Facts About Oil - Any Oily Thread - Tips, Hints, and more

[totalmotorcycle]

Facts About Oil - Any Oily Thread - Tips, Hints, and more

Many of us have mixed knowledge about oil (some of us have a lot, others less) and many of us take the plunge to change our own motorcycle oil. I thought it would be a great idea to start a Oil Thread to discuss anything you want about oil.



For starters:

1. What is API?
American Petroleum Institute (API) - classifies oils according to their capacity to protect the engine.
The letter S is used for gasoline engines and the letter C for diesel. The letter that follows the S or the C indicates the degree of performance and protection, with A the lowest and X highest.

2. What is SAE?
Society of Automotive Engineers (SAE) - defines oil according to its viscosity. Oil can be monograde or multigrade, depending on its viscosity performance at various temperatures.

3. What is viscosity?
Viscocity is defined as a fluid's resistance to flow.
For example, water has a low viscosity compared with honey, so in this case honey has a higher viscosity than water under the same temperature.

A good quality lubricant keeps its viscosity steady under different temperature and usage conditions for a longer period of time.


4. What is a multigrade oil?
Lubricants that are able to maintain their performance in high and low temperatures are called multigrade.

They are defined by two numbers. The first (followed by a W) indicates the lubricant’s viscosity at lower temperatures.

The second and higher number indicates the lubricant’s viscosity at higher temperatures. A multigrade lubricant minimizes viscosity differences over a wider temperature range than single grade lubricants.



(thanks to Shell Rotella for the above definitions)