Engine oil: everything you've always wanted to know

Mineral or synthetic? Mongrad or multigrade?

Oil is the "blood" that circulates inside an engine, carrying the necessary lubrication and refrigeration to all mobile components that require it.
Normally, when we try to obtain information about the generalities of automotive oil, manufacturers bombard us with a series of numbers, letters, codes and rare properties difficult to understand for someone who does not dedicate themselves to chemistry.
In this article we will try to explain in a simple way what engine oil consists of, how and what it is used and its main properties.

Functions
The main oil function is to avoid friction between two mobile surfaces in contact, for example between the walls of the cylinders and the pistons. If we observe them at the microscope, we can verify that there are imperfections that, if not for the oil, would end up generating excessive heat when rubbing and would melt between them, which is commonly known as "Gripaje". In this way, in addition to protecting it, when lubricating it, it is also achieved that the energy it produces is not lost due to excessive friction, increasing engine efficiency and reducing its internal wear.

Another function of oil is cooling, on its path through the engine the oil is absorbing heat of the pieces with which it contacts, cooling again when it returns to the main tank or when it passes through the radiator, decreasing the risk of overheating.

The third function is that of cleaning, the oil must be able to dilute and drag coal particles and other combustion residues, usually corrosive, avoiding oxidation and degradation of the internal parts. That is why a good oil must "get dirty", this means that it is capable of doing its detergent work avoiding waste inlays and at the same time is able to keep them in suspension, avoiding that they deposit in unwanted places.

Main properties
The classification of oils is based on two main characteristics: quality and viscosity.
The oil quality is obtained based on very varied and complex tests to determine the properties and their resistance to deterioration during its use that different organisms perform, two of the most important are:
-American Petroleum Institute (API)
-Japanese Automotive Standard Organization (Jaso)
In the API classification for gasoline engines, the first letter is a S and the second letter is the one that marks the oil quality. They begin with SA, SB, SC ... currently the highest classifications are SJ, SL, SM and SN (yes, letters I and K) skip.

The viscosity of the oil is measured by the SAE index (Society of Automotive Engineers) and basically tells us how fluid is an oil, the more under the most fluid number, the higher the thicker.
Most current motorcycle oils are multigrade, that is, they have two viscosity rates, one for the cold engine (it is followed by one W) and another for the engine at operational temperature. For example, a 20W50 behaves with index 20 when the engine is cold and is getting less fluid, until reaching 50 as it is heating.

This facilitates the starting and normal motor operation at low temperatures, while keeping the oil with an ideal consistency with the hot engine.
It is important to know that the viscosity of the oil has nothing to do with its quality, it is only a fluidity indicator. The most appropriate index for each engine is determined by the manufacturer based on the different temperatures of the environment where the motorcycle is used, keep in mind that a viscosity too small causes the lubrication system to lose pressure and protection and a very high viscosity does not allow That the oil reaches all the elements correctly when the engine is most exposed to wear, during start.

Oil types
There are many types of specific oils depending on their use on a motorcycle: forks, gearbox, motor, cardan, primary school ... Each of these oils is designed with certain additives (anti -crisp, detergents and detergents, detergents and dispersants) to provide the appropriate properties for the different functions to be performed, and it is essential to use the correct oil for each case.

The same additives does not need a separate clutch engine as another with the clutch inside the engine compartment, and the gearbox oil is subjected to pressure and temperature conditions very different from motor oil.
Regarding motor oils we have mineral and synthetic oils.
Mineral oils come from oil, and are elaborated from it after multiple processes in their production plants, in refineries. Gross oil has different components that makes it indicated for different types of final product, so it always has unwanted impurities or molecules.

Synthetic oil on the other hand is a product created from scratch in the laboratory, so it contains all the necessary components to perform its function and does not contain any product that is not necessary.

Being longer and more complex, its elaboration is more expensive than mineral oils, but in contrast they maintain their properties during extreme situations, they degrade less during use and better perform all the functions for which they are necessary (lubrication, cooling and cleanliness ).
In theory, a mineral SJ oil has the same quality as a synthetic SJ, but the synthetic will degrade later and better protect the engine from abuses or limit temperatures (making an analogy is like cooking with sunflower oil or with olive oil , the second endures use in the kitchen ...).

Conclusions
After reviewing the previous points, the importance of choosing the oil always a function of the engine manufacturer and the ambient temperature range where we are going to use the motorcycle remains to be emphasized. It is the vital fluid of the engine, and must be of the highest quality to be able to support the extreme operating conditions, protect its interior and provide a soft road march. The same tips must be applied when choosing the oil filter.

One last comment: All engines are connected somehow with the outside through the motor vents.

During periods of inactivity through these ducts, air loaded with moisture can enter, which is condensed inside the engine and mixes with the oil, degrading and oxidizing internal parts.

When the engine reaches its operational temperature, this moisture becomes steam again and is expelled through the engine's vents, so it is very important to shorten the oil changes in situations where after periods of inactivity there will be short journe The engine is not completely heated or in conditions of high environmental humidity.

And if you still have doubts about which oil to use on your machine, in this link You can see a selection of the best motorcycle oils.

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