The standard hig octane fuel for aviation piston engines. It has a high lead content and is dyed green. There are two major specifications for Avgas 100. The ASTM D 910 and UK DEF STAN 91-90.This grade is the low lead version of Avgas 100. Low lead is a relative term. There is still up to 0.56 g/litre of lead in Avgas 100LL. This grade is listed in the same specifications as Avgas 100, namely ASTM D 910 and UK DEF STAN 91-90.
Emissions of piston engine aircraft using aviation gasoline (avgas) Piston or Spark Ignition Engine aircrafts use gasoline or petrol-based fuel called Avgas or Aviation Gasoline which is derived from regular commercial gasoline.
Turbine engines use more heavier diesel like fuel which is specially formulated in order to cope with extreme conditions at high altitude.