Idle Reduction

Photo of fleet trucks

Idling Facts

  • Medium-duty trucks use about 2.5 billion gallons of fuel to idle each year, or 6.7% of the total fuel they consume.
  • More than 650,000 long-haul heavy-duty trucks idle overnight for required rest stops at least some fraction of the time, using more than 685 million gallons of fuel per year.
Source: Argonne National Laboratory presentation in the Transportation Research Record.

Idle reduction describes technologies and practices that reduce the amount of time drivers idle their engines unnecessarily. Reducing idling time has many benefits, including reductions in fuel costs, engine wear, emissions, and noise.

Drivers idle for a variety of reasons, such as to keep vehicles warm, operate radios, or power equipment. Sometimes drivers idle for no reason at all. Each year, U.S. passenger cars, light 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.

Idling can usually be reduced without compromising driver comfort or vehicle equipment operations. Learn about: