Cirrus and the search for 100LL’s replacement

As the industry scrambles to find a replacement for 100LL, officials at Cirrus Aircraft weighed in recently on what it’s doing to ensure its customers can continue flying. In a letter posted at, President and CEO Brent Wouters notes that while the company supports the transition to unleaded fuel, “Cirrus Aircraft does not believe that a 94UL solution is desirable for its owners or the health of the industry, and will strive for a better replacement fuel.”

The letter outlines the company’s take on several alternatives, including Swift fuel and GAMI’s G100UL, but also notes there are “many issues beyond simply octane rating,” such as “operation at temperature extremes, fuel stability over time, health and safety aspect of the fuel and its combustion products, material compatibility, ‘producibility’, cost and so on.”

Wouters also notes the company’s efforts are focused in three main directions:

  • Leadership & Advocacy: Cirrus chairs the primary industry working group team which began as a GAMA-based committee and has expanded to collaborate with AOPA, EAA, and other key stakeholder groups. This provides Cirrus with the information and access to the key stakeholders, including oil companies, to help guide efforts that will promote the best solution, which, again, is preferably a 100 octane or near-100 octane transparent replacement avgas.
  • Fuels Research Support: Cirrus has availed itself to support the needs of aviation fuels research entities. This support can range from on-aircraft testing, to chemical compatibility testing for airframe structures and system components, to feedback on operational and cost aspects. Cirrus also participates in the Coordinating Research Council (CRC) technical research group and the ASTM unleaded fuel group.
  • Flexible Aircraft Solutions: Due to the uncertainty involved in this issue, Cirrus is developing solutions for both existing and new aircraft that address a wide range of possible fuel specification outcomes. This doesn’t change our commitment to finding a transparent solution. This week we are introducing a new aircraft model in the SR22 family which is flexible to a wide range of future fuel octane ratings. At the same time, we are working help ensure that all of our aircraft models, both new and in the field, will be compatible with a future unleaded fuel in either a transparent sense or with reasonable upgrade paths.

Read the full letter here.


  1. says

    Sooner will be better than later. I have been following Swift Fuel for a long time. What is taking so long. If the feds are serious about going “GREEN”, then tell then to “get the lead out” and DO something.

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