105-456: The gallon is a unit of volume in British imperial units and United States customary units . Three different versions are in current use: There are two pints in a quart and four quarts in a gallon. Different sizes of pints account for the different sizes of the imperial and US gallons. The IEEE standard symbol for both US (liquid) and imperial gallon is gal , not to be confused with
210-483: A barleycorn . A system of measurement is a collection of units of measurement and rules relating them to each other. As science progressed, a need arose to relate the measurement systems of different quantities, like length and weight and volume. The effort of attempting to relate different traditional systems between each other exposed many inconsistencies, and brought about the development of new units and systems. Systems of units vary from country to country. Some of
315-459: A US fluid ounce is 1 / 16 of a US pint, or 1 / 128 of a US gallon. Thus, the imperial gallon, quart, pint, cup and gill are approximately 20% larger than their US counterparts, meaning these are not interchangeable, but the imperial fluid ounce is only approximately 4% smaller than the US fluid ounce, meaning these are often used interchangeably. Historically,
420-420: A US gallon. In order to overcome the effects of expansion and contraction with temperature when using a gallon to specify a quantity of material for purposes of trade, it is common to define the temperature at which the material will occupy the specified volume. For example, the volume of petroleum products and alcoholic beverages are both referenced to 60 °F (15.6 °C) in government regulations. Since
525-661: A common bottle size for liquor in the US was the " fifth ", i.e. one-fifth of a US gallon (or one-sixth of an imperial gallon). While spirit sales in the US were switched to metric measures in 1976, a 750 mL bottle is still sometimes known as a "fifth". The term derives most immediately from galun , galon in Old Norman French , but the usage was common in several languages, for example jale in Old French and gęllet (bowl) in Old English. This suggests
630-521: A common origin in Romance Latin , but the ultimate source of the word is unknown. The gallon originated as the base of systems for measuring wine and beer in England. The sizes of gallon used in these two systems were different from each other: the first was based on the wine gallon (equal in size to the US gallon), and the second one either the ale gallon or the larger imperial gallon. By
735-456: A condition called "stale fuel". Gasoline containing ethanol is especially subject to absorbing atmospheric moisture, then forming gums, solids, or two phases (a hydrocarbon phase floating on top of a water-alcohol phase). The presence of these degradation products in the fuel tank or fuel lines plus a carburetor or fuel injection components makes it harder to start the engine or causes reduced engine performance On resumption of regular engine use,
840-449: A controlled process called deflagration . However, the unburned mixture may autoignite by pressure and heat alone, rather than igniting from the spark plug at exactly the right time, causing a rapid pressure rise that can damage the engine. This is often referred to as engine knocking or end-gas knock. Knocking can be reduced by increasing the gasoline's resistance to autoignition , which is expressed by its octane rating. Octane rating
945-489: A crucial role in human endeavour from early ages up to the present. A multitude of systems of units used to be very common. Now there is a global standard, the International System of Units (SI), the modern form of the metric system . In trade, weights and measures are often a subject of governmental regulation, to ensure fairness and transparency. The International Bureau of Weights and Measures (BIPM)
1050-443: A fine mist. Quality gasoline should be stable for six months if stored properly, but can degrade over time. Gasoline stored for a year will most likely be able to be burned in an internal combustion engine without too much trouble. However, the effects of long-term storage will become more noticeable with each passing month until a time comes when the gasoline should be diluted with ever-increasing amounts of freshly made fuel so that
1155-400: A fuel for engines , gasoline is chemically composed of organic compounds derived from the fractional distillation of petroleum and later chemically enhanced with gasoline additives . It is a high-volume profitable product produced in crude oil refineries. The fuel-characteristics of a particular gasoline-blend, which will resist igniting too early are measured as the octane rating of
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#17327799485411260-470: A greater volume fraction of aromatics. Finished marketable gasoline is traded (in Europe) with a standard reference of 0.755 kilograms per liter (6.30 lb/U.S. gal), (7,5668 lb/ imp gal) its price is escalated or de-escalated according to its actual density. Because of its low density, gasoline floats on water, and therefore water cannot generally be used to extinguish a gasoline fire unless applied in
1365-412: A growing annual target of total gallons blended. Although the mandate does not require a specific percentage of ethanol, annual increases in the target combined with declining gasoline consumption have caused the typical ethanol content in gasoline to approach 10 percent. Most fuel pumps display a sticker that states that the fuel may contain up to 10 percent ethanol, an intentional disparity that reflects
1470-574: A high compression ratio. A high expansion ratio is also one of the two key reasons for the efficiency of diesel engines , along with the elimination of pumping losses due to throttling of the intake airflow. The lower energy content of LPG by liquid volume in comparison to gasoline is due mainly to its lower density. This lower density is a property of the lower molecular weight of propane (LPG's chief component) compared to gasoline's blend of various hydrocarbon compounds with heavier molecular weights than propane. Conversely, LPG's energy content by weight
1575-401: A higher compression ratio through the concomitant higher expansion ratio on the power stroke, which is by far the greater effect. The higher expansion ratio extracts more work from the high-pressure gas created by the combustion process. An Atkinson cycle engine uses the timing of the valve events to produce the benefits of a high expansion ratio without the disadvantages, chiefly detonation, of
1680-643: A nation with a good supply of high-octane gasoline would have the advantage in air power. In 1943, the Rolls-Royce Merlin aero engine produced 980 kilowatts (1,320 hp) using 100 RON fuel from a modest 27 liters (1,600 cu in) displacement. By the time of Operation Overlord , both the RAF and USAAF were conducting some operations in Europe using 150 RON fuel (100/150 avgas ), obtained by adding 2.5 percent aniline to 100-octane avgas. By this time,
1785-424: A quantity may be described as multiples of that of a familiar entity, which can be easier to contextualize than a value in a formal unit system. For instance, a publication may describe an area in a foreign country as a number of multiples of the area of a region local to the readership. The propensity for certain concepts to be used frequently can give rise to loosely defined "systems" of units. For most quantities
1890-417: A representative species, performs the chemical reaction: By weight, combustion of gasoline releases about 46.7 megajoules per kilogram (13.0 kWh /kg; 21.2 MJ/ lb ) or by volume 33.6 megajoules per liter (9.3 kWh/L; 127 MJ/U.S. gal; 121,000 BTU/U.S. gal), quoting the lower heating value . Gasoline blends differ, and therefore actual energy content varies according to
1995-500: A result, units of measure could vary not only from location to location but from person to person. Units not based on the human body could be based on agriculture, as is the case with the furlong and the acre , both based on the amount of land able to be worked by a team of oxen . Metric systems of units have evolved since the adoption of the original metric system in France in 1791. The current international standard metric system
2100-400: A small set of units is required. These units are taken as the base units and the other units are derived units . Thus base units are the units of the quantities which are independent of other quantities and they are the units of length, mass, time, electric current, temperature, luminous intensity and the amount of substance. Derived units are the units of the quantities which are derived from
2205-433: A unit is necessary to communicate values of that physical quantity. For example, conveying to someone a particular length without using some sort of unit is impossible, because a length cannot be described without a reference used to make sense of the value given. But not all quantities require a unit of their own. Using physical laws, units of quantities can be expressed as combinations of units of other quantities. Thus only
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#17327799485412310-739: Is 10 percent ethanol, and 98E5, which is 5 percent ethanol. Most gasoline sold in Sweden has 5–15 percent ethanol added. Three different ethanol blends are sold in the Netherlands—E5, E10 and hE15. The last of these differs from standard ethanol–gasoline blends in that it consists of 15 percent hydrous ethanol (i.e., the ethanol–water azeotrope ) instead of the anhydrous ethanol traditionally used for blending with gasoline. The Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) requires gasoline for automobile use to have 27.5 percent of ethanol added to its composition. Pure hydrated ethanol
2415-426: Is a mixture of paraffins ( alkanes ), olefins ( alkenes ), napthenes ( cycloalkanes ), and aromatics . The use of the term paraffin in place of the standard chemical nomenclature alkane is particular to the oil industry (which relies extensively on jargon). The composition of a gasoline depends upon: The various refinery streams blended to make gasoline have different characteristics. Some important streams include
2520-457: Is a naturally colorless liquid, many gasolines are dyed in various colors to indicate their composition and acceptable uses. In Australia, the lowest grade of gasoline (RON 91) was dyed a light shade of red/orange, but is now the same color as the medium grade (RON 95) and high octane (RON 98), which are dyed yellow. In the U.S., aviation gasoline ( avgas ) is dyed to identify its octane rating and to distinguish it from kerosene-based jet fuel, which
2625-509: Is also available as a fuel. Legislation requires retailers to label fuels containing ethanol on the dispenser, and limits ethanol use to 10 percent of gasoline in Australia. Such gasoline is commonly called E10 by major brands, and it is cheaper than regular unleaded gasoline. The federal Renewable Fuel Standard (RFS) effectively requires refiners and blenders to blend renewable biofuels (mostly ethanol) with gasoline, sufficient to meet
2730-460: Is called E85 . The most extensive use of ethanol takes place in Brazil , where the ethanol is derived from sugarcane . In 2004, over 13 billion liters (3.4 × 10 ^ U.S. gal) of ethanol was produced in the U.S. for fuel use, mostly from corn and sold as E10. E85 is slowly becoming available in much of the U.S., though many of the relatively few stations vending E85 are not open to
2835-485: Is central to the scientific method . A standard system of units facilitates this. Scientific systems of units are a refinement of the concept of weights and measures historically developed for commercial purposes. Science , medicine , and engineering often use larger and smaller units of measurement than those used in everyday life. The judicious selection of the units of measurement can aid researchers in problem solving (see, for example, dimensional analysis ). In
2940-469: Is defined as exactly 4.54609 dm (4.54609 litres). It is used in some Commonwealth countries, and until 1976 was defined as the volume of water at 62 °F (16.67 °C) whose mass is 10 pounds (4.5359237 kg). There are four imperial quarts in a gallon, two imperial pints in a quart, and there are 20 imperial fluid ounces in an imperial pint, yielding 160 fluid ounces in an imperial gallon. The US liquid gallon (frequently called simply "gallon")
3045-478: Is derived from a 160-liter (42 U.S. gal) barrel of crude oil . Material separated from crude oil via distillation , called virgin or straight-run gasoline, does not meet specifications 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 a homogeneous mixture of hydrocarbons with between 4 and 12 carbon atoms per molecule (commonly referred to as C4–C12). It
3150-409: Is expressed as the product of a numerical value { Z } (a pure number) and a unit [ Z ]: For example, let Z {\displaystyle Z} be "2 metres"; then, { Z } = 2 {\displaystyle \{Z\}=2} is the numerical value and [ Z ] = m e t r e {\displaystyle [Z]=\mathrm {metre} } is the unit. Conversely,
3255-490: Is higher than gasoline's due to a higher hydrogen -to- carbon ratio. Molecular weights of the species in the representative octane combustion are 114, 32, 44, and 18 for C 8 H 18 , O 2 , CO 2 , and H 2 O, respectively; therefore one kilogram (2.2 lb) of fuel reacts with 3.51 kilograms (7.7 lb) of oxygen to produce 3.09 kilograms (6.8 lb) of carbon dioxide and 1.42 kilograms (3.1 lb) of water. Spark-ignition engines are designed to burn gasoline in
Gallon - Misplaced Pages Continue
3360-422: Is left colorless. In Canada, the gasoline for marine and farm use is dyed red and is not subject to fuel excise tax in most provinces. Oxygenate blending adds oxygen -bearing compounds such as MTBE , ETBE , TAME , TAEE , ethanol , and biobutanol . The presence of these oxygenates reduces the amount of carbon monoxide and unburned fuel in the exhaust. In many areas throughout the U.S., oxygenate blending
3465-410: Is legally defined as 231 cubic inches , which is exactly 3.785411784 litres. A US liquid gallon can contain about 3.785 kilograms or 8.34 pounds of water at 3.98 °C (39.16 °F), and is about 16.7% less than the imperial gallon. There are four quarts in a gallon, two pints in a quart and 16 US fluid ounces in a US pint , which makes the US fluid ounce equal to 1 / 128 of
3570-501: Is mandated by EPA regulations to reduce smog and other airborne pollutants. For example, in Southern California fuel must contain two percent oxygen by weight, resulting in a mixture of 5.6 percent ethanol in gasoline. The resulting fuel is often known as reformulated gasoline (RFG) or oxygenated gasoline, or, in the case of California, California reformulated gasoline (CARBOB). The federal requirement that RFG contain oxygen
3675-448: 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 ratings, so the same physical fuel may have several different octane ratings based on the measure used. One of the best known is the research octane number (RON). The octane rating of typical commercially available gasoline varies by country. In Finland , Sweden , and Norway , 95 RON
3780-419: Is now defined as exactly 0.0254 m , and the US and imperial avoirdupois pound is now defined as exactly 0.453 592 37 kg . While the above systems of units are based on arbitrary unit values, formalised as standards, natural units in physics are based on physical principle or are selected to make physical equations easier to work with. For example, atomic units (au) were designed to simplify
3885-458: Is sporadic or seasonal (little to no use for one or more seasons of the year). Users have been advised to keep gasoline containers more than half full and properly capped to reduce air exposure, to avoid storage at high temperatures, to run an engine for ten minutes to circulate the stabilizer through all components prior to storage, and to run the engine at intervals to purge stale fuel from the carburetor. Gasoline stability requirements are set by
3990-478: Is tasked with ensuring worldwide uniformity of measurements and their traceability to the International System of Units (SI). Metrology is the science of developing nationally and internationally accepted units of measurement. In physics and metrology, units are standards for measurement of physical quantities that need clear definitions to be useful. Reproducibility of experimental results
4095-489: Is the International System of Units (abbreviated to SI). An important feature of modern systems is standardization . Each unit has a universally recognized size. Both the imperial units and US customary units derive from earlier English units . Imperial units were mostly used in the British Commonwealth and the former British Empire . US customary units are still the main system of measurement used in
4200-514: Is the conversion of the unit of measurement in which a quantity is expressed, typically through a multiplicative conversion factor that changes the unit without changing the quantity. This is also often loosely taken to include replacement of a quantity with a corresponding quantity that describes the same physical property. One example of the importance of agreed units is the failure of the NASA Mars Climate Orbiter , which
4305-493: Is the standard for regular unleaded gasoline and 98 RON is also available as a more expensive option. In the United Kingdom, over 95 percent of gasoline sold has 95 RON and is marketed as Unleaded or Premium Unleaded. Super Unleaded, with 97/98 RON and branded high-performance fuels (e.g., Shell V-Power, BP Ultimate) with 99 RON make up the balance. Gasoline with 102 RON may rarely be available for racing purposes. In
Gallon - Misplaced Pages Continue
4410-658: Is used as the primary fuel economy unit in the United Kingdom and as a supplementary unit in Canada on official documentation. Other than the United States, petrol is sold by the US gallon in 13 other countries, and one US territory: The latest country to cease using the gallon is El Salvador in June 2021. Both the US gallon and imperial gallon are used in the Turks and Caicos Islands (due to an increase in tax duties which
4515-710: Is used in Canada and the U.S. to boost octane rating. Its use in the U.S. has been restricted by regulations, although it is currently allowed. Its use in the European Union is restricted by Article 8a of the Fuel Quality Directive following its testing under the Protocol for the evaluation of effects of metallic fuel-additives on the emissions performance of vehicles. Gummy, sticky resin deposits result from oxidative degradation of gasoline during long-term storage. These harmful deposits arise from
4620-884: The 4th and 3rd millennia BC among the ancient peoples of Mesopotamia , Egypt and the Indus Valley , and perhaps also Elam in Persia as well. Weights and measures are mentioned in the Bible (Leviticus 19:35–36). It is a commandment to be honest and have fair measures. In the Magna Carta of 1215 (The Great Charter) with the seal of King John , put before him by the Barons of England, King John agreed in Clause 35 "There shall be one measure of wine throughout our whole realm, and one measure of ale and one measure of corn—namely,
4725-566: The European Union the gallon was removed from the list of legally defined primary units of measure catalogue in the EU directive 80/181/EEC for trading and official purposes, effective from 31 December 1994. Under the directive the gallon could still be used, but only as a supplementary or secondary unit. As a result of the EU directive Ireland and the United Kingdom passed legislation to replace
4830-449: The U.S. Clean Air Act banned the sale of leaded fuel for use in on-road vehicles in the U.S. The use of TEL also necessitated other additives, such as dibromoethane . European countries began replacing lead-containing additives by the end of the 1980s, and by the end of the 1990s, leaded gasoline was banned within the entire European Union with an exception for Avgas 100LL for general aviation . The UAE started to switch to unleaded in
4935-484: The United States outside of science, medicine, many sectors of industry, and some of government and military, and despite Congress having legally authorised metric measure on 28 July 1866. Some steps towards US metrication have been made, particularly the redefinition of basic US and imperial units to derive exactly from SI units. Since the international yard and pound agreement of 1959 the US and imperial inch
5040-457: The dry measure is one-eighth of a US Winchester bushel of 2,150.42 cubic inches, it is equal to exactly 268.8025 cubic inches, which is 4.404 883 770 86 L . The US dry gallon is not used in commerce, and is also not listed in the relevant statute, which jumps from the dry pint to the bushel. As of 2021, the imperial gallon continues to be used as the standard petrol unit on 10 Caribbean island groups , consisting of: All 12 of
5145-421: The gal (symbol: Gal), a CGS unit of acceleration . The gallon currently has one definition in the imperial system, and two definitions (liquid and dry ) in the US customary system. Historically, there were many definitions and redefinitions. There were a number of systems of liquid measurements in the United Kingdom prior to the 19th century. The British imperial gallon (frequently called simply "gallon")
5250-534: The kilogram -litre relationship, the imperial gallon was based on the volume of 10 pounds of distilled water weighed in air with brass weights with the barometer standing at 30 inches of mercury (100 kilopascals ; 15 pounds per square inch ) and at a temperature of 62 °F (17 °C). In 1963, this definition was refined as the space occupied by 10 pounds of distilled water of density 0.998 859 g/mL weighed in air of density 0.001 217 g/mL against weights of density 8.136 g/mL (the original "brass"
5355-401: The metric system , the imperial system , and United States customary units . Historically many of the systems of measurement which had been in use were to some extent based on the dimensions of the human body. Such units, which may be called anthropic units , include the cubit , based on the length of the forearm; the pace , based on the length of a stride; and the foot and hand . As
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#17327799485415460-553: The social sciences , there are no standard units of measurement. A unit of measurement is a standardized quantity of a physical property, used as a factor to express occurring quantities of that property. Units of measurement were among the earliest tools invented by humans. Primitive societies needed rudimentary measures for many tasks: constructing dwellings of an appropriate size and shape, fashioning clothing, or bartering food or raw materials. The earliest known uniform systems of measurement seem to have all been created sometime in
5565-467: The Caribbean islands use miles per hour for speed limits signage, and drive on the left side of the road . The United Arab Emirates ceased selling petrol by the imperial gallon in 2010 and switched to the litre, with Guyana following suit in 2013. In 2014, Myanmar switched from the imperial gallon to the litre. Antigua and Barbuda has proposed switching to selling petrol by litres since 2015. In
5670-626: The London quart;—and one width of dyed and russet and hauberk cloths—namely, two ells below the selvage..." As of the 21st century, the International System is predominantly used in the world. There exist other unit systems which are used in many places such as the United States Customary System and the Imperial System. The United States is the only industrialized country that has not yet at least mostly converted to
5775-477: The Rolls-Royce Merlin 66 was developing 1,500 kilowatts (2,000 hp) using this fuel. Gasoline, when used in high- compression internal combustion engines, tends to auto-ignite or "detonate" causing damaging engine knocking (also called "pinging" or "pinking"). To address this problem, tetraethyl lead (TEL) was widely adopted as an additive for gasoline in the 1920s. With a growing awareness of
5880-692: The U.S., octane ratings in unleaded fuels vary between 85 and 87 AKI (91–92 RON) for regular, 89–90 AKI (94–95 RON) for mid-grade (equivalent to European regular), up to 90–94 AKI (95–99 RON) for premium (European premium). As South Africa's largest city, Johannesburg , is located on the Highveld at 1,753 meters (5,751 ft) above sea level, the Automobile Association of South Africa recommends 95-octane gasoline at low altitude and 93-octane for use in Johannesburg because "The higher
5985-468: The US), which in turn are further divided into two gills . Thus, both gallons are equal to four quarts, eight pints, sixteen cups, or thirty-two gills. The imperial gill is further divided into five fluid ounces, whereas the US gill is divided into four fluid ounces, meaning an imperial fluid ounce is 1 / 20 of an imperial pint, or 1 / 160 of an imperial gallon, while
6090-400: The United Kingdom. Historically, gallons of various sizes were used in many parts of Western Europe. In these localities, it has been replaced as the unit of capacity by the litre . Unit of measurement A unit of measurement , or unit of measure , is a definite magnitude of a quantity , defined and adopted by convention or by law, that is used as a standard for measurement of
6195-410: The addition of 5–100 ppm of antioxidants , such as phenylenediamines and other amines . Hydrocarbons with a bromine number of 10 or above can be protected with the combination of unhindered or partially hindered phenols and oil-soluble strong amine bases, such as hindered phenols. "Stale" gasoline can be detected by a colorimetric enzymatic test for organic peroxides produced by oxidation of
6300-457: The altitude the lower the air pressure, and the lower the need for a high octane fuel as there is no real performance gain". Octane rating became important as the military sought higher output for aircraft engines in the late 1920s and the 1940s. A higher octane rating allows a higher compression ratio or supercharger boost, and thus higher temperatures and pressures, which translate to higher power output. Some scientists even predicted that
6405-588: The announcement "the end of one toxic era". However, leaded gasoline continues to be used in aeronautic, auto racing, and off-road applications. The use of leaded additives is still permitted worldwide for the formulation of some grades of aviation gasoline such as 100LL , because the required octane rating is difficult to reach without the use of leaded additives. Different additives have replaced lead compounds. The most popular additives include aromatic hydrocarbons , ethers ( MTBE and ETBE ), and alcohols , most commonly ethanol . Lead replacement petrol (LRP)
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#17327799485416510-414: The base quantities and some of the derived units are the units of speed, work, acceleration, energy, pressure etc. Different systems of units are based on different choices of a set of related units including fundamental and derived units. Following ISO 80000-1 , any value or magnitude of a physical quantity is expressed as a comparison to a unit of that quantity. The value of a physical quantity Z
6615-521: The benzene limit is set at one percent by volume for all grades of automotive gasoline. This is usually achieved by avoiding feeding C6, in particular cyclohexane , to the reformer unit, where it would be converted to benzene. Therefore, only (desulfurized) heavy virgin naphtha (HVN) is fed to the reformer unit Gasoline can also contain other organic compounds , such as organic ethers (deliberately added), plus small levels of contaminants, in particular organosulfur compounds (which are usually removed at
6720-612: The buildup may or may not be eventually cleaned out by the flow of fresh gasoline. The addition of a fuel stabilizer to gasoline can extend the life of fuel that is not or cannot be stored properly, though removal of all fuel from a fuel system is the only real solution to the problem of long-term storage of an engine or a machine or vehicle. Typical fuel stabilizers are proprietary mixtures containing mineral spirits , isopropyl alcohol , 1,2,4-trimethylbenzene or other additives . Fuel stabilizers are commonly used for small engines, such as lawnmower and tractor engines, especially when their use
6825-418: The bushel 8 in × ( 9 + 1 / 4 in) × π ≈ 2150.42017 cubic inches . The bushel was later defined to be 2150.42 cubic inches exactly, thus making its gallon exactly 268.8025 in ( 4.404 883 770 86 L ); in previous centuries, there had been a corn gallon of between 271 and 272 cubic inches. The wine , fluid , or liquid gallon has been the standard US gallon since
6930-506: The crew confusing tower instructions (in metres) and altimeter readings (in feet). Three crew and five people on the ground were killed. Thirty-seven were injured. In 1983, a Boeing 767 (which thanks to its pilot's gliding skills landed safely and became known as the Gimli Glider ) ran out of fuel in mid-flight because of two mistakes in figuring the fuel supply of Air Canada 's first aircraft to use metric measurements. This accident
7035-468: The different systems include the centimetre–gram–second , foot–pound–second , metre–kilogram–second systems, and the International System of Units , SI. Among the different systems of units used in the world, the most widely used and internationally accepted one is SI. The base SI units are the second, metre, kilogram, ampere, kelvin, mole and candela; all other SI units are derived from these base units. Systems of measurement in modern use include
7140-511: The earlier definition with π approximated to 22 / 7 . π r 2 h ≈ 22 7 × ( 7 i n 2 ) 2 × 6 i n = 231 i n 3 . {\displaystyle \pi r^{2}h\approx {\frac {22}{7}}\times \left({\frac {7~\mathrm {in} }{2}}\right)^{2}\times 6~\mathrm {in} =231~\mathrm {in} ^{3}.} Although
7245-413: The early 19th century. The wine gallon, which some sources relate to the volume occupied by eight medieval merchant pounds of wine, was at one time defined as the volume of a cylinder 6 inches deep and 7 inches in diameter, i.e. 6 in × ( 3 + 1 / 2 in) × π ≈ 230.907 06 cubic inches . It was redefined during the reign of Queen Anne in 1706 as 231 cubic inches exactly,
7350-519: The early 2000s. Reduction in the average lead content of human blood may be a major cause for falling violent crime rates around the world including South Africa. A study found a correlation between leaded gasoline usage and violent crime (see Lead–crime hypothesis ). Other studies found no correlation. In August 2021, the UN Environment Programme announced that leaded petrol had been eradicated worldwide, with Algeria being
7455-418: The end of production for cars using leaded gasoline in member states. At this stage, a large percentage of cars from the 1980s and early 1990s which ran on leaded gasoline were still in use, along with cars that could run on unleaded fuel. However, the declining number of such cars on British roads saw many gasoline stations withdrawing LRP from sale by 2003. Methylcyclopentadienyl manganese tricarbonyl (MMT)
7560-401: The end of the 18th century, there were three definitions of the gallon in common use: The corn or dry gallon is used (along with the dry quart and pint) in the United States for grain and other dry commodities. It is one-eighth of the (Winchester) bushel, originally defined as a cylindrical measure of 18 + 1 / 2 inches in diameter and 8 inches in depth, which made
7665-405: The following: The terms above are the jargon used in the oil industry, and the terminology varies. Currently, many countries set limits on gasoline aromatics in general, benzene in particular, and olefin (alkene) content. Such regulations have led to an increasing preference for alkane isomers, such as isomerate or alkylate, as their octane rating is higher than n-alkanes. In the European Union,
7770-510: The fuel blend. Gasoline blends with stable octane ratings are produced in several fuel-grades for various types of motors. A low octane rated fuel may cause engine knocking and reduced efficiency in reciprocating engines . Tetraethyl lead was once widely used to increase the octane rating but are not used in modern automotive gasoline due to the health hazard . Aviation, off-road motor vehicles, and racing car motors still use leaded gasolines. Interest in gasoline-like fuels started with
7875-515: The gallon with the litre as a primary unit of measure in trade and in the conduct of public business, effective from 31 December 1993, and 30 September 1995 respectively. Though the gallon has ceased to be a primary unit of trade, it can still be legally used in both the UK and Ireland as a supplementary unit. However, barrels and large containers of beer, oil and other fluids are commonly measured in multiples of an imperial gallon. Miles per imperial gallon
7980-419: The gas) that can withstand the vapor pressure of the gasoline without venting (to prevent the loss of the more volatile fractions) at a stable cool temperature (to reduce the excess pressure from liquid expansion and to reduce the rate of any decomposition reactions). When gasoline is not stored correctly, gums and solids may result, which can corrode system components and accumulate on wet surfaces, resulting in
8085-653: The gasoline. Gasolines are also treated with metal deactivators , which are compounds that sequester (deactivate) metal salts that otherwise accelerate the formation of gummy residues. The metal impurities might arise from the engine itself or as contaminants in the fuel. Gasoline, as delivered at the pump, also contains additives to reduce internal engine carbon buildups, improve combustion and allow easier starting in cold climates. High levels of detergent can be found in Top Tier Detergent Gasolines . The specification for Top Tier Detergent Gasolines
8190-461: The invention of internal combustion engines suitable for use in transportation applications. The 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 at 125.62 °C (258.12 °F) ), it
8295-400: The last country to deplete its reserves. UN Secretary-General António Guterres called the eradication of leaded petrol an "international success story". He also added: "Ending the use of leaded petrol will prevent more than one million premature deaths each year from heart disease, strokes and cancer, and it will protect children whose IQs are damaged by exposure to lead". Greenpeace called
8400-629: The metric system. The systematic effort to develop a universally acceptable system of units dates back to 1790 when the French National Assembly charged the French Academy of Sciences to come up such a unit system. This system was the precursor to the metric system which was quickly developed in France but did not take on universal acceptance until 1875 when The Metric Convention Treaty was signed by 17 nations. After this treaty
8505-425: The numerical value expressed in an arbitrary unit can be obtained as: Units can only be added or subtracted if they are the same type; however units can always be multiplied or divided, as George Gamow used to explain. Let Z {\displaystyle Z} be "2 metres" and W {\displaystyle W} "3 seconds", then There are certain rules that apply to units: Conversion of units
8610-406: The older gasoline may be used up. If left undiluted, improper operation will occur and this may include engine damage from misfiring or the lack of proper action of the fuel within a fuel injection system and from an onboard computer attempting to compensate (if applicable to the vehicle). Gasoline should ideally be stored in an airtight container (to prevent oxidation or water vapor mixing in with
8715-455: The oxidation of alkenes and other minor components in gasoline (see drying oils ). Improvements in refinery techniques have generally reduced the susceptibility of gasolines to these problems. Previously, catalytically or thermally cracked gasolines were most susceptible to oxidation. The formation of gums is accelerated by copper salts, which can be neutralized by additives called metal deactivators . This degradation can be prevented through
8820-414: The percentage of lighter products compared to simple distillation. Commercial gasoline as well as other liquid transportation fuels are complex mixtures of hydrocarbons. The performance specification also varies with season, requiring less volatile blends during summer, in order to minimize evaporative losses. Gasoline is produced in oil refineries . Roughly 72 liters (19 U.S. gal) of gasoline
8925-454: The phaseout of leaded motor fuels in the United Kingdom, Australia , South Africa , and some other countries. Consumer confusion led to a widespread mistaken preference for LRP rather than unleaded, and LRP was phased out 8 to 10 years after the introduction of unleaded. Leaded gasoline was withdrawn from sale in Britain after 31 December 1999, seven years after EEC regulations signaled
9030-427: The refinery). On average, U.S. petroleum refineries produce about 19 to 20 gallons of gasoline, 11 to 13 gallons of distillate fuel diesel fuel and 3 to 4 gallons of jet fuel from each 42 gallon (152 liters) barrel of crude oil. The product ratio depends upon the processing in an oil refinery and the crude oil assay . The specific gravity of gasoline ranges from 0.71 to 0.77, with higher densities having
9135-497: The same kind of quantity . Any other quantity of that kind can be expressed as a multiple of the unit of measurement. For example, a length is a physical quantity . The metre (symbol m) is a unit of length that represents a definite predetermined length. For instance, when referencing "10 metres" (or 10 m), what is actually meant is 10 times the definite predetermined length called "metre". The definition, agreement, and practical use of units of measurement have played
9240-434: The same unit for the distance between two cities and the length of a needle. Thus, historically they would develop independently. One way to make large numbers or small fractions easier to read, is to use unit prefixes . At some point in time though, the need to relate the two units might arise, and consequently the need to choose one unit as defining the other or vice versa. For example, an inch could be defined in terms of
9345-445: The season and producer by up to 1.75 percent more or less than the average. On average, about 74 liters (20 U.S. gal) of gasoline are available from a barrel of crude oil (about 46 percent by volume), varying with the quality of the crude and the grade of the gasoline. The remainder is products ranging from tar to naphtha . A high-octane-rated fuel, such as liquefied petroleum gas (LPG), has an overall lower power output at
9450-701: The seriousness of the extent of environmental and health damage caused by lead compounds, however, and the incompatibility of lead with catalytic converters , governments began to mandate reductions in gasoline lead. In the U.S., the Environmental Protection Agency issued regulations to reduce the lead content of leaded gasoline over a series of annual phases, scheduled to begin in 1973 but delayed by court appeals until 1976. By 1995, leaded fuel accounted for only 0.6 percent of total gasoline sales and under 1,800 metric tons (2,000 short tons; 1,800 long tons) of lead per year. From 1 January 1996,
9555-481: The size of the degree and for the circumference of the Earth was therefore about 25% too small. Historical Legal Metric information Petrol Gasoline ( North American English ) or petrol ( Commonwealth English ) is a petrochemical product characterized as a transparent, yellowish, and flammable liquid normally used as a fuel for spark-ignited internal combustion engines . When formulated as
9660-455: The standard ASTM D4814. This standard describes the various characteristics and requirements of automotive fuels for use over a wide range of operating conditions in ground vehicles equipped with spark-ignition engines. A gasoline-fueled internal combustion engine obtains energy from the combustion of gasoline's various hydrocarbons with oxygen from the ambient air, yielding carbon dioxide and water as exhaust. The combustion of octane ,
9765-408: The typical 10:1 compression ratio of an engine design optimized for gasoline fuel. An engine tuned for LPG fuel via higher compression ratios (typically 12:1) improves the power output. This is because higher-octane fuels allow for a higher compression ratio without knocking, resulting in a higher cylinder temperature, which improves efficiency . Also, increased mechanical efficiency is created by
9870-510: The varying actual percentage. In parts of the U.S., ethanol is sometimes added to gasoline without an indication that it is a component. In October 2007, the Government of India decided to make five percent ethanol blending (with gasoline) mandatory. Currently, 10 percent ethanol blended product (E10) is being sold in various parts of the country. Ethanol has been found in at least one study to damage catalytic converters. Though gasoline
9975-515: The wave equation in atomic physics . Some unusual and non-standard units may be encountered in sciences. These may include the solar mass ( 2 × 10 kg ), the megaton (the energy released by detonating one million tons of trinitrotoluene , TNT) and the electronvolt . To reduce the incidence of retail fraud, many national statutes have standard definitions of weights and measures that may be used (hence " statute measure "), and these are verified by legal officers. In informal settings,
10080-482: The wine gallon had been used for centuries for import duty purposes, there was no legal standard of it in the Exchequer , while a smaller gallon (224 cu in) was actually in use, requiring this statute; the 231 cubic inch gallon remains the US definition today. In 1824, Britain adopted a close approximation to the ale gallon known as the imperial gallon , and abolished all other gallons in favour of it. Inspired by
10185-458: Was accidentally destroyed on a mission to Mars in September 1999 (instead of entering orbit) due to miscommunications about the value of forces: different computer programs used different units of measurement ( newton versus pound force ). Considerable amounts of effort, time, and money were wasted. On 15 April 1999, Korean Air cargo flight 6316 from Shanghai to Seoul was lost due to
10290-585: Was developed by four automakers: GM , Honda , Toyota , and BMW . According to the bulletin, the minimal U.S. EPA requirement is not sufficient to keep engines clean. Typical detergents include alkylamines and alkyl phosphates at a level of 50–100 ppm. In the EU, 5 percent ethanol can be added within the common gasoline spec (EN 228). Discussions are ongoing to allow 10 percent blending of ethanol (available in Finnish, French and German gasoline stations). In Finland, most gasoline stations sell 95E10, which
10395-402: Was developed for vehicles designed to run on leaded fuels and incompatible with unleaded fuels. Rather than tetraethyllead, it contains other metals such as potassium compounds or methylcyclopentadienyl manganese tricarbonyl (MMT); these are purported to buffer soft exhaust valves and seats so that they do not suffer recession due to the use of unleaded fuel. LRP was marketed during and after
10500-745: Was disguised by levying the same duty on the US gallon (3.79 L) as was previously levied on the Imperial gallon (4.55 L)) and the Bahamas . In some parts of the Middle East, such as the United Arab Emirates and Bahrain , 18.9-litre water cooler bottles are marketed as five-gallon bottles. Both the US liquid and imperial gallon are divided into four quarts ( quart er gallons), which in turn are divided into two pints , which in turn are divided into two cups (not in customary use outside
10605-478: Was dropped on 6 May 2006 because the industry had developed VOC -controlled RFG that did not need additional oxygen. MTBE was phased out in the U.S. due to groundwater contamination and the resulting regulations and lawsuits. Ethanol and, to a lesser extent, ethanol-derived ETBE are common substitutes. A common ethanol-gasoline mix of 10 percent ethanol mixed with gasoline is called gasohol or E10, and an ethanol-gasoline mix of 85 percent ethanol mixed with gasoline
10710-405: Was refined as the densities of brass alloys vary depending on metallurgical composition), which was calculated as 4.546 091 879 L to ten significant figures. The precise definition of exactly 4.546 09 cubic decimetres (also 4.546 09 L , ≈ 277.419 433 in ) came after the litre was redefined in 1964. This was adopted shortly afterwards in Canada, and adopted in 1976 in
10815-528: Was signed, a General Conference of Weights and Measures (CGPM) was established. The CGPM produced the current SI, which was adopted in 1954 at the 10th Conference of Weights and Measures. Currently, the United States is a dual-system society which uses both the SI and the US Customary system. The use of a single unit of measurement for some quantity has obvious drawbacks. For example, it is impractical to use
10920-560: Was the result of both confusion due to the simultaneous use of metric and Imperial measures and confusion of mass and volume measures. When planning his journey across the Atlantic Ocean in the 1480s, Columbus mistakenly assumed that the mile referred to in the Arabic estimate of 56 + 2 / 3 miles for the size of a degree was the same as the actually much shorter Italian mile of 1,480 metres. His estimate for
11025-516: 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
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