Automobile

Fuel and propulsion technologies
Older automobiles were generally powered by a steam engine, which was fed by burning gasoline. Most automobiles in use today however are propelled by a internal combustion engine, fueled by deflagration of gasoline (also known as petrol) or diesel. Both fuels are known to cause air pollution and are also blamed for contributing to climate change and global warming. Increasing costs of oil-based fuels, tightening environmental laws and restrictions on greenhouse gas emissions are propelling work on alternative power systems for automobiles. Efforts to improve or replace existing technologies include the development of hybrid vehicles, electric and hydrogen vehicles that do not release pollution into the air.