Car Engine Oil Grades

What is Engine Oil?

Engine oil is a lubricant that is used to reduce friction and wear between the moving parts of an engine. It also helps to cool the engine and to keep it clean.

Oil Grades

Engine oils are graded according to their viscosity, which is a measure of their resistance to flow. The higher the viscosity, the thicker the oil. Oils are also graded according to their API service category, which is a measure of their ability to protect the engine from wear and tear.

Viscosity Grades

The viscosity of an oil is measured in units called centiStokes (cSt). The higher the cSt, the thicker the oil. Oils are typically classified into the following viscosity grades:

0W-20
5W-20
5W-30
10W-30
10W-40
15W-40
20W-50

The first number in the viscosity grade indicates the oil’s viscosity at a low temperature. The lower the number, the thinner the oil at low temperatures. The second number indicates the oil’s viscosity at a high temperature. The higher the number, the thicker the oil at high temperatures.

API Service Categories

The API service category of an oil is indicated by a two-letter code. The first letter indicates the type of engine the oil is intended for. The second letter indicates the level of protection the oil provides against wear and tear.

The following are the API service categories for gasoline engines:

The following are the API service categories for diesel engines:

Choosing the Right Oil

The best way to choose the right oil for your car is to consult your owner’s manual. The owner’s manual will specify the viscosity grade and API service category of oil that is recommended for your car. You can also use the oil selector tool on the website of your favorite oil brand.

Changing Your Oil

It is important to change your oil regularly to keep your engine running smoothly. The frequency with which you need to change your oil depends on the type of oil you are using and the driving conditions. Most manufacturers recommend changing your oil every 5,000 to 7,500 miles.

You can change your oil yourself or you can have it changed at a mechanic shop. If you are changing your oil yourself, be sure to follow the instructions in your owner’s manual.

Conclusion

Engine oil is an important part of your car’s maintenance. By choosing the right oil and changing it regularly, you can help to keep your engine running smoothly for many years to come.