Gasoline

See also Gasoline (disambiguation) or Petrol (disam-biguation).Gasoline /ˈɡæsəliːn/, or petrol /ˈpɛtrəl/, is a transpar-

A jar of gasoline

A Shell gasoline station.

ent, petroleum-derived liquid that is used primarily as afuel in internal combustion engines. It consists mostly of

organic compounds obtained by the fractional distillationof petroleum, enhanced with a variety of additives; a 42gallon barrel of crude oil yields about 19 gallons of gaso-line, when processed in an oil refinery.The quality of gasoline as a fuel in internal combustionengines is measured by its octane rating. Gasoline isproduced in several grades of octane rating. Lead com-pounds are no longer used in most areas for octane im-provement, but many other additives are put into gasolineto improve its stability and performance. Some gasolinesalso contain ethanol as an alternative fuel.The main concern with gasoline on the environment,aside from the complications of its extraction and refin-ing, is the potential effect on the climate. The chief risksof leaks come not from vehicles, but from gasoline de-livery truck accidents and leaks from storage tanks. Be-cause of this risk, most (underground) storage tanks nowhave extensive measures in place to detect and preventany such leaks, such as monitoring systems. The materialsafety data sheet for unleaded gasoline shows at least 15hazardous chemicals occurring in various amounts. Ben-zene and many antiknocking additives are carcinogenic.Inhaled (huffed) gasoline vapor is a common intoxicantthat has become epidemic in some poorer communi-ties and indigenous groups in Australia, Canada, NewZealand, and some Pacific Islands.[1] In response, Opalfuel has been developed by the BP Kwinana Refineryin Australia, and contains only 5% aromatics (unlike theusual 25%), which weakens the effects of inhalation.[2]

1 Octane rating

Main article: Octane rating

Spark ignition engines are designed to burn gasoline ina controlled process called deflagration. In some cases,however, the unburned mixture can autoignite (detonatefrom pressure and heat alone, rather than ignite fromthe spark plug at exactly the right time), which causesrapid pressure rise which can damage the engine. Thisphenomenon is often referred to as engine knocking orend-gas knock. One way to reduce knock in spark ig-nition engines is to increase the gasoline’s resistance toautoignition, which is expressed by its octane rating.Octane rating is measured relative to a mixture of 2,2,4-trimethylpentane (an isomer of octane) and n-heptane.There are different conventions for expressing octane rat-

1

2 3 ENERGY CONTENT

ings, so a fuel may have several different octane rat-ings based on the measure used. Research octane num-ber (RON) for commercially-available gasoline varies bycountry. In Finland, Sweden, and Norway, 95 RON isthe standard for regular unleaded gasoline and 98 RON isalso available as a more expensive option. In the UK, or-dinary regular unleaded gasoline is 95 RON (commonlyavailable), premium unleaded gasoline is always 97 RON,and super unleaded is usually 97-98 RON. However, bothShell and BP produce fuel at 102 RON for cars with high-performance engines, and the supermarket chain Tescobegan in 2006 to sell super unleaded gasoline rated at99 RON. In the US, octane ratings in unleaded fuels canvary between 85[3] and 87 AKI (91-92 RON) for regular,through 89-90 AKI (94-95 RON) for mid-grade (Euro-pean regular), up to 90-94 AKI (95-99 RON) for pre-mium (European premium).South Africa’s largest city is Johannesburg is located onthe Highveld at 1,753 metres (5,751 ft) above sea-level.So the South African AA recommends 95 octane petrol(gasoline) as low altitude and 93 octane for use in Johan-nesburg because “The higher the altitude the lower the airpressure, and the lower the need for a high octane fuel asthere is no real performance gain”.[4]

The octane rating became important as the militarysought higher output for aircraft engines in the late 1930sand the 1940s. A higher octane rating allows a highercompression ratio or supercharger boost, and thus highertemperatures and pressures, which translate to higherpower output. Some scientists even predicted that a na-tion with a good supply of high octane gasoline wouldhave the advantage in air power. In 1943, the RollsRoyce Merlin aero engine produced 1,320 horsepower(984 kW) using 100 RON fuel from amodest 27 liter dis-placement. Towards the end of the second world war, ex-periments were conducted using 150 RON fuel (100/150avgas), obtained by adding 2.5% aniline to 100 octaneavgas.[5]

2 Stability

Quality gasoline should be stable almost indefinitely ifstored properly. Such storage should be in an airtight con-tainer (to prevent oxidation or water vapors mixing) thatcan withstand the vapor pressure of the gasoline withoutventing ( to prevent the loss of the more volatile frac-tions) at a stable cool temperature (to reduce the excesspressure from liquid expansion, and to reduce the rateof any decomposition reactions). When gasoline is notstored correctly, gums and solids may be created, whichcan corrode system components and accumulate on wet-ted surfaces, resulting in a condition called “stale fuel”.Gasoline containing ethanol is especially subject to ab-sorbing atmospheric moisture, then forming gums, solids,or two phases (a hydrocarbon phase floating on top of awater-alcohol phase).

The presence of these degradation products in fuel tank,lines, carburetor or fuel injection components makes itharder to start the engine, or causes reduced engine per-formance. On resumption of regular engine use, thebuildup is often eventually cleaned out by the flow offresh gasoline. The addition of a fuel stabilizer to gaso-line can extend the life of fuel that is not or cannot bestored properly. Some typical fuel stabilizers are propri-etary mixtures containing mineral spirits, isopropyl alco-hol, 1,2,4-trimethylbenzene,or other additives. Fuel sta-bilizer is commonly used for small engines, such as lawn-mower and tractor engines, especially when their use isseasonal (low to no use for one or more seasons of theyear). Users have been advised to keep gasoline contain-ers more than half full and properly capped to reduce airexposure, to avoid storage at high temperatures, to run anengine for ten minutes to circulate the stabilizer throughall components prior to storage, and to run the engine atintervals to purge stale fuel from the carburetor.[6]

3 Energy content

Energy is obtained from the combustion of gasoline bythe conversion of a hydrocarbon to carbon dioxide andwater. The combustion of octane follows this reaction:

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

Gasoline contains about 42.4 MJ/kg (120 MJ/US gal,33.3 kWh/US gal) quoting the lower heating value .Gasoline blends differ, and therefore actual energy con-tent varies according to the season and producer by upto 4% more or less than the average, according to theUS EPA. On average, about 74 L of gasoline (19.5 USgal, 16.3 imp gal) are available from a barrel of crude oil(about 46% by volume), varying due to quality of crudeand grade of gasoline. The remainder are products rang-ing from tar to naphtha.[7]

A high-octane-rated fuel, such as liquefied petroleum gas(LPG) has an overall lower power output at the typi-cal 10:1 compression ratio of a gasoline engine. How-ever, with an engine tuned to the use of LPG (i.e. viahigher compression ratios, such as 12:1 instead of 10:1),this lower power output can be eliminated. This is be-cause higher-octane fuels allow for a higher compres-sion ratio without knocking, resulting in a higher cylin-der temperature, which improves efficiency. Also, in-creased mechanical efficiency is created by a higher com-pression ratio through the concomitant higher expansionratio on the power stroke, which is by far the greater ef-fect. The higher expansion ratio extracts more work fromthe high-pressure gas created by the combustion process.An Atkinson cycle engine uses the timing of the valveevents to produce the benefits of a high expansion ratiowithout the disadvantages, chiefly detonation, of a highcompression ratio. A high expansion ratio is also one of

3

the two key reasons for the efficiency of diesel engines,along with the elimination of pumping losses due to throt-tling of the intake air flow.The lower energy content (per liter) of LPG in compari-son to gasoline is due mainly to its lower density. Energycontent per kilogram is higher than for gasoline (higherhydrogen to carbon ratio, for an example see Standardenthalpy of formation).

4 Density

The density of gasoline ranges from 0.71–0.77 kg/L(719.7 kg/m3 ; 0.026 lb/in3; 6.073 lb/US gal; 7.29lb/imp gal), higher densities having a greater volume ofaromatics.[8] Since gasoline floats on water, water can-not generally be used to extinguish a gasoline fire unlessused in a finemist. Finishedmarketable gasoline is tradedwith a standard reference of 0.755 kg/L, and its price isescalated/de-escalated according to its actual density.

5 Chemical analysis and produc-tion

A pumpjack in the United States

Gasoline is produced in oil refineries. Roughly 19 gallonsof gasoline is derived from a 42 gallon barrel of crude oil.Material separated from crude oil via distillation, calledvirgin or straight-run gasoline, does not meet specifica-tions for modern engines (particularly the octane rating,see below), but can be pooled to the gasoline blend.The bulk of a typical gasoline consists of hydrocarbonswith between 4 and 12 carbon atoms per molecule (com-monly referred to as C4-C12).[6]

An oil rig in the Gulf of Mexico

Some of the main components of gasoline: isooctane, butane, 3-ethyltoluene, and the octane enhancer MTBE.

The various refinery streams blended to make gasolinehave different characteristics. Some important streamsare:

• straight-run gasoline, usually also called naphthais distilled directly from crude oil. Once the leadingsource of fuel, its low octane rating required leadadditives. It is low in aromatics (depending on thegrade of crude oil), containing some cycloalkanes(naphthenes) and no olefins. Between 0 and 20% ofthis stream is pooled into the finished gasoline, be-cause the supply of this fraction is insufficient and itsRON is too low.. The chemical properties (namelyoctane and RVP) of the straight-run gasoline canbe improved through reforming and isomerisation.However, before feeding those units, the naphthaneeds to be split in light and heavy naphtha. Straight-run gasoline can be also used as a feedstock intosteam-crackers to produce olefins.

• reformate, produced in a catalytic reformer has ahigh octane rating with high aromatic content, andrelatively low olefins (alkenes). Most of the benzene,

4 6 ADDITIVES

toluene, and xylene (the so-called BTX) are morevaluable as chemical feedstocks and are thus re-moved to some extent.

• catalytic cracked gasoline or catalityc crackednaphtha, produced from a catalytic cracker, witha moderate octane rating, high olefins (alkene) con-tent, and moderate aromatics level.

• hydrocrackate (heavy, mid, and light) producedfrom a hydrocracker, with medium to low octanerating and moderate aromatic levels.

• alkylate is produced in an alkylation unit, using asfeedstocks isobutane and alkenes. Alkylate containsnil aromatics and olefins and has high MON.

• isomerate is obtained by isomerizing low octanestraight run gasoline to iso-parafins (like isooctane).Isomerate has medium RON and MON, but nil aro-matics and olefins.

The terms above are the jargon used in the oil industryand terminology varies.Overall, a typical gasoline is predominantly a mixtureof paraffins (alkanes), cycloalkanes (naphthenes), andolefins (alkenes). The actual ratio depends on:

• the oil refinery that makes the gasoline, as not allrefineries have the same set of processing units;

• crude oil feed used by the refinery;

• the grade of gasoline, in particular, the octane rating.

Currently, many countries set limits on gasolinearomatics in general, benzene in particular, and olefin(alkene) content. Such regulations led to increasingpreference for high octane pure paraffin (alkane) com-ponents, such as alkylate, and is forcing refineries to addprocessing units to reduce benzene content. In the EUthe benzene limit is set at 1% volume for all grade ofautomotive gasoline.Gasoline can also contain other organic compounds, suchas organic ethers (deliberately added), plus small levels ofcontaminants, in particular organosulfur compounds, butthese are usually removed at the refinery.

6 Additives

See also: List of gasoline additives

6.1 Antiknock additives

Almost all countries in the world have phased out auto-motive leaded fuel. In 2011 six countries[9] in the world

A plastic container for storing gasoline used in Germany

were still using leaded gasoline: Afghanistan, Myanmar,North Korea, Algeria, Iraq and Yemen. It was expectedthat by the end of 2013 those countries would ban leadedpetrol,[10] but actually it will take longer. Algeria will re-place leaded with unleaded automotive fuel only in 2015.Different additives have replaced the lead compounds.The most popular additives include aromatic hydrocar-bons, ethers and alcohol (usually ethanol or methanol).For technical reasons the use of leaded additives is stillpermitted world-wide for the formulation of some gradesof aviation gasoline such as 100LL, because the requiredoctane rating would be technically infeasible to reachwithout the use of leaded additives.

6.1.1 Tetraethyllead

Main article: Tetraethyllead

Gasoline, when used in high-compression internal com-bustion engines, tends to autoignite (detonate) causingdamaging "engine knocking" (also called “pinging” or“pinking”) noise. To address this problem, tetraethyllead(TEL) was widely adopted as an additive for gasoline inthe 1920s. With the discovery of the extent of environ-mental and health damage caused by the lead, however,and the incompatibility of lead with catalytic converters,leaded gasoline was phased out beginning in 1973. By1995, leaded fuel accounted for only 0.6% of total gaso-line sales and less than 2000 short tons (1814 t) of lead peryear in the USA. From 1 January 1996, the U.S. CleanAir Act banned the sale of leaded fuel for use in on-roadvehicles in the USA. The use of TEL also necessitatedother additives, such as dibromoethane. First Europeancountries started replacing lead by the end of the 80’s andby the end of the 90’s leaded petrol was banned within theentire European Union.

6.3 Detergents 5

6.1.2 MMT

Methylcyclopentadienyl manganese tricarbonyl (MMT)is used in Canada and in Australia to boost octane. Italso helps old cars designed for leaded fuel run on un-leaded fuel without need for additives to prevent valveproblems. Its use in the US has been restricted by regu-lations.

6.2 Fuel stabilizers (antioxidants andmetal deactivators)

Substituted phenols and derivatives of phenylenediamine arecommon antioxidants used to inhibit gum formation in gasoline(gasoline).

Gummy, sticky resin deposits result from oxidative degra-dation of gasoline upon long term storage. These harm-ful deposits arise from the oxidation of alkenes and otherminor components in gasoline (see drying oils). Improve-ments in refinery techniques have generally reduced thesusceptibility of gasolines to these problems. Previously,catalytically or thermally cracked gasolines are most sus-ceptible to oxidation. The formation of these gums isaccelerated by copper salts, which can be neutralized byadditives called metal deactivators.This degradation can be prevented through theaddition of 5–100 ppm of antioxidants, such asphenylenediamines and other amines.[6] Hydrocarbonswith a bromine number of 10 or above can be protectedwith the combination of unhindered or partially hinderedphenols and oil soluble strong amine bases, such ashindered phenols. “Stale” gasoline can be detectedby a colorimetric enzymatic test for organic peroxidesproduced by oxidation of the gasoline.[11]

Gasolines are also treated with metal deactivators, whichare compounds that sequester (deactivate) metal salts thatotherwise accelerate the formation of gummy residues.The metal impurities might arise from the engine itselfor as contaminants in the fuel.

6.3 Detergents

Gasoline, as delivered at the pump, also contains addi-tives to reduce internal engine carbon buildups, improvecombustion, and to allow easier starting in cold climates.High levels of detergent can be found in Top Tier De-tergent Gasolines. The specification for Top Tier Deter-gent gasolines was developed by four automakers: GM,Honda, Toyota and BMW. According to the bulletin, theminimal EPA requirement is not sufficient to keep en-gines clean.[12] Typical detergents include alkylaminesand alkyl phosphates at the level of 50-100 ppm.[6]

6.4 Ethanol

See also: Ethanol fuel

6.4.1 European Union

In the EU, 5% ethanol can be added within the commongasoline spec (EN 228). Discussions are ongoing to allow10%blending of ethanol (available in Finnish, French andGerman gas stations). In Finland most gasoline stationssell 95E10, which is 10% of ethanol; and 98E5, whichis 5% ethanol. Most gasoline sold in Sweden has 5-15%ethanol added.

6.4.2 Brazil

In Brazil, the Brazilian National Agency of Petroleum,Natural Gas and Biofuels (ANP) requires gasoline for au-tomobile use to have from 18 to 25% of ethanol added toits composition.[13]

6.4.3 Australia

Legislation requires retailers to label fuels containingethanol on the dispenser, and limits ethanol use to 10% ofpetrol in Australia. Such petrol is commonly called E10by major brands, and it is cheaper than regular unleadedpetrol.

6.4.4 United States of America

The federal Renewable Fuel Standard (RFS) effectivelyrequires refiners and blenders to blend renewable biofuels(mostly ethanol) with gasoline, sufficient to meet a grow-ing annual target of total gallons blended. Although themandate does not require a specific percentage of ethanol,annual increases in the target combined with declininggasoline consumption has caused the typical ethanol con-tent in gasoline to approach 10%. Most fuel pumps dis-play a sticker that states that the fuel may contain upto 10% ethanol, an intentional disparity that reflects the

6 7 SAFETY

varying actual percentage. Until late 2010, fuels retailerswere only authorized to sell fuel containing up to 10 per-cent ethanol (E10), and most vehicle warranties (exceptfor flexible fuel vehicles) authorize fuels that contain nomore than 10 percent ethanol.[14] In parts of the UnitedStates, ethanol is sometimes added to gasoline without anindication that it is a component.

6.4.5 India

The Government of India in October 2007 decided tomake 5% ethanol blending (with gasoline) mandatory.Currently, 10% Ethanol blended product (E10) is beingsold in various parts of the country.[15][16]

6.5 Dye

Main article: Fuel dyes

In Australia, the lowest grade of petrol (RON 91) is dyeda light shade of red/orange and the medium grade (RON95) is dyed yellow.[17]

In the United States, aviation gasoline (avgas) is dyedto identify its octane rating and to distinguish it fromkerosene-based jet fuel, which is clear.[18]

In Canada the gasoline for marine and farm use is dyedred and is not subject to road tax .

6.6 Oxygenate blending

Oxygenate blending adds oxygen-bearing compoundssuch asMTBE, ETBE and ethanol. The presence of theseoxygenates reduces the amount of carbon monoxide andunburned fuel in the exhaust gas. In many areas through-out the US, oxygenate blending is mandated by EPA regu-lations to reduce smog and other airborne pollutants. Forexample, in Southern California, fuel must contain 2%oxygen by weight, resulting in a mixture of 5.6% ethanolin gasoline. The resulting fuel is often known as refor-mulated gasoline (RFG) or oxygenated gasoline, or inthe case of California, California reformulated gasoline.The federal requirement that RFG contain oxygen wasdropped on 6 May 2006 because the industry had devel-oped VOC-controlled RFG that did not need additionaloxygen.[19]

MTBE use is being phased out in some states due to is-sues with contamination of ground water. In some places,such as California, it is already banned. Ethanol and, toa lesser extent, the ethanol-derived ETBE are commonreplacements. A common ethanol-gasoline mix of 10%ethanol mixed with gasoline is called gasohol or E10, andan ethanol-gasoline mix of 85% ethanol mixed with gaso-line is called E85. The most extensive use of ethanoltakes place in Brazil, where the ethanol is derived from

sugarcane. In 2004, over 3.4 billion US gallons (2.8 bil-lion imp gal/13 million m³) of ethanol was produced inthe United States for fuel use, mostly from corn, andE85 is slowly becoming available in much of the UnitedStates, though many of the relatively few stations vend-ing E85 are not open to the general public.[20] The use ofbioethanol, either directly or indirectly by conversion ofsuch ethanol to bio-ETBE, is encouraged by the EuropeanUnion Directive on the Promotion of the use of biofuelsand other renewable fuels for transport. Since producingbioethanol from fermented sugars and starches involvesdistillation, though, ordinary people in much of Europecannot legally ferment and distill their own bioethanol atpresent (unlike in the US, where getting a BATF distilla-tion permit has been easy since the 1973 oil crisis).

7 Safety

HAZMAT Class 3 Gasoline

7.1 Environmental considerations

Combustion of 1 US gallon (3.8 L) of gasoline produces8,788 grams (19.374 lb) of carbon dioxide (2.3 kg/l), agreenhouse gas.[21]

The main concern with gasoline on the environment,aside from the complications of its extraction and re-fining, is the potential effect on the climate. Unburntgasoline and evaporation from the tank, when in theatmosphere, react in sunlight to produce photochemicalsmog. Vapor pressure initially rises with some additionof ethanol to gasoline, but the increase is greatest at 10%by volume. At higher concentrations of ethanol above10%, the vapor pressure of the blend starts to decrease.At a 10% ethanol by volume, the rise in vapor pressuremay potentially increase the problem of photochemical

7

smog. This rise in vapor pressure could be mitigated byincreasing the percentage of ethanol in the gasoline mix-ture.The chief risks of such leaks come not from vehicles,but from gasoline delivery truck accidents and leaks fromstorage tanks. Because of this risk, most (underground)storage tanks now have extensive measures in place to de-tect and prevent any such leaks, such as monitoring sys-tems (Veeder-Root, Franklin Fueling).

7.2 Toxicity

The material safety data sheet for unleaded gasolineshows at least 15 hazardous chemicals occurring in var-ious amounts, including benzene (up to 5% by volume),toluene (up to 35% by volume), naphthalene (up to 1% byvolume), trimethylbenzene (up to 7% by volume), methyltert-butyl ether (MTBE) (up to 18% by volume, in somestates) and about ten others.[22] Hydrocarbons in gasolinegenerally exhibit low acute toxicities, with LD50 of 700 –2700 mg/kg for simple aromatic compounds.[23] Benzeneand many antiknocking additives are carcinogenic.

7.3 Inhalation

Huffed gasoline is a common intoxicant that has becomeepidemic in some poorer communities and indigenousgroups in Australia, Canada, New Zealand, and some Pa-cific Islands.[1] In response, Opal fuel has been developedby the BP Kwinana Refinery in Australia, and containsonly 5% aromatics (unlike the usual 25%), which weak-ens the effects of inhalation.[2]

7.4 Flammability

Uncontrolled burning of gasoline produces large quantities ofsoot and carbon monoxide.

Like other alkanes, gasoline burns in a limited rangeof its vapor phase and, coupled with its volatility, this

makes leaks highly dangerous when sources of ignitionare present. Gasoline has a lower explosion limit of 1.4%by volume and an upper explosion limit of 7.6%. If theconcentration is below 1.4%, the air-gasoline mixture istoo lean and does not ignite. If the concentration is above7.6%, the mixture is too rich and also does not ignite.However, gasoline vapor rapidly mixes and spreads withair, making unconstrained gasoline quickly flammable.

8 Use and pricing

Main articles: gasoline usage and pricing and Peak oilThe United States accounts for about 44% of the world’s

UK gasoline prices

gasoline consumption.[24] In 2003 The US consumed 476gigaliters (126 billion U.S. gallons; 105 billion imperialgallons),[25] which equates to 1.3 gigaliters (340 millionU.S. gallons; 290 million imperial gallons) of gasolineeach day. The US used about 510 gigaliters (130 billionU.S. gallons; 110 billion imperial gallons) of gasoline in2006, of which 5.6% was mid-grade and 9.5% was pre-mium grade.[26]

8.1 Europe

Unlike the US, countries in Europe impose substantialtaxes on fuels such as gasoline. The price of gasoline inEurope is typically more than twice that in the US. InItaly, due to the amendments imposed by Monti’s Gov-ernment in December 2011, the price of gasoline haspassed, in the period of two weeks, from 1.50 €/l (7.48US$/gal) to 1.75 €/l (8.72 US$/gal); on March 17, agasoline station located near Ancona has reached the psy-chological threshold of 2 €/l: the price was €2.001/l(9.97 US$/gal). This chart must be compared to the USAnational average price of gasoline of 0.71 €/l.

8.2 United States

From 1998 to 2004, the price of gasoline fluctuated be-tween $1 and $2 USD per U.S. gallon.[27] After 2004, the

8 12 SEE ALSO

price increased until the average gas price reached a highof $4.11 per U.S. gallon in mid-2008, but receded to ap-proximately $2.60 per U.S. gallon by September 2009.[27]More recently, the U.S. experienced an upswing in gasprices through 2011,[28] and by 1 March 2012, the na-tional average was $3.74 per gallon.In the United States, most consumer goods bear pre-taxprices, but gasoline prices are posted with taxes included.Taxes are added by federal, state, and local governments.As of 2009, the federal tax is 18.4¢ per gallon for gasolineand 24.4¢ per gallon for diesel (excluding red diesel).[29]Among states, the highest gasoline tax rates, includingthe federal taxes as of 2005, are New York (62.9¢/gal),Hawaii (60.1¢/gal), and California (60¢/gal).[28] How-ever, many states’ taxes are a percentage and thus varyin amount depending on the cost of the gasoline.About 9% of all gasoline sold in the US in May 2009was premium grade, according to the Energy Informa-tion 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.”[30] The Associ-ated Press said premium gas—which is a higher octaneand costs more per gallon than regular unleaded—shouldbe used only if the manufacturer says it is “required”.[31]Cars with turbocharged engines and high compressionratios often specify premium gas because higher oc-tane fuels reduce the incidence of “knock”, or fuel pre-detonation.[32] If regular fuel is used, the engine computerusually switches to a less aggressive fuel map to protectthe engine, and performance is decreased.

9 History

The first automotive combustion engines, so-called Ottoengines, were developed in the last quarter of the 19thcentury in Germany. The fuel was a relatively volatile hy-drocarbon obtained from coal gas. With a boiling pointnear 85 °C (octanes boil about 40 °C higher), it was wellsuited for early carburetors (evaporators). The devel-opment of a “spray nozzle” carburetor enabled the useof less volatile fuels. Further improvements in engineefficiency were attempted at higher compression ratios,but early attempts were blocked by knocking (prema-ture explosion of fuel). In the 1920s, antiknock com-pounds were introduced by Migley and Boyd, specificallytetraethyllead (TEL). This innovation started a cycle ofimprovements in fuel efficiency that coincided with thelarge-scale development of oil refining to provide moreproducts in the boiling range of gasolines. In the 1950s oilrefineries started to focus on high octane fuels, and thendetergents were added to gasoline to clean the jets andcarburetors. The 1970s witnessed greater attention to theenvironmental consequences of burning gasoline. Theseconsiderations led to the phasing out of TEL and its re-placement by other antiknock compounds. Subsequently,low-sulfur gasoline was introduced, in part to preserve the

catalysts in modern exhaust systems.[6]

10 Etymology and terminology

“Gasoline” is cited (under the spelling “gasolene”) from1863 in the Oxford English Dictionary. It was never atrademark, although it may have been derived from oldertrademarks such as “Cazeline” and “Gazeline”.[33]

Variant spellings of “gasoline” have been used to re-fer to raw petroleum since the 16th century.[33] “Petrol”was first used as the name of a refined petroleum prod-uct around 1870 by British wholesaler Carless, Capel& Leonard, who marketed it as a solvent.[34] When theproduct later found a new use as a motor fuel, FrederickSimms, an associate of Gottlieb Daimler, suggested toCarless that they register the trade mark “petrol”,[35] butby this time the word was already in general use, possi-bly inspired by the French pétrole,[33] and the registrationwas not allowed. Carless registered a number of alterna-tive names for the product, while their competitors usedthe term “motor spirit” until the 1930s.[36][37]

In many countries, gasoline has a colloquial name de-rived from that of the chemical benzene (e.g., GermanBenzin, Dutch benzine, Italian benzina, Polish benzyna,Chile bencina, Thai เบนซิน bayn sin , Greek βενζίνη ven-zini, Romanian benzină, Swedish bensin, Arabic بنزينbinzīn). Argentina, Uruguay and Paraguay use the col-loquial name nafta derived from that of the chemicalnaphtha.[38]

The terms “mogas”, short for motor gasoline, or“autogas”, short for automobile gasoline, are usedto distinguish automobile fuel from aviation fuel, or"avgas".[39][40][41]

11 Comparison with other fuels

See also: Energy content of biofuel

Volumetric and mass energy density of some fuels com-pared with gasoline (in the rows with gross and net, theyare from[42]):(*) Diesel fuel is not used in a gasoline engine, so its low octanerating is not an issue; the relevant metric for diesel engines isthe cetane number

12 See also• Aftermarket fuel economy device

• Aviation fuel

• Biobutanol – replacement fuel for use in unmodifiedgasoline engines

13.1 Notes 9

• Diesel fuel

• Filling station

• Fuel dispenser

• Gasoline and diesel usage and pricing

• Gasoline gallon equivalent

• Internal combustion engine (ICE)

• Jerrycan

• List of automotive fuel brands

• Natural-gas condensate#Drip gas

• Octane rating

• Oil price increases since 2003

13 References

13.1 Notes[1] gasoline Sniffing Fact File Sheree Cairney, www.abc.net.

au, Published 24th November 2005. Retrieved 13th Oc-tober 2007, a modified version of the original article, nowarchived

[2] Fuel technology www.bp.com. Retrieved 8th June 2007.

[3]

[4] “95/93 – What is the Difference, Really?". AutomobileAssociation of South Africa (AA). Retrieved September2014.

[5] “Best Gasoline Will Win War of the Future” Popular Me-chanics, April 1935 article at bottom of page 524

[6] Werner Dabelstein, Arno Reglitzky, Andrea Schützeand Klaus Reders “Automotive Fuels” in Ullmann’s En-cyclopedia of Industrial Chemistry 2007, Wiley-VCH,Weinheim.doi:10.1002/14356007.a16_719.pub2

[7] “Oil Industry Statistics from Gibson Consulting”. Re-trieved 31 July 2008.

[8] Bell Fuels. “Lead-Free gasoline Material Safety DataSheet”. NOAA. Retrieved 6 July 2008.

[9] “List of countries using leaded petrol in 2011”.

[10] “UN: Leaded fuel to be gone by 2013”.

[11] A1 AU 2000/72399 A1 Gasoline test kit

[12] “Top Tier Detergent Gasoline (Deposits, Fuel Economy,No Start, Power, Performance, Stall Concerns), GM Bul-letin, 04-06-04-047, 06-Engine/Propulsion System, June2004

[13] http://www.senado.gov.br/atividade/materia/detalhes.asp?p_cod_mate=100053

[14] [citation needed]

[15] “Government to take a call on ethanol price soon”. TheHindu (Chennai, India). 21 Nov 2011. Retrieved 25 May2012.

[16] “India to raise ethanol blending in gasoline to 10%". 22November 2011. Retrieved 25 May 2012.

[17] http://www.aip.com.au/topics/mr_pdf/AIP_media_release_280912.pdf

[18] Aviation Advocacy | EAA

[19] “Removal of Reformulated Gasoline Oxygen Content Re-quirement (national) and Revision of Commingling Pro-hibition to Address Non-0xygenated Reformulated Gaso-line (national)". U.S. Environmental Protection Agency.22 February 2006.

[20] “Alternative Fueling Station Locator”. U.S. Departmentof Energy.

[21] “HowGasoline Becomes CO2”. SlateMagazine. Novem-ber 1, 2006.

[22] Material safety data sheet Tesoro petroleum Companies,Inc., U.S., 8 February 2003

[23] Karl Griesbaum et al. “Hydrocarbons” in Ullmann’s En-cyclopedia of Industrial Chemistry 2005, Wiley-VCH,Weinheim.doi:10.1002/14356007.a13_227

[24] http://www.worldwatch.org/node/5579 , http://www.eia.doe.gov/emeu/international/oilconsumption.html

[25] EarthTrends: Energy and Resources — Transportation:Motor gasoline consumption Units: Million liters

[26] “U.S. Prime Supplier Sales Volumes of petroleum Prod-ucts”. United States Energy Information Administration.Retrieved 24 October 2007.

[27] Fuel Economy.gov, FAQ

[28] http://www.taxfoundation.org/UserFiles/Image/Fiscal%20Facts/gas-tax-690px.jpg

[29] “When did the Federal Government begin collecting thegas tax? — Ask the Rambler — Highway History —FHWA”. Fhwa.dot.gov. Retrieved 17 October 2010.

[30] Car reviews and ratings from Consumer Reports

[31] Associated Press, “Gassing up with premium probably awaste,” 19 August 2009.

[32] Fact or Fiction?: Premium Gasoline Delivers PremiumBenefits to Your Car - Scientific American

[33] gasoline, n., and gasoline, n., Oxford English Dictionaryonline edition

[34] "Carless, Capel & Leonard", vintagegarage.co.uk, ac-cessed 2012-08-05

[35] "Carless, Capel and Leonard Ltd Records: AdministrativeHistory", The National Archives, accessed 2012-08-05

[36] Online Etymology Dictionary

10 14 EXTERNAL LINKS

[37] Ron Hincks (2004). “Our Motoring Heritage: gasoline &Oil”. Chrysler Collector (154): 16–20.

[38] Spanish Dict

[39] Federal Aviation Administration (5 April 2000).“Revised Special Airworthiness Information Bulletin(SAIB) Number CE-00-19R1”. Archived from theoriginal on 12 October 2006. Retrieved 28 October2006. “The FAA highly recommends installing placardsstating the use of 82UL is or is not approved on thoseairplanes that specify unleaded autogas as an approvedfuel.”

[40] Pew, Glenn (November 2007). “Avgas: Group Asks EPATo Get The Lead Out”. Retrieved 18 February 2008.

[41] , Mogas, Alcohol Blend, Octane, Aviation Fuels and Spec-ifications

[42] Appendix B, Transportation Energy Data Book from theCenter for Transportation Analysis of the Oak Ridge Na-tional Laboratory

[43] Thomas, George: Overview of Storage DevelopmentDOE Hydrogen Program PDF (99.6 KB). Livermore,CA. Sandia National Laboratories. 2000.

[44] Eyidogan, Muharrem; Ozsezen, Ahmet Necati; Canakci,Mustafa; Turkcan, Ali (2010). “Impact of alcohol–gasoline fuel blends on the performance and combustioncharacteristics of an SI engine”. Fuel 89 (10): 2713.doi:10.1016/j.fuel.2010.01.032.

[45] Bioenergy Feedstock Development Programs at OakRodge National Laboratory

[46] The National Hydrogen Association FAQs

13.2 Bibliography

• Graph of inflation-corrected historic prices, 1970–2005. Highest in 2005

• The Low-Down on High Octane Gasoline

• MMT-US EPA

• An introduction to the modern petroleum science,and to the Russian-Ukrainian theory of deep, abioticpetroleum origins.

• What’s the difference between premium and regulargas? (from The Straight Dope)

• “Here Comes Winter Gasoline” R-Squared EnergyBlog 14 September 2006

• International Fuel Prices 2005 with diesel and gaso-line prices of 172 countries

• EIA — Gasoline and Diesel Fuel Update

• World Internet News: “Big Oil Looking for AnotherGovernment Handout”, April 2006.

• Durability of various plastics: Alcohols vs. Gasoline

• Dismissal of the Claims of a Biological Connectionfor Natural petroleum.

• Fuel Economy Impact Analysis of RFG i.e. refor-mulated gasoline. Has lower heating value data, ac-tual energy content is higher see higher heating value

14 External links• EFOA

• CNN/Money: Global gas prices

• EEP: European gas prices

• Transportation Energy Data Book

• Energy Supply Logistics Searchable Directory of USTerminals

• 2011 NACS Annual Fuels Report

• Definition of basic terms, Graphs of Gas prices. allin Slovak language

• Gasoline from Vinegar | MIT Technology Review

• High octane fuel, leaded and LRP gasoline— articlefrom robotpig.net

• CDC - NIOSH Pocket Guide to Chemical Hazards

Images

• Down the Gasoline Trail Handy Jam Organization,1935 (Cartoon)

11

15 Text and image sources, contributors, and licenses

15.1 Text• Gasoline Source: http://en.wikipedia.org/wiki/Gasoline?oldid=632107619 Contributors: Derek Ross, Mav, Wesley, Bryan Derksen,Robert Merkel, Jeronimo, Ed Poor, Andre Engels, 0, Rmhermen, William Avery, DavidLevinson, Ben-Zin, Maury Markowitz, Heron,Camembert, Hfastedge, Bdesham, JohnOwens, Polimerek, Norm, Liftarn, Ixfd64, Gbleem, Ahoerstemeier, Mac, Ronz, Jimfbleak, Docu,G-Man, Angela, Jdforrester, Glenn, Michael Shields, Gabriel, Andres, Samw, Lukobe, Nertzy, Smack, JidGom, Mulad, TheSeez, Timwi,Bemoeial, Harris7, Hydnjo, Audin, Fuzheado, WhisperToMe, PeterGrecian, Timc, Gestumblindi, Maximus Rex, LMB, SEWilco, Omega-tron, Shizhao, Topbanana, Dbabbitt, Secretlondon, Proteus, Francs2000, Drxenocide, EdwinHJ, Robbot, Dale Arnett, Josh Cherry, PBS,Mirv, Henrygb, Academic Challenger, Sekicho, Jondel, Bkell, Rebrane, Hadal, Superm401, Jooler, David Gerard, Alexwcovington, Jpo,Giftlite, DocWatson42, MPF, Yama, ShaneCavanaugh, Fudoreaper, Peruvianllama, Everyking, Frencheigh, Malyctenar, Unconcerned,Guanaco, Yekrats, Dmmaus, Edsuom, Jorge Stolfi, BesigedB, Eequor, Solipsist, Darrien, Jackol, Bobblewik, Golbez, Chowbok, Gadfium,Sonjaaa, Quadell, Sendervictorius, Antandrus, Beland, WhiteDragon, Jossi, SimonArlott, MacGyverMagic, H Padleckas, Kevin B12, Ge-oGreg, Bk0, Mrtrey99, Yossarian, Gscshoyru, Nickptar, Creidieki, Neutrality, DanMatan, Joyous!, Quota, Ukexpat, Andy Christ, Sonett72,Fabrício Kury, Deglr6328, Todd Kloos, Adashiel, Lacrimosus, DmitryKo, Metahacker, Mike Rosoft, Freakofnurture, Sysy, Plexust, Nary-athegreat, Discospinster, ElTyrant, Rich Farmbrough, Guanabot, Supercoop, Cacycle, AxSkov, Vsmith, Ponder, Zazou, Dbachmann,GPoss, Andrejj, Violetriga, Evice, Smallbone10, Joel Russ, Bletch, Kwamikagami, Sietse Snel, RoyBoy, Dennis Brown, Bookofjude,Coolcaesar, Femto, Perfecto, Lensim, Bastique, Afed, Bobo192, Spalding, Key45, Chtito, Walkiped, Dreish, Mricon, Mtruch, Jerry-seinfeld, Cavrdg, Kjkolb, Storm Rider, Danski14, Alansohn, Anthony 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