The sump pan, directly below the engine block, collects engine oil that has been pumped around the engine. The sump plug is a bolt at the base of the sump pan that is unscrewed to allow oil to be drained. You may have heard of wet sump and dry sump systems, but what’s the difference? The vast majority of cars use the wet sump system, in which all of the engine’s oil is collected in the sump pan before being recirculated around the engine. This system can be upgraded with superior parts to fine-tune oil control and boost engine power. The dry sump system is generally restricted to professional racing cars that require the highest amount of power and engine-oil control. The difference with this system is that the oil is pumped out of the sump pan to be stored in a separate tank before it is redistributed around the engine by an external pump – leaving the sump pan ‘dry’. This system has a number of advantages to top-level racers, including less weight on the rotating assembly, more space for the rotating assembly to spin, higher oil capacity and increased oil pressure. Because the sump pan hangs down below the engine, it can easily be damaged by loose debris or speed bumps. If this happens to your vehicle, it must be replaced as soon as possible.