ocr: STUICHIUMETRIC AS stoichiometric Tuel-air miHture is the theoretically perrect ratio of fuel to air for complete fuel combustion with no excess air. In fact, gas engines generally run best a little Rich, (with the remaining fuel burned in the catalytic converter), whereas Diesels run very Lean overall, but of course during combustion, as the fuel is being sprayed into the cylinder near top dead center the microclimate" of the fuel is much richer.
