Piston-engine planes are a remarkably small market. Automotive dominates the fuel market in total, and jet fuel (which is a lead-free kerosene derivative) domin

Piston-engine planes are a remarkably small market. Automotive dominates the fuel market in total, and jet fuel (which is a lead-free kerosene derivative) dominates the aviation market. As far as I can tell, no one has demonstrated any tangible cost from the (very small) amount of leaded fuel still burned in piston-engine planes. Even imputed cost from environmental lead levels is iffy -- the only places you can find detectable lead are the immediate environs of long-used GA airports.