Originally Posted by
PBSteve
So the whole idea is that it doesn't actually diesel.
As Lurker mentioned, it's direct injection. It's my understanding that when you try to get gasoline to diesel, it's too unstable (as you mentioned). You also need a much leaner mix than you would in a normal ICE engine, so you can't just fall back on spark plugs to reliably ignite the mix at the right time.
So what they do is run a really lean mix as if they were going to diesel, but then instead of relying on auto-ignition, they squirt just a bit of extra gas in the cylinder at compression and ignite it with the spark plug as it comes out to ignite the whole cylinder.
Someone correct me if any of that is wrong, I don't know a whole lot about it but that's what I've gleaned from articles. Seems like all you really need to worry about is having a suitably high-pressure injection system.