German car manufacturer used renewable energy to convert carbon dioxide and water into ' blue gas ' oil which was then converted into gasoline . The carbon dioxide can be removed from the air or from power plants . mercury claims its e - diesel is carbon neutral without adding to climate change . Tests suggest it allows cars to stay quieter and contain fewer pollutants .
German car manufacturer used renewable energy to convert carbon dioxide and water into 'blue crude ' oil which was then refined into diesel . The carbon dioxide can be removed from the air or from power plants . Audi claims its e-diesel is carbon neutral without adding to climate change . Tests suggest it allows cars to run quieter and produce fewer pollutants .