NOVELTY - A system for regulating the operation of an engine comprises: product gas generator for producing a product gas comprising a substantially stoichiometric mix of hydrogen and oxygen; and product gas injector for dynamically adding the product gas to the combustion air in a substantially predetermined ratio with hydrocarbon fuel, from the source of hydrocarbon fuel, presently consumed by the engine.    USE - The system and method are useful for regulating the operation of an engine (claimed).    ADVANTAGE - The system is highly efficient, reliable and promotes a higher degree of oxidative completion, and extracts more energy from the fuel and reduces the level of unburned hydrocarbons in the combustion exhaust.    DETAILED DESCRIPTION - A system for regulating the operation of an engine which receives hydrocarbon fuel from a source of hydrocarbon fuel and combustion air from a source of combustion air, where a mixture of the hydrocarbon fuel and combustion air is combusted in the engine to release at least one of mechanical energy and thermal energy as well as combustion by-products, the system for regulating the operation of an engine comprises: product gas generator for producing a product gas comprising a substantially stoichiometric mix of hydrogen and oxygen; and product gas injector for dynamically adding the product gas to the combustion air in a substantially predetermined ratio with hydrocarbon fuel, from the source of hydrocarbon fuel, presently consumed by the engine. An INDEPENDENT CLAIM is a method for regulating the operation of an engine which receives hydrocarbon fuel from a source of hydrocarbon fuel and combustion air from a source of combustion air, where a mixture of the hydrocarbon fuel and combustion air is combusted in the engine to release at least one of mechanical energy and thermal energy as well as combustion by-products, the method for regulating the operation of an engine comprises: producing a product gas comprising a substantially stoichiometric mix of hydrogen and oxygen; and dynamically adding the product gas to the combustion air in a substantially predetermined ratio with hydrocarbon fuel, from the source of hydrocarbon fuel, presently consumed by the engine.