Comment Re: Why (Score 5, Interesting) 395
The issue is the particulate filters that are nowadays standards seem to be worse for your health: particles are so thin you can't see them anymore (hence no more belch smoke) but they're also so thin they can now enter your bloodstream more easily.
The issue is that there were always fine particulates, and they can't be trivially filtered out. But perhaps you missed it when we discussed here that gasoline engines produce as much soot as diesels, and it is all of the exceptionally-fine kind. Now that the big stuff is being filtered out of the diesel exhaust, all we have left is a relatively small amount of that PM2.5.
Ideally we'd do away with the ICEs entirely and eliminate all that crap, get down to worrying about how to eliminate it from the tires. But what's really pathetic is that we've had the technology at least since the 1800s to solve all of these problems. It's called electrified rail. With modern levels of traffic, it is worthwhile to have people in packets smaller than train cars, however, yet with the distances which must be covered the vehicles must have their own power storage. Current battery and self-driving vehicle technology permits just this particular use case. We have every piece we need to replace cars entirely with PRT save for the will, starting in the densest city centers and moving outwards in stages related primarily to the availabilty of parking.
AHEM. Back on topic. "invisible smoke doesn't mean it's better" is exactly why diesel is better than gasoline. And yet, soot isn't even the worst emission that cars produce! It's unburned hydrocarbons, also known as raw fuel. And by their nature, diesels which are running properly run lean all the time, that's just how they operate. That means they're burning their fuel. It also means they produce more NOx, but that's why diesels now have catalysts.