Steam is primarily an engine driven by gas pressure (as are most combustion engines). I see the compressed air car as an evolution of the Steam car. https://en.

Steam is primarily an engine driven by gas pressure (as are most combustion engines). I see the compressed air car as an evolution of the Steam car. https://en.wikipedia.org/wiki/Compressed_air_car https://en.wikipedia.org/wiki/Compressed_air_car