The Study of Fuel Consumption for Idling Stop Systems in Different Traffic Conditions

Idling stop systems have been used to improve engine fuel consumption during vehicle stopping. The idling stop technology would turn off the engine when the vehicle is in a stationary condition (often in areas with heavy urban traffic). When the traffic begins moving the driver releases the brake pedal to start the engine to provide vehicle power and drive on the road. In urban traffic congested road conditions, vehicles with the idling stop systems operating frequently could cause more fuel consumption than vehicles without the idling stop systems. This study used the on-board automatic diagnosis system to connect to the Bluetooth OBDII(On Board Diagnostics) vehicle diagnostic device. The same vehicle and driving route were used to conduct this research. Two-stage tests were taken under simple road conditions and actual road conditions to analyze the experimental data, such as vehicle speed and fuel consumption. The experimental results showed that in the simple road condition case with IS (idling stop), 20.5% of fuel consumption was saved over the IC (idling continue). Under actual road conditions using the IS during weekday hours, more than 15% fuel consumption was saved. During peak traffic hours, IS only saved 3.67% of fuel consumption under the same conditions. However, if the idling stop time is less than 10 seconds, the fuel consumption increases.