Abner Doble was an American mechanical engineer who built and sold steam-powered automobiles as Doble Steam Cars. His steam engine design was used in various automobiles from the early 1900s, including a 1969 General Motors prototype and the first successful steam-powered aeroplane.

A steam car is a car (automobile) propelled by a steam engine. A steam engine is an external combustion engine (ECE), whereas the gasoline and diesel engines that eventually became standard are internal combustion engines (ICE). ECEs have a lower thermal efficiency, but carbon monoxide production is more readily regulated.