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Engine Oil API Quality Classifications

Oils were classified in the 1960's by the American Petroleum Institute (API) in terms of their performance. Engine oils were divided into two groups; "S" for gasoline engines, "C" for diesel engines. In every group, oils were ranked in terms of developing engine technology with letters A, B, C etc.

API ClassDefinition
SAMineral oil with no additives. Recommended for old motors that do not require oil with additives.
SBOil with no cleaning agent additive but with additives that prevent oxidation and corrosion in small quantities. It should be used only when car manufacturer recommends it.
SCOil for gasoline engine, which is designed for the requirements of 1964 – 1967 model vehicles, which prevents oxidation, rust and corrosion and which provides deposit control.
SDOil for gasoline engines, which is designed for the requirements of 1968 – 1970 model vehicles; prevents oxidation, rust and corrosion more than SC and provides deposit control. It is more resistant than SC grade.
SEDesigned for the requirements of 1971-1979 model vehicles. Engine oil that prevents oxidation, rust and corrosion and provides deposit control better than CS.
SFOil for gasoline engine, which passed American automobile manufacturers 1980 guarantee tests and which prevents oxidation, rust and corrosion better and provides deposit control better than SE.
SGGasoline engine oil which passed American automobile manufacturers 1989 guarantee tests and which prevents oxidation, rust and corrosion better and provides deposit control better than SE. Also corresponds to the CC diesel engine oil category of API. Oils within the SG category are API, SE, SF and SF/CC. They may also be used for engines, for which SE/CC oils are recommended.
SHGasoline engine oil that passed American automobile manufacturers 1994 guarantee tests and whose tests and production take place in accordance with CMA (Chemical Manufacturers Association) product approval code.
SJDesigned for the requirements of gasoline engine vehicles established in 1997. Gasoline engine oil with less volatility, more compliance with catalysts and higher low temperature qualities in addition to its SH performance.
SLGasoline engine oil category launched on 1 July 2001 and designed for the requirements of engines produced in 2002. Also usable in previously manufactured vehicles. Gasoline engine oil that provides better deposit control and low oil consumption at high temperatures.
SMGasoline engine oil category launched in November 2004. Provides better engine cleaning, higher performance at low working temperatures and less corrosion than SL and has a longer oil change interval and antioxidant quality.
SNIntroduced in October 2010, 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.

Diesel Engine Oil API Quality Classifications

API ClassDefinition
CALaunched in 1940, light and intermediate powered ordinary diesel engine oil that prevents corrosion and deposit formation.
CBThe category published in 1949 for diesel engine requirements working under light and intermediate conditions. Provides a better protection against corrosion and deposit formation than CA category.
CDThe category with high protection against corrosion and deposit control, published in 1955. Oil developed for ordinary diesel engines with turbo and supercharge that runs on fuel with high sulphide rate. Protective against deposit formation and berth corrosion in high temperatures.
CCThe category published in 1961 that fulfills the requirements of ordinary diesel engine vehicles with turbo charge and supercharge, running under intermediate and heavy conditions. Prevents corrosion, rust and amortization and performs deposit control. Passed MIL-L-2104 B and 46152 B tests.
CD-IIDiesel engine oil which fulfills need of two stroke diesel engines and is appropriate for API CD category. Revised in 1985.
CEIt is the level developed in 1983 for heavy duty diesel engines with turbo charge and supercharge which runs under low speed-heavy load and high speed-heavy load. It provides better protection against oil loss, deposit formation and corrosion than CD level.
CFDeveloped in 1994 for diesel engines with indirect injection, turbo charge and supercharge which runs on high sulphide fuel. It has higher piston deposit control and berth corrosion prevention than CD.
CF-4Applied in 1990, is it the level that provides less deposit formation and oil consumption in addition to CE performance. Oil for heavy duty diesel engines with turbo charge and supercharge that runs under conditions of low speed-heavy load and high speed-heavy load.
CF-2Engine oil launched in 1994 that prevent corrosion of cylinder and piston ring and deposit formation better in two stroke diesel engines in addition to CF performance requirements.
CG-4It is the Heavy Duty Engine Service category published in 1994. Provides better piston deposit control and less carbon accumulation. It is the category that fulfills the needs of high-speed, heavy-duty diesel engines with four stroke, direct injection and turbo charge, used on both highways and lands.
CH-4Diesel engine oil launched on 1 December 1998, fulfilling exhaust emission standards, also used in stroke engines. Developed specially for high-speed, four stroke diesel engines running on fuels that consists of sulphide up to 0.5 %. It also fulfills the standards of CD, CE, CF-4 and CG-4.
CI-4Heavy-duty diesel engine oil launched in 2002. Engine oil that fulfills 2004 exhaust emission standards, used in four stroke high-speed engines. Higher persistence on high and low temperatures, higher piston deposit control, higher soot control, higher corrosion and oil cost controls.
CJ-4Engine oil developed heavy-duty diesel engines, which fulfills 2007 API performance standards and provides outstanding exhaust cleaning system. Features advanced antioxidant and soot control on high temperatures, better pumpability on low temperatures and low oil consumption. It also meets American EPA 2007 standards.
CK-4API 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.
FA-4API 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 sulfur. For fuels with sulfur content greater than 15 ppm, refer to engine manufacturer recommendations

Gasoline Engine Oil API Quality Classifications

In 1996 the ACEA (Association des Constructaeurs Europeens d'Automobile) developed a new engine oil quality classification instead of the old classification of CCMC organization. According to this classification, gasoline engine oils are indicated with A, light-duty diesel engine oils are indicated with B and heavy-duty diesel engine oils are indicated with E.

ACEA ClassDefinition
A1Gasoline engine oil with viscosity protection and oxidation persistence over limits of CCMC G-4, which provides fuel economy and is valid for low viscosity classes.
A2Conventional gasoline engine oil usually on CCMC G-4 performance, whose oxidation persistence is equivalent for G-5.
A3High performance gasoline engine oil with low consumption and long oil change period and with viscosity protection and oxidation persistence over limits of CCMC G-5.
A4Gasoline engine oil developed for direct injection engines.
A5Gasoline engine oil developed for high performance gasoline engines with low viscosity, high friction minimizing quality, long oil change period.

Light-duty Diesel Engine Oils ACEA Quality Classification

ACEA ClassDefinition
B1Diesel engine oil with viscosity protection over limits of CCMC PD-2, which provides fuel economy and is valid for low viscosity classes.
B2Conventional diesel engine oil with generally CCMC PD-2 performance and advanced viscosity protection function.
B3High performance diesel engine oil with viscosity protection over limits of CCMC PD-2 limits, whose viscosity increase is controlled under intense soot.
B4Diesel engine oil that passed direct injection engine tests in addition to performance of B3-98.
B5Diesel engine oil with high rate of friction minimizing, which provides fuel economy in indirect and direct injection engines with long oil change periods.

Quality Classification of Gasoline and Diesel Engine Oils Pursuant to ACEA 2016

ACEA SınıfıTanımı
C1Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low friction, low viscosity, low SAPS (Sulphated ash, phosphorus and sulphur) oils with a minimum HTHS (High Temperature and High Shear) viscosity of 2.9 mPa.s.
C2Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines designed to be capable of using low friction, low viscosity oils with a minimum HTHS (High Temperature High Shear) viscosity of 2.9mPa.s.
C3Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines, with a minimum HTHS (High Temperature High Shear) viscosity of 3.5mPa.s.
C4Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low SAPS (Sulphated ash, phosphorus and sulphur) oil with a minimum HTHS (High Temperature High Shear) viscosity of 3.5mPa.s.
C5Stable, stay-in-grade oil intended for use as catalyst compatible oil in vehicles with DPF and TWC in high performance car and light van diesel and gasoline engines requiring low high viscosity, low SAPS (Sulphated ash, phosphorus and sulphur) oil with a minimum HTHS (High Temperature High Shear) viscosity of 3.5mPa.s.

Quality Classification of Gasoline and Diesel Engine Oils Pursuant to ACEA 2016

ACEA SınıfıTanımı
A1/B1This class is appropriate for extended oil change interval in gasoline and light diesel engine vehicles (private car and light Van) that has low friction rate and use low viscosity oil with high temperature and high cutting rate (HT/HS) of 2.6 mPa.s for xW-20 viscosity class and between 2,9 - 3,5 mPa.s for other viscosity classes.
A3/B3Oil defined under this class is appropriate for heavy conditions of use defined by engine manufacturers, where extended oil change interval is given by high performance gasoline and light diesel vehicles (private car and light Van) engine manufacturers, where oil with low viscosity is used.
A3/B4Oil defined under this class is appropriate for high performance, gasoline and direct injection diesel engine vehicles. Besides, it is appropriate for usage defined in A3/B3.
A5/B5This class is appropriate for extended oil change interval in gasoline and light diesel engine vehicles (private car and light Van) that has low friction rate and use low viscosity oil with high temperature and high cutting rate (HT/HS) of 2.9-3 5 mPa.s.

Gasoline Engine Oil API Quality Classifications

In 1996 the ACEA (Association des Constructaeurs Europeens d'Automobile) developed a new engine oil quality classification instead of the old classification of CCMC organization. According to this classification, gasoline engine oils are indicated with A, light-duty diesel engine oils are indicated with B and heavy-duty diesel engine oils are indicated with E.

ACEA ClassDefinition
A1Gasoline engine oil with viscosity protection and oxidation persistence over limits of CCMC G-4, which provides fuel economy and is valid for low viscosity classes.
A2Conventional gasoline engine oil usually on CCMC G-4 performance, whose oxidation persistence is equivalent for G-5.
A3High performance gasoline engine oil with low consumption and long oil change period and with viscosity protection and oxidation persistence over limits of CCMC G-5.
A4Gasoline engine oil developed for direct injection engines.
A5Gasoline engine oil developed for high performance gasoline engines with low viscosity, high friction minimizing quality, long oil change period.

Light-duty Diesel Engine Oils ACEA Quality Classification

ACEA ClassDefinition
B1Diesel engine oil with viscosity protection over limits of CCMC PD-2, which provides fuel economy and is valid for low viscosity classes.
B2Conventional diesel engine oil with generally CCMC PD-2 performance and advanced viscosity protection function.
B3High performance diesel engine oil with viscosity protection over limits of CCMC PD-2 limits, whose viscosity increase is controlled under intense soot.
B4Diesel engine oil that passed direct injection engine tests in addition to performance of B3-98.
B5Diesel engine oil with high rate of friction minimizing, which provides fuel economy in indirect and direct injection engines with long oil change periods.
API ClassDefinition
GL-1Pure mineral oil for spiral, conic, worm gear type differential and straight transmission running under light conditions.
GL-2Special extrinsic oil for worm gear type differentials running under normal conditions.
GL-3Special extrinsic oil for spiral and conic differentials and straight transmissions running under normal conditions.
GL-4Oil that contains excessive pressure and other special additives for hypoid gear type differentials running under heavy conditions and that fulfills MIL-L-2105 specifications.
GL-5Oil that contains additives to balance excessive pressure and pulsed load for hypoid gear type differentials running under heavy conditions and that fulfills MIL-L-2105 specifications.
MT-1Gear oil that contains excessive pressure additives for gear cases running under heavy conditions and unsynchronized mechanical transmissions and that passed foam preventing, thermal persistence and elastomer compliance tests.
SAE Viscosity Class
Max. Viscosity as cP at °C temperature.
Pumping Limit Temp. °C Max.for 60.000 cP ViscosityViscosity as cSt at 100 °C'
WinterSummercP°CMin.Max.
0 W-6200-35-403,8-
5 W-6600-30-353,8-
10 W-7000-25-304,1-
15 W-7000-20-255,6-
20 W-9500-15-205,6-
25 W-13000-10-159,3-
-20--5,69,3
-30--9,312,5
-40--12,516,3
-50--16,321,9
-60--21,926,1
ISO Viscosity ClassKinematic Viscosity at 40 °C cStKinematik Viscosity Limits at 40 °C cSt (mm2/s)ASTM Saybolt Viscosity NumberSaybolt Viscosity at 37,8 °C SUS
Min.Max.Min.max.
22,21,982,423234,035,5
33,22,883,523636,538,2
54,64,145,064039,942,7
76,86,127,485045,750,3
10109,0011,06055,562,8
151513,516,5757283
222219,824,210596115
323228,835,2150135164
464641,450,6215191234
686864,274,8315280345
10010090,0110465410500
150150135165700615750
22022019824210009001110
320320288352150013101600
460460414506215018802300
680680612748315028003400
100010009001100465041005000
1500150013501650700061007500

ISO: Abbreviation for "International Standardization Organization".
In VG 68 definition of ISO: VG states Viscosity Grade; 68 states viscosity as centistokes (cSt) at 40 °C with +/-%10 tolerance.

Rust and Oxidation Preventing Gear Oils AGMA No:ISO Viscosity ClassExcessive Pressure (EP) Gear Oils AGMA No:
146-
2682 EP
31003 EP
41504 EP
52205 EP
63206 EP
7 Compunded4607 EP
8 Compunded6808 EP
8 A Compounded10008 A EP

AGMA: Abbreviation for "American Gear Manufacturer's Association".

NLGI No:Penetration (1/10 mm) processed at 25 °C
000445-475
00400-430
0355-385
1310-340
2265-295
3220-250
4175-205
5130-160
685-115

VISCOSITIES AT VARIOUS TEMPERATURES (VI of oils is taken as 95)

Not:

  • Viscosities at various temperatures are read horizontally.
  • SAE Gear and Engine Oil specifications are given only at 100 °C.
  • Multigrade oil viscosities don't state viscosities of other temperatures.
Saybolt Universal (Sn) 100 °F (37,8°C)Saybolt Universal (Sn) 122 °F (50°C)Saybolt Furol (Sn) 122 °F (50°C)Redwood No:1 (Sn) 100 °F (37,8°C)Redwood No:1 (Sn) 122 °F (50°C)Kinematik (Centistokes) 100 °F (37,8°C)Kinematik (Centistokes) 122 °F (50°C)Engler (Degrees) 68 °F (20°C)Engler (Degrees) 122 °F (50°C)
3231,5-28,5-1,83-1,19-
3533,5-33,2-2,682,251,31,16
4037-37,234,74,253,31,541,25
4540,1-41,437,25,824,291,841,33
5043,5-45,640,17,375,352,161,43
5546,3-49,842,69,856,252,481,51
6049,1-544,810,37,12,831,57
6552-58,547,211,727,953,21,65
7055-62,849,813,068,853,551,74
7557,8-6752,414,389,653,91,81
8060,5-71,754,515,6610,44,31,88
8563-765716,9211,24,651,95
9065,5-79,858,918,1411,85,052,01
9568-84,661,219,3412,65,422,08
10071-8963,720,613,45,852,15
11077-9768,522,914,86,652,31
12083-1067425,216,47,52,48
13089-1147927,5188,352,65
14094-1238429,719,29,32,78
15099-132883220,5-2,93
160105-1409334,221,7-3,08
170110-151489736,323-3,23
180115-15810238,624-3,36
190120-1616610640,825,3-3,5
200125-1751114326,4-3,65
220135-17,419311947,428,6-3,9
240145-20912751,730,8-4,2
260155-19,12261365633,3-4,5
280165-24614460,435,3-4,75
300174-20,826315364,737,5-5
325186-28316370,139,9-5,3
350198-22,830517475,542,7-5,7
375210-32618480,546,2-6
40022225,335019486,348-6,35
42533526,437220591,750,7-6,8
45024727,439321597,153-7,05
47525928,7416226102,555,8-7,4
50027129,843823710858,3-7,7
55029532,148225911963,5-8,4
60031834,7525279129,568,5-9
65034036,7568299140,273,5-9,8
70036238,751531615178-10,3
75038541652336161,883-10,9
80041043,3700358172,688,2-11,6
85043045,27453786183,492,5-12,2
90045047,1790392194,296,5-12,8
95047549,8830416205102,5-13,6
100049551,8785432215,8107-14,2
120058060,51050509259126-16,6
140066568,9122558230,2144-19
16007456,31405648345160-21,2
180083085,21570725388179-23,6
200090593,11750790435196-25,9
25001100112,32180965540237-31,3
30001300133,42625113565028-37,2
35001490152,630501310756323-42,9
40001650167,735101446867355-47,2
45001850187,839401620975398-52,7

Pursuant to Waste Oil Control Regulation

  • Do not pour waste oil on soil, water, or in sewers or trash cans.
  • Do not mix it with any petroleum product or chemical.
  • Do not burn it in a stove or boiler.
  • Deliver to closest waste oil storage center in a clean, secure, closed case freely.
  • Keep it away from children.
  • Avoid constant and long-term contact.
  • Call for medical assistance when swallowed, do not force vomit.
  • Dispose in accordance with applicable regulations
  • Avoid releasing into environment.

Product Storage Conditions

  • Keep products away from sunlight.
  • Keep in indoor areas.
  • Do not keep in humid or moist areas.