Eli5: Why steam cars aren’t used anymore?

Question

I was told that Steam cars were fast, clean, and efficient, and at one time it was the vehicle of choice.

In: 6

Answer 1

They weren’t efficient compared to todays internal combustion engines.

Steam can be more efficient, but that’s only true for huge systems, and those then take ages to fire up, wich is why we also stopped using them for (non-nuclear) ships