a measure of the total acidity or basicity of an oil; this includes organic or inorganic acids or bases or a combination thereof.

a coarse filter element (pore size over approximately 40 µm).

ability of a fuel or lubricant to resist oxidation under high temperature operating conditions.

a condition of lubrication in which the film thickness of the lubricant is such that the friction between the surfaces is determined by the properties of the surfaces as well as by the viscosity of the lubricant.

the ability of a non-water-soluble fluid to form an emulsion with water.

one of the multiviscosity number oils in which one oil combines three SAE viscosity number grades. For example, multigrade SAE 1 OW-40 grade may be used where SAE 1 OW, SAE 20W, SAE 20, SAE 30, or SAE 40 grades are specified. These oils are made possible by improved refining processes and the use of polymer additives.

an oil meeting the requirements of more than one SAE viscosity grade classification, and may therefore be suitable for use over a wider temperature range than a single-grade oil.

engineering science pertaining to gaseous pressure and flow.

a combination of pump, pump drive, reservoir, controls and conditioning components which may be required for its application.

force per unit area, usually expressed in pounds per square inch.