[30][31], Many general aviation aircraft engines were designed to run on 80/87 octane,[citation needed] roughly the standard (as unleaded fuel only, with the "{R+M}/2" 87 octane rating) for North American automobiles today. Motor Octane Number (MON). Kilograms = 11,339.81. metric tons = 11.34. The new standard requires the 16,000 remaining USA sources of lead, which include lead smelting, airplane fuels, military installations, mining and metal smelting, iron and steel manufacturing, industrial boilers and process heaters, hazardous waste incineration, and production of batteries, to reduce their emissions by October 2011.[92][93][95]. All grades of avgas that meet CAN 2–3, 25-M82 have a density of 6.01 pounds per US gallon (720 g/l) at 15 °C (59 °F). Examples include some Cherokees with the 160 hp (120 kW) Lycoming O-320 or 180 hp (130 kW) O-360, or the Cessna 152 with the O-235. Helpful Aviation Facts & Conversions Mach = Speed of Sound 669.11=Knots or 770=MPH Weight of Jet Fuel (Jet 1-A Clear to Straw color) 1 US Gallon = 6.46 - 7 pounds Weight of 100LL or AVGas (blue color) 1 US Gallon = 6.02 pounds Liter/Litre to Gallons Conversion 1 Liter/Litre = .264172 US Gallons Engines with displacements of 235, 320, 360, and 540 cubic inches make up almost 90% of the models approved for UL94. "[8], The annual US usage of avgas was 186 million US gallons (700,000 m3) in 2008, and was approximately 0.14% of the motor gasoline consumption. The industry … Divide that number in half. [62] Because tetraethyllead is a toxic additive, the minimum amount needed to bring the fuel to the required octane rating is used; actual concentrations are often lower than the permissible maximum. Each candidate fuel must meet a checklist of 12 fuel specification parameters and 4 distribution and storage parameters. Industry analysts have indicated that it will likely cost as much as or more than existing 100LL. Did Britney Spears cheat on Justin Timberlake? Avgas 100LL. Depends on the API gravity of the gasoline, which varies by grade and refinery. The high octane ratings were traditionally achieved by the addition of tetraethyllead, a highly toxic substance that was phased out of automotive use in most countries in the late 20th century. [65][71][72][73][74][75][76], The FAA found Swift Fuel to have a motor octane number of 104.4, 96.3% of the energy per unit of mass, and 113% of the energy per unit of volume as 100LL, and to meet most of the ASTM D910 standard for leaded aviation fuel. [70] [9], In Europe, avgas remains the most common piston-engine fuel. [89], In December 2013 Shell Oil announced that they had developed an unleaded 100 octane fuel and will submit it for FAA testing with certification expected within two to three years. [citation needed], Automotive gasoline is not a fully viable replacement for avgas in many aircraft, because many high-performance and/or turbocharged airplane engines require 100 octane fuel and modifications are necessary in order to use lower-octane fuel. GALLON [U.S.] OF AVIATION GASOLINE TO POUND/GALLON [US] (TO lb/gal) CHART 1 gallon [U.S.] of aviation gasoline in pound/gallon [US] = 1099590.49524576 10 gallon [U.S.] of aviation gasoline in pound/gallon [US] = 10995904.95245764 That means that for every 1 gallon of avgas made, 144 gallons of Jet A fuel were produced. No information has yet been published in its performance, producibility or price. For context, Plane and Pilot Magazine reports that in 2016 there were 576 million barrels (approximately 24 billion gallons) of Jet A fuel produced, and only 4 million barrels (approximately 168 million gallons) of 100LL produced. Add those two numbers together! How long will the footprints on the moon last? This grade is the low-lead version of Avgas 100. UL91 is currently being sold in Europe. The United States Environmental Protection Agency (EPA) has noted that exposure to even very low levels of lead contamination has been conclusively linked to loss of IQ in children's brain function tests, thus providing a high degree of motivation to eliminate lead and its compounds from the environment. By November 2013, the company had built its pilot plant and received approval to produce fuel in it. What moral lesson you get from the legend of magat river? Used to power piston-engine ultralight aircraft. AKI is the octane rating used to grade all U.S. automotive gasoline (typical values at the pump can include 87, 89, 91, and 93), and also the 93UL fuel from Airworthy AutoGas. [92] What are the Advantages of indirect cold water system over direct cold water system? [52], Since May 2016, UL94, now a product of Swift Fuels, is available for sale at dozens of US airports. [citation needed] This ethanol-treated fuel can flood the fuel system with water which can cause in-flight engine failure. Additives such as TEL help to control detonation and provide lubrication. [37] )[1] Density increases to 6.41 pounds per US gallon (768 g/l) at −40 °C (−40 °F), and decreases by about 0.1% per 1 °C (1.8 °F) increase in temperature. Some refineries also use reformate. [citation needed], In addition to vapor locking potential, automotive gasoline does not have the same quality tracking as aviation gasoline. [10], Many grades of avgas are identified by two numbers associated with its What does 1 gallon of avgas weigh in pounds. [citation needed] Additionally, the phase-separated fuel can leave remaining portions that do not meet octane requirements due to the loss of the ethanol in the water-absorption process. What does ability to understand and deal fairly with issues mean? Is the additional weight the reason the FAA rejected this fuel as an 100LL alternative? [citation needed] Ethanol-treated gasoline is susceptible to phase-separation which is very possible due to the altitude/temperature changes light airplanes undergo in ordinary flight. Avgas (100-130 or 100-130LL) weight is calculated at 6 pounds per gallon; Jet A at 6.84 pounds per gallon. The production economics of this new fuel have not been confirmed but it is anticipated that it will cost at least as much as 100LL. ASTM D6227; similar to automobile gasoline but without automotive additives. The publication of the SAIB, especially the August 2016 revision, eliminated the need for many of the UL94 STCs being sold by Swift Fuels, as the majority of the aircraft on the STC's Approved Model List are type-certified to use 80-octane or lower avgas. [106] Fifteen of 17 airports monitored during a year-long study in the US by the EPA have lead emissions well below the current National Ambient Air Quality Standard (NAAQS) for lead. After World War II, there were generally three grades of leaded avgas available. The first was 80/87, which contained a maximum of 0.5 grams of lead per gallon and was dyed red. Phased out in the late 20th century. [citation needed] Some oxygenates other than ethanol are approved, but these STC’s prohibit ethanol-laced gasolines. alkyl derivatives of 1,4-diaminoanthraquinone, like, This page was last edited on 29 November 2020, at 07:23. 1 US gallon = 3.78541178 liters. At an EPA public consultation held in June 2008 on the new standards, Andy Cebula, the Aircraft Owners and Pilots Association's executive vice president of government affairs, stated that general aviation plays a valuable role in the USA economy and any changes in lead standards that would change the current composition of avgas would have a "direct impact on the safety of flight and the very future of light aircraft in this country". The company eventually intends to produce the fuel from renewable biomass feedstocks, and aims to produce something competitive in price with 100LL and currently available alternative fuels. (Unleaded avgas is also available.) This fuel is made by blending existing refinery products and yields detonation margins comparable to 100LL. Learn how and when to remove this template message, phased out of automotive use in most countries, The AKI rating of typical automotive fuel, United States Environmental Protection Agency, General Aviation Manufacturers Association, "Appendix F. Fuel and Energy Source Codes and Emission Coefficients", "Specified Fuels for Spark Ignited Gasoline Aircraft Engine Models", "Use of Automotive Gasoline in TCM Aircraft Engines", "U.S. Prime Supplier Sales Volumes of Petroleum Products", "Avgas: Group Asks EPA To Get The Lead Out", "Selection of Suitable Operating Fluids for 912 and 914 (series) Engines - rev 2", "EASA Safety Information Bulletin 2010–31 : Unleaded Aviation Gasoline (Avgas) Hjelmco 91/96 UL and Hjelmco 91/98 UL", "Aviation Fuel - AvGas Information Aviation Gasoline", "Regulatory Brief: AVGAS (100LL) ALTERNATIVES", "Swift developing synthetic fuel to replace 100LL", "Teledyne Continental Plans Certified Diesel Within Two Years", "Make Room in the Aerodiesel Market, Thielert — TCM Tells Aviation Consumer About Some Big Engine Plans", "TCM Buys a Diesel: Does This Make Sense? To help solve this problem, the specification for an aviation fuel known as 82UL was developed as essentially automotive gasoline with additional quality tracking and restrictions on permissible additives. 100LL has a minimum MON of 99.6.[16][52]. The answer is simple; a gallon of water weighs about 8.3 pounds. conversions. To read more about the fuel, download the Avgas 100LL MSDS now. What does 1 gallon of avgas weigh in pounds? This calculator is used to calculate the post trip fuel remaining for AvGas and Jet A. Avgas (100-130 or 100-130LL) weight is calculated at 6 pounds per gallon; Jet A (jet fuel) at 6.84 pounds per gallon. They began testing "Swift 142" in 2006[61] and patented several alternatives for non-alcohol based fuels which can be derived from biomass fermentation. If an electric boost pump is mounted in the fuel tank to push fuel toward the engine, as is common practice in fuel-injected automobiles, the fuel pressure in the lines is maintained above ambient pressure, preventing bubble formation. [44], The firm Airworthy AutoGas tested an ethanol-free 93 anti-knock index (AKI) premium auto gas on a Lycoming O-360-A4M in 2013. Swift Fuels has an agreement for distribution in Europe. Lycoming believes the industry should be pursuing 100UL instead. They cited that the aviation sector employs more than 1.3 million people in the US and has an economic direct and indirect effect that "exceeds $150 billion annually". Avgas has a density of 6.02 lb/US gallon at 15 °C, or 0.72 kg/l, and this density is commonly used for weight and balance computation. However, the alloys used in aviation engine construction are chosen for their durability and synergistic relationship with the protective features of lead, and engine wear in the valves is a potential problem on automotive gasoline conversions. Direct conversions to run on automotive fuel are fairly common, by supplemental type certificate (STC). [citation needed], Some aircraft engines were originally certified using a 91/96 avgas and have STCs available to run "premium" 91 anti-knock index (AKI) automotive gasoline. [45], Unleaded 94 Motor octane fuel (UL94) is essentially 100LL without the lead. The fuel appears to exceed the specifications of 100LL in octane number and energy per unit volume although the fuel weighs 7 pounds per gallon instead of the 6 pounds per gallon for 100LL. gal is commonly used in America for weight and balance computation.) The weights are accepted averages based on specific gravity and other variables, such as temperature and additives due to climate. The second was 100/130, which had no lead limit, but usually contained about 3 grams of lead per gallon. The extensive testing process required to obtain an STC for the engine/airframe combination helps ensure that for those eligible aircraft, 91 AKI fuel provides sufficient detonation margin under normal conditions. The EPA's own studies have shown that to prevent a measurable decrease in IQ for children deemed most vulnerable, the standard needs to be set much lower, to 0.02 µg/m3. This is the main reason why both the specific engine model as well as the aircraft in which it is installed must be supplementally certified for the conversion. The density specification for EN228 Unleaded gasoline is 0.720 to 0.775. [14], Rotax allows up to 10% ethanol (similar to E10 fuel for cars) in the fuel for Rotax 912 engines. A. [77][78] Soon afterward, AVweb reported that Continental had begun the process of certifying several of its engines to use the new fuel. In a February 2008 interview, TCM president Rhett Ross indicated belief that the aviation industry will be "forced out" of using 100LL in the near future, leaving automotive fuel and jet fuel as the only alternatives. Item. On April 6, 2017, Lycoming Engines published Service Instruction 1070V, which adds UL94 as an approved grade of fuel for dozens of engine models, 60% of which are carbureted engines. One gram of TEL contains 640.6 milligrams of lead. A minimum limit ensures adequate volatility for engine starting. [107], Avgas is occasionally used in amateur auto racing cars as its octane rating is higher than automotive gasoline thus allowing the engines to run at higher compression ratios. The FAA has requested a maximum of US$60M to fund the administration of the changeover. "There is no reason to believe 100 low-lead will become unavailable in the foreseeable future," Fuller stated. The use of unleaded auto fuels with engines designed for leaded fuels can result in excessive exhaust valve seat wear due to the lack of lead with cylinder performance deteriorating to unacceptable levels in under 10 hours. Limited batches are produced for special events such as unlimited air races. [84], In 2012, Swift Fuels LLC was formed to bring in oil and gas industry experience, scale up production and bring the fuel to market. An average gallon of gasoline will weigh 6.3 pounds (2.85 kg). [85] Its most recent patent, approved in 2013, describes methods by which the fuel can be produced from fermentable biomass. ethanol-free, antioxidant and antistatic additives; In 1991, Hjelmco Oil introduced unleaded avgas 91/96UL (also meeting leaded grade 91/98 standard ASTM D910 with the exception of transparent colour) and no lead. [53][54][55], UL94 is not intended to be a full replacement for 100LL but rather is designed to be a drop-in replacement for aircraft with lower-octane-rated engines, such as those that are approved for operation on Grade 80 avgas (or lower), UL91, or mogas. [94], The public comment period on this petition closed on March 17, 2008. Some aircraft, however, do require a FAA-approved Supplemental Type Certificate (STC) to be purchased to allow for operation on UL94. No effort is made to determine usable or unusable fuel. Avgas (aviation gasoline, also known as aviation spirit in the UK) is an aviation fuel used in aircraft with spark-ignited internal combustion engines. The FAA administrator stated that regulating lead in avgas is an EPA responsibility, resulting in widespread criticism of both organizations for causing confusion and delaying solutions. [16][29], Some of the lower-powered (100–150 horsepower or 75–112 kilowatts) aviation engines that were developed in the late 1990s are designed to run on unleaded fuel and on 100LL, an example being the Rotax 912. See first link below. The imperial gallon of water is defined as 10.02 pounds at its maximum density while the weight of US dry gallon of water is defined as 9.71 pounds. What is the plot of the abadeha the Philippines Cinderella? First, there is a large margin of safety in the one-year storage life of avgas. Aviation gasoline (avgas) has an average weight of slightly over 6 pounds per gallon (6.02) at a Standard Day temperature of 15 degrees C or 59 degrees F. [80] 100LL (pronounced "one hundred low lead") may contain a maximum of one-half the TEL allowed in 100/130 (green) avgas and pre-1975 premium leaded automotive gasoline. Owners and operators of more than 167,000 piston-engine aircraft operating in the United States rely on aviation gasoline (avgas) to power their aircraft. CO 2 per U.S. gal. [60], Swift Fuels, LLC has attained approval to produce fuel for testing at its pilot plant in Indiana. [93], While lead concentrations in the air have declined, scientific studies have demonstrated that children's neurological development is harmed by much lower levels of lead exposure than previously understood. UL94 is an unleaded fuel, but as with all ASTM International unleaded gasoline specifications, a de minimis amount of unintentionally added lead is permitted. Imperal Gallons = 3,106.99. This 94UL meets the avgas specification including vapor pressure but has not been completely tested for detonation qualities in all Continental engines or under all conditions. Only later versions of the airframe with different engine cowling and exhaust arrangements are applicable for the automotive fuel STC, and even then require fuel-system modifications. "[98][99], Despite assertions in the media that leaded avgas will be eliminated in the US by 2017 at the latest date, the EPA confirmed in July 2010 that there is no phase-out date and that setting one would be an FAA responsibility as the EPA has no authority over avgas. Density increases to 6.40 lb/US gallon at -40 °C, and decreases by about 0.5% per 5 °C increase in temperature. In May 2010, TCM announced that they had licensed development of the SMA SR305 diesel engine. ,[81] satisfactorily tested by the FAA,[82] tested by Purdue University,[83] and approved under ASTM specification D7719 for high-octane Grade UL102, allowing the company to test more economically in non-experimental aircraft. [18], Fuel dyes aid ground crew and pilots in identifying and distinguishing the fuel grades[13] ", "FAA Fuel Committee: 11-Year Timeline for Avgas Replacement", "Continental: Maybe 94 Unleaded Fuel Will Fly", "Groups Act On Potential Leaded-Fuel Rulemaking", "Big-Engine Type Groups Unite On Fuel Issue", "100 Octane Unleaded Aviation Fuel - Demand No Less! Freezing point of avgas: -58°C Emission coefficient of avgas: 18.4 lbs. Kerosene is also used by most diesel piston engines developed for aviation use, such as those by SMA Engines, Austro Engine, and Thielert. Limited quantities are produced for testing. [48][49][50][51], In November 2015, UL94 was added as a secondary grade of unleaded aviation gasoline to ASTM D7547, which is the specification that governs UL91 unleaded avgas. The EPA responded with a notice of petition for rulemaking. Usually, regular unleaded gasoline has a gravity of around 58 and a weight per gallon of 6.216 pounds per gallon. One hectopascal (hPa) or millibar (mb) = 0.02953 in. Swift Enterprises' claims that the fuel could eventually be manufactured much more cheaply than 100LL have been debated in the aviation press. A larger problem stems from the higher and wider range of allowable vapor pressures found in automotive gasoline; this can pose some risk to aviation users if fuel system design considerations are not taken into account. What is basic steps of kalapati folk dance. In June 2010, clubs such as the American Bonanza Society, the Malibu Mirage Owners and Pilots Association, and the Cirrus Owners and Pilots Association collectively formed the Clean 100 Octane Coalition to represent them on this issue and push for unleaded 100 octane avgas. The reduced pressure in the line can cause the more volatile components in automotive gasoline to flash into vapor, forming bubbles in the fuel line and interrupting fuel flow. The EPA indicated: "This action will describe the lead inventory related to use of leaded avgas, air quality and exposure information, additional information the Agency is collecting related to the impact of lead emissions from piston-engine aircraft on air quality and will request comments on this information. [91], TEL found in leaded avgas and its combustion products are potent neurotoxins that have been shown in scientific research to interfere with brain development in children. Alternatively, Friends of the Earth requests that EPA commence a study and investigation of the health and environmental impacts of lead emissions from general aviation aircraft, if EPA believes that insufficient information exists to make such a finding. U.S. drivers alone account for 44% Litres / Liters = 14,124.67. Likewise, if the fuel tank is mounted above the engine and fuel flows primarily due to gravity, as in a high-wing airplane, vapor lock cannot occur, using either aviation or automotive fuels. The exact density cannot therefore be determined, but there is a range which is from 0.71Kg/L to 0.77Kg/L in commonwealth countries and roughly 6.073lb/gallon in the US. Its availability is very limited. Sensitivity is roughly 8–10 points, meaning that a 91 AKI fuel might have a MON of as low as 86. "[58] In August 2016, the FAA revised SAIB HQ-16-05 to include similar wording regarding the acceptability of using UL94 in aircraft and engines that are approved to operate with avgas that has a minimum Motor octane rating of 80 or lower, including Grade 80/87.[59]. GC–FID testing showed the fuel to be made primarily of two components — one about 85% by weight and the other about 14% by weight. 0.81 kg/L or 6.76 lb/US gallon, or API density 44.3° OR. [citation needed], The examples and perspective in this article, 93UL (Ethanol-free 93AKI automotive gasoline), Petroleum prehistoric to petrochemicals, G.A.Purdy 1957, Copp Clark Publishing Company, Vancouver, Toronto, Montreal, p.312 and 342. [65][66][67][68], In 2008, an article by technology writer and aviation enthusiast Robert X. Cringely attracted popular attention to the fuel,[69] as also did a cross-country Swift-Fueled flight by the However, all of their engines require that an oil additive be used when unleaded fuel is used: "When using the unleaded fuels identified in Table 1, Lycoming oil additive P/N LW-16702, or an equivalent finished product such as Aeroshell 15W-50, must be used. For example, 100/130 avgas has an octane rating of 100 at the lean settings usually used for cruising and 130 at the rich settings used for take-off and other full-power conditions.[12]. [16] The main petroleum component used in blending avgas is alkylate, which is a mixture of various isooctanes. [32], The 100LL phase-out has been called "one of modern GA's most pressing problems",[33] because 70% of 100LL aviation fuel is used by the 30% of the aircraft in the general aviation fleet that cannot use any of the existing alternatives. The lower Avgas volatility reduces the chance of vapor lock in fuel lines at altitudes up to 22,000 ft.[6]. That’s less than the weight of water which weighs 8.4 pounds. [42][43] In July 2014, nine companies and consortiums submitted proposals to the Piston Aviation Fuels Initiative (PAFI) to assess fuels without tetraethyl lead. However, the answer comes with a caveat. [93], On November 16, 2007, the environmental group Friends of the Earth formally petitioned the EPA, asking them to regulate leaded avgas. AVGAS CONVERSION TABLE JET A-1 7.8666 330.25 1.26 52.83 1250 3.78541 200 158.9872 METRIC TONNES BARRELS LITRES US GALLONS DRUMS US GALLONS DRUMS LITRES BARRELS METRIC TONNES 3.78541 4.5 5.79 1.2 0.695 6.97 2.63 2.205 1.53 3.16 For Avgas at SG=0.695 Note: with arrow, multiply by factor shown; away from arrow, divide by factor shown. [94], Under a federal court order to set a new standard by October 15, 2008, the EPA cut the acceptable limits for atmospheric lead from the previous standard of 1.5 µg/m3 to 0.15 µg/m3. [97], Publication in the USA Federal Register of an Advance Notice of Proposed Rulemaking by the USA EPA occurred in April 2010. The fuel is certified under Lycoming Service Instruction 1070 and ASTM D4814. Gasoline weighs roughly 6.073 pounds a gallon, although that number varies based on the additives included in the fuel. [100][101][102][103][104], In April 2011 at Sun 'n Fun, Pete Bunce, head of the General Aviation Manufacturers Association (GAMA), and Craig Fuller, president and CEO of the Aircraft Owners and Pilots Association, indicated that they both are confident that leaded avgas will not be eliminated until a suitable replacement is in place. AOPA's Dave Hirschman. [90] The fuel is alkylate-based with an additive package of aromatics. For aircraft weight and balance purposes, what are the respective weights for avgas, jet-A, turbine engine oil, and water at standard temperature? Even an average IQ loss of 1–2 points in children has a meaningful impact for the nation as a whole, as it would result in an increase in children classified as mentally challenged, as well as a proportional decrease in the number of children considered "gifted". gal. AOPA has asked the EPA to account for the cost and the safety issues involved with removing lead from avgas. Avgas is less volatile, with a Reid vapor pressure range of 5.5 to 7 psi, than automotive gasoline, with a range of 8 to 14 psi. Light sport aircraft that are specified by the manufacturer to tolerate alcohol in the fuel system can use up to 10% ethanol. The main petroleum component used in blending avgas is alkylate, which is a mixture of various isooctanes. [38][39][40], In November 2008, National Air Transportation Association president Jim Coyne indicated that the environmental impact of aviation is expected to be a big issue over the next few years and will result in the phasing out of 100LL because of its lead content. [citation needed], Vapor lock typically occurs in fuel systems where a mechanically-driven fuel pump mounted on the engine draws fuel from a tank mounted lower than the pump. Composed of approximately 85% mesitylene and 15% isopentane, the fuel is reportedly scheduled for extensive testing by the FAA to receive certification under the new ASTM D7719 guideline for unleaded 100LL replacement fuels. Density increases to 6.41 pounds per US gallon (768 g/l) at −40 °C (−40 °F), and decreases by about 0.1% per 1 °C (1.8 °F) increase in temperature. Carbon Dioxide Emissions Coefficients by Fuel Pounds CO 2 Kilograms CO 2 Pounds CO 2 Kilograms CO 2; Carbon Dioxide (CO 2) Factors: Per Unit of Volume or Mass Volume or Mass When did organ music become associated with baseball? Some refineries also use reformate. Dyes for the fuel are required in some countries. Composed primarily of aviation alkylate (same as used for 100LL). [46][47], In June 2010, Lycoming Engines indicated their opposition to 94UL. [41], By May 2012, the US Federal Aviation Administration (FAA Unleaded Avgas Transition rulemaking committee) had put together a plan in conjunction with industry to replace leaded avgas with an unleaded alternative within 11 years. [54][56][57], UL94 has a minimum Motor octane number (MON, which is the octane rating employed for grading aviation gasoline) of 94.0. [86], The FAA scheduled UL102 for 2 years of phase 2 testing in its PAFI initiative beginning summer 2016. [18], Automotive gasoline – known as mogas or autogas among aviators – that does not contain ethanol may be used in certified aircraft that have a Supplemental Type Certificate for automotive gasoline, as well as in experimental aircraft and ultralight aircraft. Pounds (lbs) = 25,000.00. [14], Friends of the Earth has filed a petition with EPA, requesting that EPA find pursuant to section 231 of the Clean Air Act that lead emissions from general aviation aircraft cause or contribute to air pollution that may reasonably be anticipated to endanger public health or welfare and that EPA propose emissions standards for lead from general aviation aircraft. What are similarities between the scheme of work and lesson plan? gal is commonly used in America for weight and balance computation. [citation needed] Historically, many post-WWII developed, low-powered 4- and 6-cylinder piston aircraft engines were designed to use leaded fuels; a suitable unleaded replacement fuel has not yet been developed and certified for most of these engines. 100/130 Avgas is a higher grade of fuel, hence is lighter than 80/87 Avgas. What would you say the qualities deeply esteemed by the people of those time? The Lycoming position is supported by aircraft type clubs representing owners of aircraft that would be unable to run on lower octane fuel. US Gallons = 3,731.34. The particular mixtures in use today are the same as when they were first developed in the 1940s, and were used in airline and military aero engines with high levels of supercharging; notably the Rolls-Royce Merlin engine used in the Spitfire and Hurricane fighters, Mosquito fighter-bomber and Lancaster heavy bomber (the Merlin II and later versions required 100-octane fuel), as well as the liquid-cooled Allison V-1710 engine, and air-cooled radial engines from Pratt & Whitney, Wright, and other manufacturers on both sides of the Atlantic. Kerosene-based jet fuel is formulated to suit the requirements of turbine engines which have no octane requirement and operate over a much wider flight envelope than piston engines. This was the first change to the standard since 1978 and represents an order of magnitude reduction over previous levels. The upper limits are related to atmospheric pressure at sea level, 14.7 psi, for motor vehicles and ambient pressure at 22,000 ft, 6.25 psi, for aircraft. This does not constitute an insurmountable obstacle, but merely requires examination of the fuel system, ensuring adequate shielding from high temperatures and maintaining sufficient pressure in the fuel lines. Volume to weight, weight to volume and cost conversions for Refrigerant R-507, liquid (R507) with temperature in the range of -51.12°C (-60.016°F) to 60°C (140°F) Weights and Measurements tonne per square centimeter (t/cm²) is a metric measurement unit of surface or areal density.