Improvement of Fuel Consumption by Stopping Some Fuel Injectors while Operating Both Intake and Exhaust Valves in Gasoline Engines 2012-01-0421

To reduce fuel consumption without complicated engine valve systems, we attempted to stop some fuel injectors, while operating both intake and exhaust valves normally, under idling, no-load and lighter load conditions. This study stopped one or two injectors in an in-line four-cylinder gasoline engine, and two or three injectors in an in-line six-cylinder gasoline engine, and then investigated the resulting fuel consumption and variation rates of engine speed. We calculated fuel consumption by measuring fuel injection time and engine speed. Results indicate that, in an in-line four-cylinder gasoline engine, deactivating every other fuel injector, in cylinder firing order, making two deactivated injectors, reduced fuel consumption, compared to the usual condition with all fuel injectors activated, under idling, no-load and lighter load conditions. The variation rate of engine speed with this two deactivated injectors was almost the same as that without deactivated injectors, except when idling. In an in-line six-cylinder gasoline engine, both two and three deactivated injectors also reduced fuel consumption, compared to the usual condition with all fuel injectors activated, under idling and no-load conditions. The variation rate of engine speed with both two and three deactivated injectors was also almost the same as that without deactivated injectors, again except when idling.