Patent ID: 7740004

Claim:
A turbocharged or supercharged spark ignition engine system which uses both port fuel injection of gasoline from a first source and direct fuel injection of an anti-knock agent that is a fuel from a second source comprising: a spark ignition engine; a turbocharger or supercharger; means for port fuel injection of gasoline from the first source; means for direct fuel injection of a liquid anti-knock agent that is a fuel from the second source; wherein during part of the engine operating time, the engine is fueled both by gasoline that is port fuel injected and the anti-knock agent that is directly injected; and a fuel management system which increases the relative amount of anti-knock agent in the engine with increasing torque so as to prevent knock where the fuel management system uses closed loop control to control the amount of directly injected anti-knock agent and employs information from a knock detector; and where the engine is operated with a substantially stoichiometric fuel/air ratio.