What are lubricants?

Lubricants are substances (mostly liquid) introduced between two moving surfaces to reduce friction, thereby increasing efficiency and reducing to minimum the wear of those surfaces.

What is tribology?

Using lubricants is historically certified since 900 B.C., when animal or vegetable fats were used to lubricate the wood or to facilitate transport. With crude oil processing, a new generation of mineral based lubricants came to replace the old lubricants.
Although lubricants are almost as old as mankind, the scientific foundation that focuses on lubrication technology is relatively new. Tribology is a term that emerged in 1966 and is the science that studies and provides solutions for processes of friction, wear and lubrication. Tribology term is now used worldwide to describe this vast interdisciplinary nature in all its aspects and provides a scientific basis for understanding the various ways of lubrication in tribology systems.

What are the functions of lubricants?

Lubricants functions are:

  • Reduce friction and wear between parts in contact leading to energy saving;
  • Functioning as a coolant for the very hot parts;
  • Neutralization of acids in the engine;
  • Suspension and removal of deposits;
  • Extension of the engine;
  • Reducing fuel consumption, sealing;
  • Facilitating the transfer of power and cooling;
  • Corrosion protection.

Lubricating oils consist generally in proportion of 90% of base oils (crude oil fractions obtained by processing oil and compounds resulted from synthesizing oil). Additives, in a lower proportion of 10%, vary depending on the severity of working condition and can be used as a depressant, viscosity index improver, antioxidant, corrosion and so on. To mix the oil components, there are also placed in chemicals and detergents or dispersants.

What is the composition of lubricants?

To meet more than 90% of all applications of lubricants, are required between 5,000 and 10,000 different formulations which end in obtaining the lubricants required by the technical specifications of manufacturers of engines and machinery. Calculating an average, lubricants are composed of approximately 93% base oil and 7% chemical additives or other components.

How many types of lubricants are?

Depending on the composition, lubricants are:

  1. Mineral Lubricants:: mineral oil + anti-wear additives, antioxidants

    • Low viscosity;
    • High temperatures evaporate more quickly than synthetics;
    • Oxidizes in contact with air.
  2. Semisynthetic Lubricants::mineral oil mixture with synthetic oils intended to keep their viscosity grades

    • Less tendency to evaporation comparing to mineral oils;
    • Much thinner than conventional cold-15W (fast lubrication at startup and reducing wear and fuel consumption).
  3. Synthetic lubricants:: synthetic bases with no added oil

    • Behaves excellent high load;
    • Low tendency to evaporation;
    • Protects the engine against wear and corrosion agents;
    • Maintain a steady pressure, not coke;
    • Allow faster engine starting at low temperatures.

Contrary to general belief, the features described are certifying that synthetics are the best, followed by semi-synthetic and mineral. Synthetic oils are extremely powerful and can be used to change intervals longer than mineral oils or semisynthetic.

In what fields are lubricants used?

Liquid lubricants are used in several sectors:

  1. Automotive Sector: engine oil, gear oil, hydraulic oil, brake fluids, greases.
  2. The agricultural sector (tractors); universal transmission oil for tractors (UTTO) and universal super-oil for tractors (STOU, and motor).
  3. Industry: hydraulic oils, oils for air compressors, gas compressors oils, gear oils, rolling oils and circular system oils, refrigeration compressor oil, oils for steam and gas turbines.
  4. Aviation: engine oil for gas turbines, reciprocating engine oils.
  5. Maritime sector: oils for cross cylinder head, crankcase engine oils, hollow piston engine oils main thoroughfare, lubricants stern.

What is motor oil?

The oil is first to determine the sustainability of a motor. It contains two basic components: base oils and additives.
Base oils are the main part of the oil.
It lubricates internal moving parts.
Base oils of engine oil can be made from oil, chemically synthesized materials, a combination of synthetic and petroleum.
Petroleum based oil is composed of different percentage of oil which form the final product. In general, the stock of the oil molecules are long carbon bonds which may be sensitive to impact and boil at relatively low temperatures. Engine temperatures weaken the molecular bonds, changing the physical properties of the oil.
The difference from synthetic based oils is that the molecules are more resistant to impact.

What is the purpose of motor oil?

Modern motor oil is a specialized product developed with care by engineers and chemists to meet several essential functions.

  • To avoid metal to metal contact between moving parts, resulting in decreased energy consumption and wear parts;
  • To evacuate heat and cool the moving parts of the engine;
  • To protect internal engine surfaces against corrosion caused by water and acids resulted from combustion;
  • To participate in motor sealing in order to ensure optimum compression ratio.

The mentioned oil functions are supplemented by a number of features, which are differentiated by the type of oil: synthetic, semi-synthetic or mineral.

What is the composition of motor oils?

Engine oils are composed of three elements:

  • Base oils which may be mineral, synthetic, or a combination of the two. Base oils for engine oils are mineral oil fractions obtained by processing crude oil containing hydrocarbons (paraffinic, cyclic, aromatics) and other compounds (sulfur, nitrogen, organic-metallic and others). Base oils for synthetic motor oils are obtained from compounds resulting from petrochemical processes by synthesizing them. Synthetic oils are made from polyalkaline glycol ethers dibasic acids, synthetic hydrocarbons, silicones (which have special properties at high temperatures and low temperatures). Base oils for semi-synthetic motor oils are a blend of base oils for engine oils and mineral base oils for synthetic motor oils.
  • Additives are added according to the severity of working conditions and can be used as a depressant, viscosity index improver, antioxidant, anti-corrosion and others. Additives are “inputs” from petrochemical processes results.
  • Detergents or dispersants are used to mix oil components
  • .

What are the conditions that today motor oils should meet?

General development trends of the construction of engines are: Increasing the ratio of power and engine capacity;

  • Increasing fuel economy and reliability;
  • Improve the properties of the starting;
  • Indicators and overall weight loss.

Solving any of these problems is closely related to the problems using motor oil. To ensure reliable operation of the engines, the motor oils which are used in these, must possess certain operating properties.
Engine operation reliability is determined in most cases on how we know to choose the optimal viscosity oils. In a wide range of operating condition, the most effective oils are those whose viscosity changes in the least if the oil temperature changes. To ensure a minimum degree of wear of engine parts, it is better to use high viscosity oils. However, an increase in viscosity over the measurement, increases friction losses, which increases fuel consumption. Initial viscosity decrease, usually improves the pumping of oil at low temperatures, which characterizes the oil capacity to reach places for lubrication when starting the engine. The more good pumping capacity with the lower degree of wear of engine parts at startup, the higher the return on diminishing fuel. Therefore manufacturers tend to choose the optimal oil viscosity depending on the type of engine and operating conditions.
Main ways to increase the “per liter specific power” in modern engines and perspective are:

  • Coefficient increased compression engine cylinders;
  • Optimization of fuel – air mixture composition (e.g. direct injection of fuel under high pressure);
  • Turbo air supply.

However, this leads to increased thermal and mechanical loads on engine parts and substantially tightens the conditions of oil action. Intensive contact with oil in the crankcase gases that enter its oxidation speeds. The action of fuel gas and of the heated surfaces on the oil film from the group of cylinder and piston parts leads to the formation of deposits containing very high temperature carbon (soot and lakes). Coking grooves for piston rings may limit the degree of sliding of the segments resulting in high wear and scratching the surface of the cylinder liner and ultimately damage the piston ring, followed by loss of engine compression.
In order to facilitate weight engine builders turn to the diminution of the lubrication system, resulting in increased oil circulation per unit time and increasing its oxidation process. Lowering the effective rate of formation of soot and lakes in the engine lubrication system is possible only if the oil has high properties of washing, dispersion and antioxidant.
To increase reliability and ensure high resource of the engine is necessary that the motor oils have a high level of preventing of the parameters of wear and scratches.
To reduce wear and corrosion of parts in Group cylinders and pistons and crankshaft bearings caused by acidic products of combustion, motor oils must take action to neutralize.
The requirements that the motor oil must meet are determined not only depending on the engine type, the engineering properties of aggregates and are also depending on the operating conditions and fuel quality. Thus, if the engine is running without being heated as a result of incomplete combustion of fuel, in the crankcase will enter components that oxidize and clog oil products. As a result, under moisture condensation in the crankcase, there can be a considerable increase in the degree of formation of low temperature deposition (bank). Bank formation in the crankcase can be prevented by using oils that have high dispersion properties.
Engine reliability depends to a significant extent on the ability of the oil to maintain its operating properties where water enters, which is a characteristic of the oils that are used on ships.
Oils produced by modern technology have to maintain their operation for a long period (from 500 to 2000 hours engine running, about 12-4.5000 km traveled). The period between changing oils must be correlated with exchange between the filter elements and technical conditions to operate the engine. Also there must be low oil consumption. The terms of the behavior of oils in different categories and construction of engines may vary widely, which makes it a difficult choice of oil for some engines. To ease the selection process of motor oils from the particular operating conditions and technical classification, there was developed the classification of motor oils.

How can motor oils be classified?

At the base of the national system of marking motor oils stands data referring to the class of viscosity and a group of exploitation properties.
Classification of motor oils according to viscosity (SAE standard).
Classification of motor oils according to operating properties (rules API and ACEA).
Specifications of engine manufacturers.

Classification of motor oils according to viscosity (SAE standard). The Society of Automotive Engineers.

A little history

In most developed countries in the world, classifying engine oils according to viscosity, commonly used, is determined by the SAE (Society of Automotive Engineers U.S.) in standard SAE J300 DEC 99, which came into force in August 2001. You wonder perhaps what it means 15W-40 or why is it better using it during the summer comparing to 15W-30. Or why during the winter, a 0W-40 is more appropriate than a 10W-50?
Let’s start from the beginning. The beginnings of the car, of course! At that time, there was no way to describe the ability of lubricating oils to reach operating temperature of 100 ° C. It was found that it is directly proportional to the oil viscosity at that temperature: higher viscosity oil has better lubrication factors. And here occurred the Society of Automotive Engineers (Society of Automotive Engineers). SAE, founded in 1911, proposed the standard that bears its name, by calculating the mean of the drain or through a given hole.
SAE viscosity grade is nothing but the time interval in seconds. But not to confuse the public with various figures, SAE proposed a staging system: so if a specific motor oil has leakage time between 5 seconds and 14 seconds, it has the SAE 10 viscosity grade, and so on up to SAE 50.
Okay you would say, but what is with the specification SAE 10W particle? In 1952 it became obvious that some engines cannot be switched on during winter with SAE 30 oils. Considering this, it was taken into account the oil viscosity at 0 ° C. SAE 15W and SAE 25W were added later to increase the accuracy of the SAE index .
SAE classification includes 11 classes:
6 for winter – 0w, 5w, 10w, 15w, 20w, 25w (w – winter);
5 for summer – 20, 30, 40, 50, and 60.
For multiple degrees oils, double hyphen is used, first class winter index notation ( index w) and the second class notation indicating summer , e.g. SAE 5W -40, SAE 10W -30 and so on.
Summer oils are characterized by two peaks at low temperature viscosity ( dynamic ) and the minimum kinematic viscosity at 100 ° C. Summer oils are characterized by the limitations of kinematic viscosity at 100 ° C and also by the minimum value of dynamic viscosity at high temperature (150 ° C) and the movement velocity gradient 106 c -1.
Classification of motor oils according to viscosity / SAE J 300

SAE degree

Dynamic Viscosity

Pumping ability limited temperature

Kinematic Viscosity at 100 ° C


mPa s

Max. ° C

Max ° C



mPa s 150 ° C

Winter degrees













































Summer degrees






































  • The smaller the number in front of the letter “W” (SAE), the oil viscosity is lower at low temperature, respectively; cold starting the engine is lighter.
  • The higher the figure after the dash is (SAE), the higher the oil viscosity at high temperature and more trusted engine lubrication is at high ambient temperatures (summer, hot weather, etc.).

API classification (American Petroleum Institute)

The most famous international classification of motor oils according to the field and the operating properties is the API (American Petroleum Institute). From the date of implementation (1947), this classification has been completed many times, although the principle of division of oils into 2 categories (S and C) was kept until now.
In this classification system, motor oil is denoted by 2-letter symbols. The first letter indicates the category: category “S” (Service) are oils for gasoline 4-stroke and in category “C” (Commercial) are oils that are designed for diesel engines for construction technique of equipment destined off road and agriculture . Universal motor oils are those that can be used to lubricate both gasoline and diesel. The second letter indicates the oil group depending on operating characteristics. As further is the letter from the beginning of the Latin alphabet, the higher the degree of operating characteristics of the motor oil.


API Standard

Engine Manufacturer’s Requirements



First gasoline and diesel engines (obsolete).

Motor oil without additives.


Minimum requirements for gasoline engines (obsolete).

Anti-oxidant additives.


Released in 1964 (obsolete).

Requirements for 1967 engines.


Released in 1968 (obsolete).

Requirements for 1968 – 1971 engines.


Released in 1972 (obsolete).

Requirements for 1972 – 1979 engines.


Released in 1980 (obsolete).

Requirements for 1980 – 1988 engines.


Released in 1989 (obsolete).

Requirements for 1989 – 1993 engines.


Released in 1944 (obsolete).

Requirements for 1994 – 1996 engines.


Released in 1997.

Requirements for 1997 – 2000 engines.


Released in 2001.

Requirements for 2001 engines. Can be used as replacement for motor oils meeting API SJ standards.


Released in 2005.

Requirements for 2005 engines. Can be used as replacement for motor oils meeting API SJ and SL standards.



For light diesel engines with high quality fuel (obsolete).

Military requirements 1940 – 1954.


For average diesel engines with poor quality fuel (obsolete).

Military requirements 1949.


For medium and heavy diesel engines and gasoline engines (obsolete).

Military requirements 1961-1964.


For heavy diesel engines, aspirated and turbo (obsolete).

Introduced in 1955.


2-stroke diesel engines (obsolete).

Meets the requirements of API CD and Detroit Diesel engines 6V53T.


For 1983 heavy duty diesel engines (1983).

Meets the requirements of API, CC, CD.


For diesel engines with direct and indirect injections for which the fuel can exceed 5% sulfur.

Meets the requirements of API CC and CD. It is effective against deposits on pistons, wear and corrosion.


For 2-stroke heavy diesel 1994 engines.

Meets the requirements of API CD-II.


For heavy and light diesel turbo 4-stroke low emission engines. Introduced in 1991.

Exceeds the requirements for API CE and can be used as replacement for oils that meet API CC, CD and CE.


Speed ​​diesel engines in off-road applications where diesel must contain sulfur between 0.05% and 0.5%. Introduced in 1994.

Prevents wear and piston deposits in high temperature, prevents oxidation and soot accumulation. Can be used as replacement for oils meeting API CD, CE and CF-4.


Speed ​​diesel engines, off-road where diesel must contain sulfur between 0.05% and 0.5%. Introduced in 1999.

It has superior control against deposits on pistons, wear, corrosion and soot, having good stability to oxidation. Can be used as replacements for oils meeting API CD, CE, CF-4 and CG-4.


Speed ​​diesel engines, off-road and heavy where diesel must contain sulfur between 0.05% and 0.5%. Introduced in 2003.

This new category is superior in performance to the API CH-4 and was designed to fulfill the requirements of environmental legislation relating to vehicles equipped with EGR (exhaust gas recirculation).


Speed ​​diesel engines, off-road and heavy where diesel must contain sulfur between 0.05% and 0.5%. Introduced in 2003.

Has the same qualities as the CI-4 but is superior in anti-wear protection of deposits of soot and provides high resistance to shear (breakage of the oil film).


For the new generation of diesel engines manufactured since 2007 that are using diesel with sulfur content between 0.005% and 0.05%. It is also recommended for engines manufactured before 2007.

Provides the most advanced protection on engines, catalytic converters and particle filters, also providing a longer period between oil changes. Can be used as replacement for oils meeting the requirements of API CH-4, CI-4 and CI-4 +.

ACEA specifications (European Automobile Manufacturers Association) for motor oils

Given that the main criteria of operating characteristics are the results of tests on special series engines, the differences in terms of the construction and methodology to determine the properties of the motor oil led to the creation of European ACEA classification.
The European Automobile Manufacturers Association(ACEA ), which includes the most famous car companies : BMW , DAF, Ford of Europe , General Motors Europe , MAN , Mercedes -Benz , Peugeot, Porsche , Renault, Rolls -Royce , Rover , Saab – Scania, Volkswagen , Volvo, FIAT and so on, introduced since 1996 a new classification of motor oils that is based on European testing methods. It is also using some of the recognized American methods of testing the engines and physicochemical according to API, SAE and ASTM. This classification replaced the existing classification of CCMC (Committee of Common Market country producers) at the middle 90s.
Unlike American classification API, in which until now there has not been highlighted an independent class oils for diesel cars, the European – ACEA classifies motor oils into three main groups according to their purpose:
A – for gasoline;
B – for diesel cars;
C – for diesel trucks.
Within each category, the operational characteristics of these oils are shown in separate groups, denoted by a number after the letter. The higher the number, the better the engine is operating in severe conditions, respectively, the higher the oil quality requirements. Last two digits (with the hyphen) indicate the year of introduction of oil marking category. For some new classes, the notation from the old classification remained valid, but with the adding of the last fabrication number.
A1 – multiple degrees oil for gasoline, average temperature shearing stability, ensures fuel economy;
A2 – normal viscosity multiple degrees oil for gasoline engines;
A3 – shearing stability, multiple degrees oil of low volatility. Very good cleaning properties, excellent stability;
B1 – diesel oil, shearing stability at medium temperatures and low loads, provides fuel economy;
B2 – motor oil for diesel engines with low loads;
B3 – motor oil for diesel engines with low loads. Beats prescriptions from B1 and B2 on the conditions of wear, deposits and soot formation.
B4 – an advantage, primarily in direct injection diesel engines.
E1 – normal oil change interval, slightly supercharged engines.
E2 – normal oil change interval, average supercharged engines.
E3 – E2 -96 Standard Superior, SHPD oil ensures impeccable cleanliness and protection against wear. Meet EURO 1 and EURO 2.
E4 – stricter standards than E3, ensures the longest duration.
E5 – provides better cleaning of pistons, high wear protection and a better oxidation stability.




Oil applications and properties

Gasoline and diesel (passenger cars)



Intended for gasoline and diesel engines. Specially designed to reduce friction and save energy; having low viscosity at high temperatures (2.6 – 3.5 mPa s).


Very stable oil intended for use in most gasoline or diesel engines with a big period between oil changing. Do not use for engines highly exploited.


Resistant to destruction. Designed for gasoline or diesel engines heavily exploited and / or exploitation big time intervals between oil changing (considering the engine manufacturers’ recommendations) and / or use in all seasons and / or operate in tough conditions (specified by the engine manufacturer).


Resistant to destruction. Designed for powerful engines being highly exploited for which it is possible to use oils that reduce friction and have low viscosity at high temperatures. (2.9 – 3.5 mPa s). May not be used in some particular engines.

Oils compatible with catalytic converters



Designed for engines from vehicles equipped with three-way catalyst (TWC) and diesel particle filter (DPF). Also for gasoline or diesel powerful engines requiring low viscosity friction and high temperature operation. These oils significantly increase the life of the diesel particle filter and catalyst.


Designed for automotive engines equipped with three-way catalyst (TWC) and diesel particle filter (DPF). Also for gasoline or diesel powerful engines requiring low viscosity friction and high temperature operation (HTHS> 2.9 mPa s) These oils significantly increase the life of the diesel particle filter and catalyst.


Designed for automotive engines equipped with three-way catalyst (TWC) and diesel particle filter (DPF). These oils significantly increase the life of the diesel particle filter and catalyst.


Designed for engines from vehicles equipped with three-way catalyst (TWC) and diesel particle filter (DPF). Also for gasoline or diesel performance engines requiring a low content of ash, phosphorus and sulfur and also require HTHS> 3.5 mPa s) These oils significantly increase the life of the diesel particle filter and catalyst.

Diesel engines highly exploited (trucks)



Designed for simple turbo diesel engines installed on trucks who work in medium or heavy conditions with normal interval between changing oils.


Stable oils that provide an excellent degree of cleaning and perfect lubrication of the piston. Designed for diesel engines that meet Euro-1 standards, EURO-2, EURO-3 and EURO-4. Recommended for engines without particle filters, and for some Engines with Exhaust Gas Recirculation (EGR). Can work in long intervals between oil changes.


Resistant to destruction. Stable oils that provide an excellent degree of cleaning and perfect lubrication of the piston. Designed for diesel engines that meet Euro-1 standards, EURO-2, EURO-3 and EURO-4. Recommended for engines with or without particle filters, and for some Engines with Exhaust Gas Recirculation (EGR). E6 is highly recommended for engines equipped with diesel particle filters fueled with low content of sulfur.


Resistant to destruction. They have better quality than E4 and E6. For heavily exploited engines that meet the standards of EURO-1, EURO-2, EURO-3 and EURO-4 working with increased intervals between oil changes.

Engine manufacturers’ specifications

Besides the API, ACEA and ESA; engine manufacturers are very interested that oils will comply with testing procedures required by them and meet performance requirements. Thus, if an oil meets the specified performance set, it can be approved by the manufacturer.

BMW Standard


BMW Special

Motor oils for diesel and gasoline engines manufactured before 1998.

BMW – Longlife 98

Motor oils for gasoline special engines manufactured since 1998.

BMW – Longlife 01

Motor oils for gasoline special engines manufactured after 2001.

BMW – Longlife 01 – FE

Motor oils for gasoline engines manufactured after 2001.

BMW Longlife 04

Moto oils for some gasoline engines manufactured after 2004.

Ford Standard


WSS – M2C 912 – A1

Motor oils for gasoline and diesel engines excepting 1.9 TDI Diesel (Ford Galaxy) and 1.4 TDCI (Ford Fiesta).

WSS – M2C 913 – A

Motor oils for gasoline and diesel engines excepting 1.9 TDI Diesel (Ford Galaxy) and 1.4 TDCI (Ford Fiesta).

WSS – M2C 917 – A

Motor oils for 1.9 TDCI engines (Ford Galaxy).

Mercedes-Benz Standard


MB 228.1

Multiple degrees motor oils for diesel engines.

MB 228.3

UHPD engine oils (Ultra High Performance Diesel) for diesel engines working in charge, with extended interval between oil changes.

MB 228.5

UHPD motor oils (Ultra High Performance Diesel) for diesel engines in heavy duty working with extended intervals between oil changes, towards 45,000 km limit. In the weight class it is possible to use close to 60,000 km.

MB 228.51

Motor oils UHPD / 228.5 with particle filters for Euro 4 engines.

MB 229.1

Motor oils for passenger cars (gasoline and diesel engines) where the demands are increased compared with A2-96/A3-96 and B2-96/B3-96.

MB 229.3

Motor oils for vehicles.

MB 229.31

Motor oils for diesel engines with particle filters.

MB 229.5

Motor oils for cars with extended intervals between oil changes (20,000 km) and low emissions of pollutants.

Opel Standard


GM – LL – A – 025

Motor oils for gasoline engines with high performance in fuel economy.

GM – LL – B – 025

Motor oils for diesel engines with high performance in fuel economy.

VW Standard


VW 500 00

Smooth flowing motor oils for gasoline and diesel aspirated engines. Only for SAE 0W-XX, 5W and 10W-XX-XX oils

VW 501 01

Multiple degrees motor oils with easy flow for aspirate gasoline and diesel engines.

VW 502 00

Motor oils with easy flow for diesel and gasoline engines operating in difficult conditions.

VW 503 00

Oils for gasoline engines that work in highly demanding mode, with a larger interval between changing oil (WIV: 30.000 km, 2 years). Responds to requirements higher than 502 00 (HTHS 2.9 mPa s).

VW 503 01

Oils for gasoline engines that work in highly demanding mode, with longer intervals between changing oils (WIV), like Audi S3, TT (HTHS > 3.5 mPa s).

VW 504 00

Motor oils for vehicles with a long interval of working mode, for diesel and gasoline engines, including diesel engines equipped with particle filter system without additives in the fuel.

VW 505 00

All seasons motor oils for diesel engines without turbo system.

VW 505.01

All seasons motor oils for diesel engines with suction pipe.

VW 506.00

Motor oils for diesel engines with a longer interval between changing oils (WIV: 50.000 km, 2 years, HTHS 2.9 mPa s).

VW 506.01

Motor oils for diesel engines with suction pipe and longer interval between changing oils.

VW 507 00

Motor oils for vehicles with long interval of working mode, for diesel and gasoline engines, including diesel engines equipped with particles filter system without additives in the fuel.

How do we choose the motor oil?

First consult your vehicle manual where it must be specified the type of oil used. Some car manufacturers even specify the brand, others do not. Contrary to popular beliefs, it is advisable to follow the recommendations in the car’s manual. Also here or in the book of terms of service and maintenance, should be mentioned the oil exchange period for the used motor oil. It’s good to know that motor oil loses its use by both wear and time passing. This means that even if we made the number of kilometers that specified in the service manual but I passed the time, the motor oil must be replaced. IT IS MANDATORY when replacing the motor oil to replace the oil filter (do not clean, do not leave there old).
In general, the information specified by vehicle manufacturers in the instructions book, considering the type of oil used are:

  • SAE viscosity grade (e.g. SAE 5W30, 15W40 and so on)
  • Vehicle manufacturer’s standards (e.g. VW 505 00, BMW LL04 and so on)

Other classifications may be specified, but the above are the most common and in general, according to them, the right choice is made for the proper motor oil.

The wrong motor oil and the engine’s response.

Wear of camshaft, the rocker or cam follower:

  • wear occurs by polishing concave cam cleats with rounded tip;
  • tappets thinning can lead to order off the valve.

Corrosion liners:

  • too low viscosity of lubricant, excessive overheating due to an overload or fuel dilution can cause a faulty lubrication because of the oil film rupture;
  • corrosion of bearings can be caused by the presence of organic acids in the lubricant at high temperature.

Wear at start:

  • a high viscous lubricant at cold forces starting or trains the engine to operate without lubrication resulting in rapid destruction of bushings, bearings, crankshaft and camshaft;
  • on starting wear occurs also if pumping and viscosity are not compatible with the oil pump to ensure good vacuum and proper discharge along the oil distribution chain – filter and pipe sizes.

Cylinder wear, the rings, the liners:

  • high temperature during the motion of the segment in channel, causes the channel to wear, thing that might lead to the breakage of the segment;
  • at the contact plunger – liners: The oil film rupture results in abnormal heat (no cooling, pre-ignition – ignition phenomena) and cancels functional motion.

Perforation of the piston:

  • may occur due to soot deposited on the piston head and the crown, it is a compound of carbon, resulting from burning fuel;
  • deposits are incandescent and are acting as a source of pre-ignition piston punching accompanied by destruction.

High consumption of oil:

  • is due to the lowered flash point, high volatility and gas passing along segments, which induces a higher consumption of oil;
  • too low oil viscosity leads to an increase in the flow rate through the abnormal movements of the seals.

How to interpret the color of the smoke?

  • Blue smoke smelling like oil:

Possible causes: worn piston rings, seals, used crankshaft at the valves, valve waste guides worn, and / or used motor, and oil being sucked through the PCV valve.
If the blue smoke appears only on startup, the rings are almost worn but still functional.
Possible solution: segmentation, change of the crankshafts, valves and guides

  • Gray smoke:

Possible problems with the assisted braking, brake fluid being aspirated. The brake fluid level will be checked. For the automatic gearbox, the transmission oil is being sucked.
It will check the brake fluid and oil.
The level of the brake fluid and of the motor oil will be checked.

  • Thick white smoke and irritating, pungent and sweet odor:

Possible cause: antifreeze and coolant oil are entering the combustion chamber.
Possible defect: cracked cylinder head gasket, cracked cylinder head, cracked liner, or even crack in the engine block. It will be checked if the antifreeze level drops or bubbles in the expansion tank when turing the engine. Check if the oil level is raised or if the oil is opaque, bleached, or on the oil cap or dipstick appears slime or whitish foam. This means that the oil is mixing with antifreeze.
Another possible cause could be the PCV valve stuck open, dirty or clogged.
For the automatic gearbox transmission oil extraction is possible.
If you filled with too much oil, this can cause white smoke. The dipstick will be checked in order to verify the level of the oil.
Possible fixing: change the cylinder head seals, PCV valve, welding cylinder head, block, cylinder liners change.

Can different motor oils be mixed? “Yes”

Last generation lubricants, either synthetic or mineral, can mix without jeopardizing the functioning of your engine. Mixing oils of different viscosities lead to slight modification of final viscosity; it tends toward resulting in lower viscosity motor oils.

Are supplementary additives needed? ”No”

This engine treatment can be compared with a “massage to a wooden leg”. These products mostly contain additional substances that improve the viscosity of oils. If you want this effect you can buy from the beginning, an oil with a good viscosity, the difference in price being lower than it would cost an additional additive. A lot of tests were done by independent laboratories (not funded by the manufacturers of such additives) demonstrated their inefficiency. Great engine manufacturers prohibit the use of additional additives, their use leading to loss of warranty. Lubricants are already being added enough additives; the additive level being reflected in the performance standards of the oil.

What is the transmission oil?

Automatic Transmission Oil is recommended for lubricating and operating semiautomatic and automatic gear shifters and hydraulic systems (e.g. steering) of cars, buses, trucks and commercial vehicles. It provides safe operation of equipment in a wide temperature range.

What are the most important performance classes of transmission oils?


Manual transmissions, final transmissions, worm gears, easy to service, low sliding speed.


Worm gears, when API GL-1 oils are not satisfying the requirements.


Manual transmissions, final transmissions, when API GL-1 oils are not satisfying the requirements.


Synchronizing manual transmission, final transmissions and hypoid gear shafts, small, for ships (in accordance to manufacturer’s specifications).


Final transmission with hypoid gear and shafts, large, for ships (manual transmissions for which the manufacturer recommends API GL-5 oils).


Final transmissions with hypoid gear and differentials with auto locking (LP Limited Slip).


Gear Lubricant.

* Please consider the performance classes of the following manufacturers: MERCEDES BENZ, MANN, FORD, VW, VOITH, ZF, RENK, GM,  OPEL, VOLVO, ALLISON, CATERPILAR.

How many types of transmission oil exist?

Transmission oils are divided into two types:
Transmission oil for manual gearbox and rear axle (A)
Automatic transmission fluid (B)
(A) 1. Transmission oils for manual gearbox and the rear axle are generally classified by American standards API:
GL-1 gear boxes, axles, worm gears with low load, low speed sliding;
GL-2 worm gears;
GL-3 is used if GL-2 is not appropriate;
GL-4 hypoid gears with small displacement;
GL-5 hypoid gears with average displacement;
GL-6 hypoid gears with large displacement and extreme demands (Ford ESW-M2D 105A)
(A) 2. Classification of transmission oils by viscosity / SAE J 06:

SAE degree

Kinematic viscosity 100oC

150.000 CP Viscosity at:



Maximum temperature (oC)









































(B) 1. Automatic transmission oils are classified by the standards of General Motors (ATF – Automatic Transmission Fluid)
ATF Tasa Number A, Suffix A, standard introduced in 1957
ATF DEXRON B No. B, standard introduced in 1967
ATF DEXRON II No. C standard introduced in 1973
ATF DEXRON II D Count D standard introduced in 1981
ATF DEXRON II E Number E, standard introduced in 1991
ATF DEXRON III Number F, standard introduced in 1994
ATF DEXRON III Number G, standard introduced in 1997
DEXRON is a registered trademark of General Motors Corporation, A … G numbers being classifications of QUALFICATION ARMOUR INSTITUTE.
(B) 2. Ford also issued its own rules for automatic transmission oils 1. SQM-2C9007A
M2C33-G oil type G
2. SQM-2C9010A
M2C138-CJ CJ oil type
3. ESPM-2C166-H H Oil
4. MERCON regulations issued in 1987
5. MERCON updated in 1993
6. MERCON is a trademark of Ford Motor Company
(B) 3. In addition to these internationally recognized standards, different manufacturers of transmissions issued their own rules, for which special permission is obtained from the original equipment manufacturer. These are:
Mercedes Benz
For the automatic transmission fluids, the viscosity is not an important criterion, it being implicitly understood from international specifications (e.g. all fluids that meet ATF D II have approximately the same viscosity).

What are hydraulic oils?

Hydraulic oils are among the most widely used products in the most diverse applications, from hydraulic systems for bulldozers, excavators and other construction machinery and equipment used in steering systems for ships and aircraft, as well as large industrial presses, capable of providing pressures of thousands of tons.
In power transmission, movement mechanical parts are also involved, so hydraulic fluids are required to ensure lubrication in specific operating conditions.
When choosing a hydraulic oil, we must take into account the following considerations:

  1. Composition and performance;
  2. By viscosity.

How many types of hydraulic oils exist?

Hydraulic oils can be:
Mineral based;
Rapidly biodegradable.

Mineral based hydraulic oils

HLP DIN 51 524 T2.

Mineral oils with additives for anti-oxidation, anti-corrosion and EP proprieties.

HVLP DIN 51 524 T3

HLP oils with superior quality, higher viscosity (IV>150) and multiple functions characteristics.


Detergent oils with additional water absorption proprieties and cleaning maintenance in the hydraulic circuit.


High viscosity oils (IV>150), detergents, with additional water absorption proprieties and cleaning maintenance in the hydraulic circuit.

Rapidly biodegradable mineral oils


(Hydraulic oil Environment Ester Synthetic), rapid biodegradability fluids based on synthetic esters with high performance properties.


(Hydraulic oil Environment Ester Synthetic), rapid biodegradability fluids based on polyglycols, for special usage (should not be mixed with other hydraulic fluids).


(Hydraulic oil Environment Ester Synthetic), rapid biodegradability fluids based on vegetable oils with low performance properties (limited).

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