Idle reduction describes technologies and practices that reduce the amount of time an engine idles unnecessarily. Reducing idling time has many benefits, including reductions in fuel costs, engine wear, emissions, and noise.
Engines idle for a variety of reasons, such as to keep vehicles warm, operate emergency lighting or radios, or power off-board equipment. Each year, U.S. passenger cars, light-duty trucks, medium-duty trucks, and heavy-duty vehicles consume more than 6 billion gallons of diesel fuel and gasoline—without even moving. Roughly half of that fuel is wasted by passenger vehicles.