A group called the Clean 100-Octane Coalition met with FAA last week and made it clear that any 100 Low Lead (100LL) replacement fuel must be able to accommodate high-power piston engines. There has been controversy surrounding proposals to develop fuels that would operate well with most piston aircraft engines, but not the higher-powered models, such as those found in Bonanzas, Malibus, etc. Though it's estimated that piston aircraft that require the higher octane fuels represent only 20 percent of the fleet, it is also asserted that they represent a much higher percentage of the fleet hours flown. Jon Sisk is president of the Malibu/Mirage Association and a key player in the Clean 100-Octane Coalition. He asserts that not only must any new fuel operate with his members' engines, but also that the FAA rules and standards must be clear up front. And that the FAA must assert its authority on the issue, not leaving any ambiguity as to who steps up to deliver the final rules on new fuel. He said, "We want to make sure the FAA is creating an environment where the innovators — the people who are actually going to come up with the fuels — understand the process they're going to have to go through to get these fuels approved. People are not going to expend the capital to do these things if the rules aren't clear and the playing field is not level."