All I can say is that I am not ready to experiment with my airplane to see if G100UL will damage it in any way - either paint (which is costly to repair) or gaskets, o-rings, hoses or other components that are essential to the safety of flight. I would be delighted to use any fuel in my aircraft that does not have lead, but not at the expense of failure of components. I suspect that my airplane will fly just fine on 93 octane UL mogas for which there is an STC, but I am an architect, not an engineer, so I need to rely on experts, not folks with a vested interest. I am not saying that Mr. Luvara is right or wrong, but he does bring up valid points and concern.