> Comprehensive government regulation would create such an infrastructure. Or, it would destroy small engine general aviation. > and you can bet that there wi

> Comprehensive government regulation would create such an infrastructure. Or, it would destroy small engine general aviation. > and you can bet that there will be engine vendors selling modification kits and maintenance infrastructure, since now everyone knows that there will be a massive market coming up as everyone has to adapt to the new rules if they want to keep flying! What if, you know, people can't adapt? What if people can't afford to replace their 40 years old aircrafts with sparkling new ones, costing 5-10 times much? Sure, some of them will, but there are many hobbyists who can afford loan payments and insurance on a plane worth $100k, but couldn't do the same on one worth $500k. Yes, this would stop emissions of TEL, sure, but at tremendous cost. Is that cost worth it? To our (and FAA, and EPA) best knowledge, probably not, as lead emissions from GA have much different characteristic than the ones from cars.