Editing Gasoline (section)

=== U.S. ===
{{update section|date=April 2016}}
[[File:USRegularGasolinePricesUpto2019.png|thumb|U.S. Regular Gasoline Prices through 2018]]
[[File:RBOB Gasoline Prices.webp|thumb|right|300px|{{center|[[Reformulated Blendstock for Oxygenate Blending|RBOB Gasoline Prices]]}} [[Reformulated Blendstock for Oxygenate Blending|RBOB]] plus [[Fuel taxes in the United States|excise taxes on gasoline]] reflect prices paid at the pump]]
From 1998 to 2004, the price of gasoline fluctuated between {{convert|1|and|2|$/U.S.gal|sp=us|order=flip|$/l}}.<ref name="FE.gov2">{{cite web |title=Gas Prices: Frequently Asked Questions |url=http://www.fueleconomy.gov/feg/gasprices/faq.shtml#History |url-status=dead |archive-url=https://web.archive.org/web/20110121193757/http://fueleconomy.gov/feg/gasprices/FAQ.shtml#History |archive-date=21 January 2011 |access-date=16 August 2009 |work=fueleconomy.gov |df=dmy-all}}</ref> After 2004, the price increased until the average gasoline price reached a high of {{Convert|4.11|$/U.S.gal|$/l|sp=us|order=flip}} in mid-2008 but receded to approximately {{Convert|2.60|$/U.S.gal|$/l|sp=us|order=flip}} by September 2009.<ref name="FE.gov2" /> The U.S. experienced an upswing in gasoline prices through 2011,<ref name="taxfoundation.org2">{{cite web |title=Fiscal Facts |url=http://www.taxfoundation.org/UserFiles/Image/Fiscal%20Facts/gas-tax-690px.jpg |url-status=dead |archive-url=https://web.archive.org/web/20090706073258/http://www.taxfoundation.org/UserFiles/Image/Fiscal%20Facts/gas-tax-690px.jpg |archive-date=6 July 2009 |access-date=12 June 2009 }}</ref> and, by 1 March 2012, the national average was {{Convert|3.74|$/U.S.gal|$/l|sp=us|order=flip}}. California prices are higher because the California government mandates unique California gasoline formulas and taxes.<ref>{{Cite web |title=Regional gasoline price differences - U.S. Energy Information Administration (EIA) |url=https://www.eia.gov/energyexplained/gasoline/regional-price-differences.php |url-status=live |archive-url=https://web.archive.org/web/20211115150945/https://www.eia.gov/energyexplained/gasoline/regional-price-differences.php |archive-date=15 November 2021 |access-date=15 November 2021}}</ref>

In the U.S., most consumer goods bear pre-tax prices, but gasoline prices are posted with taxes included. Taxes are added by federal, state, and local governments. {{As of|2009}}, the federal tax was {{Convert|0.184|$/U.S.gal|$/l|sp=us|order=flip}} for gasoline and {{Convert|0.244|$/U.S.gal|$/l|sp=us|order=flip}} for [[Diesel fuel|diesel]] (excluding [[red diesel]]).<ref>{{cite web |title=When did the Federal Government begin collecting the gas tax?—Ask the Rambler — Highway History |url=https://www.fhwa.dot.gov/infrastructure/gastax.cfm |url-status=live |archive-url=https://web.archive.org/web/20100529003035/http://www.fhwa.dot.gov/infrastructure/gastax.cfm |archive-date=29 May 2010 |access-date=17 October 2010 |publisher=FHWA |df=dmy-all}}</ref>

About nine percent of all gasoline sold in the U.S. in May 2009 was premium grade, according to the Energy Information Administration. ''[[Consumer Reports]]'' magazine says, "If [your owner's manual] says to use regular fuel, do so—there's no advantage to a higher grade."<ref>{{cite web |title=New & Used Car Reviews & Ratings |url=http://www.consumerreports.org/cro/cars/tires-auto-parts/car-maintenance/save-at-the-pump/overview/save-at-the-pump-ov.htm |url-status=live |archive-url=https://web.archive.org/web/20130223032546/http://www.consumerreports.org/cro/cars/tires-auto-parts/car-maintenance/save-at-the-pump/overview/save-at-the-pump-ov.htm |archive-date=23 February 2013 |work=Consumer Reports |df=dmy-all}}</ref> The ''Associated Press'' said premium gas—which has a higher octane rating and costs more per gallon than regular unleaded—should be used only if the manufacturer says it is "required".<ref>{{cite web |date=19 August 2009 |title=Gassing up with premium probably a waste |url=http://www.philly.com/philly/business/personal_finance/081909_premium_gas.html |url-status=dead |archive-url=https://web.archive.org/web/20090821162543/http://www.philly.com/philly/business/personal_finance/081909_premium_gas.html |archive-date=21 August 2009 |work=philly.com}}</ref> Cars with [[Turbocharger|turbocharged]] engines and high compression ratios often specify premium gasoline because higher octane fuels reduce the incidence of "knock", or fuel pre-detonation.<ref>{{cite web |last=Biello |first=David |title=Fact or Fiction?: Premium Gasoline Delivers Premium Benefits to Your Car |url=http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-premium-g |url-status=live |archive-url=https://web.archive.org/web/20121012015036/http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-premium-g |archive-date=12 October 2012 |work=Scientific American |df=dmy-all}}</ref> The price of gasoline varies considerably between the summer and winter months.<ref>{{cite web |date=6 June 2008 |title=Why is summer fuel more expensive than winter fuel? |url=http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm |url-status=dead |archive-url=https://web.archive.org/web/20150530115419/http://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm |archive-date=30 May 2015 |access-date=30 May 2015 |publisher=[[HowStuffWorks]] |df=dmy-all}}</ref>

There is a considerable difference between summer oil and winter oil in gasoline vapor pressure (Reid Vapor Pressure, RVP), which is a measure of how easily the fuel evaporates at a given temperature. The higher the gasoline volatility (the higher the RVP), the easier it is to evaporate. The conversion between the two fuels occurs twice a year, once in autumn (winter mix) and the other in spring (summer mix). The winter blended fuel has a higher RVP because the fuel must be able to evaporate at a low temperature for the engine to run normally. If the RVP is too low on a cold day, the vehicle will be difficult to start; however, the summer blended gasoline has a lower RVP. It prevents excessive evaporation when the outdoor temperature rises, reduces ozone emissions, and reduces smog levels. At the same time, vapor lock is less likely to occur in hot weather.<ref>{{Cite web |date=2008-06-06 |title=Why Is Gas More Expensive in the Summer Than in the Winter? |url=https://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm |url-status=live |archive-url=https://web.archive.org/web/20211024171528/https://auto.howstuffworks.com/fuel-efficiency/fuel-consumption/summer-fuel.htm |archive-date=24 October 2021 |access-date=2021-10-13 |website=HowStuffWorks |language=en}}</ref>