What makes a diesel engine different to a regular gas engine, and is one better than the other?

Diesel engines cannot work without oxygen, so how do diesel submarines operate when they're underwater? Their propulsion ...

A diesel engine is simultaneously incredibly simple and incredibly violent, using compression as a means of ignition. This is because of the properties of diesel fuel: Namely, diesel is less volatile ...

Scientists are exploring a surprisingly simple way to clean up diesel engines: adding tiny droplets of water to the fuel. During combustion, the water rapidly vaporizes, triggering micro-explosions ...