FWIW, 100LL (most common grade) avgas has 1.2-2.1 grams of tetraethyl lead (TEL) per gallon of fuel. Leaded gasoline had up to 2.2 gr/gal. Unleaded gas can contain up to 0.001 gr/gal.
https://en.wikipedia.org/wiki/Avgas#Grades
https://en.wikipedia.org/wiki/Tetrae...ation_gasoline