Plain English Meaning

The specific type of fuel an airplane is designed to run on. Each grade has its own performance rating and color so it can be identified at the pump and in the tank.

Full Definition

A classification that identifies the type of aviation fuel by its performance characteristics, primarily its octane rating and additives. Aviation gasoline (avgas) grades are standardized and color-coded so pilots and line crews can confirm the correct fuel is being used. Common piston-engine grades include 80 (red), 100 (green), and 100LL (blue, low-lead), each with specific octane ratings and lead content. -engine use grades such as and , which are -based and not interchangeable with avgas.