A review on idling reduction strategies to improve fuel economy and reduce exhaust emissions of transport vehicles

• Introduce various idling reduction technologies for transport vehicles.
• Exhibit their energy use, advantages, disadvantages to understand their capability.
• Conduct critical review to improve fuel economy and exhaust emissions.
• Suggest better technology according to their performance ability.

To achieve reductions in vehicle idling, strategies and actions must be taken to minimize the time spent by drivers idling their engines. A number of benefits can be obtained in limiting the idling time. These benefits include savings in fuel use and maintenance costs, vehicle life extension, and reduction in exhaust emissions. The main objective of idling reduction (IR) devices is to reduce the amount of energy wasted by idling trucks, rail locomotives, and automobiles. During idling, gasoline vehicles emit a minimum amount of nitrogen oxides (NOx) and negligible particulate matter (PM). However, generally a large amount of carbon monoxide (CO) and hydrocarbons (HC) are produced from these vehicles. Gasoline vehicles consume far more fuel at an hourly rate than their diesel counterparts during idling. Higher NOx and comparatively larger PM are produced by diesel vehicles than gasoline vehicles on the average during idling. Auxiliary power unit (APU), direct-fired heaters, fuel cells, thermal storage system, truck stop electrification, battery-based systems, engine idle management (shutdown) systems, electrical (shore power) solutions, cab comfort system, and hybridization are some of the available IR technologies whose performances for reducing fuel consumption and exhaust emissions have been compared. This paper analyzes the availability and capability of most efficient technologies to reduce fuel consumption and exhaust emissions from diesel and gasoline vehicles by comparing the findings of previous studies. The analysis reveals that among all the options direct fired heaters, APUs and electrified parking spaces exhibit better reduction of fuel consumption and exhaust emissions than others.