"German car manufacturer Audi has reportedly invented a carbon-neutral diesel fuel, made solely from water, carbon dioxide and renewable energy sources. And the crystal clear 'e-diesel' is already being used to power the Audi A8 owned by the country’s Federal Minister of Education and Research, Johanna Wanka."



Apparently, the process is known as the Fischer-Tropsch process  which typically requires vast amounts of energy to produce however this well known car manufacturer has claimed it can bring down costs to about 1.5 Euros per litre when demand increases and mass production economy chains get underway.


Read all about it in this Science Alert article by Fiona MacDonald:
http://www.sciencealert.com/audi-have-successfully-made-diesel-fuel-from-air-and-water