Motor oil

Motor oil is an engine lubricant usually made from petroleum. It reduces friction on moving parts. In four stroke engines commonly found in cars, it is separate from the gasoline. In two stroke engines, like in some boat and lawnmower engines, it is mixed with the fuel.

Conventional motor oil is made from petroleum. Synthetic motor oil can be made from a variety of sources, including natural gas. Blends are also available that combine the benefits of full synthetics with a cost more similar to conventional.

Typical automobile motors require about five to eight quarts of oil. If the level is too low or too high, the engine can be damaged. The level can be checked by means of a metal or plastic dipstick, and oil added if needed.

Oil usually lasts for several thousand miles, but does need to be changed from time to time. There are service stations that specialize in this, such as Jiffy Lube.

Motor oil is available in different viscosities. 10W-30 and 5W-30 are common. Thinner viscosities are useful in colder climates, where oil tends to thicken and flow poorly. Thicker viscosities hold up a little better in high temperatures.