As others have said, car fuels simply don't have enough oil in them for plane engines. On the reverse side of things, plane fuels work perfectly well in car engines. I have plane engines that I consider to be barely run in after 10 hours and I expect them to last for hundreds of hours but I don't skimp on how much oil I mix in when I make my fuel. Put it this way, the engine runs on the methanol and nitro but it's the oil that keeps it running .