Avgas's a high-octane aviation fuel used to power many aircraft and racing cars. Avgas's a portmanteau for aviation gasoline, as distinguished from mogas (motor gasoline), which's the everyday gasoline used in cars. Some light aircraft also use automobile fuel instead of avgas. Avgas's used in aircraft that've piston or Wankel engines. Gas turbines can operate on avgas, but typically don't. Turbine and diesel engines are designed to use kerosene-based jet fuel. Avgas properties and varieties T… (More on Avgas)