With stringent vehicle emissions regulations, high efficiency and cleanliness have become the development target of engine combustion and fuel technology. The gasoline additives could enhance fuel performance and thus contribute to engine combustion efficiency improvement and emissions control. In this study, the influences of gasoline detergent, friction modifier, and combustion improver on engine combustion and emissions are reviewed. Literature studies have shown that the gasoline detergent reduces carbon monoxide (CO), hydrocarbons (HC), and particulate matter (PM) emissions, and improves fuel economy by removing engine deposits and inhibiting their formation. There is an optimal concentration of gasoline detergent, which means that gasoline detergent with too low or too high concentration cannot effectively remove engine deposits. Combustion improvers contribute to faster and more complete fuel combustion, resulting in reduced pollutant emissions and increased engine power output. With the addition of friction modifiers, a liquid film is formed between the piston and the cylinder, which reduces friction losses between the engine moving parts, resulting in a small improvement in engine fuel economy.