A method of stoichiometrically operating an internal combustion engine. The engine is equipped with a pre-engine catalyst, which produces syngas from natural gas and air. The engine receives the syngas, as well as natural gas, and recirculated exhaust gas. The amount of syngas and the amount of recirculated exhaust gas are maximized for a desired engine efficiency and NO.sub.x emissions level.
Jack A. Smith;Daniel J. Podnar;James J. Cole;John T. Kubesh;Gordon J. Bartley