With the leading European General Aviation show of the year (Aero Friedrichshafen) now behind us we came back with a significantly higher number of requests for information about the future of Aviation Gasoline (Avgas)100LL and the long term availability of Avgas 100LL. It is true that Avgas 100LL has been in use since WWII and while modern aircraft and avionics are showing the progress of technology, our aircraft engines, while extremely reliable, have shown little evolution in their design.

Over 90% of aviation gasoline use could be switched to Unleaded UL94 without any aircraft technical modification

At the same time the world has become a lot more conscious of the environment and we all want to contribute to reduce our footprint while sustaining safety for the people in aviation and the general public. Puma Aviation, Europe’s largest producer of Aviation gasoline and Europe’s only producer of unleaded Aviation Gasoline AVGAS UL94 has invested significantly to make available UL94 as an eco-friendlier alternative to Avgas 100LL.  UL94 is produced to the ASTM7547 which is recognized by most engine manufacturers. This means that many people could be flying on Avgas UL9

4 without even knowing that it is possible. UL94 is the highest available octane level that can be achieved without adding the Tetra-Ethyl-Lead (TEL) ingredient. At the same time it is an aviation grade fuel with all the quality requirements that go along with it.

We have done a number of studies for specific airfields who are considering migrating to Avgas UL94. In many of those cases we found that over 90% of the gasoline use could be switched to UL94 with only a small part of the fleet remaining at Avgas 100LL. We will be happy to work with specific airfields to discuss their long term strategy and assist them in the adoption of Unleaded Aviation Gasoline UL94. Airfield operators and aeroclubs are invited to get in touch when they have questions regarding migration.

People who are interested to check the compatibility of their Engine are recommend to check their engine handbook compatibility listing. Engine manufacturer sites can also consulted below :

Lycoming Engines : Service Instruction SI1070

Continental Engines : https://www.aopa.org/news-and-media/all-news/2022/july/26/continental-seeks-faa-approval-for-ul-9194-in-lower-compression-engines

Rotax Engines : Rotax Service Instruction 12-10-00 

Finally, what many people do not know is that service intervals on Lycoming engines as well as Rotax engines are longer when using unleaded fuels. A Lycoming engine can switch to 100hr oil changes when using unleaded fuels. Please consult your engine manual for the exact data for your specific engine.