Comment by wolvoleo

Yes when I was flying I really hated having to walk around in lead fumes :( The problem is the whole GA industry stopped innovating the single engine piston market. The engines we used were literally from the 1950s. But nobody cares about certifying modern engines because it's so costly.

Only in the ultralight market they have some newer ones that can run on normal unleaded car gas because regulations are much lighter. In this case I do really think the regulations are holding back innovation and environment.