Chapter 10: Final Review & Key Terms

1.1. Key Terms

additives A chemical package that improves the original properties of the base stock oil.

American Petroleum Institute (API) An organization that has developed specifications to define engine oil performance standards.

anti-drainback valve A valve that prevents the oil in the engine from returning to the crankcase when the engine is shut down.

base stock The raw mineral oil processed from crude oil.

cartridge filter A filter element consisting simply of filter media unenclosed by a metal container.

dynamic viscosity A measurement of a fluid’s resistance to flow when acted upon by different bearing loads.

hot-draining Draining the oil filter at or near engine operating temperature. After the filter is removed from the engine while it is still warm, it is punctured or crushed and drained.

kinematic viscosity A measurement of a fluid’s resistance to flow while acted upon by only the forces of gravity.

multigrade oil A blend of several different oils with different viscosities; also known as multiweight oil.

oil quality sensor An electric device that measures the amount of soot loading in engine oil.

polyalphaolefin (PAO) A man-made base stock (synthetic) used in place of mineral oil. PAO molecules are smaller and more consistent in size; no impurities are found in this oil because it is derived through chemical processes.

scheduled oil sampling (SOS) An extremely detailed analysis of the condition of the engine and the quality of the engine oil.

Society of Automotive Engineers (SAE) viscosity rating An oil performance criteria that indicates an oil’s flow characteristics.

spin-on filter Filter media enclosed in a metal can that is threaded onto a filter header.

synthetic oil Oil made from base stock that is synthetically derived or manufactured.

total acid number (TAN) The acidity of an oil. Certain contaminants cause engine oil to increase in acidity, which is measured using this index.

total base number (TBN) The measurement of a lubricant’s reserve alkalinity, which aids in the control of acids formed during the combustion process.

virtual sensors Nonphysical sensors that produce data based on predictive algorithms or mathematical formulas that generate data based on other sensor inputs. An engine oil life monitor is a common example of a virtual sensor.

viscosity A measure of an oil’s resistance to flow.

viscosity index (VI) A measurement of the total amount of change in an oil’s viscosity due to temperature.

viscosity index (VI) improver An additive that prevents oil from thickening when cold and thinning when hot.