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Speak with an Aviation Gasoline Specialist
Speak with an Aviation Gasoline Specialist
100LL is the most popular type of aviation gasoline (avgas) used for piston engine aircraft. The name refers to the 100-octane level and “low lead” as 100LL is combined with lead to prevent engine damage. Today, 100LL is commonly used for small piston engine planes, certain helicopters, and drones both in commercial, military, and personal use.
Historically, the first planes used the same automobile gasoline as automobiles, but as technology advanced, aviation companies created gasoline with higher octane levels, raising the fuel’s ability to withstand compression in the engine without detonating (as beneficial for flights in higher altitudes). This new fuel was also lighter in density and dyed blue to differentiate from other avgas products. Additionally, turbine-engine aircraft uses jet fuel like avgas, some of the most popular types being Jet A, Jet A-1, and Jet B.
Today, avgas is a highly refined product specifically manufactured to meet the demanding performance requirements of aircraft engines. Avgas specifications make it difficult to meet all the requirements with a single refinery stream, even one such as light alkylate produced specially for avgas. So, avgas, like motor gasoline and most other refinery products, is usually produced by blending two or more components to achieve the desired properties. Grades 100 and avgas 100LL are based on alkylate. As such, it is mainly a synthetic product – few of the compounds in avgas come directly from crude oil. Toluene is often added to Grade 100LL to help meet the rich-mixture antiknock requirement.
The primary components of 100LL aviation fuel include:
The lead content in 100LL is significantly lower than in older avgas formulations, but it is still present to ensure high performance. The blue dye is added to differentiate it from other types of aviation fuels.
For avgas 100LL to be sold as a commercial product, the gasoline must meet certain regulatory requirements (as discussed later in this article). Primarily, the product is measured across the following properties: Energy content, knock resistance, stability, fluidity, volatility, non-corrosivity, and cleanliness.
100LL is the most popular type of aviation gasoline (avgas) used for piston engine aircraft, which may include brands such as Cessna, Piper, and Beechcraft. The aircraft could be commonly used for recreational flying, flight training, agriculture, and light cargo transport. Robinson helicopters and other piston engine brands also utilize 100LL as well as some military drones.
In recent years, the use of piston engine aircraft has decreased due to the rise in popularity of turbine-engine aircraft. For example, in 2002, total avgas production in the United States was 0.76 million gallons per day, a very small amount compared to the production of turbine fuel (68 million gallons per day) or motor gasoline (372 million gallons per day). In 2023, the worldwide Avgas market size was estimated to be $2.0 billion while the North America market size was $1.19 billion.
Avgas 100LL is known for its excellent performance characteristics. The high-octane rating allows for higher compression ratios, leading to more efficient engine performance and better fuel economy. It also provides reliable ignition and combustion, ensuring smooth operation of the aircraft engines.
For best fuel quality, storage time between use should be limited to one year shelf life. Fuel subjected to longer storage or to improper storage or handling should be tested to be sure it meets all applicable specification requirements before use.
However, it’s important to note that 100LL does produce lead emissions, which have environmental and health impacts. This has led to ongoing efforts to develop unleaded alternatives that can match the performance of 100LL while reducing its negative effects.
Avgas can be hazardous if not handled properly. First, and foremost, it is easy to ignite, and it burns rapidly. Second, exposure to aviation fuel liquid or vapor should be limited. Anyone planning to handle aviation fuel should obtain and read the Material Safety Data Sheet (MSDS) issued by the supplier. The lead content in 100LL aviation fuel if mishandled could cause negative environmental and health concerns. Lead is a toxic substance that can cause serious health problems, including neurological damage. The emissions also contribute to air pollution around airports. As a result of the environmental concerns, the Federal Aviation Administration (FAA) and industrial stakeholders seek to create a lead-free fuel alternative to replace 100LL.
The use and production of 100LL aviation fuel are regulated by several international and national bodies to ensure safety and environmental compliance. Key regulatory frameworks include:
The main challenge facing 100LL includes the environmental and health concerns of using a product produced with lead. An unleaded fuel that would satisfy the most critical piston engines in the existing aircraft fleet would need the same anti-knock performance as Grade 100LL. The Coordinating Research Council is testing potential blend components for such fuel. However, the challenge is daunting because the antiknock properties of tetraethyl lead are truly unique.
Several alternative fuels are being tested, including:
100LL remains the most popular Avgas product for piston engine aircraft. The fuel is uniquely blended with additives for optimal performance at high altitudes and dyed bright blue. Although the lead content within avgas causes environmental and health concerns, the fuel can be safe for use if handled and stored properly. Also, the antiknock properties of tetraethyl lead are truly unique for the aircraft. Sergeant Oil & Gas is an unbranded dealer for several global refineries selling aviation gasoline (100LL) internationally. If you are seeking to place an order of avgas, please contact us.
