# Chemistry:Gasoline

Short description: Transparent, petroleum-derived liquid used primarily as fuel
Gasoline in a mason jar measuring roughly 24 U.S. fl oz (700 milliliters)
A typical gasoline container holds 1.0 U.S. gallon (3.8 L).

Gasoline (American English; /ˈɡæsəln/) or petrol (British English; /ˈpɛtrəl/) (see Etymology for naming differences and geographic usage) is a transparent, petroleum‑derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. On average, a 42-U.S.-gallon (160-liter) barrel of crude oil can yield up to about 19 U.S. gallons (72 liters) of gasoline after processing in an oil refinery, depending on the crude oil assay and on what other refined products are also extracted.[1] The characteristic of a particular gasoline blend to resist igniting too early (which causes knocking and reduces efficiency in reciprocating engines) is measured by its octane rating, which is produced in several grades. Tetraethyl lead and other lead compounds, once widely used to increase octane ratings, are no longer used except in aviation[2] and off-road and auto-racing applications.[3] Other chemicals are frequently added to gasoline to improve chemical stability and performance characteristics, control corrosiveness, and provide fuel system cleaning. Gasoline may contain oxygen-containing chemicals such as ethanol, MTBE, or ETBE to improve combustion.

Gasoline can enter the environment (uncombusted), both as liquid and as vapor, from leakage and handling during production, transport, and delivery (e.g., from storage tanks, from spills, etc.). As an example of efforts to control such leakage, many underground storage tanks are required to have extensive measures in place to detect and prevent such leaks.[4] Gasoline contains known carcinogens.[5][6][7] Burning 0.26 U.S. gallons (1 L) of gasoline emits about 5.1 pounds (2.3 kg) of CO
2
, a greenhouse gas, contributing to human-caused climate change.[8][9]

## Etymology

"Gasoline" is an English word that denotes fuel for automobiles. The term is thought to have been influenced by the trademark "Cazeline" or "Gazeline", named after the surname of British publisher, coffee merchant, and social campaigner John Cassell. On 27 November 1862, Cassell placed an advertisement in The Times of London:

The Patent Cazeline Oil, safe, economical, and brilliant … possesses all the requisites which have so long been desired as a means of powerful artificial light.[10]

This is the earliest occurrence of the word to have been found. Cassell discovered that a shopkeeper in Dublin named Samuel Boyd was selling counterfeit cazeline and wrote to him to ask him to stop. Boyd did not reply and changed every ‘C’ into a ‘G’, thus coining the word "gazeline".[10] The Oxford English Dictionary dates its first recorded use to 1863 when it was spelled "gasolene". The term "gasoline" was first used in North America in 1864.[11]

In most Commonwealth countries (except Canada), the product is called "petrol", rather than "gasoline". The word petroleum, originally used to refer to various types of mineral oils and literally meaning "rock oil", comes from Medieval Latin petroleum (petra, "rock", and oleum, "oil").[12][13] "Petrol" was used as a product name in about 1870, as the name of a refined mineral oil product sold by British wholesaler Carless, Capel & Leonard, which marketed it as a solvent.[14] When the product later found a new use as a motor fuel, Frederick Simms, an associate of Gottlieb Daimler, suggested to John Leonard, the owner of Carless, that they register the trademark "Petrol",[15] but by that time the word was already in general use, possibly inspired by the French pétrole,[16] and the registration was not allowed because the word was a general descriptor; Carless was still able to defend its use of "Petrol" as a product name due to their having sold it under that name for many years by then. Carless registered a number of alternative names for the product, but "petrol" nonetheless became the common term for the fuel in the British Commonwealth.[17][18]

British refiners originally used "motor spirit" as a generic name for the automotive fuel and "aviation spirit" for aviation gasoline. When Carless was denied a trademark on "petrol" in the 1930s, its competitors switched to the more popular name "petrol". However, "motor spirit" had already made its way into laws and regulations, so the term remains in use as a formal name for petrol.[19][20] The term is used most widely in Nigeria, where the largest petroleum companies call their product "premium motor spirit".[21] Although "petrol" has made inroads into Nigerian English, "premium motor spirit" remains the formal name that is used in scientific publications, government reports, and newspapers.[22]

The use of the word gasoline instead of petrol is uncommon outside North America,[23] although gasolina is used in Spanish and Portuguese.

In many languages, the name of the product is derived from benzene, such as Benzin in Persian and German or benzina in Italian; but in Argentina, Uruguay, and Paraguay, the colloquial name nafta is derived from that of the chemical naphtha.[24]

Some languages,like French and Italian, use the respective words for gasoline to indicate diesel fuel.[25][26]

## History

The first internal combustion engines suitable for use in transportation applications, so-called Otto engines, were developed in Germany during the last quarter of the 19th century. The fuel for these early engines was a relatively volatile hydrocarbon obtained from coal gas. With a boiling point near 85 °C (185 °F) (n-octane boils about 40 °C higher), it was well-suited for early carburetors (evaporators). The development of a "spray nozzle" carburetor enabled the use of less volatile fuels. Further improvements in engine efficiency were attempted at higher compression ratios, but early attempts were blocked by the premature explosion of fuel, known as knocking.

In 1891, the Shukhov cracking process became the world's first commercial method to break down heavier hydrocarbons in crude oil to increase the percentage of lighter products compared to simple distillation.

### 1903 to 1914

The evolution of gasoline followed the evolution of oil as the dominant source of energy in the industrializing world. Before World War One, Britain was the world's greatest industrial power and depended on its navy to protect the shipping of raw materials from its colonies. Germany was also industrializing and, like Britain, lacked many natural resources which had to be shipped to the home country. By the 1890s, Germany began to pursue a policy of global prominence and began building a navy to compete with Britain's. Coal was the fuel that powered their navies. Though both Britain and Germany had natural coal reserves, new developments in oil as a fuel for ships changed the situation. Coal-powered ships were a tactical weakness because the process of loading coal was extremely slow and dirty and left the ship completely vulnerable to attack, and unreliable supplies of coal at international ports made long-distance voyages impractical. The advantages of petroleum oil soon found the navies of the world converting to oil, but Britain and Germany had very few domestic oil reserves.[27] Britain eventually solved its naval oil dependence by securing oil from Royal Dutch Shell and the Anglo-Persian Oil Company and this determined from where and of what quality its gasoline would come.

During the early period of gasoline engine development, aircraft were forced to use motor vehicle gasoline since aviation gasoline did not yet exist. These early fuels were termed "straight-run" gasolines and were byproducts from the distillation of a single crude oil to produce kerosene, which was the principal product sought for burning in kerosene lamps. Gasoline production would not surpass kerosene production until 1916. The earliest straight-run gasolines were the result of distilling eastern crude oils and there was no mixing of distillates from different crudes. The composition of these early fuels was unknown and the quality varied greatly as crude oils from different oil fields emerged in different mixtures of hydrocarbons in different ratios. The engine effects produced by abnormal combustion (engine knocking and pre-ignition) due to inferior fuels had not yet been identified, and as a result, there was no rating of gasoline in terms of its resistance to abnormal combustion. The general specification by which early gasolines were measured was that of specific gravity via the Baumé scale and later the volatility (tendency to vaporize) specified in terms of boiling points, which became the primary focuses for gasoline producers. These early eastern crude oil gasolines had relatively high Baumé test results (65 to 80 degrees Baumé) and were called Pennsylvania "High-Test" or simply "High-Test" gasolines. These would often be used in aircraft engines.

By 1910, increased automobile production and the resultant increase in gasoline consumption produced a greater demand for gasoline. Also, the growing electrification of lighting produced a drop in kerosene demand, creating a supply problem. It appeared that the burgeoning oil industry would be trapped into over-producing kerosene and under-producing gasoline since simple distillation could not alter the ratio of the two products from any given crude. The solution appeared in 1911 when the development of the Burton process allowed thermal cracking of crude oils, which increased the percent yield of gasoline from the heavier hydrocarbons. This was combined with the expansion of foreign markets for the export of surplus kerosene which domestic markets no longer needed. These new thermally "cracked" gasolines were believed to have no harmful effects and would be added to straight-run gasolines. There also was the practice of mixing heavy and light distillates to achieve the desired Baumé reading and collectively these were called "blended" gasolines.[28]

Gradually, volatility gained favor over the Baumé test, though both would continue to be used in combination to specify a gasoline. As late as June 1917, Standard Oil (the largest refiner of crude oil in the United States at the time) stated that the most important property of a gasoline was its volatility.[29] It is estimated that the rating equivalent of these straight-run gasolines varied from 40 to 60 octane and that the "High-Test", sometimes referred to as "fighting grade", probably averaged 50 to 65 octane.[30]

### World War I

Prior to the American entry into World War I, the European Allies used fuels derived from crude oils from Borneo, Java, and Sumatra, which gave satisfactory performance in their military aircraft. When the United States entered the war in April 1917, the U.S. became the principal supplier of aviation gasoline to the Allies and a decrease in engine performance was noted.[31] Soon it was realized that motor vehicle fuels were unsatisfactory for aviation, and after the loss of several combat aircraft, attention turned to the quality of the gasolines being used. Later flight tests conducted in 1937 showed that an octane reduction of 13 points (from 100 down to 87 octane) decreased engine performance by 20 percent and increased take-off distance by 45 percent.[32] If abnormal combustion were to occur, the engine could lose enough power to make getting airborne impossible and a take-off roll became a threat to the pilot and aircraft.

On 2 August 1917, the United States Bureau of Mines arranged to study fuels for aircraft in cooperation with the Aviation Section of the U.S. Army Signal Corps and a general survey concluded that no reliable data existed for the proper fuels for aircraft. As a result, flight tests began at Langley, McCook and Wright fields to determine how different gasolines performed under different conditions. These tests showed that in certain aircraft, motor vehicle gasolines performed as well as "High-Test" but in other types resulted in hot-running engines. It was also found that gasolines from aromatic and naphthenic base crude oils from California, South Texas, and Venezuela resulted in smooth-running engines. These tests resulted in the first government specifications for motor gasolines (aviation gasolines used the same specifications as motor gasolines) in late 1917.[33]

### United States, 1918–1929

Engine designers knew that, according to the Otto cycle, power and efficiency increased with compression ratio, but experience with early gasolines during World War I showed that higher compression ratios increased the risk of abnormal combustion, producing lower power, lower efficiency, hot-running engines, and potentially severe engine damage. To compensate for these poor fuels, early engines used low compression ratios, which required relatively large, heavy engines with limited power and efficiency. The Wright brothers' first gasoline engine used a compression ratio as low as 4.7-to-1, developed only 12 horsepower (8.9 kW) from 201 cubic inches (3,290 cc), and weighed 180 pounds (82 kg).[34][35] This was a major concern for aircraft designers and the needs of the aviation industry provoked the search for fuels that could be used in higher-compression engines.

Between 1917 and 1919, the amount of thermally cracked gasoline utilized almost doubled. Also, the use of natural gasoline increased greatly. During this period, many U.S. states established specifications for motor gasoline but none of these agreed and they were unsatisfactory from one standpoint or another. Larger oil refiners began to specify unsaturated material percentage (thermally cracked products caused gumming in both use and storage while unsaturated hydrocarbons are more reactive and tend to combine with impurities leading to gumming). In 1922, the U.S. government published the first specifications for aviation gasolines (two grades were designated as "Fighting" and "Domestic" and were governed by boiling points, color, sulfur content, and a gum formation test) along with one "Motor" grade for automobiles. The gum test essentially eliminated thermally cracked gasoline from aviation usage and thus aviation gasolines reverted to fractionating straight-run naphthas or blending straight-run and highly treated thermally cracked naphthas. This situation persisted until 1929.[36]

The automobile industry reacted to the increase in thermally cracked gasoline with alarm. Thermal cracking produced large amounts of both mono- and diolefins (unsaturated hydrocarbons), which increased the risk of gumming.[37] Also, the volatility was decreasing to the point that fuel did not vaporize and was sticking to spark plugs and fouling them, creating hard starting and rough running in winter and sticking to cylinder walls, bypassing the pistons and rings, and going into the crankcase oil.[38] One journal stated, "...on a multi-cylinder engine in a high-priced car we are diluting the oil in the crankcase as much as 40 percent in a 200-mile run, as the analysis of the oil in the oil-pan shows."[39]

Being very unhappy with the consequent reduction in overall gasoline quality, automobile manufacturers suggested imposing a quality standard on the oil suppliers. The oil industry in turn accused the automakers of not doing enough to improve vehicle economy, and the dispute became known within the two industries as "The Fuel Problem". Animosity grew between the industries, each accusing the other of not doing anything to resolve matters, and their relationship deteriorated. The situation was only resolved when the American Petroleum Institute (API) initiated a conference to address "The Fuel Problem" and a Cooperative Fuel Research (CFR) Committee was established in 1920, to oversee joint investigative programs and solutions. Apart from representatives of the two industries, the Society of Automotive Engineers (SAE) also played an instrumental role, with the U.S. Bureau of Standards being chosen as an impartial research organization to carry out many of the studies. Initially, all the programs were related to volatility and fuel consumption, ease of starting, crankcase oil dilution, and acceleration.[40]

With the increased use of thermally cracked gasolines came an increased concern regarding its effects on abnormal combustion, and this led to research for antiknock additives. In the late 1910s, researchers such as A.H. Gibson, Harry Ricardo, Thomas Midgley Jr., and Thomas Boyd began to investigate abnormal combustion. Beginning in 1916, Charles F. Kettering of General Motors began investigating additives based on two paths, the "high percentage" solution (where large quantities of ethanol were added) and the "low percentage" solution (where only 2–4 grams per gallon were needed). The "low percentage" solution ultimately led to the discovery of tetraethyllead (TEL) in December 1921, a product of the research of Midgley and Boyd and the defining component of leaded gasoline. This innovation started a cycle of improvements in fuel efficiency that coincided with the large-scale development of oil refining to provide more products in the boiling range of gasoline. Ethanol could not be patented but TEL could, so Kettering secured a patent for TEL and began promoting it instead of other options.

### United States, 1930–1941

In the five years prior to 1929, a great amount of experimentation was conducted on different testing methods for determining fuel resistance to abnormal combustion. It appeared engine knocking was dependent on a wide variety of parameters including compression, ignition timing, cylinder temperature, air-cooled or water-cooled engines, chamber shapes, intake temperatures, lean or rich mixtures, and others. This led to a confusing variety of test engines that gave conflicting results, and no standard rating scale existed. By 1929, it was recognized by most aviation gasoline manufacturers and users that some kind of antiknock rating must be included in government specifications. In 1929, the octane rating scale was adopted, and in 1930, the first octane specification for aviation fuels was established. In the same year, the U.S. Army Air Force specified fuels rated at 87 octane for its aircraft as a result of studies it had conducted.[43]

During this period, research showed that hydrocarbon structure was extremely important to the antiknocking properties of fuel. Straight-chain paraffins in the boiling range of gasoline had low antiknock qualities while ring-shaped molecules such as aromatic hydrocarbons (for example benzene) had higher resistance to knocking.[44] This development led to the search for processes that would produce more of these compounds from crude oils than achieved under straight distillation or thermal cracking. Research by the major refiners led to the development of processes involving isomerization of cheap and abundant butane to isobutane, and alkylation to join isobutane and butylenes to form isomers of octane such as "isooctane", which became an important component in aviation fuel blending. To further complicate the situation, as engine performance increased, the altitude that aircraft could reach also increased, which resulted in concerns about the fuel freezing. The average temperature decrease is 3.6 °F (2.0 °C) per 1,000-foot (300-meter) increase in altitude, and at 40,000 feet (12 km), the temperature can approach −70 °F (−57 °C). Additives like benzene, with a freezing point of 42 °F (6 °C), would freeze in the gasoline and plug fuel lines. Substituted aromatics such as toluene, xylene, and cumene, combined with limited benzene, solved the problem.[45]

The development of 100-octane aviation gasoline on an economic scale was due in part to Jimmy Doolittle, who had become Aviation Manager of Shell Oil Company. He convinced Shell to invest in refining capacity to produce 100-octane on a scale that nobody needed since no aircraft existed that required a fuel that nobody made. Some fellow employees would call his effort "Doolittle's million-dollar blunder" but time would prove Doolittle correct. Before this, the Army had considered 100-octane tests using pure octane but at $25 a gallon, the price prevented this from happening. In 1929 Stanavo Specification Board, Inc. was organized by the Standard Oil companies of California, Indiana, and New Jersey to improve aviation fuels and oils and by 1935 had placed their first 100 octane fuel on the market, Stanavo Ethyl Gasoline 100. It was used by the Army, engine manufacturers and airlines for testing and for air racing and record flights.[47] By 1936 tests at Wright Field using the new, cheaper alternatives to pure octane proved the value of 100 octane fuel, and both Shell and Standard Oil would win the contract to supply test quantities for the Army. By 1938 the price was down to 17.5 cents a gallon, only 2.5 cents more than 87 octane fuel. By the end of WW II the price would be down to 16 cents a gallon.[48] In 1937, Eugene Houdry developed the Houdry process of catalytic cracking, which produced a high-octane base stock of gasoline which was superior to the thermally cracked product since it did not contain the high concentration of olefins.[28] In 1940, there were only 14 Houdry units in operation in the U.S.; by 1943, this had increased to 77, either of the Houdry process or of the Thermofor Catalytic or Fluid Catalyst type.[49] The search for fuels with octane ratings above 100 led to the extension of the scale by comparing power output. A fuel designated grade 130 would produce 130 percent as much power in an engine as it would running on pure iso-octane. During WW II, fuels above 100-octane were given two ratings, a rich and a lean mixture, and these would be called 'performance numbers' (PN). 100-octane aviation gasoline would be referred to as 130/100 grade.[50] ### World War II #### Germany Oil and its byproducts, especially high-octane aviation gasoline, would prove to be a driving concern for how Germany conducted the war. As a result of the lessons of World War I, Germany had stockpiled oil and gasoline for its blitzkrieg offensive and had annexed Austria, adding 18,000 barrels per day of oil production, but this was not sufficient to sustain the planned conquest of Europe. Because captured supplies and oil fields would be necessary to fuel the campaign, the German high command created a special squad of oil-field experts drawn from the ranks of domestic oil industries. They were sent in to put out oil-field fires and get production going again as soon as possible. But capturing oil fields remained an obstacle throughout the war. During the Invasion of Poland, German estimates of gasoline consumption turned out to be vastly too low. Heinz Guderian and his Panzer divisions consumed nearly 1 US gallon per mile (2.4 l/km) of gasoline on the drive to Vienna. When they were engaged in combat across open country, gasoline consumption almost doubled. On the second day of battle, a unit of the XIX Corps was forced to halt when it ran out of gasoline.[51] One of the major objectives of the Polish invasion was their oil fields but the Soviets invaded and captured 70 percent of the Polish production before the Germans could reach it. Through the German-Soviet Commercial Agreement (1940), Stalin agreed in vague terms to supply Germany with additional oil equal to that produced by now Soviet-occupied Polish oil fields at Drohobych and Boryslav in exchange for hard coal and steel tubing. Even after the Nazis conquered the vast territories of Europe, this did not help the gasoline shortage. This area had never been self-sufficient in oil before the war. In 1938, the area that would become Nazi-occupied produced 575,000 barrels per day. In 1940, total production under German control amounted to only 234,550 barrels (37,290 m3).[52] By the spring of 1941 and the depletion of German gasoline reserves, Adolf Hitler saw the invasion of Russia to seize the Polish oil fields and the Russian oil in the Caucasus as the solution to the German gasoline shortage. As early as July 1941, following the 22 June start of Operation Barbarossa, certain Luftwaffe squadrons were forced to curtail ground support missions due to shortages of aviation gasoline. On 9 October, the German quartermaster general estimated that army vehicles were 24,000 barrels (3,800 m3) short of gasoline requirements.[53] Virtually all of Germany's aviation gasoline came from synthetic oil plants that hydrogenated coals and coal tars. These processes had been developed during the 1930s as an effort to achieve fuel independence. There were two grades of aviation gasoline produced in volume in Germany, the B-4 or blue grade and the C-3 or green grade, which accounted for about two-thirds of all production. B-4 was equivalent to 89-octane and the C-3 was roughly equal to the U.S. 100-octane, though lean mixture was rated around 95-octane and was poorer than the U.S. version. Maximum output achieved in 1943 reached 52,200 barrels a day before the Allies decided to target the synthetic fuel plants. Through captured enemy aircraft and analysis of the gasoline found in them, both the Allies and the Axis powers were aware of the quality of the aviation gasoline being produced and this prompted an octane race to achieve the advantage in aircraft performance. Later in the war, the C-3 grade was improved to where it was equivalent to the U.S. 150 grade (rich mixture rating).[54] #### Japan Japan, like Germany, had almost no domestic oil supply and by the late 1930s, produced only 7% of its own oil while importing the rest – 80% from the United States. As Japanese aggression grew in China (USS Panay incident) and news reached the American public of Japanese bombing of civilian centers, especially the bombing of Chungking, public opinion began to support a U.S. embargo. A Gallup poll in June 1939 found that 72 percent of the American public supported an embargo on war materials to Japan. This increased tensions between the U.S. and Japan, and it led to the U.S. placing restrictions on exports. In July 1940, the U.S. issued a proclamation that banned the export of 87 octane or higher aviation gasoline to Japan. This ban did not hinder the Japanese as their aircraft could operate with fuels below 87 octane and if needed they could add TEL to increase the octane. As it turned out, Japan bought 550 percent more sub-87 octane aviation gasoline in the five months after the July 1940 ban on higher octane sales.[55] The possibility of a complete ban of gasoline from America created friction in the Japanese government as to what action to take to secure more supplies from the Dutch East Indies and demanded greater oil exports from the exiled Dutch government after the Battle of the Netherlands. This action prompted the U.S. to move its Pacific fleet from Southern California to Pearl Harbor to help stiffen British resolve to stay in Indochina. With the Japanese invasion of French Indochina in September 1940, came great concerns about the possible Japanese invasion of the Dutch Indies to secure their oil. After the U.S. banned all exports of steel and iron scrap, the next day Japan signed the Tripartite Pact and this led Washington to fear that a complete U.S. oil embargo would prompt the Japanese to invade the Dutch East Indies. On 16 June 1941 Harold Ickes, who was appointed Petroleum Coordinator for National Defense, stopped a shipment of oil from Philadelphia to Japan in light of the oil shortage on the East coast due to increased exports to Allies. He also telegrammed all oil suppliers on the East coast not to ship any oil to Japan without his permission. President Roosevelt countermanded Ickes' orders telling Ickes that the "... I simply have not got enough Navy to go around and every little episode in the Pacific means fewer ships in the Atlantic".[56] On 25 July 1941, the U.S. froze all Japanese financial assets and licenses would be required for each use of the frozen funds including oil purchases that could produce aviation gasoline. On 28 July 1941, Japan invaded southern Indochina. The debate inside the Japanese government as to its oil and gasoline situation was leading to invasion of the Dutch East Indies but this would mean war with the U.S., whose Pacific fleet was a threat to their flank. This situation led to the decision to attack the U.S. fleet at Pearl Harbor before proceeding with the Dutch East Indies invasion. On 7 December 1941, Japan attacked Pearl Harbor, and the next day the Netherlands declared war on Japan, which initiated the Dutch East Indies campaign. But the Japanese missed a golden opportunity at Pearl Harbor. "All of the oil for the fleet was in surface tanks at the time of Pearl Harbor," Admiral Chester Nimitz, who became Commander in Chief of the Pacific Fleet, was later to say. "We had about 4 12 million barrels [720,000 m3] of oil out there and all of it was vulnerable to .50 caliber bullets. Had the Japanese destroyed the oil," he added, "it would have prolonged the war another two years."[57] #### United States Early in 1944, William Boyd, president of the American Petroleum Institute and chairman of the Petroleum Industry War Council said: "The Allies may have floated to victory on a wave of oil in World War I, but in this infinitely greater World War II, we are flying to victory on the wings of petroleum". In December 1941 the United States had 385,000 oil wells producing 1.4 billion barrels of oil a year and 100-octane aviation gasoline capacity was at 40,000 barrels a day. By 1944, the U.S. was producing over 1.5 billion barrels a year (67 percent of world production) and the petroleum industry had built 122 new plants for the production of 100-octane aviation gasoline and capacity was over 400,000 barrels a day – an increase of more than ten-fold. It was estimated that the U.S. was producing enough 100-octane aviation gasoline to permit the dropping of 20,000 short tons (18,000 metric tons) of bombs on the enemy every day of the year. The record of gasoline consumption by the Army prior to June 1943 was uncoordinated as each supply service of the Army purchased its own petroleum products and no centralized system of control nor records existed. On 1 June 1943 the Army created the Fuels and Lubricants Division of the Quartermaster Corps, and from their records they tabulated that the Army (excluding fuels and lubricants for aircraft) purchased over 2.4 billion gallons of gasoline for delivery to overseas theaters between 1 June 1943, through August 1945. That figure does not include gasoline used by the Army inside the United States.[58] Motor fuel production had declined from 701,000,000 barrels in 1941 down to 608,000,000 barrels in 1943.[59] World War II marked the first time in U.S. history that gasoline was rationed and the government imposed price controls to prevent inflation. Gasoline consumption per automobile declined from 755 gallons per year in 1941 down to 540 gallons in 1943, with the goal of preserving rubber for tires since the Japanese had cut the U.S. off from over 90 percent of its rubber supply which had come from the Dutch East Indies and the U.S. synthetic rubber industry was in its infancy. Average gasoline prices went from a record low of$0.1275 per gallon ($0.1841 with taxes) in 1940 to$0.1448 per gallon ($0.2050 with taxes) in 1945.[60] Even with the world's largest aviation gasoline production, the U.S. military still found that more was needed. Throughout the duration of the war, aviation gasoline supply was always behind requirements and this impacted training and operations. The reason for this shortage developed before the war even began. The free market did not support the expense of producing 100-octane aviation fuel in large volume, especially during the Great Depression. Iso-octane in the early development stage cost$30 a gallon and even by 1934, it was still $2 a gallon compared to$0.18 for motor gasoline when the Army decided to experiment with 100-octane for its combat aircraft. Though only 3 percent of U.S. combat aircraft in 1935 could take full advantage of the higher octane due to low compression ratios, the Army saw that the need for increasing performance warranted the expense and purchased 100,000 gallons. By 1937 the Army established 100-octane as the standard fuel for combat aircraft and by 1939 production was only 20,000 barrels a day. In effect, the U.S. military was the only market for 100-octane aviation gasoline and as war broke out in Europe this created a supply problem that persisted throughout the duration.[61][62]

With the war in Europe a reality in 1939, all predictions of 100-octane consumption were outrunning all possible production. Neither the Army nor the Navy could contract more than six months in advance for fuel and they could not supply the funds for plant expansion. Without a long-term guaranteed market, the petroleum industry would not risk its capital to expand production for a product that only the government would buy. The solution to the expansion of storage, transportation, finances, and production was the creation of the Defense Supplies Corporation on 19 September 1940. The Defense Supplies Corporation would buy, transport and store all aviation gasoline for the Army and Navy at cost plus a carrying fee.[63]

When the Allied breakout after D-Day found their armies stretching their supply lines to a dangerous point, the makeshift solution was the Red Ball Express. But even this soon was inadequate. The trucks in the convoys had to drive longer distances as the armies advanced and they were consuming a greater percentage of the same gasoline they were trying to deliver. In 1944, General George Patton's Third Army finally stalled just short of the German border after running out of gasoline. The general was so upset at the arrival of a truckload of rations instead of gasoline he was reported to have shouted: "Hell, they send us food, when they know we can fight without food but not without oil."[64] The solution had to wait for the repairing of the railroad lines and bridges so that the more efficient trains could replace the gasoline-consuming truck convoys.

### United States, 1946 to present

The development of jet engines burning kerosene-based fuels during WW II for aircraft produced a superior performing propulsion system than internal combustion engines could offer and the U.S. military forces gradually replaced their piston combat aircraft with jet powered planes. This development would essentially remove the military need for ever increasing octane fuels and eliminated government support for the refining industry to pursue the research and production of such exotic and expensive fuels. Commercial aviation was slower to adapt to jet propulsion and until 1958, when the Boeing 707 first entered commercial service, piston powered airliners still relied on aviation gasoline. But commercial aviation had greater economic concerns than the maximum performance that the military could afford. As octane numbers increased so did the cost of gasoline but the incremental increase in efficiency becomes less as compression ratio goes up. This reality set a practical limit to how high compression ratios could increase relative to how expensive the gasoline would become.[65] Last produced in 1955, the Pratt & Whitney R-4360 Wasp Major was using 115/145 Aviation gasoline and producing 1 horsepower per cubic inch at 6.7 compression ratio (turbo-supercharging would increase this) and 1 pound of engine weight to produce 1.1 horsepower. This compares to the Wright Brothers engine needing almost 17 pounds of engine weight to produce 1 horsepower.

### Carbon dioxide

About 2.353 kg/l (19.64 lb/US gal) of carbon dioxide (CO2) are produced from burning gasoline that does not contain ethanol. About 2.682 kg/l (22.38 lb/US gal) of CO2 are produced from burning diesel fuel.[133]

The U.S. EIA estimates that U.S. motor gasoline and diesel (distillate) fuel consumption for transportation in 2015 resulted in the emission of about 1,105 million tons of CO2 and 440 million tons of CO2, respectively, for a total of 1,545 million tons of CO2.[133] This total was equivalent to 83% of total U.S. transportation-sector CO2 emissions and equivalent to 29% of total U.S. energy-related CO2 emissions in 2015.[133]

Most of the retail gasoline now sold in the United States contains about 10% fuel ethanol (or E10) by volume.[133] Burning E10 produces about 2.119 kg/l (17.68 lb/US gal) of CO2 that is emitted from the fossil fuel content. If the CO2 emissions from ethanol combustion are considered, then about 2.271 kg/l (18.95 lb/US gal) of CO2 are produced when E10 is combusted.[133] About 1.525 kg/l (12.73 lb/US gal) of CO2 are produced when pure ethanol is combusted.[133]

### Contamination of soil and water

Gasoline enters the environment through the soil, groundwater, surface water, and air. Therefore, humans may be exposed to gasoline through methods such as breathing, eating, and skin contact. For example, using gasoline-filled equipment, such as lawnmowers, drinking gasoline-contaminated water close to gasoline spills or leaks to the soil, working at a gas station, inhaling gasoline volatile gas when refueling at a gas station is the easiest way to be exposed to gasoline.[138]

## Use and pricing

Main pages: Finance:Gasoline and diesel usage and pricing and Unsolved:Peak oil

### Europe

Countries in Europe impose substantially higher taxes on fuels such as gasoline when compared to the United States. The price of gasoline in Europe is typically higher than that in the U.S. due to this difference.[139]

### United States

US Regular Gasoline Prices through 2018, in US dollars

From 1998 to 2004, the price of gasoline fluctuated between US$1 and US$2 per U.S. gallon.[140] After 2004, the price increased until the average gas price reached a high of $4.11 per U.S. gallon in mid-2008, but receded to approximately$2.60 per U.S. gallon by September 2009.[140] The U.S. experienced an upswing in gasoline prices through 2011,[141] and by 1 March 2012, the national average was \$3.74 per gallon. California prices are higher because the California government mandates unique California gasoline formulas and taxes.[142]

In the United States, 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 18.4¢ per gallon for gasoline and 24.4¢ per gallon for diesel (excluding red diesel).[143]

About 9 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."[144] 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".[145] Cars with turbocharged engines and high compression ratios often specify premium gas because higher octane fuels reduce the incidence of "knock", or fuel pre-detonation.[146] The price of gas varies considerably between the summer and winter months.[147]

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.[148]

## Gasoline production by country

Gasoline production, thousand barrels per day, 2014 (thousand barrels per day, Source: US Energy Information Administration, TheGlobalEconomy.com)[149]
Country Gasoline production
US 9571
China 2578
Japan 920
Russia 910
India 755
Brazil 533
Germany 465
Saudi Arabia 441
Mexico 407
South Korea 397
Iran 382
UK 364
Italy 343
Venezuela 277
France 265
Singapore 249
Australia 241
Indonesia 230
Taiwan 174
Thailand 170
Spain 169
Netherlands 148
South Africa 135
Argentina 122
Sweden 112
Greece 108
Belgium 105
Malaysia 103
Finland 100
Belarus 92
Turkey 92
Colombia 85
Poland 83
Norway 77
Kazakhstan 71
Algeria 70
Romania 70
Oman 69
Egypt 66
UA Emirates 66
Chile 65
Turkmenistan 61
Kuwait 57
Iraq 56
Vietnam 52
Lithuania 49
Denmark 48
Qatar 46

## Comparison with other fuels

Below is a table of the volumetric and mass energy density of various transportation fuels as compared with gasoline. In the rows with gross and net, they are from the Oak Ridge National Laboratory's Transportation Energy Data Book.[150]

Fuel type[lower-alpha 1] Gross MJ/L      MJ/kg Gross BTU/gal
(imp)
Gross BTU/gal
(U.S.)
Net BTU/gal (U.S.)     RON
Conventional gasoline 34.8 44.4[151] 150,100 125,000 115,400 91–98
Autogas (LPG) (Consisting mostly of C3 and C4 hydrocarbons) 26.8 46 95,640 108
Ethanol 21.2[151] 26.8[151] 101,600 84,600 75,700 108.7[152]
Methanol 17.9 19.9[151] 77,600 64,600 56,600 123
Butanol[2] 29.2 36.6 125,819 104,766 91–99[clarification needed]
Gasohol 31.2 145,200 120,900 112,400 93/94[clarification needed]
Diesel(*) 38.6 45.4 166,600 138,700 128,700 25
Biodiesel 33.3–35.7[153][clarification needed] 126,200 117,100
Avgas (high octane gasoline) 33.5 46.8 144,400 120,200 112,000
Jet fuel (kerosene based) 35.1 43.8 151,242 125,935
Jet fuel (naphtha) 127,500 118,700
Liquefied natural gas 25.3 ~55 109,000 90,800
Liquefied petroleum gas 46.1 91,300 83,500
Hydrogen 10.1 (at 20 kelvin) 142 130[154]

(*) Diesel fuel is not used in a gasoline engine, so its low octane rating is not an issue; the relevant metric for diesel engines is the cetane number.

## Notes

1. The type needs more references which specify compositions of each fuel, plus citations, to avoid vagueness in numbers

## References

1. "Gasoline—a petroleum product". U.S Energy Information Administration. 12 August 2016.
2. "Preventing and Detecting Underground Storage Tank (UST) Releases" (in en). United States Environmental Protection Agency. 13 October 2014.
3. Mehlman, MA (1990). "Dangerous properties of petroleum-refining products: carcinogenicity of motor fuels (gasoline).". Teratogenesis, Carcinogenesis, and Mutagenesis 10 (5): 399–408. doi:10.1002/tcm.1770100505. PMID 1981951.
4. Baumbach, JI; Sielemann, S; Xie, Z; Schmidt, H (15 March 2003). "Detection of the gasoline components methyl tert-butyl ether, benzene, toluene, and m-xylene using ion mobility spectrometers with a radioactive and UV ionization source.". Analytical Chemistry 75 (6): 1483–90. doi:10.1021/ac020342i. PMID 12659213.
5. Global Climate Change: Vital Signs of the Planet. NASA. doi:10.1088/1748-9326/8/2/024024. Retrieved 16 September 2021.
6. See:
• Oxford Dictionaries (blog): The etymology of gasoline
• 38th Congress. Sessions I. Chapter 173: An Act to provide Internal Revenue to support the Government, to pay Interest on the Public Debt, and for other Purposes, 1864, p. 265. " … ; And provided, also, That naphtha of specific gravity exceeding eighty degrees, according to Baume's hydrometer, and of the kind usually known as gasoline, shall be subject to a tax of five per centum ad valorem." See Library of Congress (US)
• See also: Stevens, Levi, "Improved apparatus for vaporizing and aerating volatile hydrocarbon," U.S. Patent no. 45,568 (issued: 20 December 1864). From p. 2 of the text: "One of the products obtained from the distillation of petroleum is a colorless liquid having an ethereal odor and being the lightest in specific gravity of all known liquids. This material is known now in commerce by the term "gasoline." "
7. "petroleum" , in the American Heritage Dictionary
8. Medieval Latin: literally, rock oil = Latin petr(a) rock (< Greek pétra) + oleum oil "Petroleum". Petroleum. Retrieved 16 September 2021.
9. "Carless, Capel & Leonard", vintagegarage.co.uk, accessed 5 August 2012
10. "Carless, Capel and Leonard Ltd Records: Administrative History ", The National Archives, accessed 5 August 2012
11. gasoline, n., and gasoline, n., Oxford English Dictionary online edition
12. Hincks, Ron (2004). "Our Motoring Heritage: gasoline & Oil". Chrysler Collector (154): 16–20.
13. Kemp, John (18 March 2017). "India's thirst for gasoline helps spur global oil demand: Kemp". Reuters. "India's drivers used 500,000 barrels per day of motor spirit in the 12 months ending in February 2016, according to the Petroleum Planning and Analysis Cell of the Ministry of Petroleum."
14. National Energy Advisory Committee (Australia) (1981) (in en). Motor Spirit: Vehicle Emissions, Octane Ratings and Lead Additives: Further Examination, March 1981. Australian Government Publishing Service. p. 11. ISBN 978-0-642-06672-5. "Based on estimated provided by the oil refining industry, the Department of National Development and Energy has estimated that the decision to reduce the RON of premium motor spirit from 98 to 97 has resulted in an annual saving equivalent to about 1.6 million barrels of crude oil."
15. Udonwa, N. E.; Uko, E. K.; Ikpeme, B. M.; Ibanga, I. A.; Okon, B. O. (2009). "Exposure of Petrol Station Attendants and Auto Mechanics to Premium Motor Sprit Fumes in Calabar, Nigeria". Journal of Environmental and Public Health 2009: 281876. doi:10.1155/2009/281876. PMID 19936128.
16. Daniel Yergen, The Prize, The Epic Quest for Oil, Money & Power, Simon & Schuster, 1992, pp. 150–63.
17. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, pp. 1–4.
18. Farm Implements. Farm Implement Publishing Company. 1917. Retrieved 9 November 2019.
19. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 10.
20. Schlaifer, Robert (1950). Development of Aircraft Engines: Two Studies of Relations Between Government and Business. p. 569. Retrieved 4 September 2020.
21. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 252
22. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 3.
23. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, pp. 6–9.
24. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 74.
25. Vincent, J. G. (1920). "Adapting Engines to the Use of Available Fuels". SAE Technical Paper Series. 1. p. 346. doi:10.4271/200017.
26. Pogue, Joseph E. (September 1919). "The Engine-Fuel Problem". The Journal of the Society of Automotive Engineers: 232. Retrieved 18 June 2018.
27. Kovarik, William (2005-10-01). "Ethyl-leaded Gasoline: How a Classic Occupational Disease Became an International Public Health Disaster". International Journal of Occupational and Environmental Health 11 (4): 384–397. doi:10.1179/oeh.2005.11.4.384. ISSN 1077-3525. PMID 16350473.
28. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 22.
29. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 20.
30. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, p. 34.
31. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, pp. 12–19.
32. Mingos, Howard, ed (1936). The Aircraft Year Book for 1936 (18th ed.). New York: Aeronautical Chamber of Commerce of America. Retrieved 2 April 2020.
33. Bishop, Benjamin W. (December 2014). Jimmy Doolittle: The Commander Behind the Legend. The Drew Papers. Maxwell Air Force Base, Alabama: Air University Press. ISBN 978-1-58566-245-6. Retrieved 29 March 2020.
34. Matthew Van Winkle, Aviation Gasoline Manufacture, McGraw-Hill, 1944, pp. 94–95.
35. ﻿Aviation Gasoline Production and Control﻿ (Report). Air Historical Office Headquarters, Army Air Forces: Army Air Forces Historical Studies. September 1947. p. 2. Retrieved 10 November 2018.
36. Robert W. Czeschin, The Last Wave; Oil, War, and Financial Upheaval in the 1990s, Agora Inc., 1988, pp. 13–14.
37. Robert W. Czeschin, The Last Wave; Oil, War, and Financial Upheaval in the 1990s, Agora Inc., 1988, p. 17.
38. Robert W. Czeschin, The Last Wave; Oil, War, and Financial Upheaval in the 1990s, Agora Inc., 1988, p. 19.
39. Daniel Yergin, The Prize, Simon & Schuster, 1992, pp. 310–12
40. Daniel Yergin, The Prize, Simon & Schuster, 1992, pp. 316–17
41. Daniel Yergen, The Prize, The Epic Quest for Oil, Money & Power, Simon & Schuster, 1992, p. 327
42. Erna Risch and Chester L. Kieffer, United States Army in World War II, The Technical Services, The Quartermaster Corps: Organization, Supply, and Services, Office of the CHief of Military History, Department of the Army, Washington, D.C., 1955, p. 128-129
43. Robert E. Allen, Director of Information, American Petroleum Institute, The American Year Book – 1946, Thomas Nelson & Sons, 1947, p. 499
44. Robert E. Allen, Director of Information, American Petroleum Institute, The American Year Book – 1946, Thomas Nelson & Sons, 1947, pp. 512–18
45. ﻿Aviation Gasoline Production and Control﻿ (Report). Air Historical Office Headquarters, Army Air Forces: Army Air Forces Historical Studies. September 1947. p. 3. Retrieved 10 November 2018.
46. Robert E. Allen, Director of Information, American Petroleum Institute, The American Year Book – 1944, Thomas Nelson & Sons, 1945, p. 509
47. ﻿Aviation Gasoline Production and Control﻿ (Report). Air Historical Office Headquarters, Army Air Forces: Army Air Forces Historical Studies. September 1947. p. 4. Retrieved 10 November 2018.
48. Robert E. Allen, Director of Information, American Petroleum Institute, The American Year Book – 1946, Thomas Nelson & Sons, 1947, p. 498
49. Kavanagh, F. W.; MacGregor, J. R.; Pohl, R. L.; Lawler, M. B. (1959). "The economics of HIGH-OCTANE GASOLINES". SAE Transactions 67: 343–350.
50. Sanders, Gold V. (June 1946). Popular Science. pp. 124–126. Retrieved 4 May 2019.
51. Werner Dabelstein, Arno Reglitzky, Andrea Schütze and Klaus Reders "Automotive Fuels" in Ullmann's Encyclopedia of Industrial Chemistry 2007, Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_719.pub2
52. Huess Hedlund, Frank; Boier Pedersena, Jan; Sinc, Gürkan; Garde, Frits G.; Kragha, Eva K.; Frutiger, Jérôme (February 2019). "Puncture of an import gasoline pipeline—Spray effects may evaporate more fuel than a Buncefield-type tank overfill event". Process Safety and Environmental Protection 122: 33–47. doi:10.1016/j.psep.2018.11.007. Retrieved 18 September 2021.
53. "Gasoline—a petroleum product". U.S Energy Information Administration. 12 August 2016.
54. Demirel, Yaşar (26 January 2012). Energy: Production, Conversion, Storage, Conservation, and Coupling. Springer Science & Business Media. p. 33. ISBN 978-1-4471-2371-2. Retrieved 31 March 2020.
55. Ryan Lengerich Journal staff. "85-octane warning labels not posted at many gas stations". Rapid City Journal.
56. "95/93 – What is the Difference, Really?". Automobile Association of South Africa (AA).
57. Hearst Magazines (April 1936). "Popular Mechanics". Popular Mechanics (Hearst Magazines): 524–. ISSN 0032-4558.
58. Marrs, Dave (22 January 2013). "Ban on lead may yet give us respite from crime". Business Day.
59. Reyes, J. W. (2007). "The Impact of Childhood Lead Exposure on Crime". National Bureau of Economic Research. "a" ref citing Pirkle, Brody, et. al (1994). Retrieved 17 August 2009.
60. "Highly polluting leaded petrol now eradicated from the world, says UN". BBC News. 31 August 2021.
61. Miranda, Leticia; Farivar, Cyrus (12 April 2021). "Leaded gas was phased out 25 years ago. Why are these planes still using toxic fuel?". NBC News.
62. Seggie, Eleanor (5 August 2011). "More than 20% of SA cars still using lead-replacement petrol but only 1% need it". Engineering News (South Africa).
63. Clark, Andrew (14 August 2002). "Petrol for older cars about to disappear". The Guardian (London).
64. "AA warns over lead replacement fuel". The Daily Telegraph (London). 15 August 2002.
65. Hollrah, Don P.; Burns, Allen M. (11 March 1991). "MMT Increases Octane While Reducing Emissions".
66. Gasoline test kit
67. "Top Tier Detergent Gasoline (Deposits, Fuel Economy, No Start, Power, Performance, Stall Concerns)", GM Bulletin, 04-06-04-047, 06-Engine/Propulsion System, June 2004
68. "Government to take a call on ethanol price soon". The Hindu (Chennai, India). 21 November 2011.
69. "EAA – Avgas Grades". 17 May 2008.
70. "Removal of Reformulated Gasoline Oxygen Content Requirement (national) and Revision of Commingling Prohibition to Address Non-0xygenated Reformulated Gasoline (national)". U.S. Environmental Protection Agency. 22 February 2006.
71. "Alternative Fueling Station Locator". U.S. Department of Energy.
72. Material safety data sheet Tesoro petroleum Companies, Inc., U.S., 8 February 2003
73. Karl Griesbaum et al. "Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a13_227
74. E Reese and R D Kimbrough (December 1993). "Acute toxicity of gasoline and some additives". Environmental Health Perspectives 101 (Suppl 6): 115–131. doi:10.1289/ehp.93101s6115. PMID 8020435.
75. University of Utah Poison Control Center (24 June 2014), Dos and Don'ts in Case of Gasoline Poisoning, University of Utah, retrieved 15 October 2018
76. Agency for Toxic Substances and Disease Registry (21 October 2014), Medical Management Guidelines for Gasoline (Mixture) CAS# 86290-81-5 and 8006-61-9, Centers for Disease Control and Prevention, retrieved 13 December 2018
77. gasoline Sniffing Fact File Sheree Cairney, www.abc.net.au, Published 24 November 2005. Retrieved 13 October 2007, a modified version of the original article , now archived [1]
78. Lauwers, Bert (1 June 2011). "The Office of the Chief Coroner's Death Review of the Youth Suicides at the Pikangikum First Nation, 2006–2008". Office of the Chief Coroner of Ontario.
79. Wortley, R.P. (29 August 2006). "Anangu Pitjantjatjara Yankunytjatjara Land Rights (Regulated Substances) Amendment Bill". Legislative Council (South Australia) (Hansard). Retrieved 27 December 2006.
80. Brady, Maggie (27 April 2006). "Community Affairs Reference Committee Reference: Petrol sniffing in remote Aboriginal communities". Official Committee Hansard (Senate) (Hansard): 11. Retrieved 20 March 2006.
81. Kozel, Nicholas; Sloboda, Zili, eds (1995). ﻿Epidemiology of Inhalant Abuse: An International Perspective﻿ (Report). National Institute on Drug Abuse. NIDA Research Monograph 148.
82. Williams, Jonas (March 2004). "Responding to petrol sniffing on the Anangu Pitjantjatjara Lands: A case study". Social Justice Report 2003. Human Rights and Equal Opportunity Commission.
83. Submission to the Senate Community Affairs References Committee by BP Australia Pty Ltd Parliament of Australia Web Site. Retrieved 8 June 2007.
84.
85. "How Gasoline Becomes CO2". Slate Magazine. 1 November 2006.
86. "How much carbon dioxide is produced by burning gasoline and diesel fuel?". U.S. Energy Information Administration (EIA).  This article incorporates text from this source, which is in the public domain.
87. V. F. Andersen; J. E. Anderson; T. J. Wallington; S. A. Mueller; O. J. Nielsen (May 21, 2010). "Vapor Pressures of Alcohol−Gasoline Blends". Energy Fuels 24 (6): 3647–3654. doi:10.1021/ef100254w.
88. Phys.Org, 4 Mar. 2015 "New Models Yield Clearer Picture of Emissions' True Costs"
89. Shindell, Drew T. (2015). "The social cost of atmospheric release". Climatic Change 130 (2): 313–326. doi:10.1007/s10584-015-1343-0. Bibcode2015ClCh..130..313S.
90. "Fuel Prices and New Vehicle Fuel Economy in Europe". MIT Center for Energy and Environmental Policy Research. August 2011. Retrieved 20 April 2020.
91. "Gassing up with premium probably a waste". philly.com. 19 August 2009.