Here you can read more about engine oil and what the different terms actually mean in the different types of oil.

For example:

What is Viscosity?

What are the different certificates?

The various designations of the engine oil etc.

Ten facts about engine oils

1. A number of mechanical components are used as transmission and brakes use their respective engine oil. Make sure to replace them if necessary.

2. Synthetic engine oil protects your vehicle under extreme temperature conditions, but will not greatly increase performance or efficiency.

3. Oils for different components have different degrees and viscosity.

4. There are three types of engine oils - mineral, semi-synthetic and synthetic. Be sure to check if SAE's international rating corresponds to the vehicle recommended by the manufacturer.

5. High engine speeds create more strain on vehicle components. Ensure that engine oils are checked and replaced if necessary.

6. Commonly known as 'Dark Oil Myth', partially dark engine oil does not indicate oil change. However, make sure it is replaced at the correct oil change interval, either after a certain number of kilometers, or after a certain time interval.

7. Service intervals and change of engine oils vary from place to place. Make sure you consult your mechanic about the perfect service time, or it's always a good idea to refer to the car owner's manual.

8. Make sure the oil filter is replaced while changing the engine oil. They are the first line of defense against pollution and protect the component.

9. Changing engine oil too often will do nothing. Change the oil only if it benefits the vehicle. Non-synthetic oils should be replaced at 5000 km intervals.

10. Today's car design and equipment does not make it easy to change oil at home and especially filters. It can be very tricky and may need special tools, which vary from manufacturer to manufacturer. In some cases, access to the oil filter may cause other components to be removed from the engine compartment or sump guard. So if you have no experience working with your car yourself, it is a job best left to the pros. What you can easily do at home is to add different oils and fluids if the level has dropped.


The oil viscosity class according to the SAE system.

This designation speaks of how viscous the engine oil is at cold start and how easily the oil is at hot engine and load.

The SAE system only talks about the flow properties of the oil.

The SAE system consists of a number of winter classes,

0W, 5W, 10W, 15W and a number of summer classes,

20, 30, 40, 50, 60 and 70. The higher the number in each class, the thicker the engine oil.

SAE Pumpability limit value


Min Max

0W -35 ° C

5W -30 ° C

10W -25 ° C

15W -20 ° C

20W -15 ° C

25W -10 ° C

Organizations and car manufacturers have different types of engine oil and rating systems

For a long time, there has been a need to be able to classify the quality of engine oils for a long time. Today, it is perhaps more important than ever, given the accelerating pace at which new requirements for lower emissions are introduced. The oils need to be developed to cope with the impact of these technologies, such as EGR (heavier diesels) and soot handling. Often it can be difficult to understand what the different designations mean on the packaging and labels of the engine oils.


There are three organizations today that set engine oil classification systems API, ILSAC and ACEA.

API - American Petroleum Institue. API administers licenses and certifications for engine oils according to a system that meets the requirements of the vehicle manufacturers for guarantees, maintenance and lubrication. API also administers ILSAC's licenses against the oil companies.

ILSAC - the International Lubricants Standardization and Approval Committe, was established in 1992 by the American Automobile Manufacturers Association (AAMA) and is representative of the DaimlerChrysler Corporation, Ford Motor Company, General Motors Corporation and JAMA (Japan Automobile Manufacturers Association) to define the need, parameters, licensing and administration of the lubricant specifications.

ACEA - European Automobile Manufacturers Association regulates the requirements and wishes of the European car manufacturers.

Car Manufacturer and OEM Specifications

Several independent organizations - such as API and ACEA and others - are working to create a classification system for engine oils that creates order and clears the chaos among all oils on the market. Their goal is to maintain a set of specifications that help manufacturers and consumers compare different products and choose what is right for their vehicles.

However, some car manufacturers do not find these standards adequate for their lubrication needs. So they created their own standards (OEM standards), and they require an oil to meet their specifications before being allowed to use in their own cars.


norm is always indicated by two letters, where a first letter is always


norm is always indicated by two letters, where a first letter is always S for gasoline engines.

The second letter of the API standard indicates the quality. The higher the letter, the higher the quality.

SE class

Provides better protection against oxidation, corrosion and deposits than oils in classes SD and SC.

SF class

Meets higher requirements than SE.

SG class

This means that there is a higher requirement for oxidation stability and antiwear (AW) additives, sludge formation, deposits and corrosion than is required by SF.

SH class

About the same as the API SG class, but with much tougher requirements on who is allowed to perform the assessment and testing of the oil.

SJ class

In this class, higher requirements have been set for volatility, low and high temperature properties compared to the SH class.

SL Class

Has much tougher requirements on oxidation resistance, compared to SJ class. Can be compared with ACEA A3.

SM Class

The SM class of engine oils provides better resistance to oxidation, better wear protection and better performance at low temperatures during the life of the oil.

SN class

Engine oil with SN class gives improved characteristics for exhaust systems and turbo, it gives lower fuel consumption and is suitable for ethanol-containing fuels up to E85.

diesel engines

CF Class

For high speed pre-chamber diesel engines in construction machinery and other diesel engines that use fuel with more than 0.5% by weight of sulfur.

Can be used where category CD oils are recommended

CD-2 class

For highly loaded 2-stroke engines.

This oil can be used instead of CD-II oils.

CF-4 class

Engine oil for high-speed suction and turbocharged 4-stroke engines.

This oil can be used instead of CD or CE oils.

CG-4 class

Engine oil for high-load and high-speed 4-stroke engines there

fuel with less than 0.5% by weight of sulfur is normally used.

CG-4 engine oils are required for engines that meet the 1994 exhaust emission standard.

Can be used instead of oils of category CD, CE and CF-4.

CH-4 class

Engine oil for high-speed 4-stroke engines manufactured to meet the 1998 exhaust emission standard.

The CH-4 engine oil composition makes them suitable for diesel fuels with a sulfur content of up to 0.5% by weight of sulfur ..

This engine oil can also be used where oils of categories CD, CE, CF-4 and CG-4 are prescribed.

CI-4 class

Engine oil for high-speed 4-stroke diesel engines built to meet the 2004 exhaust emission standard.

CI-4 engine oils are manufactured to protect and increase the service life of engines equipped with EGR valves and engines that use diesel fuel with up to 0.5% by weight of sulfur.

This oil can also be used where oils of category CD, CE, CF-4, CG-4 and CH-4 are prescribed.

Which oil should I choose?

Engine oils must be able to operate under difficult conditions and high temperatures. The engine oil should be pumpable at low temperatures and yet have the ability to form a lubricating film at high temperatures. the viscosity of the engine oil must not vary too much in temperature. The engine oil has several tasks. One of the most important tasks is to lubricate the friction surfaces in the engine. The engine oil should also cool by dissipating heat. The engine oil should also protect the engine parts against corrosion and rust. The engine oil should reduce vibration and attenuate the engine noise. The engine oil also has a cleaning function, which washes the engine from combustion residues such as soot and resin.

Different types of transmission oil

Transmission oil is mainly used in three places in a vehicle.

• In the gearbox both in manual and automatic boxes

• In the rear axle

• In the final gearbox and / or hub reduction on heavier vehicles At these places the oil has the task of lubricating and cooling. How well the oil does this, the so-called API classification talks about. There are 3 classes.

GL-1 For lightly loaded straight gears and planetary gears.

The class usually applies to manual gearboxes.

Without EP additive.

GL-4 For lightly loaded hypoid gears. The class usually applies

in front wheel drive cars where the gearbox and differential are

assembled and "parts" on the same oil.

Contains some EP additive.

GL-5 For heavily loaded hypoid gears in rear axles, final gears etc.

Contains more EP additive than a GL-4.

First and foremost, it is the load on the cogs of the transmission, but also the choice of material on the synchronization rings and bearings is of great importance for the right choice. Since it can be difficult to know what type of transmission the vehicle has, there is only one advice to look in the instruction manual. It always states which classification of the oil to choose.

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