Sorry, this article is currently incomplete. We'll have this finished up soon. In the meantime, check out some other articles on Cars Simplified!A liquid fills the container it is put in, but different liquids flow differently. The internal friction of a liquid slows the movement of the fluid, and is measured with the term viscosity. A high viscosity is the "thickest" or slowest to flow, while a low viscosity is the "thinnest" or quickest to flow.
Motor Oil Viscosity
Motor oil has many different viscocity options, and the right kind for your car/engine will be different than other vehicles. The American Petroleum Institute sets standards for motor oil viscocity standards (as well as chemical compatability and other factors) for motor oil to meet.
The viscosity rating consists of two numbers, a "winter" viscosity for cold temperatures, and a second number for operating temperature viscosity. The first number is followed by a "W" to note that it is the "winter" viscosity.