First we consult the auto vehicle manual were specified the oil type being used. Some producers even specify the oil brand and what kind of oil we can use, but some don’t. The opposite of the general idea, it is indicated to respect those specifications that you can find in your car manual. Also, still in the vehicle book or in the service book, you can find the interval that you need to respect in changing your engine oil.

It is recommended that you know, that the properties of the oil engine are loosed trough the attrition of use and trough the attrition of time. This thing means that even you did not achieved the number of kilometers, which implies the change of the oil; you still need to change the oil if it stays a larger period of time. When you replaced the oil you must also replaced the oil filter, don’t clean the old one or leave just there it can conduct some serious damage to your car, and even more damage if you have a sport tuning to the engine or to the oil chamber. If you look for sport oil you must know that this type of oil is expensive and its main characteristics are that it resists to a higher temperature but the replacement of it must be done more often. Being exposed to a higher temperature the oil loses its properties faster and if the pistons are not correctly lubricant they will break the cylinders.

In a general view the main oil manufactures use some specification for the oil engine, and those are:

• Oiliness degree SAE (Ex: SAE 5W30, 15W40 etc)

• The quota of the vehicles manufacturer (Ex: VW 505 00, BMW LL04 etc)
Other ways that classifies the specifications of the oil, without the ones in our previous words, exists, but the previous description gives us enough information to choose the right oil for our engine.

     For the optimal function of the vehicles engine, the oil must have the fallowing properties:

• It must avoid the metal-metal contact between the movement parts of the engine and avoid the corrosion of the parts.

• To evacuate the heat, that is generated by the speed of the pistons, and also to cool down the moving parts.

• To protect the internal surfaces of the engine against the water corrosion and the acids that result after the combustion.

• To participate in the tightness of the engine and to assure that the compression rapport is well provided.

     The basic functions of the oil are eked out by a series of characteristics that are different by the oil kind: synthetics, semi synthetics or minerals.

     To assure a better functionality of the engines, the oil that you use most have some exploitations properties. The friability of the engine is determined in most of the cases by the way you choose the oil type. In a large scale of exploitations conditions the most efficient oils are those that changes its oiliness very little in conditions of a high temperatures. To assure a minimum scale of attrition to the engine it is better that you use a oil that is more oiliest.