Aviation gasoline (two primary grades, 80 and 100 octane)

High octane leaded petrol, 100 octane or higher.

Avgas is a high-octane fuel used for aircraft and, in the past, racing cars. Avgas is a portmanteau for aviation gasoline, as distinguished from mogas (motor gasoline), which is the everyday gasoline used in cars. Avgas is used in aircraft that use piston or Wankel engines; gas turbines can operate on avgas, but typically do not.