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.
Steam-powered automobiles were popular with early buyers. Steam was safe, reliable, and familiar. People had decades of experience with it in trains and boats, and even in experimental road vehicles. However, early steam cars required constant care and attention—and up to 30 minutes to start. Automated quick-firing boilers solved these problems, but not before more efficient gasoline engines took over the market and made steam cars obsolete.The first experimental steam-powered cars were built in the 18th and 19th centuries, but it was not until after Richard Trevithick had developed the use of high-pressure steam around 1800 that mobile steam engines became a practical proposition. By the 1850s there was a flurry of new steam car manufacturers.
Development was hampered by adverse legislation from the 1860s as well as the rapid development of internal combustion engine technology in the 1900s, leading to the commercial demise of steam-powered vehicles. Relatively few remained in use after the Second World War. Many of these vehicles were acquired by enthusiasts for preservation.
The search for renewable energy sources has led to an occasional resurgence of interest in using steam technology to power road vehicles.
