What type of motor uses premix for fuel?

A two-stroke motor uses premix for fuel because it relies on a specific oil-to-fuel ratio to ensure proper lubrication of the engine components. In two-stroke engines, the oil is mixed directly with gasoline before fueling the engine since these engines do not have a dedicated lubrication system. As the mixture is drawn into the combustion chamber, the oil lubricates the moving parts during the compression and exhaust strokes, which occur almost simultaneously. This design allows for simpler construction and lighter weight, making two-stroke motors popular in applications like small recreational vehicles and tools, where a high power-to-weight ratio is advantageous.

In contrast, four-stroke motors utilize a separate lubrication system where oil is circulated within the engine, eliminating the need for premixed fuel. Electric motors do not use fuel in the traditional sense, operating on electrical energy, and diesel motors have their own unique fuel system that does not involve mixing with oil in the same manner as a two-stroke engine.