Types of Aviation Fuel: Jet-A, Avgas, SAF and All Aircraft Fuel Types Compared

The aviation industry stands at the cusp of a sustainable revolution, with Sustainable Aviation Fuel (SAF) being the torchbearer. For business aviation operators, the transition to SAF is not just an environmental imperative but also an economic benefit of using sustainable aviation fuel. Government incentives for SAF play a pivotal role in this transition. This article delves into the economic benefits that underscore the importance of SAF for business aviation operators.

Types of Aviation Fuel: A Complete Reference Guide

Aviation fuels are specialized petroleum-based or synthetic fuels formulated to meet the performance, safety, and certification requirements of aircraft propulsion systems. They differ from road vehicle fuels in their flash point, freezing point, energy density, and contamination standards, all of which are tightly specified to ensure reliable performance across the wide temperature and pressure ranges experienced during flight.

There are two primary categories of aviation fuel: jet fuel (also called aviation turbine fuel or ATF), used in turbine-powered aircraft including jets and turboprops, and aviation gasoline (Avgas), used in piston-engined aircraft. Sustainable Aviation Fuel (SAF) is an emerging third category: a drop-in alternative to conventional jet fuel produced from non-petroleum feedstocks.

Comparison Table 1: Types of Aviation Fuel Overview

Note: Flash point values are approximate and may vary by specification. Always refer to the current fuel specification sheet for the fuel uplifted at each airport.

Aviation Fuel Specifications and Properties: Jet Fuel, Avgas and SAF Compared

Jet-A and Jet-A1

Jet-A and Jet-A1 are kerosene-type aviation turbine fuels and are the most widely used aviation fuels in the world. The primary difference between them is their freezing point specification: Jet-A has a maximum freezing point of minus 40 degrees Celsius, while Jet-A1 has a maximum freezing point of minus 47 degrees Celsius. This lower freezing point makes Jet-A1 the international standard, as it remains pumpable at the low temperatures experienced at high altitudes on long-haul international routes. Jet-A is predominantly used in the continental United States, while Jet-A1 is the standard fuel everywhere else.

Both fuels are governed by the ASTM D1655 standard (ASTM International) and the DEF STAN 91-091 specification (UK Ministry of Defence). The energy content of both is approximately 43.2 megajoules per kilogram (MJ/kg).

Jet-B

Jet-B is a wide-cut fuel that blends gasoline and kerosene fractions, giving it a lower flash point and better cold-weather performance than Jet-A or Jet-A1. Its lower flash point also makes it more volatile and more hazardous to handle, which is why its use is restricted to operations in extremely cold climates (typically below minus 50 degrees Celsius ambient) where Jet-A1’s freezing point would be a concern during ground fueling operations. It is used primarily in Canada and Alaska.

Avgas 100LL

Avgas 100LL (100 Low Lead) is the most widely available aviation gasoline and the standard fuel for piston-engined general aviation aircraft worldwide. The “100” designation refers to the fuel’s octane rating, and “LL” indicates a reduced lead content relative to the older Avgas 100 (high lead) formulation. Avgas 100LL still contains tetraethyllead (TEL) as an anti-knock additive, which is the reason the aviation industry is actively working to develop lead-free Avgas alternatives.

Avgas 100LL is dyed blue for identification and governed by the ASTM D910 specification.

Avgas UL91 and G100UL

Avgas UL91 is an unleaded aviation gasoline approved for use in lower-compression piston engines whose fuel systems are compatible with the formulation. G100UL (General Aviation Unleaded) is a fully unleaded Avgas that has received FAA approval for use across all aircraft currently approved for Avgas 100LL, making it a direct drop-in replacement. The transition to unleaded Avgas is a major industry priority driven by environmental and public health concerns about lead emissions near general aviation airports.

Comparison Table 2: Aviation Fuel Specifications

Understanding SAF and Its Economic Implications

Sustainable Aviation Fuel (SAF) represents a significant advancement in aviation technology, offering a cleaner-burning alternative to conventional jet fuel derived from finite fossil resources. SAF is produced from various sustainable feedstocks, such as waste oils, fats, green and municipal waste, non-food crops, and can also be synthesized through carbon capture methods directly from the atmosphere. These feedstocks are considered sustainable because they do not compete with food production, water resources, or contribute to deforestation.

 

Technically, SAF can reduce CO2 emissions by up to 80% over its life cycle compared to traditional jet fuel. This reduction is achieved because the carbon emitted during the combustion of SAF is partially offset by the carbon absorbed by the biomass from which it was produced during its growth phase. Moreover, SAF is designed to be a drop-in fuel, meaning it can be blended with conventional jet fuel and used without modifications to existing aircraft engines or fuel distribution infrastructures.

Global Adoption of Sustainable Aviation Fuel (SAF)

The adoption of SAF is gaining momentum worldwide. According to the International Energy Agency (IEA), the demand for SAF is expected to increase significantly, with a notable rise in planned capacity across the United States, Europe, and other regions. The International Air Transport Association (IATA) reported that SAF production tripled in 2023, reaching over 600 million liters, indicating a growing trend in the industry.

Sustainable Aviation Fuel Compared to Conventional Jet Fuel: Cost, Carbon, and Performance

Cost of SAF vs Jet fuel has historically been a barrier to its widespread adoption. In 2020, the price of conventional jet fuel was approximately $0.5 per liter, while SAF was priced at more than double, around $1.1 per liter. However, the gap is expected to close as production technologies mature and scale. The International Air Transport Association (IATA) projects that SAF could contribute around 65% of the emission reductions required for the aviation industry to reach net-zero CO2 emissions by 2050. This will necessitate a substantial increase in production to meet the growing demand, with the most significant acceleration anticipated in the 2030s as policy support becomes global, SAF achieves price parity with fossil kerosene, and credible carbon offsets become scarcer.

Comparison Table 3: SAF vs Conventional Jet Fuel

Note: SAF price multiples are approximate and vary significantly by feedstock, production pathway, supply region, and volume. CORSIA eligibility applies to approved SAF production pathways as determined by ICAO’s CORSIA Eligible Fuels list. Always verify current SAF pricing with your fuel supplier.

For business aviation operators looking to incorporate SAF into their operations, Just Aviation’s sustainable solutions service provides SAF sourcing coordination and sustainability reporting support.

To facilitate this transition, IATA advocates for harmonized policies across countries and industries that are technology and feedstock agnostic. SAF incentives should be implemented to expedite deployment, and while SAF is in the early stages of market development, mandates should be used cautiously and only as part of a broader strategy to enhance SAF production and reduce unit costs.

Government SAF Incentives for SAF Impact

The role of government policy in promoting SAF use is pivotal. Government SAF incentives are crucial for bridging the cost gap between SAF and conventional jet fuel. The European Union’s ReFuelEU Aviation initiative is a policy measure that mandates an increasing share of SAF in aviation fuel supplies, with a specific quota for synthetic aviation fuels. This policy is designed to boost economic benefits of using sustainable aviation fuel consumption and reduce aviation emissions.

Economic Benefits of Using Sustainable Aviation Fuel (SAF)

The economic benefits of using sustainable aviation fuel are multi-faceted.. In the United States, SAF producers can receive a tax credit ranging from $1.25 to $1.75 per gallon, depending on the greenhouse gas emissions reduction achieved. This incentive structure is vital for enhancing SAF’s market competitiveness and encouraging investments in sustainable fuel technologies.

Impact on Flight Operations and Maintenance

The use of sustainable aviation fuel delivers measurable operational benefits. Studies have shown that SAF can reduce particulate matter emissions from jet engines by up to 70%, contributing to cleaner operations and potentially lower maintenance costs. Moreover, the European Union Aviation Safety Agency (EASA) has been actively involved in facilitating the uptake of SAF within the aviation industry.

Future Projections for Sustainable Aviation Fuel (SAF) Development and Utilization

Future projections suggest a substantial increase in sustainable aviation fuel production to meet the aviation industry’s goals. By 2050, it is estimated that millions of tonnes of SAF will be required annually to achieve net-zero carbon emissions targets set by the aviation sector. For a broader overview of how SAF fits within aviation’s full decarbonization strategy, see Just Aviation’s guide to decarbonization solutions in business aviation. This growth is contingent on technological advancements and the scaling up of production facilities.

International Cooperation and Agreements on Sustainable Aviation Fuel (SAF)

International cooperation is pivotal for the widespread adoption of SAF. The International Civil Aviation Organization (ICAO) has established a global framework to promote SAF production and usage, aiming to reduce CO2 emissions in international aviation by 5% by 2030. Such agreements are essential for aligning global efforts towards sustainable aviation.

How Can Operators Be Incentivized To Use SAF

To incentivize operators to use SAF, financial mechanisms such as tax credits are employed. The role of government policy in promoting SAF incentives lowered the economic hurdles associated with transitioning to SAF and supported its integration into the aviation fuel mix. The U.S. Sustainable Skies Act, for example, proposes a credit starting at $1.50 per gallon for SAF with a 50% or greater lifecycle greenhouse gas savings, with higher rewards for greater reductions, up to a maximum of $2.00 per gallon.

 

Just Aviation supports business aviation operators in accessing aviation fuel and SAF at airports across our global network. Our aviation fuel coordination service covers Jet-A1 uplift, SAF availability verification at planned destination airports, and fuel cost optimization as part of the trip planning process. For operators looking to incorporate SAF into their regular operations or to understand SAF availability on specific routes, contact Just Aviation’s operations team to discuss your fuel requirements.