Avgas

Avgas (Aviation Gasoline) is a specialized fuel used in spark-ignition (piston) aircraft engines. The most common grade is 100LL (Low Lead), dyed blue, with an octane rating of 100. The "LL" indicates reduced tetraethyl lead content compared to the older 100/130 grade.

Avgas differs from automotive gasoline in its higher octane rating, tighter quality specifications, and anti-detonation properties required for aircraft engines operating at varying altitudes and temperatures. The aviation industry is transitioning to unleaded alternatives (e.g., G100UL, UL94) to reduce lead emissions.