Very good text, I'm studying automotive engineering by the way. Your English is very good, just a few minor mistakes. There should be a space right after a comma, like in this sentence. Everything else is marked.

How to choose the best oil for your car

Engine oil is a lubricant used in the engine of the cars and also in machines in order to reduces friction and wear between moving parts, transfers heat away from the engine, absorbs shock between moving parts and cleans the inside of the engine. Therefore the engine cannot run without oil. It will damage during the engine in a short time.

There are many properties; you should depend on them to choose the best oil for your car. Here I will talk about two of them.
First is viscosity: a number is printed on container. It is a measurement of resistance of flow.
If the oil is cold it will be very thick and resists to flow and if it is too hot the oil will be thin and the oil film can break down and parts contact can result.
Single viscosity SAE 10, 20, 30, 40 and 50 have a limited range of operating temperatures.
Multi viscosity SAE 10W-30, 25W-40 AND 20W-50 exhibits characteristics of a thin light oil when cold and a thicker heavy oil when hot.
Second API American Petroleum Institution this property will show if the oil is designed for gasoline or diesel engines, or for both. And it also will show the quality of the oil. API is also a number printed on the container, for example API SJ, APISI, APISF….etc these for gasoline engines because it has letter (s) and API CH, API CE ….etc for diesel engines because it has letter (C) and API CJ/SM, API CH/SJ….etc it can be used for both gasoline and diesel engines.

Finally, it is better to use engine oil with multi grade viscosity, single API and the letter after API should be away for example SJ is better than SI and SI is better than SH and so on.

Mechanical Eng. Telly