FUEL WASTE: Whether a light-duty car, SUV or pickup, or commercial truck, needless idling burns hard earned dollars or company profits through the tailpipe. At $3.25/gal, an averaged sized car like a Toyota Camry can cost around $125 annually when idling excessively while parked. The average light-duty vehicle burns 0.375 gal/hr.; heavy-duty up to one gal/hr.
ENGINE WEAR: For every two minutes of idling, one mile could be traveled. "Ghost miles" accumulate on an idling engine. According to reliable sources, including the study: Oak Ridge National Laboratory Operations Best Practices Guide: Idle Reduction, "Excessive idling can create engine wear and carbon soot buildup in the engine and components". This can lead to shortened life of motor oil, spark plugs and exhaust systems, plus decreased fuel mileage and the need to adhere to a "severe duty" maintenance schedule. For similar reasons, many owners manuals recommend avoiding excessive idling. For heavy-duty vehicle engine wear, read engine manufacturer's information on the Heavy-Duty page.
LIGHT-DUTY VEHICLES: Overall, the latest light-duty gasoline-powered vehicles have come a long way in reducing harmful exhaust chemicals, such as carbon monoxide, nitrogen oxide, sulfur dioxide, hydrocarbons, and benzene. But there are still factors where this exhaust is harmful to humans. A catalytic converter cannot render these chemical emissions less harmful until warmed up (a catalytic converter warms up faster when a vehicle is driven as opposed to idling). A caravan of idling vehicles, such as at a drive-thru or a school pickup queue greatly increase these emissions. Idling emissions are more toxic during hot and cold weather extremes. And carbon monoxide poisoning remains a threat for occupants of idling vehicles in enclosed spaces or in deep snow banks.
HEAVY-DUTY VEHICLES: Diesel engines in commercial trucks and school buses are durable and economical sources of power. And newer diesels are 90% cleaner than those manufactured prior to 2010. But older diesels -- which last 20-30 years -- contain toxic exhaust components such as particulate matter and volatile organic compounds that cause significantly higher levels of harmful emissions when idling.
Greenhouse gas emissions from vehicles, chiefly carbon dioxide (CO2), contribute to climate change. Overwhelming scientific evidence, including from NASA, NOAA, the IPCC, Politifact, even the Pentagon, link climate change and global warming — in part from human activities — to the highest temperatures ever recorded on Earth, melting polar ice caps, rising sea levels, increasingly severe weather events, droughts, wildfires, flooding, and to the threat of many plant and animal species. And global warming caused by human emissions has most likely intensified the drought in California by 15 to 20 percent, scientists say.
According to the Air Resources Board, transportation amounts to 37% of California's greenhouse gas emissions, the highest economic sector in the state and higher than the national average of 26%.
Many of us are aware of conserving and saving energy, from turning off lights when leaving a room, to recycling. Turning off the keys of our parked vehicles is a simple energy conserving habit to get into.
Most gasoline and diesel fuels are derived from crude oil, a non-renewable resource. While the threat of depletion of oil has lessened — as North America has partially transitioned from exporting foreign "conventional" petroleum to the extraction of "unconventional" petroleum (primarily using the method of hydraulic fracturing or "fracking") — the critical challenge of the future remains to transition from fossil fuels to clean, renewable forms of energy. Why? Unconventional oil is much harder to extract making it more expensive, much dirtier, more environmentally harmful, and will increase the challenge of coming to grips with the global climate crisis. We still need oil, but there are opportunities to use less of it; to keep it in the ground. From extraction to emissions, oil is harmful to humans and our planet.
Idle Reduction Technology installed in commercial vehicles reduces idling from 25-75%. Ex.: Stealth Power
*The U.S. Dept. of Energy states, "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." For California then, while there are no far ranging studies on vehicle idling in the state, a rough estimate is the idling of all vehicles wastes 750,000,000 gallons of fuel. This is 7.5 million tons of CO2 emitted by all idling vehicles in California. Studies show that about one-half of all idling occurs when parked (not in traffic).1, 2. Therefore, it is estimated all vehicles idling when parked in California waste about 375,000,000 gallons of fuel and emit 3.75 million tons of CO2.
1Vanderbilt University study: Costly myths: An analysis of idling beliefs and behavior in personal motor vehicles (p.4). "...the average American idles for roughly 16 min a day. Over 51%...can be accounted for by individuals idling while in traffic...the remaining 49%...results from idling to warm and while waiting, both of which are avoidable and, in many cases, unnecessary."
2University of Vermont study: Passenger vehicle idling in Vermont (p.25): "Discretionary idling is a large enough percent of all idling in Vermont (approximately half) to suggest policies to pursue behavior change over purely vehicle technologies which eliminate all idling emissions by turning off during travel and at stops."
For light-duty vehicles in cold and hot weather extremes, idling can be necessary for several reasons. In colder weather, warm up idling may be necessary for adequate windshield/window/outside mirror defogging/defrosting. This can be a visibility issue even at more than 50º in the morning. Below 10º, a warm up of 1 to 2 minutes is recommended to allow thickened motor oil to fully circulate in an engine.
It is strongly recommended to seek alternatives to being in a parked vehicle in weather extremes. But if there is no place else to go, for factors of safety and health, idling may have to occur (although it can in alternating on-off cycles). This is especially true if there is an elderly person, infant, or pet in the vehicle. On a very hot day, especially if not parked in the shade, the vehicle will need to idle with windows closed and AC on.
For safety reasons, it is not recommended to turn off engines at stop lights; however, in prolonged situations such as at railroad crossings and road construction zones, it is recommended to turn off engines.
Spare the Air: Turn the Key – Be Idle Free! San Francisco Bay Area
Grades of Green - No Idle Zone Los Angeles South Bay area
U.S. DOE Clean Cities coalitions: California has 13 Clean Cities implementing various degrees of idle reduction, as well as Clean Cities in other states. In general, Clean Cities offers their IdleBox Toolkit for idling reduction projects.
Keep it Clean. Be Idle Free. Washoe County, NV
Idle Free Utah - Utah Clean Cities
Engines Off!, Denver CO
Kentuckiana Air Education (KAIRE) Idle Free, Louisville, KY
IdleFreePhilly, Philadelphia, PA (and suburbs)
Idle-Free VT, Vermont
Idle-Free Toolkit, Clean Nova Scotia
Idle Free for Our Kids, Halifax, Nova Scotia
U.S. national: It's Your Turn - Turn It Off Sustainable America
U.S. national: IdleBox Toolkit for Idling Reduction Projects Dept. of Energy Clean Cities