| Topic | Summary |
| The lubrication system |
The lubrication system is designed to keep the components in the engine lubricated and to reduce friction. |
| Splash system |
In the splash lubrication system, a dipper or slinger splashes oil through the internal parts of the engine. Oil is also splashed up to the valve mechanism. |
| Pressure system |
In force-feed lubrication, pressure forces oil around the engine. In a wet-sump system, oil is kept in the sump ready for the next use. In a dry sump system, oil falls to the bottom of the engine and a scavenge pump sends it to an oil tank. |
| 2-stroke engine premix fuel systems |
Most 2-stroke gasoline engines use a set gasoline-oil mixture for lubrication. As the air, fuel and oil enter the crankcase, the fuel evaporates, leaving behind enough oil to keep parts coated and lubricated. |
| 2-stroke engine oil injection systems |
An oil injection system doesn't need the oil and gasoline mixed manually. An engine-driven oil pump takes oil from a tank and pumps a measured amount directly into the engine where it mixes with the fuel and lubricates the internal engine parts. |
| Rotary engine lubrication system |
In addition to normal internal lubrication, the rotary engine uses oil injection. A pump injects a measured amount into the intake manifold. Oil from these nozzles goes to the engine and lubricates the rotor seals. |
| Corrosion/noise reduction | Engine oil performs many other functions apart from lubricating moving components. Two other functions are corrosion protection and noise suppression. |