What part of the engine holds the oil supply?

What part of the engine holds the oil supply? In a typical wet-sump engine, the oil pan holds the oil supply.

The oil pan, also called the sump, is mounted at the bottom of the engine beneath the crankcase. After oil lubricates bearings, the crankshaft, pistons, and valve-train components, gravity lets it drain back into the pan. An oil pump then draws it from there and sends it through the filter and internal oil passages for another cycle.

Most production cars use a wet-sump system because it is compact, relatively inexpensive, and simple. The pan also helps shield the oil and may include baffles that limit oil movement during hard cornering, braking, or acceleration. A drain plug at its lowest point allows old oil to be removed during servicing.

The main exception is a dry-sump engine. In that arrangement, a shallow sump collects returning oil while scavenge pumps move it to a separate external reservoir. The oil pump—not the oil pan—circulates the lubricant, and the oil filter cleans it; neither normally serves as the engine’s main storage container.