Why Diesels Have Turbos?

This is where the turbocharger is critical to the power output and efficiency of the diesel engine. It is the job of the turbocharger to compress more air flowing into the engine's cylinder. ... This increase in air means that more fuel can be added for the same size naturally aspirated engine.

Can a diesel run without turbo?

Yes a engine will start and run without a turbo just make sure the oil line is capped off or you'll have mess.

Why do diesels use turbos instead of superchargers?

The Low exhaust temperatures are fairly easy on turbo's. Diesels also don't make much for rpm, the turbo can be tuned to kick in very early and still perform very well under peak rpm. Turbos ar the ideal on Diesels. Superchargers are good but spinning a turbo from scavenged exhaust pressure is a bit more efficient.