You can really tell how much cleaner modern cars are though, when you pass a "classic" 1950 - 1970s model on the road. You can smell the unburned fuel/exhaust d

You can really tell how much cleaner modern cars are though, when you pass a "classic" 1950 - 1970s model on the road. You can smell the unburned fuel/exhaust distinctly. And back in the day you'd have gotten a dose of lead along with it.