Automobile allows the building of powerful and quick armor units.
It is a prerequisite of Mass Production.
It negates the effects of Copernicus' Observatory and replaces the knight unit.
Civilopedia
The first practical Automobiles were developed in the late 19th Century, although experiments with steam-powered wagons had been carried out over one hundred years earlier. The critical invention that made the Automobile a success was the internal Combustion engine. This relatively small but powerful engine could be mounted within the frame of the "horseless carriage" and drive the wheels. The Automobile had a tremendous impact on the economy and lifestyles of the rich Western nations, and it also revolutionized warfare. Armed and armored Automobiles, known as tanks, became a dominant weapon on the battlefield.