Fish, have any links to how the 2-stroke system works? Did a quick search, but couldn't find anything too authorative and would rather read something with more technical information on it.
Benk, Interesting comments. In my eyes, I've been thinking super-critical (basically phase change before injection) fuel injection would be the next generation to get rid of the need of a particulate filter (still would need a NOx trap for diesels though. Didn't think about the application towards gas, but that would negate the need for particulate filtering there as well. Also agree the port+GDI approach seems brutish.
2003Silverado and ib, I was surprised to even see the idea of particulate filters for gas engines make it to the stage it's at now. I always thought they would just work with injector nozzles and raise pressures to get closer to diesel injection pressures for better atomization. At least the gas motors would remain a little simpler since I don't think they would need a NOx catalyst. But I'll be watching how these future regulations unfold.
