What type of oil pump is most commonly used in current highway diesel engines?

The most commonly used type of oil pump in current highway diesel engines is the external gear pump. This pump operates by utilizing two gears that rotate within a casing. As the gears turn, they create a suction effect that draws oil in from the pan and pushes it out under pressure to the engine's vital components.

External gear pumps are favored in diesel engines primarily due to their ability to provide a steady flow of oil at high pressure, which is essential for effective lubrication and cooling of engine parts. The mechanical simplicity and reliability of gear pumps also contribute to their widespread use, as they can withstand the demanding environments and conditions found in highway diesel engines. These characteristics make them effective at maintaining oil pressure, which is crucial for engine performance and longevity.

Other oil pump types, while effective in certain applications, do not offer the same combination of flow consistency and pressure stability that external gear pumps provide, especially in the context of modern diesel engine requirements.