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Jet A vs Avgas: Understand the Differences in Aviation Fuels

6 February 2024   Around the Airport

Have you been researching Jet A vs Avgas and wonder about the difference between the two aviation fuels? We work with them every day at Monmouth Jet Center. Our clients have 24/7 access to Avgas and Jet A fuel for their various aircraft, provided on-field under a unique covered fueling canopy. Our aviation fuel is competitively priced and just one of the many FBO services we provide. Let’s look at the differences between Jet A and Avgas.

Different Engines Require Different Aviation Fuels 

Different engines require different aviation fuels. Aircraft with turbine engines, such as jets and turboprops, need jet fuel to fly. Jet fuel is a refined kerosene-based, colorless fuel available in two main types – Jet A  and Jet A1. There are some differences in the manufacturing specifications, but you can use both fuels interchangeably for flight operations.  

Aircraft with piston engines, such as those used at flying clubs and for crop dusting, use Avgas (aviation gasoline). The main grades are Avgas 100 and Avgas 100 LL (low lead). Each Avgas grade is dyed a different color to make identification easier – Avgas 100 is green, and Avgas 100LL is blue.

The Performance Variances in Aircraft Engines   

Aviation requires consistent fuel performance across rapidly changing environments and multiple engines. Jet A fuel is highly stable and refined to remove impurities and ensure consistent performance. Its auto-ignition temperature is lower, which lowers the associated pressures inside the plane’s engines.

Avgas contains small amounts of tetraethyl lead. The lead is an octane booster for higher engine performance and reduces wear in valve assemblies. Avgas 100 has an octane rating of 100, which serves as a measure of the fuel’s resistance to detonation – the operating condition in which the fuel ignites spontaneously under compression.

How They Differ With Different Weather Operations   

Overflying polar routes is the ultimate cold weather operations challenge. Fortunately, Jet A fuels are designed to be predictable in extreme temperatures. Jet A fuel has a freezing point of -40 degrees Celsius (-40 Fahrenheit), but Jet A1 has a lower freezing point at -47°C (-52.6°F), making it suitable for long-haul international flights. 

How do weather operations affect Avgas? Avgas 100LL will freeze at -58°C (-72°F), and though most pilots will not fly in such cold conditions, it is good to know that the airplane fuel will not freeze. However, if there is any water in your fuel tanks, it might freeze in your fuel lines during a flight.  

Cost Analysis for Each Kind of Fuel   

Global events impact aviation fuel prices, just as it affects vehicle gas and diesel prices. Aviation fuel, like automobile fuel, comes from refining crude oil. There are many factors to consider when doing a cost analysis for the various aviation fuel types. Jet A fuel is easier to obtain, and you can use the International Air Transport Association (IATA) Jet Fuel Price Monitor site to see the latest price data. The price of Avgas varies between countries as local supply logistics impact the cost. Fortunately, Monmouth Jet Center fuel prices are among the most competitive in the Tri-state area.

Monmouth Jet Center (MJC) at Monmouth Executive Airport (BLM) is an attractive alternative to crowded New York City, Philadelphia, and Jersey Shore gateway airports. We are conveniently located outside “Class B” airspace and just a 20-minute helicopter ride from the center of Manhattan. Do you need to arrange for Jet A vs Avgas upon your arrival or departure? Contact our team at Monmouth Jet Center today.