Editing Motorcycle (section)

==Environmental impact==
Motorcycles and scooters' low fuel consumption has attracted interest in the United States from environmentalists and those affected by increased fuel prices.<ref name="LATimesEmissions">{{cite news|newspaper=LA Times|url=http://www.latimes.com/news/la-hy-throttle11-2008jun11-story.html|date=11 June 2008|title=Motorcycles and emissions: The surprising facts|access-date=8 August 2008|author-link=Susan Carpenter|first=Susan|last=Carpenter|archive-date=18 May 2014|archive-url=https://web.archive.org/web/20140518152848/http://www.latimes.com/news/la-hy-throttle11-2008jun11-story.html|url-status=live}}</ref><ref>{{cite news|url=http://madisonmagazine.com/article.php?section_id=918&xstate=view_story&story_id=234751|title=Baby, You Can Drive My Vespa|access-date=8 August 2008|publisher=Madison Magazine |first=Judy |last=Dahl |date=September 2007 |archive-url=https://web.archive.org/web/20071011162519/http://madisonmagazine.com/article.php?section_id=918&xstate=view_story&story_id=234751 |archive-date=11 October 2007 }}</ref>
[[Piaggio Group Americas]] supported this interest with the launch of a "Vespanomics" website and platform, claiming lower per-mile carbon emissions of 0.4&nbsp;lb/mile (113&nbsp;g/km) less than the average car, a 65% reduction, and better fuel economy.<ref>{{cite web|url=http://www.vespausa.com/wwh/Vespanomics-platform.pdf|title=Vespanomics – Vespa Economics|publisher=Piaggio Group USA|access-date=8 February 2010|archive-date=13 January 2010|archive-url=https://web.archive.org/web/20100113230545/http://vespausa.com/wwh/Vespanomics-platform.pdf|url-status=dead}}</ref>

However, a motorcycle's [[Vehicle emissions control|exhaust emissions]] may contain 10–20 times more [[NOx|oxides of nitrogen (NOx)]], [[carbon monoxide]], and [[unburned hydrocarbon]]s than exhaust from a similar-year passenger car or SUV.<ref name="LATimesEmissions"/><ref>{{cite web |url=http://www.grist.org/article/umbra-motorcycles/ |title=On motorcycles – Ask Umbra |first=Umbra |last=Fisk |publisher=Grist |date=28 May 2003 |access-date=28 January 2010 |archive-date=29 June 2011 |archive-url=https://web.archive.org/web/20110629082804/http://www.grist.org/article/umbra-motorcycles |url-status=live }}</ref>
This is because many motorcycles lack a [[catalytic converter]], and the [[emission standard]] is much more permissive for motorcycles than for other vehicles.<ref name="LATimesEmissions"/> While catalytic converters have been installed in most gasoline-powered cars and trucks since 1975 in the United States, they can present fitment and heat difficulties in motorcycle applications.<ref name="LATimesEmissions"/> {{better source needed|date=September 2014}}

[[United States Environmental Protection Agency]] 2007 certification result reports for all vehicles versus on highway motorcycles (which also includes scooters),<ref>{{cite web |url= http://www.epa.gov/otaq/crttst.htm |title= Certified Highway Motorcycle Test Result Report Data (2007) |date= 8 January 2008 |publisher= [[United States Environmental Protection Agency|US EPA]] |access-date= 3 September 2008 |archive-date= 15 July 2008 |archive-url= https://web.archive.org/web/20080715055537/http://www.epa.gov/otaq/crttst.htm |url-status= live }}</ref> the average certified emissions level for 12,327 vehicles tested was 0.734. The average "Nox+Co End-Of-Useful-Life-Emissions" for 3,863 motorcycles tested was 0.8531. 54% of the tested 2007-model motorcycles were equipped with a catalytic converter.

===United States emissions limits===
The following table shows maximum acceptable legal emissions of the combination of hydrocarbons, oxides of nitrogen, and carbon monoxide for new motorcycles sold in the United States with 280&nbsp;cc or greater [[piston displacement]].<ref name=usepa>{{cite web |url=http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=0a57ac29b59ade8455648e60e739a181&rgn=div5&view=text&node=40:19.0.1.1.2&idno=40#40:19.0.1.1.2.5 |title=EPA Emissions Regulations for 1978 and Later New Motorcycles, General Provisions |access-date=7 December 2013 |publisher=[[United States Environmental Protection Agency]] |archive-date=30 March 2014 |archive-url=https://web.archive.org/web/20140330155049/http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=0a57ac29b59ade8455648e60e739a181&rgn=div5&view=text&node=40:19.0.1.1.2&idno=40#40:19.0.1.1.2.5 |url-status=live }}</ref>

{| class="wikitable"
|-
! Tier
! Model year
! HC+NOx (g/km)
! CO (g/km)
|-
| Tier 1
| 2006&ndash;2009
| 1.4
| 12.0
|-
| Tier 2
| 2010 and later
| 0.8
| 12.0
|}

The maximum acceptable legal emissions of hydrocarbon and carbon monoxide for new Class I and II motorcycles (50&nbsp;cc&ndash;169&nbsp;cc and 170&nbsp;cc&ndash;279&nbsp;cc respectively) sold in the United States are as follows:<ref name=usepa/>
{| class="wikitable"
|-
! Model year
! HC (g/km)
! CO (g/km)
|-
| 2006 and later
| 1.0
| 12.0
|}

===Europe===
[[European emission standards#Emission standards for motor cycles (two and three wheelers) – L-category vehicles|European emission standards]] for motorcycles are similar to those for cars.<ref>{{cite report |last1=Leonidas |first1=Ntziachristos |last2=Savas |first2=Geivanidis |last3=Zissis |first3=Samaras |last4=Anastasios |first4=Xanthopoulos |last5=Heinz |first5=Steven |last6=Bernd |first6=Bugsel |title=Study on possible new measures concerning motorcycle emissions |date=September 2009 |page=16 |url=http://righttoride.eu/regulationdocuments/report_measures_motorcycle_emissions_en.pdf |access-date=27 July 2020 |archive-date=5 December 2020 |archive-url=https://web.archive.org/web/20201205045250/http://righttoride.eu/regulationdocuments/report_measures_motorcycle_emissions_en.pdf |url-status=live }}</ref> New motorcycles must meet Euro 5 standards,<ref>{{cite web |url=http://www.motorcycle-usa.com/313/1572/Motorcycle-Article/Motorcycle-Emissions-Regs-Examined.aspx |title=Motorcycle Emissions Regs Examined |publisher=Motorcycle-USA.com |access-date=28 January 2010 |date=15 February 2007 |last=Madson |first=Bart |archive-date=8 February 2010 |archive-url=https://web.archive.org/web/20100208114510/http://www.motorcycle-usa.com/313/1572/Motorcycle-Article/Motorcycle-Emissions-Regs-Examined.aspx |url-status=live }}</ref> while cars must meet Euro 6D-temp standards. Motorcycle emission controls are being updated and it has been proposed to update to Euro 5+ in 2024.<ref>{{cite web |url=http://www.dealernews.com/dealernews/article/euro-5-cycle-emissions-proposed-2015 |title=EURO 5 Cycle Emissions Proposed for 2015 |publisher=Dealernews.com |access-date=28 January 2010 |date=8 December 2008 |archive-url=https://web.archive.org/web/20150217121931/http://www.dealernews.com/dealernews/article/euro-5-cycle-emissions-proposed-2015 |archive-date=17 February 2015 |url-status=dead }}</ref>

=== Asia ===

In [[Asia]], motorcycles are a common mode of transportation and are putting significant pressure on the region's environment.<ref>{{Cite web |last= |first= |date=2006-12-15 |title=Sustainable Management of Twoand Three-Wheelers in Asia |url=https://theicct.org/sites/default/files/publications/ICCT_Asia23wheelers_2011_1.pdf |access-date=2025-03-13 |website=International Council on Clean Transportation |language=en}}</ref><ref name="challenges-in-addressing-air-pollution-in-large-cities">{{Cite web |title=Challenges in addressing air pollution in large cities |url=https://vietnamnews.vn/society/1663233/challenges-in-addressing-air-pollution-in-large-cities.html |access-date=2025-03-13 |website=vietnamnews.vn |language=en}}</ref> With a massive number of motorcycles, they contribute significantly to [[greenhouse gas emissions]] and [[Air pollution|urban air pollution]].<ref name="challenges-in-addressing-air-pollution-in-large-cities" /><ref>{{Cite web |last=Sâm |first=Huyền |date=2024-12-18 |title=Kiểm định xe máy từ 5 năm tuổi, có quá sớm? |url=https://kinhtedothi.vn/kiem-dinh-xe-may-tu-5-nam-tuoi-co-qua-som.html |access-date=2025-03-13 |website=Báo Kinh tế đô thị - Đọc tin tức thời sự kinh tế 24h mới nhất |language=vi}}</ref> In [[India]], road transport accounts for about 12% of the country's energy-related CO₂ emissions.<ref>{{Cite web |title=Lượng khí thải carbon toàn cầu tăng trở lại gần mức trước đại dịch |url=https://backan.gov.vn/pages/luong-khi-thai-carbon-toan-cau-tang-tro-lai-gan-mu-dbe2.aspx |access-date=2025-03-13 |website=backan.gov.vn}}</ref> In [[Vietnam]], motorcycles contribute up to 87% of the CO emissions and 94% of hydrocarbons (HC) released by vehicles in [[Hanoi]] and [[Ho Chi Minh City]].<ref>{{Cite web |last= |first= |date=2024-12-17 |title=Kiểm định khí thải xe máy liên quan đến sức khỏe người dân, không thể chần chừ |url=https://tuoitre.vn/kiem-dinh-khi-thai-xe-may-lien-quan-den-suc-khoe-nguoi-dan-khong-the-chan-chu-20241217085812373.htm#:~:text=C%C5%A9ng%20theo%20th%E1%BB%91ng%20k%C3%AA,%20t%E1%BA%A1i,c%C3%A1c%20lo%E1%BA%A1i%20xe%20c%C6%A1%20gi%E1%BB%9Bi |access-date=2025-03-13 |website=TUOI TRE ONLINE |language=vi}}</ref><ref>{{Cite web |last= |first= |date=2024-12-17 |title=Kiểm định khí thải xe máy liên quan đến sức khỏe người dân, không thể chần chừ |url=https://tuoitre.vn/kiem-dinh-khi-thai-xe-may-lien-quan-den-suc-khoe-nguoi-dan-khong-the-chan-chu-20241217085812373.htm |access-date=2025-03-13 |website=TUOI TRE ONLINE |language=vi}}</ref><ref>{{Cite journal |last1=Tong |first1=Yen Dan |last2=Maraseni |first2=Tek |last3=Nguyen |first3=Phuong-Duy |last4=An-Vo |first4=Duc-Anh |last5=Tradenta |first5=Julio Mancuso |last6=Thuy Ai Dong Tran |date=2024 |title=Potential for greenhouse gas (GHG) emissions savings from replacing short motorcycle trips with active travel modes in Vietnam |journal=Transportation |volume=51 |issue=5 |pages=1999–2018 |doi=10.1007/s11116-023-10394-0 |pmid=37363369 |pmc=10166047 |language=en }}</ref> Environmental studies show that motorcycles in Vietnam contribute approximately 29% of NOx, 90% of CO, 65% of NMVOC, and nearly 38% of PM dust in total traffic emissions.<ref>{{Cite web |last= |first= |date= 2 August 2024|title=Kiểm định khí thải xe máy: Xem xét lộ trình cụ thể |url=https://www.sggp.org.vn/kiem-dinh-khi-thai-xe-may-xem-xet-lo-trinh-cu-the-post752158.html#:~:text=Tuy%20nhi%C3%AAn,%20%E1%BB%9F%20g%C3%B3c%20%C4%91%E1%BB%99,ph%C3%A1t%20th%E1%BA%A3i%20b%E1%BB%A5i%20si%C3%AAu%20m%E1%BB%8Bn |access-date=2025-03-13 |website=BÁO SÀI GÒN GIẢI PHÓNG |language=vi}}</ref><ref>{{Cite web |title=Dinh vi xe may |url=https://dinhvigps.vn/dinh-vi-xe-may |access-date=2025-03-13 |website= |language=en}}</ref><ref>{{Cite web |last=Tùng |first=Nguyên |date=2019-04-20 |title="Xe máy là nguồn gây ô nhiễm không khí lớn nhất cho TPHCM" |url=https://dantri.com.vn/xa-hoi/xe-may-la-nguon-gay-o-nhiem-khong-khi-lon-nhat-cho-tphcm-20190420083816021.htm |access-date=2025-03-13 |website=Báo điện tử Dân Trí |language=vi}}</ref> In [[Thailand]], gasoline-powered motorcycles are reported to emit significantly higher pollution per kilometer compared to gasoline-powered cars, exacerbating urban smog.<ref>{{Cite news |last=Raphael Salmi |first= |date=2024-03-06 |title=The next two-wheel revolution |url=https://www.bangkokpost.com/business/motoring/2753894/the-next-two-wheel-revolution |access-date=2025-03-13 |work=Bangkok Post |language=en}}</ref><ref>{{Cite web |title=Evaluation of real-world vehicle emissions and standards in Jakarta |url=https://www.trueinitiative.org/news/2022/november/evaluation-of-real-world-vehicle-emissions-and-standards-in-jakarta |access-date=2025-03-13 |website=The Real Urban Emissions Initiative}}</ref> In [[Singapore]], the NEA reported that while motorcycles account for only 15 percent of vehicles, they contribute to over 53 percent of carbon monoxide emissions from vehicles.<ref>{{Cite news |date=2018-04-12 |title=Owners of older bikes query if they can be behind more than half of vehicle emissions |url=https://www.straitstimes.com/singapore/owners-of-older-bikes-query-if-they-can-be-behind-more-than-half-of-vehicle-emissions#:~:text=NEA%20said%20its%20studies%20have,carbon%20monoxide%20emissions%20from%20vehicles. |access-date=2025-03-13 |work=The Straits Times |language=en |issn=0585-3923}}</ref><ref>{{Cite web |title=Government To Incentivise De-Registration Of Older, More Pollutive Motorcycles Over Next Five Years, Before Phasing Them Out In 2028 |url=https://www.nea.gov.sg/media/news/news/index/government-to-incentivise-de-registration-of-older-more-pollutive-motorcycles-over-next-five-years-before-phasing-them-out-in-2028 |access-date=2025-03-13 |website=www.nea.gov.sg |language=en}}</ref>