Definition
A specialized grade of gasoline produced for piston-engine aircraft, formulated to specific octane ratings, vapor pressure limits, and additive standards that allow safe combustion at altitude and across wide temperature ranges. It is identified by grade (such as 100 or 100LL) and dyed a specific color so it can be visually distinguished from automotive fuel and from jet fuel.
Plain English
It is the fuel made specifically for piston-engine airplanes. It is not the same as car gasoline and not the same as jet fuel, and the different grades are colored differently so you can tell them apart.
Context Anchor
Pilots encounter aviation gasoline during fuel planning, refueling, preflight inspection, and when checking the approved fuel grade in the aircraft manual or near the fuel filler.
Derivation
The word 'gasoline' comes from 'gas' (originally a 17th-century coinage based on the Greek 'chaos,' meaning a formless substance) plus the chemical suffix '-ine.' 'Aviation' is added to mark it as a fuel built to a different specification than the gasoline sold for cars.
Why Pilots Care
Using the wrong fuel can cause engine damage or failure in flight; confirming the correct aviation gasoline grade is a required preflight step.
Intuition Check
Do not assume aviation gasoline means any gasoline used near an airplane. In this context, it means a specific aircraft fuel made and approved for gasoline-burning aircraft engines.
Example Sentence 1
Before departure, the pilot checked that the fuel truck was delivering 100LL aviation gasoline and confirmed the blue color in the fuel sample.
Example Sentence 2
The handbook warns that using automotive gasoline instead of aviation gasoline can produce detonation in the engine.