Research on Variable Cylinders of the Tandem 4-Cylinder Gasoline Engine for Fuel Economy

With progress in internal combustion engine fuel economy, variable cylinder systems have attracted attention. We measured fuel consumption in cylinder cutoff by stopping the injector alone, collected data changing the location and number of cutoff cylinders and when varying the cutoff cylinder, and compared the difference in fuel cost reduction. A transistor is inserted serially into the injector control circuit of the electronic control unit (ECU). By controlling the transistor via microcomputer, the injector is turned on or off independently from ECU control in obtain cylinder cutoff. The amount of fuel consumption is measured using enhancement mode of a failure diagnostic device based on the OBD II standard to collect injection time and rotational speed of the injector for a predetermined time and calculated based on this data. We confirmed that by stopping the injector alone, fuel consumption was reduced 6 to 22% and is reduced when the cutoff cylinder is varied.