In modern motorcycles, the same oil is usually used in both the engine and the wet clutch. Motor oils with normal friction properties are not good enough for this purpose. To ensure that the correct oil is used, motorcycle manufacturers usually require that it meet one of the following JASO standards.
Oils that meet the JASO T 903 standard can be divided into four classes: JASO MA, JASO MA1, JASO MA2 and JASO MB. The classification is based on the results of the JASO T 904 clutch friction test. The standard was revised in 2002, 2006, 2011 and 2016. In the new versions, the test conditions were slightly changed, as well as the requirements for the chemical composition of the additives.
For an engine oil to meet one of the JASO standards mentioned above, it must meet at least one of the following quality levels:
- API SG, SH, SJ, SL, SM
- ILSAC GF-1, GF-2, GF-3
- ACEA A1/B1, A3/B3, A3/B4, A5/B5, C2, C3
Furthermore, the Dynamic Friction Index (DFI), Static Friction Index (SFI), and Stop Time Index (STI) must be within the following limits as determined by the JASO 904:2006 friction test:
| JASO MA | JASO MB | |
| ≥1.45 and<2.5 | ≥0.5 and<1.45 | |
| ≥1.15 and<2.5 | ≥0.5 and<1.15 | |
| ≥1.55 and<2.5 | ≥0.5 and<1.55 |
| JASO MA1 | JASO MA2 | |
| Dynamic Friction Index (DFI) | ≥1.45 and<1.8 | ≥1.8 and<2.5 |
| Static Friction Index (SFI) | ≥1.15 and<1.7 | ≥1.7 and<2.5 |
| Stop Time Index (STI) | ≥1.55 and<1.9 | ≥1.9 and<2.5 |
If all three characteristics of a JASO MA oil are within the limits specified for MA1, it may be classified as a JASO MA1 oil. If all characteristics fall within the limits set for an MA2, it is assigned to the JASO MA2 class. If some of the characteristics are in the range suitable for MA1, and others - for MA2, then we have just JASO MA oil.
Engine oils related to groups JASOMA andJASOMB
- Valvoline 10W-40 and 20W-50 - Synthetic 4-stroke engine oil
- Mobil 1 Racing 4T 10W-40
- Red Line 10W-40 – Motorcycle oil ester based oil
- Silkolene QUAD ATV 5W-40 - Fully Synthetic Four-Stroke Engine Oil
International Oil Standards. JASO classification 10.02.2014
The JASO (Japanese Automobile Standards Organization) classification has developed standards for 2-stroke, 4-stroke engines.
JASO classification of oils for 2-stroke engines
JASO has developed a standard for oils for motorcycles with 2-stroke engines - JASO M 345. It provides for four quality classes FA, FB, FC, FD, aimed at improving the performance of oils for this technique. JASO M 345 evaluates oil quality according to the following four criteria:
- Lubricity
- Washing capacity
- Low smoke
- Deposit prevention
The following quality classes of 2T oils are provided:
JASO FA- for two-stroke engines of motorcycles and other cars (oils are intended for application in developing countries)
JASO FB- for two-stroke engines of motorcycles and other cars (minimum requirements for use in Japan).
JASO FС- for two-stroke engines of motorcycles and other cars, smokeless engine oil (base oil for use in Japan).
JASO FD- for two-stroke engines of motorcycles and other cars, a smokeless engine oil with improved engine cleanliness characteristics compared to FC (the highest requirement for 2-stroke oils in Japan).
JASO classification of oils for 4-stroke engines
The JASO (Japanese Automobile Standards Organization) classification offers a special oil standard for 4-stroke motorcycles, JASO T 903. It includes three categories MA, MA1, MA2, designed specifically for oil bath clutches, and an MB category for dry clutches. , i.e. JASO MA is a high friction oil, and JASO MB is a low friction oil, no longer suitable for wet clutches. JASO MA2 has a high coefficient of friction, which ensures precise operation of the clutch when starting off, accelerating and driving at a constant speed.
For 4T motorcycle engines, automotive oils for gasoline engines are used, but they are subject to additional requirements regarding frictional properties, since there is a friction clutch mechanism in the same unit with the motorcycle engine. The engine oil must provide good traction and prevent slippage. For this purpose, low-viscosity and energy-saving oils containing additives - friction modifiers that reduce the friction coefficient are unsuitable, therefore 4 JASO classes were introduced:
JASO MA
JASO MA-2- has a higher coefficient of friction than MA-1. Ideal for wet clutch sports bikes.
JASO MA-1- differs from JASO MB in a higher coefficient of friction, but less than that of JASO MA-2. Suitable for motorcycles with wet clutch (but with less load).
Category JASO MB- has a low coefficient of friction. Not suitable for wet clutch motorcycles.
JASO classification of oils for diesel engines
In April 2008, the Automotive Diesel Engine Oil Standard (JASO M355:2005) was amended due to the revision of the chlorine content of DH-2 and DL-1 oils, and the new JASO M355:2008 Standard was adopted. Engine oils meeting JASO Standard M 355:2008 for Automotive Diesel Engine Oils are classified into DH-1, DH-2 and DL-1 grades, each of which is used in four-stroke diesel engines.
JASO DH-1 has been developed for diesel engines that must meet long-term exhaust emission regulations and include performance requirements such as wear prevention, corrosion prevention, high temperature oxidation stability, and soot reduction. In addition, oils meeting the DH-1 standard reduce piston wear, prevent high temperature deposits, foaming, reduce oil consumption by evaporation, reduce shear due to viscosity and wear of oil seals, etc. DH-1 oils may also be used in engines manufactured prior to long-term exhaust emission regulations. Subject to the recommended drain intervals specified by the engine manufacturer, DH-1 oils may be used if the sulfur content of the diesel fuel used is greater than 0.05%.
JASO DH-2 have been developed for heavy-duty truck and bus engines equipped with exhaust gas pre-treatment devices such as a diesel particulate filter (DPF) and a catalytic converter. DH-2 oils can only be used if diesel fuel with a low sulfur content not exceeding 0.005% is used.
JASO DL-1 Suitable for light to moderate duty passenger vehicles equipped with aftertreatment devices such as diesel particulate filter (DPF) and catalytic converter. DL-1 oils can only be used if diesel fuel with a low sulfur content not exceeding 0.005% is used.
As long as diesel fuel with a low sulfur content not exceeding 0.005% is used and the user follows the engine manufacturer's recommended oil change interval, DH-2 oil may be used in engines manufactured prior to short term exhaust emission regulations.
JASO (Japan Automobile Standards Organization) - Japanese organization for standardization in the automotive industry.
Extensive experience in the operation and production of two-stroke and four-stroke motorcycle engines has been accumulated in Japan, so JASO standard specifications are gaining more and more recognition. JASO has developed 4 new bench test methods to determine engine oil quality. The following quality classes of motor oils are provided:
| DX-1 | A new specification for engine oils for heavy duty diesel engines from Japanese automakers, including testing procedures used in the US, Europe and Japan. |
| FA | Oils for two-stroke engines of motorcycles and other machines (oils intended for use in developing countries) |
| Oils for two-stroke engines of motorcycles and other cars (minimum requirements for use in Japan) | |
| FC | Oils for two-stroke engines of motorcycles and other cars, smokeless engine oil (base oil for use in Japan) |
| FD | Two-stroke engine oils for motorcycles and other vehicles, smokeless engine oil with improved engine cleanliness performance compared to FC (the highest requirement for 2-stroke oils in Japan) |
| MA (MA-1 and MA-2) | Oils for four-stroke motorcycle engines. Differs from MB in a large coefficient of friction. MA-2 has a higher coefficient of friction than MA-1 |
| MB | Oils for four-stroke motorcycle engines. Has a low coefficient of friction |
For 4T motorcycle engines, automotive oils for gasoline engines are used, but they are subject to additional requirements regarding frictional properties, since there is a friction clutch mechanism in the same unit with the motorcycle engine. The engine oil must provide good traction and prevent slippage. For this purpose, low-viscosity and energy-saving oils containing additives - friction modifiers that reduce the coefficient of friction are unsuitable, therefore, 2 classes JASO MA and MB were introduced.
JASO classification of oils for diesel engines
In Japan, it has been common to use the API Performance Classification Standard to validate the quality of automotive diesel engine oils. However, it has been found that the API Performance Classification Standards may not always apply to Japanese diesel engines due to the design differences between Japanese and US made engines. Specifically, in order to meet the requirements of Japanese diesel engines, most of the diesel engine oils commonly used in Japan have improved performance parameters such as improved rocker arm wear prevention properties. In addition, car manufacturers in Japan have demanded a new Oil Quality Standard to meet the new exhaust emission regulations.
In the Asian market, where cars made in Japan have a fairly large share, in most cases diesel engine oils of lower quality than in Japan are used, so it is necessary to promote higher quality diesel engine oils to the Asian market. In this regard, the Steering Committee of the SAE (Society of Automotive Engineers) Fuels and Lubricants Division for Asia, which is attended by Japanese Automobile Manufacturers, has also requested the creation of a new Quality Standard for diesel engine oils.
In view of the above, it was decided to create a Quality Standard for engine oils for Japanese-made diesel engines. Below is the history of the emergence (creation) of Diesel Engine Oil Standards:
In April 1994, the Engine Oil Subcommittee of the Society of Automotive Engineers of Japan (JSAE), in cooperation with the Lubricating Oil Society of Japan, developed a method for testing diesel engine oil using a low sulfur fuel (0.05% sulfur content). In March 1998, using a model TD25 engine manufactured by Nissan Diesel Motor, a method for testing detergency (JASO M 336:1998) was introduced. And in April 1999. Using a model 4D34T4 engine manufactured by Mitsubishi Motors Corporation (currently Mitsubishi Fuso and Truck Corporation), a test method for valve train wear was developed (JASO M 354:1999).
Subsequently, the Japan Automobile Manufacturers Association (JAMA) and the Petroleum Association of Japan (PAJ) proposed a Diesel Engine Oil Standard, including a detergent test method, a valve train wear test method, a glow tube test method, and eight different test methods. Through the adjustment (revision) of the Quality Standard for oils offered on the market, in October 2000. Quality Standard was introduced (JASO M 355:2000)
In addition to existing diesel fuel quality standards for vehicles equipped with exhaust gas aftertreatment devices such as diesel particulate filters and nitrogen oxide catalytic converters, and complying with exhaust gas emission regulations due to the introduction of new short-term standards, quality standards have become necessary that would provide for the quantitative content in the chemical composition of the fuel of substances such as ash, phosphorus and sulfur. April 2004 JAMA and PAJ approved DH-2 for trucks/buses and DL-1 for passenger cars as recommendations. After reviewing the validity of such recommendations, the Automotive Diesel Engine Oil Standard was amended in April 2005 to add the DH-2 and DL-1 classifications to the existing DH-1 classification.
As a result of a change in the valve train wear test method (JASO M 354:2005), changes have been made to the Automotive Diesel Engine Oil Standard (JASO M 355:2005) and the DH-1 classification standards.
In April 2008, the Automotive Diesel Engine Oil Standard (JASO M355:2005) was amended due to the revision of the chlorine content of DH-2 and DL-1 oils, and a new JASO M355:2008 Standard was adopted
JASO classification
Engine oils meeting JASO Standard M 355:2008 for Automotive Diesel Engine Oils are classified into DH-1, DH-2 and DL-1 grades, each of which is used in four-stroke diesel engines
Category DH-1 has been developed for diesel engines that must meet long-term exhaust emission regulations and include performance requirements such as wear prevention, corrosion prevention, high temperature oxidation stability, and soot reduction. In addition, oils meeting the DH-1 standard (hereinafter referred to as "DH-1 oils") reduce piston wear, prevent high temperature deposits, foaming, reduce oil consumption by evaporation, reduce shear due to viscosity and wear of oil seals, etc. .
DH-1 oils may also be used in engines manufactured prior to long-term exhaust emission regulations. Provided that the recommended drain intervals specified by the engine manufacturer are observed, DH-1 oils can be used if the sulfur content in the diesel fuel used exceeds 0.05%
Categories DH-2 and DL-1 have been developed for engines equipped with exhaust aftertreatment devices such as a diesel particulate filter (DPF) and a catalytic converter in accordance with the emission regulations (requirements) for exhaust gases resulting from the adoption of new short-term regulations. While maintaining the level of performance required by the DH-1 classifications, oils meeting these standards (hereinafter referred to as "DH-2 Oils" and "DL-1 Oils") are most suitable for use in vehicles equipped with diesel particulate filters and catalytic converters. Please note that due to the different requirements for diesel oil for trucks/buses and passenger cars, such as engine life, oil change period, fuel economy, etc., the DH-2 classification is applicable for trucks/buses operating in heavy conditions, and the DL-1 classification is applicable to passenger vehicles operated under light conditions.
Oils DH-2 and DL-1 can only be used if diesel fuel with a low sulfur content not exceeding 0.005% is used.
Provided diesel fuel with a low sulfur content not exceeding 0.005% is used, and the user follows the engine manufacturer's recommended oil change interval, DH-2 oil is acceptable in engines manufactured before the introduction of short-term exhaust gas emissions standards.
Resellers and suppliers of lubricants are subject to the Automotive Diesel Engine Oil Standard (JASO M 355: 2008) established by the Society of Automotive Engineers of Japan (JSAE) when registering petroleum products with the JASO Engine Oil Standards Commission.
For two-stroke engines, the following composition is used: 85-98% base oil, the rest is various additives, which, similarly to engine oils for four-stroke engines, give the oils the above-mentioned characteristics. In principle, all base oils from brightstock, selective neutral types to fully synthetic polyalphaolefins are suitable. Because most two-stroke oils do not require high low temperature performance, brightstocks are often used to achieve the desired viscosity. High quality two-stroke engine oils, in addition to hydrocarbon types, often contain various synthetic esters, especially in the case of biodegradable oils that have been specifically formulated for marine outboards.
Additives to oils for two-stroke engines are selected in accordance with the requirements of the movement. Just like four-stroke engine oils, two-stroke engine oils contain anti-wear additives that chemically interact with metal surfaces to protect against wear, especially under boundary friction conditions. In addition to the traditionally used zinc dialkyldithiophosphates, ashless additives such as dithiophosphoric acid esters, alkyl and aryl esters or phosphoric acids are used.
To prevent the formation of deposits in the combustion chamber and around the piston rings and to maintain engine cleanliness, detergent-dispersant additives (DD-systems) are introduced into the oil. Phenolic compounds and/or alkaline earth metal compounds or alkali sulfonates are often used. As dispersing agents, high-molecular compounds are often used that are able to trap and hold contaminants in suspension. Examples of these types of substances are polybutylene succinimides, whose properties result from the chemical bonding of polar succinimide with oil-soluble polybutylenes.
In addition, two-stroke engine oils contain, in addition to anti-wear and DD additives, small amounts of antioxidants, corrosion inhibitors, anti-foam additives and flow improvers.
Low-smoke oils for two-stroke engines contain a significant amount of polybutylenes (from 10 to 50%). These are fully synthetic fluids with different viscosity grades. Compared to mineral oils, these fluids, in addition to good lubricating properties, also provide much cleaner combustion and a significantly lower degree of coke formation.
Oils for two-stroke engines are divided into functional groups that provide information on suitable applications. All of the classification systems listed below are based on a number of laboratory and functional test methods, especially the latest (bench) tests carried out on the latest two-stroke engines.
API classification
API currently classifies 2-stroke oils into 4 categories based on engine power, ranging from low power lawn mowers to high power motorcycles, and performance. Motor tests are no longer carried out, so special test motors are no longer produced by the industry. In the future, it is planned to replace the API groups with the Japanese JASO and global ISO classifications. There are still a number of oils with API classification on the market today, as this system was widely used in the past.
| Class | Description |
| API TA | Motor oils for two-stroke engines of small mopeds, lawn mowers and other similar equipment. |
| API TB | Motor oils for low power two-stroke motorcycle engines. |
| API TC | Motor oils for two-stroke engines operating on land. These oils can be used in cases where the engine manufacturer requires the oil to meet API TA or API TB classes. |
| API TD | Engine oils specially formulated for 2-stroke outboard motors |
JASO classification
JASO (Japanese Automobile Standards Organisation), which includes all of Japan's major automotive companies, divides two-stroke engine oils into 4 groups: FA, FB, FC and FD.
All four categories of oils are tested on the same test engines, and the appropriate quality category is assigned according to predetermined thresholds. Test results are determined and published against a well-defined JATRE 1 high performance reference oil. The main evaluation criteria are the lubricating properties and detergency of the oil, as well as its tendency to smoke and deposit in the exhaust system. The first low smoke oil specification was developed following the application of the JASO FC standard.
| Class | Description |
| JASO FA | For two-stroke engines of motorcycles and other cars (oils intended for use in developing countries). |
| JASO FB | For two-stroke engines of motorcycles and other vehicles (minimum requirements for use in Japan). |
| JASO FС | For two-stroke engines of motorcycles and other vehicles, smokeless engine oil (base oil for use in Japan). |
| JASO FD | For 2-stroke engines of motorcycles and other vehicles, a smokeless engine oil with improved engine cleanliness characteristics compared to FC (the highest requirement for 2-stroke oils in Japan). |
ISO classification
In the mid 90s, when JATRE 1 oils were tested by European motor test methods, it became clear that JASO FC could no longer meet the requirements of European two-stroke engines. In Europe, a series of long-term tests has been developed to meet all requirements. In addition to testing for smoke, exhaust system deposits, JASO lubricity and cleaning power, a 3-hour Honda Dio test was added to determine the degree of improvement in piston cleanliness and washing power. JATRE 1 was used as reference oil for all tests. These new guidelines were developed by CEC working groups with European engine and lubricant manufacturers.
Currently, the International Organization for Standardization (ISO) classifies oils for two-stroke engines into three categories: ISO-L-EGB, -EGC, -EGD. The fourth category (-EGE) is under development in conjunction with one of the strong European representations.
The ISO-L-EGB and -EGC categories reflect the JASO requirements for FB and FC categories and require additional proof of piston cleanliness. ISO-L-EGC and -EGD need low smoke proof similar to JASO FC. The table shows all the criteria for evaluating the results of motor tests.
| Criteria for evaluation | ISO-L-EGB (incl. JASO FB) | ISO-L-EGC (incl. JASO FC) | ISO-L-EGD |
| Lubricating properties | >95 | >95 | >95 |
| smoke | >45 | >85,2 | >85 |
| Deposits in the exhaust system | >45 | >90 | >90 |
| washing effect | > 85 (1 h test) | > 95 (1 h test) | > 125 (3 h test)* |
| Piston cleanliness | > 85 (1 h test)*) | > 90 (1 h test)*) | > 95 (3 h test)* |
* New requirements in addition to JASO FC.
The JASO oil classification, created by the Japan Automobile Standards Organization, is a relatively new engine oil standardization system among those currently existing on the international market.
At first, the Japanese did not at all seek to develop their own standards and used the American API system. However, the rapidly developing Japanese automotive industry (that's who you should learn from how to get out of the economic crisis), which does not get tired of surprising the world with new progressive ideas every year, not only caught up, but also overtook the notorious America in many developments. And this is where serious problems began with the use of API classification. Successful novelties of the Japanese car market had serious design differences from American and European engines. Engine oils, which, according to some API parameters, were suitable for these engines, according to others, were completely contraindicated for them. There is a need for new standards. Another impetus for the creation of a new classification of oils is the environmental legislative framework in Japan, Europe and the United States. They are constantly tightening limits on harmful emissions, so design engineers are always looking for new effective solutions for cleaning exhaust gases. In general, the API classification did not suit the Japanese auto industry. The final arguments in favor of creating our own standards system for Japanese motor oils were four reasons.
1. The use of API CG-4 oils in many Japanese engines led to rapid valve wear due to the high content of dispersants in oils, detergents that keep the engine clean.
2. On the pistons of Japanese engines, deposits from engine oils quickly arose. This was due to the lower position of the pistons compared to American and European-made cars.
3. The spread of the Japanese EGR exhaust gas recycling system, which needed special oils to extend its life.
4. In Asian countries, where Japanese cars occupy a fairly large market share, low-quality motor oils are often used. In order to extend the life of engines of their own production, the Japanese needed to promote high-quality motor oils to this market, certified according to their own standards.
Since 1994, new methods for testing oils for diesel engines have been introduced in Japan. The tests were carried out on the engines of Japanese cars Nissan and Mitsubishi. This was the beginning of the creation of a new classification, which we know today as JASO. Today it includes a number of oil standards for 2-stroke, 4-stroke engines, as well as for diesel engines. JASO standards are valued in the international market. For motorcycle oils, it is JASO that is considered the best classification in the world, because only this organization conducts quality testing of clutch oils in an oil bath.
Let's look at the JASO grades that define quality levels for automotive, motorcycle and other motor oils.
JASO Classes for Diesel Engines
We are talking about DH-1, DH-2, DL-1 and DX-1. In 2008, the requirements for oils of groups DH-2 and DL-1 changed due to the introduction of restrictions on the content of chlorine. Consider in detail each class of oils.
1. JASO DH-1 - engine oils designed for increased exhaust emission standards. They have excellent anti-wear characteristics and enhanced piston protection, contain strong anti-corrosion and anti-foam complexes that are resistant to oxidation and shear at elevated temperatures. These products are characterized by low soot formation and minimal carbon deposits under increased engine loads and severe operating conditions. Oils of class DH-1 are quite economical, since they have little evaporation. Another plus is that they extend the life of oil seals and other seals. The replacement of DH-1 class oils is recommended in accordance with the recommendations of the engine manufacturers. Such lubricants can be used if the sulfur in the fuel is above the 0.005% level. DH-1 grade oils can be used in engines designed prior to the introduction of long-term exhaust emission regulations. But only if you use fuel, where the sulfur content is not more than 0.005%, and also strictly observe the oil change interval specified in the manual by the engine manufacturer.
2. The JASO DH-2 class combines oils for commercial vehicles (trucks and buses) with exhaust aftertreatment systems. Oils are approved for use only when using fuel with a sulfur content of not more than 0.005%.
3. DX-1 is a class of oils for heavy commercial vehicles with turbocharging, charge air cooling systems and exhaust gas recirculation equipment. Designed for vehicles that operate under increased loads and harsh operating conditions. Oils comply with engines with an extended oil change service period and current environmental standards.
4. A group of JASO DL-1 class oils are lubricants for diesel engines of passenger cars with particulate filters and catalysts operating under standard conditions. Oils are designed exclusively for low-sulphur fuels with a sulfur content of 0.005% or less.
Oils for 2-stroke engines according to JASO
For small cars, motorcycles, mopeds, boats, chainsaws and other motorized tools, where two-stroke engines are often used, JASO has developed 4 classes:
1. JASO FA - for oils used in developing countries. Of course, the quality requirements of these products are different and adapted to the level of fuel.
2. JASO FB - oils produced according to the minimum requirements for use in Japan.
3. JASO FC - smokeless oils that meet the standard standards for Japan.
4. JASO FD - high quality engine oils with improved performance. They cover the FC standard for motor cleanliness. Oils of this level are considered the best in Japan.
Oils for 4-stroke engines according to JASO
Oils for motorcycles and motor oils differ in a complex of additives. It's all about the special requirements for frictional qualities, which are extremely important for clutch operation. Motorcycle engines do not use friction modifiers, so energy-saving and low-viscosity oils are completely unsuitable for motorcycle engines.
JASO's unique 4-stroke motorcycle engine oil standards are used worldwide today. They are indispensable in selecting the oil for every 4-stroke wet clutch engine. When buying motorcycle oil with a wet clutch, be sure to check the label for JASO MA grades. If yes, then there will be no problems with the clutch.
The MA group consists of two oils: MA1, MA2.
* JASO MA-1 indicates oils for wet clutch motorcycles operating under light duty conditions. These are oils with a high coefficient of friction.
* JASO MA-2 combines motor sports oils with wet clutches. The coefficient of friction is high.
It is important to remember that JASO MA-1 oils have a coefficient of friction higher than that of the MB group, but lower than that of MA-2.
JASO MB is a class of oils for motorcycles with a dry type of clutch. The coefficient of friction is low. Oils of this group must not be used with a wet type of clutch.
Recently, the automotive and motorcycle markets have seen trends towards globalization. Based on the international classifications ACEA, ILSAC, API and JASO, a new system is being created, the purpose of which is to combine testing technologies and, on their basis, develop new standards for motor oils that would become common to all manufacturers in the world. But that's another story. We will tell her later.
