The Oil Pump is the “heart” of the engine’s circulatory system. Its job is to pull oil from the pan and force it under pressure through the engine’s bearings, valvetrain, and pistons. Without this pressure, metal-on-metal contact would destroy an engine in a matter of seconds.

• High-Volume Pumps: These have larger gears or rotors to move more oil. They are often used in engines with larger bearing clearances or those with oil-cooled turbochargers.

• Variable Displacement Pumps: Found in many new fuel-efficient cars, these can “de-stroke” or reduce their pumping effort when the engine doesn’t need high pressure, reducing the load on the engine and saving gas.