Cirrus Service Advisory Cites GAMI G100UL As ‘Unapproved’ For SR Series

In a blow to the General Aviation Modifications Inc.’s (GAMI’s) G100UL unleaded aviation fuel program, Cirrus Aircraft posted Service Advisory SA24-14 Tuesday (June 18). The advisory informs operators of Cirrus SR-series aircraft (SR20, SR22 and SR22T) that the manufacturer “does not approve the use of GAMI G100LL fuel in Cirrus SR Series airplanes. Additionally, Cirrus does not warrant or represent in any way an operator’s use of the GAMI G100UL fuel in Cirrus SR Series airplanes.”

Cirrus further advised operators: “Per Continental and Lycoming, only approved fuels may be used for an engine to be covered by warranty. As the GAMI G100UL fuel is a non-approved fuel per Continental and Lycoming, engines known to have run this fuel may not be covered by the OEM engine warranty. For specific details, please refer to the respective Continental and Lycoming engine warranty documents.”

Those advisories were preceded in the statement by a description of Cirrus’s efforts to promote the development of unleaded aviation fuel that would serve as a drop-in replacement for 100LL. “These efforts include working directly with industry associations and all stakeholders including AOPA, GAMA, the FAA, and the FAA-Industry EAGLE [Eliminate Aviation Gasoline Lead Emissions] program through the PAFI [Piston-Engine Aircraft Fuel Initiative] certification program. As of June 2024, EAGLE is actively pursuing three potentially viable alternatives/replacements for 100LL: GAMI G100UL, LyondellBasell/VP Racing UL100E, and Swift 100R.”

Cirrus described its testing programs with GAMI’s G100UL, citing more than a decade of performance testing on materials compatibility and performance. However, Cirrus wrote, “While some aspects of the initial Cirrus testing of the GAMI G100UL fuel are encouraging, other areas, including materials compatibility, remain inconclusive.”

Controversially, while G100UL has received an FAA Supplemental Type Certificate covering virtually all aircraft piston engines, GAMI has chosen not to participate in the PAFI program to achieve ASTM International approval for its fuel.