No Idling Toolkit - Myths and Facts

Myth 1:

Vehicles should be left running for a given amount of time before being driven.


Engines need no more than a few seconds of idling time before being driven.  In addition, driving your vehicle is the best way to warm it up, because driving the vehicle warms up not only the engine, but other parts of the vehicle as well. 


Myth 2:  

Starting a vehicle uses more gas than letting the vehicle idle. 


When idling, vehicles engines operate inefficiently.  If an engine is running longer than 10 seconds, it is better and cheaper just to cut the engine off.  By eliminating just 5 minutes a day of voluntary idling, a typical family can save more than $200 per year in fuel and wear and tear costs.


Myth 3:

Frequent turning off and restarting of the engine is hard on a vehicle’s engine and battery.


Increased restarting of a vehicle’s engine does only minimal damage to the engine, while only very slightly draining the battery.  When idling, engines are forced to run on a fuel rich operating mixture that can eventually lead to decreased engine performance.  Idling can also reduce the operating life of engine oil by 75%. 

Myth 4:

Emissions from idling and driving are the same.


Idling creates worse emissions than driving.  This is because idling vehicles emit higher levels of carbon monoxide, carbon dioxide, nitrous oxide, and hydrocarbons.  These are some of the pollutants that contribute to Ozone formation.


Myth 5:

Diesel engines really do need a lot of warming time, which makes idling necessary.


Modern diesel engines only require up to 3 minutes of warming before driving.  Some states now even regulate heavy duty vehicle idling, as an effort to improve air quality.


Download No Idling Toolkit - Myths and Facts


Hinkle, H., Patricia Deacon, Kasia Duda. Anti-Idling Primer Every
Minute Counts. Hinkle Charitable Foundation. Retrieved from:

Attention Drivers! Turn Off Your Idling Engines: Reducing Vehicle
Idling Will Cut Pollution and Save You Money. Environmental Defense
Fund. (2008). Retrieved from: