Do 4 stroke engines use mixed gas?

No, 4-stroke engines do not use mixed gas. Mixed gas is a mixture of gasoline and oil, and it is typically used in 2-stroke engines. In a 2-stroke engine, the oil is mixed with the gasoline in order to lubricate the engine's moving parts. However, in a 4-stroke engine, the oil and gasoline are kept separate. The oil is stored in an oil sump, and it is circulated through the engine by an oil pump. This ensures that the engine's moving parts are properly lubricated without having to mix the oil with the gasoline.