Editing Start-stop system (section)

{{Short description|Feature of internal combustion engine vehicles}}
{{About|the automotive technology|the use of start-stop systems in telecommunication|Asynchronous serial communication}}

[[File:2019 Perodua Myvi 1.5 AV (83) (cropped).jpg|thumb|A start-stop system off button on a [[Perodua Myvi]]]]

A '''vehicle start-stop system''' or '''stop-start system''' (also known as '''S&S''', '''idling stop''', '''micro hybrid''', or '''micro hybrid electric vehicle''' ('''μHEV'''))<ref>{{Cite web |last=x-engineer.org |title=What is the difference between micro, mild, full and plug-in hybrid electric vehicles – x-engineer.org |url=https://x-engineer.org/micro-mild-full-hybrid-electric-vehicle/ |access-date=2023-10-17 |language=en-US}}</ref> automatically shuts down and restarts the [[internal combustion engine]] to reduce the amount of time the engine spends [[Idle (engine)|idling]], thereby reducing fuel consumption and [[Exhaust gas|emissions]]. This is most advantageous for vehicles that spend significant amounts of time waiting at traffic lights or frequently come to a stop in [[traffic jams]]. Start-stop technology may become more common with more stringent government fuel economy and [[emissions regulations]].<ref name="Johnson">[http://www.johnsoncontrols.com/media-center/news/press-releases/2015/09/16/johnson-controls-expands-global-production-of-startstop-batteries-to-meet-rising-automaker-demand Johnson Controls expands global production of Start-Stop batteries to meet rising automaker demand], [[Johnson Controls]] Press release, September 16, 2015</ref> This feature is present in hybrid electric vehicles, but has also appeared in vehicles that lack a hybrid electric [[powertrain]]. For non-electric vehicles, [[fuel economy]] gains from this technology are typically in the range of 3–10%, potentially as high as 12%.<ref>[http://www.edmunds.com/car-reviews/features/do-stop-start-systems-really-save-fuel.html Do Stop-Start Systems Really Save Fuel?], Edmunds.com, 11/30/2014</ref> In the United States, according to the [[United States Department of Energy|Department of Energy]], idling wastes more than {{Convert|6|e9U.S.gal|e9L e9impgal||abbr=off}} of fuel per year.<ref>{{Cite web |title=Alternative Fuels Data Center: Idle Reduction |url=https://afdc.energy.gov/conserve/idle-reduction-basics |access-date=2024-10-21 |website=afdc.energy.gov |language=en}}</ref>

In a manual transmission vehicle, stop-start is activated by stopping the car, shifting the gear to neutral, and releasing the clutch. The engine will not stop if the car is moving, even if the aforementioned steps are followed (this is not true for all cars). The engine restarts when the clutch is pressed prior to selecting a gear to move the car. The engine may also restart if there is a demand for power from, for example, the [[Automobile air conditioning|air conditioning]] system.

Since automobile accessories like [[Compressor|compressors]] and water pumps have typically been designed to run on a [[serpentine belt]] on the engine, those systems must be redesigned to function properly when the engine is turned off. Typically, an electric motor is used to power these devices instead. In vehicles where the air conditioner compressor still runs from the drive belt, some drivers turn on the air conditioner as an improvised way to disable start-stop. In the Mazda 3, a supercapacitor is used to power the air conditioner and other accessories as part of the i-ELOOP system; the air conditioner and fans are lowered significantly to minimum settings when the engine is off. With the air conditioning and fan at maximum settings, the supercapacitor will be drained in five seconds, and the engine will automatically turn on.<ref>{{Cite web |title=Understanding i-ELOOP |url=https://www.citymazda.com//en/news/view/understanding-i-eloop/24584 |access-date=2023-10-17 |website=City Mazda |language=en}}</ref><ref>{{Cite web |date=2011-11-29 |title=Mazda Introduces i-ELOOP Capacitor-Based Regenerative Braking System |url=https://www.caranddriver.com/news/a18739871/mazda-introduces-i-eloop-capacitor-based-regenerative-braking-system/ |access-date=2023-10-17 |website=Car and Driver |language=en-US}}</ref><ref>{{Cite web |date=2013-01-03 |title=Explained: Mazda's i-ELOOP recovery system {{!}} T W White & Sons Blog |url=https://www.twwhiteandsons.co.uk/technology/mazda-energy-recovery-system/ |access-date=2023-10-17 |language=en-GB}}</ref>

This technology has also been used on [[Honda]] scooters in Asian markets for the last decade.<ref>{{cite web |date=2001-01-22 |title=Honda Worldwide &#124; World News &#124; News Release &#124; January 22, 2001 |url=http://world.honda.com/news/2001/2010122.html |url-status=dead |archive-url=https://web.archive.org/web/20121012073946/http://world.honda.com/news/2001/2010122.html |archive-date=October 12, 2012 |access-date=2011-05-29 |publisher=World.honda.com}}</ref> Honda's [[Honda PCX|PCX]] 125&nbsp;cc model was released in 2010 with this technology for the European market, though its North American model does not feature it.<ref>{{cite news |date=8 June 2010 |title=Honda unveils economical scooter |url=http://www.rac.co.uk/news-advice/motoring-news/post/2010/6/honda-unveils-economical-scooter/ |url-status=dead |archive-url=https://web.archive.org/web/20120814052908/http://www.rac.co.uk/news-advice/motoring-news/post/2010/6/honda-unveils-economical-scooter/ |archive-date=14 August 2012 |access-date=2 June 2011 |publisher=RAC}}</ref>