The invention provides an automotive chemical regulator which can be generally used by pluralities of fuels. The regulator which is added in automotive fuels (gasoline, gasohol and diesel fuel) can stimulate the perfect combustion rate of the fuels and improve the heat efficiency through improving the combustion performance of the fuels in an internal-combustion engine (petrol engine and diesel engine). The invention is capable of reducing the oil consumption of a car by 10 to 16 percent, increasing the horsepower of the internal-combustion engine by 5 to 10 percent, reducing the discharge amount of harmful substances in car exhaust by 45 to 50 percent, reducing the carbon deposition in an air cylinder by 60 to 70 percent, and prolonging the service life of the internal-combustion engine. The invention also has the functions of cleaning fuel spray nozzles and fuel lines of the internal-combustion engine, reducing the precipitation of fuel colloid, being favorable for the starting of the internal-combustion engine, and the like. The regulator is liquid preparation which is prepared by organic active matters, alcohols substance, detergent, corrosion inhibitor, solvent and the like chemical substances according to proper proportion. When in use, the invention is directly added in automotive fuel according to the proportion by weight (or volume conversion proportion) of 0.2 to 0.5 / 1000. The invention is adapted to internal-combustion engines in various type, various brand fuels and various climates.