have minimum values set below the minimum value set for A3. A3 lubricants automatically meet all requirements of A2.

Passenger Car Diesel Engine Oils:
B1 - 98 :
Performance beyond that of the former CCMC PD-2, with better high temperature deposit control, soot dispersancy and valve train wear protection. Some properties, such as hightemperature high-shear (HTHS) viscosity, have maximum limits, and oil meeting B2 and B3 cannot also meet B1.

B2 - 98 :
Similar to ACEA B1, but with a higher minimum shear stability, lower evaporative loss for some viscosity grades, and a higher minimum HTHS viscosity specified for bearing protection under high temperature operating conditions. B2 lubricant cannot meet all the requirements of B1, some of which have maximum values set below the minimum value set for B2.

B3 - 98 :
Similar to ACEA B1 and B2, but with stay in grade shear stability, and much tighter limits on evaporative loss, medium temperature dispersivity and cam wear. B3 lubricant cannot meet all the requirements of B1, some of which have maximum values below the minimum value set for B3. B3 lubricant automatically meet all requirements of B2.

B4 - 98 :
Similiar to ACEA B1, B2 and B3, but with higher on piston cleanliness and ring sticking. B4 lubricant automatically meet all requirements of B2.

Heavy Duty Diesel Engine Oils:
E1 - 96 Issue 2 :
Approximately equivalent to the former CCMC D-4 and the obsolete Mercedes Benz sheets 227.0/1 with marginal improvements in shear stability and bore polishing resistance.

E2 - 96 Issue 2 :
Approximately equivalent to Mercedes Benz sheets 228.0/1, the updated MAN 270/171 and that informally described as "CCMC D-4 Plus", with marked improvements in bore polishing resistance and piston cleanliness over the former CCMC D-4. It is expected to become the OEM base requirement for heavy duty diesel engine oils.

E3 - 96 Issue 2 :
Essentially equivalent to the former CCMC D-5, approximately at the Mercedes Benz 228.2/3 level. E3 does include Mack T-8 test requirements for determining dispersancy which may eliminate some former CCMC D-5 oils.

E4 - 98 :
Similiar to ACEA E1, E2 and E3, but with stay in grade shear stability, and much tighter limits on bore polishing and piston cleanliness.

CCMC SEQUENCES

All CCMC Sequences are now obsolete.
Gasoline Engines:
CCMC G-1 :
1984, higher performance, normal viscosity specification. Approximately equivalent to API SE plus European Tests.

CCMC G-2 :
1984, higher performance, normal viscosity specification. Approximately equivalent to API SF plus European Tests.

CCMC G-3 :
1984, higher performance, low viscosity specification. Approximately equivalent to API SF/ CC plus European Tests.

CCMC G-4 :
1989, normal viscosity specification. Performance beyond API SG level, particularly in the areas of valve train wear and high temperature sludging resistance.

CCMC G-5 :
1989, low viscosity specification. Performance beyond API SG level particularly in the areas of valve train wear and high temperature sludging resistance. Restricted to 5W-xx and 10Wxx multigrades, but with severe HTHS requirements. As well, CCMC G-5 has a stringent evaporative loss requirement, more stringent than ILSAC GF-1.

Passenger Car Diesel Engines:
CCMC PD-1
1984, diesel passenger cars. Performance well beyond MIL-L-2104C minimum, with particular emphasis on ring sticking prevention.

CCMC PD-2
1989, diesel passenger cars. Better protection against ring sticking and valve train wear relative to CCMC PD-1.

Heavy Duty Diesel Engines:
CCMC D-1:
1984,naturally aspirated and turbo-charged, extra heavy-duty operation. Approximately equivalent to MIL-L-46152 (API CC/SE) plus European test.

CCMC D-2 :
1984, naturally aspirated and turbocharged, extra heavy-duty operation. Approximately equivalent to MIL-L-2104C (API CD/SD) plus European test.

CCMC D-3 :
1984,naturally aspirated and turbo-charged, extra heavy-duty operation. Performance well beyond MIL-L-2104C diesel minimum, with particular emphasis on bore polishing protection.

CCMC D-4 :
1989, commercial vehicle, heavy-duty operation. Performance well beyond CCMC D-2 minimum, with emphasis on bore polishing protection; soot dispersion and valve train wear protection.

CCMC D-5 :
1989, commercial vehicle, extra heavy-duty operation. Bore polishing protection beyond that required for CCMC D-3, plus improved soot dispersancy and valve train wear protection. Generally accepted as the level of performance for Super High Performance Diesel (SHPD) engine oil.

JASO ENGINE SERVICE CLASSIFICATIONS

The Japanese Automobile Standards Organization (JASO) has now formalized JASO Regular Grade engine oil specification, commonly referred to as "JASO SE". With the involvement of the Japanese Automobile Manufacturers Association (JAMA) in ILSAC, the requirements of Japanese manufacturers for high performance passenger car engine oil classification may be met, in the short term at least by ILSAC GF-1 and GF-2.

EMA ENGINE OIL CLASSIFICATIONS

The Engine Manufacturers Association (EMA) in the United States recognizes the engine oil performance classification system of other organizations, such as API and ACEA/CCMC. They also define categories for the classification of engine oil for spark-ignited natural gas engines and comment on the operation of natural gas (and other gaseous-fuelled) engines.

Spark Ignited (Natural Gas) Engine Oil Specifications.
Gaseous-fuelled engine oils are formulated with an additive system to these engines. Since no industry standards are available to define performance levels, field test evaluation must be used. The sulfated ash level of oils are used as an industry guideline as to various categories, but certainty ash alone will not define the performance level of oil. These ash categories are defined by the EMA as:

Constraints other than sulfated ash may be placed on the oils depending on individual engine manufacturers and the type of engine operation and environmental controls. The use of exhaust catalysts may impose limitations on the use of base metals and other elements such as zinc, sulfur and phosphorus in the oil formulation. The use of other gaseous fuels such as sour gas or landfill gas, etc., has increasing interest today. The increased hydrogen sulfide (H2S) and total organic halides (as chlorine) create additional problems for the engine and lubricating oils. The best approach to this problem would be to remove these corrosives from the fuel before they reachthe engine. If the fuels is not treated, higher Base Number (BN) engine oil, used oil analysis, reduced oil-change periods and increased jacket water temperatures are necessary. But engine life is usually sacrificed, even with all these additional requirements.

LMOA LUBRICATING OIL CLASSIFICATION SYSTEM

The Locomotive Maintenance Officers Association (LMOA) in the US has long been involved with diesel locomotive engine manufacturers, the railroads, and lubricant suppliers to solve engine lubrication related problems in the railroad industry.

The LMOA operates a classification system, which defines the performance of diesel locomotive engine lubricants. The railroads, the engine manufacturers and lubricant suppliers all recognize the LMOA "Generation" nomenclature.

Although the LMOA lubricating oil classification system is regarded as an industry guideline, field evaluations are still required by most engine manufacturers to qualify oil for service in their equipment. In many instances, the engine manufacturers’ approval specifies the additive package and base stock used to formulate the lubricant.

Increases in engine power from the same size engine, the reduction in oil consumption with the consequent cutback in top-up oil, the desire to extend oil change periods, and the need to prevent

the engine oil oxidizing and thickening in service has lead to successive LMOA Engine Oil Generations having higher levels of detergency, alkalinity reserve, and oxidation resistance.

Generation 1 - introduced 1940
Generation 1 oils included straight mineral oils, as well as some, which were lightly compounded with detergents and antioxidants. Base Number (BN) of generation 1 oils was generally bellow 7.

Generation 2 - introduced 1964
Generation 2 engine oils introduced ashless dispersants and moderate levels of detergency. Oils of this performance were developed to reduce engine sludge and extend filter life. Generation 2 engines oils had a BN of around 7.

Generation 3 - introduced 1968
Generation 3 engine oils demonstrated improved alkalinity retention, detergency and dispersancy. With a BN of around 10, Generation 3 oils were introduced to overcome increased piston ring wear.

Generation 4 - introduced 1976
Generation 4 oils provided added protection under severe operating conditions, and were designed to allow 90-day oil change intervals. The LMOA set higher base number (13), detergency and dispersancy characteristics. As well as being approved by both GE and EMD, Generation 4 engine oils must meet API Service Classification CD.

Generation 5 - introduced 1989
Generation 5 called for extended oil performance to meet the requirements of new generation "fuel efficient" and low oil consumption diesel locomotive engines, and is designed to provide 180 day oil change intervals. The LMOA does not specify a minimum Base Number for Generation 5 oils. These products have improved alkalinity reserve, detergency and antioxidation performance. Oils meeting LMOA Generation 5 must also meet API Service Classification CD, and have been field tested and approved by both GE and EMD. Before the introduction of the LMOA Generation 5 category, oils, which eventually were to meet this qualification, were described as Generation 4 "Long life”.

In move to achieve improved fuel and oil efficiency, diesel locomotive engine manufacturers are fieldtesting and approving multigrades versions of Generation 4 and 5 oils.

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