Idle (engine)

Last updated
A row of taxis idling in Hong Kong Kowloon Waterfront, Hong Kong, 2013-08-09, DD 05.jpg
A row of taxis idling in Hong Kong

Idling refers to running a vehicle's engine and the vehicle is not in motion, or when the vehicle drops to its resting point of RPMs. This commonly occurs when drivers are stopped at a red light, waiting while parked outside a business or residence, or otherwise stationary with the engine running. When idling, the engine runs without any loads except the engine accessories, and without the additional fuel via the gas pedal. If the vehicle moves while in gear and idling, the "idle speed" mechanically should be adjusted.

Contents

Idle speed

Tachometer (left) of a Volkswagen Golf Mk6 passenger car idling at just below 800 r/min. Volkswagen Golf VI 1.6 TDI Tacho.jpg
Tachometer (left) of a Volkswagen Golf Mk6 passenger car idling at just below 800  r/min.

Idle speed, sometimes simply called "idle", is the rotational speed an engine runs at when the engine is idling, that is when the engine is uncoupled from the drivetrain and the throttle pedal is not depressed. In combustion engines, idle speed is generally measured in revolutions per minute (rpm) of the crankshaft. At idle speed, the engine generates enough power to run reasonably smoothly and operate its ancillaries (water pump, alternator, and, if equipped, other accessories such as power steering), but usually not enough to perform useful work, such as moving an automobile unless it is set too high. The opposite of idle speed is redline , the maximum rotational speed the engine can be run out without risking serious engine damage.

Car, truck, and motorcycle engines

For a passenger car engine, idle speed is customarily between 600 and 1000 rpm. For medium and heavy duty trucks, it is approximately 600 rpm. [1] For many single-cylinder motorcycle engines, idle speed is set between 900 and 1100 rpm. Two-cylinder motorcycle engines are often set around 1000 rpm. [2]

If the engine is operating a large number of accessories, particularly air conditioning, the idle speed must be raised to ensure that the engine generates enough power to run smoothly and operate the accessories. Most air conditioning-equipped engines have an automatic adjustment feature in the carburetor or fuel injection system that raises the idle when the air conditioning is running.

Engines modified for power at high engine speeds, such as auto racing engines, tend to have very rough (unstable) idle unless the idle speed is raised significantly.

Idle speed may refer to the idle creep of a vehicle with an automatic transmission.

Aircraft engines

Commercial aircraft descend with a minimum thrust, that is, the engines are operating at idle speed. This situation happens when an aircraft is gliding and during the landing flare, for approach the engines are usually not operated at idle power.

Vehicle emissions

Both running an engine and idling an engine produce several pollutants that are monitored in the United States by the Environmental Protection Agency (EPA): [3]

It is often believed that stopping and restarting the engine uses more fuel than idling.[ citation needed ] According to the Environmental Defense Fund citing an engine studies report from 2000 by Environment and Climate Change Canada, an engine restart uses fuel approximately equal to 10 seconds of idling. [4] Consequently, recommendations have been made to shut off a car's engine after ten seconds of idling to reduce emissions. [5]

Winter conditions

Assuming a temperature of -1 °C (30 °F), and with a gasoline Reid vapor pressure (RVP) of 896 hPa (13.0) psi.

PollutantLDGVLDGTHDGVLDDVLDDTHDDVMC
VOC [g/min]0.3520.5120.7340.0610.0800.2110.335
CO [g/min]6.198.1211.40.1680.1911.586.47
NOx [g/min]0.1030.1250.1960.1110.1150.9450.042

Legend:

Summer conditions

Assuming a temperature of 24 °C (75 °F), and with a gasoline Reid vapor pressure of 620 hPa (9.0 psi).

PollutantLDGVLDGTHDGVLDDVLDDTHDDVMC
VOC [g/min]0.2690.4010.5970.0590.0770.2080.324
CO [g/min]3.825.6512.30.1660.1871.577.26
NOx [g/min]0.0790.0950.1700.1080.1110.9170.028

Source: [6] [3]

Health effects of idling pollutants

Health effects of idling are related to engine exhaust, and include acute effects such as eye, throat, and bronchial irritation; nausea; cough, phlegm congestion; allergic or asthma-like respiratory response; increased risk for cardiac events; cancer, and chronic effects, such as bronchitis, decreased lung function, damage to reproductive function (low birth weight and damage to sperm chromatin and DNA). [7] [8] [9]

These health effects are more damaging in those with preexisting heart disease, asthma, or other lung problems. Children are also more susceptible, due to their faster breathing rate and the fact that their respiratory system is still developing. Idling pollutants also disproportionately affect the elderly, who have limited physiological reserve to compensate for the adverse effects of the pollutants. [10]

Strategies to reduce idling in traffic

Effort has been made to reduce the amount of time engines spend idling, chiefly due to fuel economy and emissions concerns, although some engines can also be damaged if kept idling for extended periods. In the United States, about a billion gallons (3.8 billion liters) of fuel is consumed by idling heavy-duty truck and locomotive engines each year. [11] Many newer semi-trucks have small auxiliary power units (APUs) to run accessories more efficiently while the truck is parked. Hybrid vehicles typically shut down their internal combustion engines while stopped, although some conventional vehicles are also including start-stop systems to shut off the engine when it would otherwise idle.

At the macro level, governments can implement strategies to reduce reliance on motorised transport, including investing in public transport and implementing transit-oriented development.

Anti-idling legislation

Belgium

Idling is forbidden unless there is a specific reason to do so (version 1975-2026, art. 8.6 ) [12] , superseded by version 2026-09, art. 8.7 [13]

Canada

The city of Toronto enacted the first idling bylaw (No. 673-1998 Chapter 517 in the Municipal Code) in Canada in 1996 to reduce idle time to 3 minutes for vehicles and marine vessels. [14] [15] There are plans by the health department to ask for the bylaw to be amended to a limit of one minute and no exemptions to be made for the city's fleet, including the Toronto Transit Commission buses. [14]

Other Canadian municipalities have followed Toronto's lead:

Hong Kong

In a bid to reduce air pollution, the Hong Kong Government enacted the Motor Vehicle Idling (Fixed Penalty) Ordinance from December 2011. The law prohibits drivers from idling for more than three minutes in any 60-minute period. Both police traffic wardens and inspectors of the Environmental Protection Department can fine offenders HK$320. [27]

United States

Both the Department of Energy and the Environmental Protection Agency have programs in place to reduce idling. The DOE is funding research and development for alternative and advanced vehicles, which includes the gathering of quantitative data on medium-duty trucks, examining idling reduction alternatives, and the CoolCab project for semi-truck curtains and installation. [28] The EPA's programs include the Environmental Technology Verification Program, [29] the Smart Way Transport Partnership (freight incentives), the Model State Idling Law (diesel) and Clean School Bus USA. [30]

All but 11 states have at least one incentive or law in place to reduce idling, while 7 states have at least four. [31] The state of Colorado has in place a tax credit for alternative fuel and qualified idle reduction technologies, as well as the Green Truck Grant Program which allows the Governor's Energy Office to provide reimbursement of up to 25% of costs to owners of commercial trucks used in interstate commerce to reduce emissions. [32]

There are many local ordinances and programs to discourage idling, such as ordinances limiting the minutes per hour in which a vehicle can idle. [33] One example of a local program is Denver, Colorado's "Engines Off!" citywide anti-idling campaign, which aims to improve air quality and reduce greenhouse gas emissions by promoting voluntary behavior change in idling behavior. [34]

See also

Related Research Articles

<span class="mw-page-title-main">Hybrid vehicle</span> Vehicle using two or more power sources

A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Other means to store energy include pressurized fluid in hydraulic hybrids.

Vehicle emissions control is the study of reducing the emissions produced by motor vehicles, especially internal combustion engines. The primary emissions studied include hydrocarbons, volatile organic compounds, carbon monoxide, carbon dioxide, nitrogen oxides, particulate matter, and sulfur oxides. Starting in the 1950s and 1960s, various regulatory agencies were formed with a primary focus on studying the vehicle emissions and their effects on human health and the environment. As the worlds understanding of vehicle emissions improved, so did the devices used to mitigate their impacts. The regulatory requirements of the Clean Air Act, which was amended many times, greatly restricted acceptable vehicle emissions. With the restrictions, vehicles started being designed more efficiently by utilizing various emission control systems and devices which became more common in vehicles over time.

<span class="mw-page-title-main">Emission standard</span> Legal requirements governing air pollutants released into the atmosphere

Emission standards are the legal requirements governing air pollutants released into the atmosphere. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific timeframes. They are generally designed to achieve air quality standards and to protect human life. Different regions and countries have different standards for vehicle emissions.

<span class="mw-page-title-main">Exhaust gas</span> Gases emitted as a result of fuel reactions in combustion engines

Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack, or propelling nozzle. It often disperses downwind in a pattern called an exhaust plume.

<span class="mw-page-title-main">Diesel exhaust</span> Gaseous exhaust produced by a diesel engine

Diesel exhaust is the gaseous exhaust produced by a diesel type of internal combustion engine, plus any contained particulates. Its composition may vary with the fuel type or rate of consumption, or speed of engine operation, and whether the engine is in an on-road vehicle, farm vehicle, locomotive, marine vessel, or stationary generator or other application.

Hydrogen fuel enhancement is the process of using a mixture of hydrogen and conventional hydrocarbon fuel in an internal combustion engine, typically in a car or truck, in an attempt to improve fuel economy, power output, emissions, or a combination thereof. Methods include hydrogen produced through an electrolysis, storing hydrogen on the vehicle as a second fuel, or reforming conventional fuel into hydrogen with a catalyst.

<span class="mw-page-title-main">Fuel economy in automobiles</span> Distance traveled by a vehicle compared to volume of fuel consumed

The fuel economy of an automobile relates to the distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of the volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. Since fuel consumption of vehicles is a significant factor in air pollution, and since the importation of motor fuel can be a large part of a nation's foreign trade, many countries impose requirements for fuel economy.

Fuel Freedom International is a multi-level marketing company based in Altamonte Springs, Florida and co-owned by Wendy Lewis and Randy Ray. It sells pills trademarked as MPG-CAPS, which are claimed to improve fuel economy, reduce emissions and increase engine power when used as a gasoline additive.

<span class="mw-page-title-main">SmartWay Transport Partnership</span>

The SmartWay Transport Partnership is a business organization administered by the United States government and designed to encourage businesses to manage logistics in an environmentally responsible way. The program was formed in 2004, and is administered by the United States Environmental Protection Agency (USEPA) and is housed with the USEPA's Office of Transportation and Air Quality (OTAQ) - Transportation and Climate Division (TCD). SmartWay aims to voluntarily achieve improved fuel efficiency and reduce environmental impacts from freight transport. SmartWay currently has approximately 600 member businesses, membership is voluntary. The organization provides incentives and recognition for top performers to encourage continued improvement.

The Not-To-Exceed (NTE) standard promulgated by the United States Environmental Protection Agency (EPA) ensures that heavy-duty truck engine emissions are controlled over the full range of speed and load combinations commonly experienced in use. NTE establishes an area under the torque curve of an engine where emissions must not exceed a specified value for any of the regulated pollutants. The NTE test procedure does not involve a specific driving cycle of any specific length. Rather it involves driving of any type that could occur within the bounds of the NTE control area, including operation under steady-state or transient conditions and under varying ambient conditions. Emissions are averaged over a minimum time of thirty seconds and then compared to the applicable NTE emission limits.

<span class="mw-page-title-main">Idle reduction</span> Attempts to reduce idling of vehicle engines

Idle reduction describes technologies and practices that minimize the amount of time drivers idle their engines. Avoiding idling time has a multitude of benefits including: savings in fuel and maintenance costs, extending vehicle life, and reducing damaging emissions. An idling engine consumes only enough power to keep itself and its accessories running, therefore, producing no usable power to the drive train.

United States vehicle emission standards are set through a combination of legislative mandates enacted by Congress through Clean Air Act (CAA) amendments from 1970 onwards, and executive regulations managed nationally by the Environmental Protection Agency (EPA), and more recently along with the National Highway Traffic Safety Administration (NHTSA). These standards cover tailpipe pollution, including carbon monoxide, nitrogen oxides, and particulate emissions, and newer versions have incorporated fuel economy standards. However they lag behind European emission standards, which limit air pollution from brakes and tires.

<span class="mw-page-title-main">Trucking industry in the United States</span> American industry

The trucking industry serves the American economy by transporting large quantities of raw materials, works in process, and finished goods over land—typically from manufacturing plants to retail distribution centers. Trucks are also used in the construction industry, two of which require dump trucks and portable concrete mixers to move the large amounts of rocks, dirt, concrete, and other building materials used in construction. Trucks in America are responsible for the majority of freight movement over land and are tools in the manufacturing, transportation, and warehousing industries.

<span class="mw-page-title-main">Clean Air Act (United States)</span> 1963 United States federal law to control air pollution

The Clean Air Act (CAA) is the United States' primary federal air quality law, intended to reduce and control air pollution nationwide. Initially enacted in 1963 and amended many times since, it is one of the United States' first and most influential modern environmental laws.

The Diesel Emissions Reduction Act, or DERA, is a part of the Energy Policy Act of 2005. The law appropriated funds to federal and state loan programs to either rebuild diesel-powered vehicle engines to more stringent emission standards or install emission reduction systems, notify affected parties, and share the technological information with countries that have poor air quality standards.

<span class="mw-page-title-main">Environmental impact of transport</span>

The environmental impact of transport are significant because transport is a major user of energy, and burns most of the world's petroleum. This creates air pollution, including nitrous oxides and particulates, and is a significant contributor to global warming through emission of carbon dioxide. and also plant pollution, by heavy metals. Within the transport sector, road transport is the largest contributor to global warming.

The California Statewide Truck and Bus Rule was initially adopted in December 2008 by the California Air Resources Board (CARB) and requires all heavy-duty diesel trucks and buses that operate in California to retrofit or replace engines in order to reduce diesel emissions. All privately and federally owned diesel-fueled trucks and buses, and privately and publicly owned school buses with a gross vehicle weight rating (GVWR) greater than 14,000 pounds, are covered by the regulation.

<span class="mw-page-title-main">Mobile source air pollution</span> Air pollution emitted by motor vehicles, airplanes, locomotives, and other engines

Mobile source air pollution includes any air pollution emitted by motor vehicles, airplanes, locomotives, and other engines and equipment that can be moved from one location to another. Many of these pollutants contribute to environmental degradation and have negative effects on human health. To prevent unnecessary damage to human health and the environment, environmental regulatory agencies such as the U.S. Environmental Protection Agency have established policies to minimize air pollution from mobile sources. Similar agencies exist at the state level. Due to the large number of mobile sources of air pollution, and their ability to move from one location to another, mobile sources are regulated differently from stationary sources, such as power plants. Instead of monitoring individual emitters, such as an individual vehicle, mobile sources are often regulated more broadly through design and fuel standards. Examples of this include corporate average fuel economy standards and laws that ban leaded gasoline in the United States. The increase in the number of motor vehicles driven in the U.S. has made efforts to limit mobile source pollution challenging. As a result, there have been a number of different regulatory instruments implemented to reach the desired emissions goals.

Margo T. Oge is an American engineer and environmental regulator who served as the director of the Environmental Protection Agency's Office of Radiation and Indoor Air from 1990 to 1994 and director of the Office of Transportation and Air Quality from 1994 to 2012. Beginning in 2009, Oge lead the EPA team that authored the 2010-2016 and the 2017-2025 Light-Duty Vehicle Greenhouse Gas Emissions Standards. By 2025, these rules require automakers to halve the greenhouse gas emissions of cars and light duty trucks while doubling fuel economy. These rules were the US federal government's first regulatory actions to reduce greenhouse gases.

<span class="mw-page-title-main">Defeat device</span> Illegal methods in motor vehicles to overcome emissions controls

A defeat device is any motor vehicle hardware, software, or design that interferes with or disables emissions controls under real-world driving conditions, even if the vehicle passes formal emissions testing. The term appears in the US Clean Air Act and European Union regulations, to describe anything that prevents an emissions control system from working, and applies as well to power plants or other air pollution sources, as to automobiles.

References

  1. ↑ Bennett, Sean (2013). Medium/Heavy Duty Truck Engines, Fuel & Computerized Management Systems (4th ed.). Clifton Park, NY: Delmar Cengage Learning. p. 368. ISBN   978-1111645694.
  2. ↑ Woodring, Kip; Love, Kenna (2006). 101 Harley-Davidson Evolution Performance Projects (2nd ed.). St. Paul, Minnesota: Motorbooks. p. 72. ISBN   0760320853.
  3. 1 2 "Emission Facts" (PDF). Archived from the original (PDF) on 2005-07-24.
  4. ↑ "Attention drivers! Turn off your idling engines". Environmental Defense Fund. February 2009. Archived from the original on 2023-06-29. Retrieved 2023-09-06.
  5. ↑ "How You Can Help". Archived from the original on 2023-08-12. Retrieved 2023-09-06.
  6. ↑ "United States Environmental Protection Agency. Emission facts: idling vehicle emissions. April 1998" (PDF). Archived (PDF) from the original on 2005-07-24. Retrieved 2012-05-02.
  7. ↑ Calogero A.E. et al. Environmental car exhaust pollution damages human sperm chromatin and DNA. Journal of Endocrinological Investigation (2011). 34;E139-E143
  8. ↑ "Health assessment document for diesel engine exhaust". U.S. Environmental Protection Agency (EPA). 2002. Archived from the original on 2022-10-07. Retrieved 2023-09-20. Prepared by the National Center for Environmental Assessment, Washington, DC, for the Office of Transportation and Air Quality; EPA/600/8-90/057F. Available from: National Technical Information Service, Springfield, VA; PB2002-107661, and www.epa.gov/ncea.
  9. ↑ HEI Panel on the Health Effects of Traffic-Related Air Pollution. (2010) Traffic-Related Air Pollution: A Critical Review of the Literature on Emissions, Exposure, and Health Effects. HEI Special Report 17. Health Effects Institute, Boston, MA.
  10. ↑ "Health & Idling Buses". Archived from the original on 2013-12-10. Retrieved 2012-05-02.
  11. ↑ U.S. Environmental Protection Agency (EPA). "Idling Reduction." Archived 2011-02-02 at the Wayback Machine SmartWay Transport.
  12. ↑ version 1975-12->2026-09
  13. ↑ version 2026
  14. 1 2 "City Health Officials Consider Beefing Up Anti-Idling". www.citytv.com. Archived from the original on July 11, 2010.
  15. ↑ "Idling Control By-law". Archived from the original on 2013-02-04. Retrieved 2015-11-04.
  16. ↑ "Idle-Free - Help Make Mississauga an Idle-Free Zone!". Archived from the original on 2015-10-26. Retrieved 2015-11-04.
  17. ↑ "Anti-Idling". Archived from the original on August 19, 2010.
  18. ↑ "Anti-idling By-law, City of Waterloo, Ontario, Canada". Archived from the original on 2011-08-28. Retrieved 2015-11-04.
  19. ↑ "Anti-Idling Policy". Archived from the original on 2010-08-09. Retrieved 2015-11-04.
  20. ↑ "Home". Archived from the original on December 10, 2010.
  21. ↑ "Anti-idling Policy". Archived from the original on 2011-03-22. Retrieved 2015-11-04.
  22. ↑ "Vancouver's anti-idling law takes effect; Association wants truckers exempt". Todaystrucking.com. Archived from the original on 2010-12-21. Retrieved 2023-09-06.
  23. ↑ "Hamilton approves anti-idling bylaw". Archived from the original on 2016-03-05. Retrieved 2015-11-04.
  24. ↑ "Anti-Idling Policy". Archived from the original on January 15, 2010.
  25. ↑ "Anti-Idling". Archived from the original on 2010-12-15. Retrieved 2015-11-04.
  26. ↑ "Anti Idling Program - The City of Vaughan is idle-free, please turn off your engine!". Archived from the original on May 21, 2008.
  27. ↑ "Motor Vehicle Idling (Fixed Penalty) Ordinance" (PDF). Bilingual Laws Information System. Department of Justice. Archived (PDF) from the original on 2016-03-05. Retrieved 2015-11-04.
  28. ↑ "U.S. Department of Energy. Alternative and advanced vehicles. (2011)".[ permanent dead link ]
  29. ↑ "United States Environmental Protection Agency. Environmental technology verification program.(2012)". Archived from the original on 2012-05-10. Retrieved 2012-05-02.
  30. ↑ "United States Environmental Protection Agency. Smart way.(2011)". Archived from the original on 2012-05-05. Retrieved 2012-05-02.
  31. ↑ "U.S. Department of Energy. Idle reduction incentives and laws. (2011)". Archived from the original on April 1, 2012.
  32. ↑ "U.S. Department of Energy. Colorado incentives and laws for idle reduction". Archived from the original on October 18, 2011.
  33. ↑ "Smoking/Idling Vehicles". Archived from the original on August 30, 2008.
  34. ↑ "Engines off! Denver. Engines off! Denver. (2008)". Archived from the original on November 15, 2011.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.