#internal combustion

side-note; compression ignition isn't practical with petrol[gasoline] due to reasons of timing the ignition, I don't know enough about internal combustion engine design to really comment on why it can't be done beyond people who know far more than you or me about IC engines can't get it working practically.

Hey actually this is a thing I don't fully understand either. I don't believe it's a timing issue, especially in the modern day where we have direct-injection diesel we could absolutely time out petrol injection.

Typically the thing about petrol engines is that you have to avoid autoignition of your air-fuel mix before your spark plug goes because it results in knocking, and you use pre-injection because it's a volatile fuel so you let it vaporize in the cylinder for even mixing before ignition, but is there a particular reason you can't do high pressure injection into a compression petrol engine, or is it just a thing you don't do because it's impractical.

I suspect the second since I'm aware of compression-ignition petrol engines but they're niche research designs, it doesn't seem to be worth it compared to just using less-volatile diesel.