Shell has developed a lead-free replacement for 100LL avgas that will now begin going through the regulatory approvals process at the FAA and EASA, as well as the American Society for Testing and Materials. The company’s new formulation comes after 10 years of “exhaustive” research and development, as well as successful initial testing carried out in the last two months by Lycoming and Piper Aircraft. Its new fuel meets all key avgas properties and has an octane rating exceeding 100.