Why are all modern hybrid and plug in hybrid cars paired with gas engines rather than diesel engines? The diesel and hybrid pair seem like a great idea in theory.

Question

A lot of people see hybrids and plug in hybrids as a great middle ground between ICE and EV, so why not make a diesel hybrid. They can be used in a variety of vehicles, and can reduce the nox and particulate emissions diesels are known for. So why isn’t there a modern diesel hybrid being produced, at least as a passenger car?

In: Engineering

Answer 1

A lot of comments here points to the emissions regulations rather than efficiency is on-point. Diesel engines have a lot worse cold-start emissions than a gasoline engine would. For a hybrid the engine is effectively cold-starting multiple times per drive, only getting up to operating temperature for the catalytic converter in extended operation..

Diesel-Electric locomotive is standard for almost a century, and it’s a proven technology when paired up. It’s just in an automotive use cycle, diesel engines just don’t operate well in the frequent on-off cycle.